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Resistant Starch – Friend, Foe or Lover ?

//Resistant Starch – Friend, Foe or Lover ?
  • Resistant Starch - Friend, Foe or Lover ?

Resistant Starch – Friend, Foe or Lover ?


Since my first article on resistant starch (RS) titled Resistant Starch – Friend or Foe?, raw unmodified potato starch, or RUMPS as I like to call it, continues to light up the blogosphere. Like a lot of people, I was caught off guard by the overwhelmingly positive light RUMPS has been cast in. Some people have truly fallen in love with this molecule, or rather two molecules (amylose and amylopectin) all tangled up together.  Even Tom Naughton and Mark Sisson have fallen and Jimmy Moore wants to get some. The explosive interest in this topic can be traced to the extraordinary efforts of two flies in the nutritional ointment, Tim Steel, AKA Tatertot and Richard Nikoley of

The reported benefits of RUMPS include the enticing claims of better sleep and vivid dreams. Those alone make me want to buy some tonight and give it a try, but there’s more: improved gut function, curing Small Intestinal Bacterial Overgrowth, SIBO (Say what?) preferentially feeding healthy gut bacteria, preventing cancer with more butyrate, immune stimulation, toxin/carcinogen degradation, blood sugar/insulin control, improved cholesterol, triglycerides and even weight-loss.

Most of the claims about RUMPS are unproven, though some are surely real. Some research already supports RS’s effect on blunting postprandial blood sugar spikes, suggesting that RUMPS may be a powerful tool for diabetics and others who suffer from hyperglycemia. But what really caught my attention was the claim that RUMPS will “Cure” SIBO. After all, RUMPS is a form of resistant starch, which I have recommended limiting for SIBO. For more info on this counterintuitive idea, you can visit Dr. BG, AKA Grace, at Animal Pharm and Dr. Art Ayres at Cooling Inflammation. You can also see my mini-debate with Tim in the comments section on Dr. Mike Eades’ blog on heartburn.

Since this idea has been put forward, several people, including some who have experienced side effects with RUMPS, have asked for my opinion on using RUMPS if they have SIBO. Recall my concluding opinion from my first article:

“A state of fermentable substrate limitation in the gut is healthier than a state of fermentable substrate excess and more consistent with Paleo diet concepts (based on limited availability of food, regular fasting while foraging, eating seasonal fruits, etc.). A lean diet for our gut microbes fosters healthy competition in the gut that will favor the survival of well adapted organisms best suited to be our partners in digestion and health. We know that excess malabsorbed carbohydrates (lactose and fructose intolerance for instance) are linked to conditions associated with SIBO (small intestinal bacterial overgrowth) and there is reason to believe that resistant starch may contribute to imbalances in the gut microbiota including SIBO in susceptible people.”

Since writing this, I have learned a bit more about RUMPS specifically (as opposed to RS in general). I will do my best to provide some thoughts on using RUMPS for SIBO in more or less a pros and cons format. As always, please do add your comments on any points or evidence I may have missed for, or against this approach.

Could RUMPS actually help people with SIBO?

Tim and Richard contacted me recently to discuss some of the experiences people were reporting after supplementing with RUMPS. At that time, we agreed to share all information, both positive and negative about RUMPS and digestive health issues going forward. Realizing that our real goal was to help people and that science will figure this out eventually anyway, we agreed to do our best to speed things up hopefully benefiting all involved. In other words:

“Instead of making science conform to our beliefs, let’s find out what’s real and update our understanding”

And wouldn’t you know it, shortly after making this agreement, I was contacted by someone who had been on antibiotics, had confirmed SIBO and IBS symptoms for years. She had been taking probiotics, eating fermented foods and adding RUMPS to her diet. Other than some bloating and flatulence, she reported feeling better and able to eat a more varied diet without repercussions.

Even though this particular report involves one person who had previously eliminated her symptoms on the Fast Tract Diet (that limits not only RS, but several other fermentable carbs as well), a few other people have also reported improvement in heartburn or other SIBO-related symptoms using RUMPS. To me this suggests there is at least a chance that RUMPS could benefit some people with SIBO. I am open to the idea. Hey, at least we’re talking about diet these days, not PPIs, H2 blockers, gut wrecking antibiotics and some absolutely frightening IBS drugs.

RUMPS is like a “bus” for bacteria:

Pros: One idea proposed to explain why RUMPS might cure SIBO, is that any bacteria overgrowing in the small intestine will adhere to the RUMPS molecules and be whisked back into the large intestine, from whence they came. This is an interesting idea which has some support from a study showing that people infected with Vibrio cholera suffer less fluid loss and recover more quickly when RS is added to the rehydration solution

[1]. Supporting this idea is the finding that, under the right conditions, V. cholera can rapidly and efficiently adhere to starch molecules.[2]

Cons/Questions: Some questions remain to determine if these results support using RUMPS with SIBO:

  • While bacterial adherence to corn starch was very efficient (98%), adherence to other starch types did not fare as well with very little adherence to wheat starch and no significant adherence to instant potato starch – which admittedly is quite different from RUMPS. RUMPS was not tested for bacterial adherence.
  • The adherence testing for the publication was done in the laboratory. No one knows if similar adherence would occur in people’s intestines, though the results agree with the observations in treating Cholera with RS.
  • Several other types of bacteria including: L. monocytogenes, S. typhimurium, P. aeruginosa, E. coli, and A. hydrophila, absorbed to the starch much less efficiently (1 – 57% vs. 98% with Cholera). According to the authors, V. cholera can utilize starch for growth while the other bacteria don’t, potentially explaining a purpose behind V. cholera’s ability.
  • Sugars utilized by V. cholera including: glucose, maltose, sucrose, trehalose, dextrins, and fructose, blocked adhesion in the lab and could potentially affect binding in vivo (in the small intestine) as well.
  • Cholera-induced infectious diarrhea is a dramatic and acute condition caused by a specific pathogen which is quite different from diarrhea-predominant IBS, constipation-predominant or mixed IBS as well as other SIBO-related conditions that involve many different types of bacteria.

Can other resistant starches or fibers accomplish the same thing?

Pros: Another report showed that green banana or pectin fiber improved recovery times of children with diarrhea.[3] In this case, most of children had no specific infectious agent identified, while 40% were diagnosed with either rotavirus (17%), E. coli (11%), V. cholera (5%), or Salmonella (4%).

Cons/questions: The actual amount of resistant starch from green banana is unclear in this study as it was cooked. Also the control diet was rice, but the type or rice and its contribution to the total amount of RS was not determined. Also, in this study, diarrhea had a variety of causes including acute viral and bacterial infections.

Can RUMPS be fermented in the small intestine?

As a rule of thumb, the most rapidly fermentable carbohydrates, if poorly absorbed, have the highest chance of being fermented by bacteria in the small intestine (the home of SIBO for those that have it), where the capacity for excessive fermentation is most limited, and damage most likely to occur. Fructose (grrrrr) and lactose (grrrrr) are good examples of carbs fermented in the small intestine, so it’s no big surprise that they are so well known in the scientific literature as GI trouble makers. But more fermentable forms of fiber such as fructans, pectin, beta glucan and gums are relatively easy to ferment as well. At the other extreme are cellulose, methyl cellulose and lignin that are less fermentable and less of a SIBO threat. Fibers from legumes including stachyose, raffinose and verbascose fall somewhere in the middle along with sugar alcohols.

As with fiber, some forms or RS may be more fermentable than others, with the degree of gelatinization being a factor as well. RUMPS is one type of resistant starch referred to as RS2. You can find a definition of all RS types in my first article. Like the many types of fiber, the various forms of RS have different properties and are fermented at varying rates by different combinations of bacterial species (each species of bacteria have specific abilities in terms of fermenting carbs and often need to work together to get the job done finally consuming the breakdown product (glucose)). Where RUMPS falls in this fermentability continuum is at the heart of the issue in my opinion, and something I admittedly have recently been learning more about

Pros: A study by Olesen, et. al.[4] (thanks for the paper Tim) found that 50 grams of RUMPS (29 g RS), though fermentable, was less fermentable than 10 g of lactulose. Similar results were found in a second study.[5] Lower fermentability translates into fewer symptoms. Lactulose for example, is not digested or absorbed by humans but is highly fermentable by gut bacteria and can cause dramatic GI symptoms including flatulence, bloating, diarrhea, stomach pain, nausea and vomiting. (

In the Fast Tract Digestion books, I estimate the relative fermentability of fiber types. Perhaps RUMPS should be reclassified as a fiber and belongs on the lower end of that list, say above cellulose but below pectin, raffinose, stachyose and verbascose and may be less symptom provoking than more fermentable carbs.

Cons/questions: Though I don’t know the glycemic index of RUMPS specifically, the GI of another type II resistant starch, Hylon VII corn starch is 50, indicating that half of the starch is broken down and absorbed in the small intestine.[6] If human starch degrading enzymes are able to breakdown resistant starch, why wouldn’t bacteria that possess starch-degrading enzymes, known to be present in SIBO, do the same. Of course the question here is how different is RUMPS from Hylon VII.


It’s tempting to assume that if RUMPS is not fermented in the small intestine, it won’t trigger any SIBO-like symptoms. But there is the question of excessive fermentation in the large intestine. Before SIBO, excessive bacterial fermentation was referred to as dysbiosis, or a general imbalance or overgrowth of intestinal microbiota believed to be associated with bowel inflammation. Though not typically specified, dysbiosis can include bacterial overgrowth growth in the large intestine. You could think of this as LIBO for Large Intestinal Bacterial Overgrowth. Is it possible LIBO could also contribute to symptoms more commonly attributed to SIBO? Since our large intestine is designed to support more extensive fermentation, it’s easy to assume “the more fermentation the better” as long as it’s in the large intestine, but I am not so sure. Since SIBO is associated with bacteria originating from the large intestine, is it possible that LIBO can give rise to SIBO?

Years ago, I suffered chronically with acid reflux (before reducing fermentable carbs in my own diet). I often noticed occasional bouts of acid reflux some 12-24 hours after consuming foods with a high fermentation potential (hard to digest carbs). Though research on this phenomenon is lacking, I wonder if excessive fermentation in the large intestine could contribute to acid reflux, IBS and other symptoms more commonly associated with SIBO. If this were the case, even slower to metabolize fibers and RS could trigger symptoms.

Pros: The idea that RUMPS could cause symptoms via LIBO is speculative.

Cons: If correct, RUMPS could trigger symptoms via excessive fermentation in the large intestine

RUMPS GI Side Effects

I still remember the parties we had in high school. Get a hold of some beer. Invite your friends and their friends over and put on some Jimmy Hendrix (yes, it was the 70s). Early on everyone is focused on the fun and excitement, but then you realize its 2:00 AM, Bobby dropped some acid and is typing something on your mom’s typewriter, the foreign exchange student is vomiting in the bedroom and your sister’s boyfriend just tore up the front lawn with his Camaro and is now stuck dangling over the embankment (true story). At some point, common sense kicks in and it’s time to wind the party down a notch and take stock.

I think this is what’s happening with RUMPS. It’s tempting to throw caution to the wind when you’re chasing amazing health claims. But I have been surprised to see many comments from people suffering with side effects of RUMPS who continue to use the supplement, even upping the dosage in some cases. Before we resume the RUMPS party, let’s take a look at people reporting side effects on RUMPS.

In my first post on RS, I discussed the “bread and muffin study” showing that these RS-containing foods invoked more symptoms in people with IBS, I noted that 80 % of cystic fibrosis patients, who are often deficient for the release of starch degrading amylase enzyme and test positive for SIBO, suffer from acid reflux (Refer to Fast Tract Digestion Heartburn for the evidence tying acid reflux to SIBO). I also talked about the similarity between the symptoms of SIBO and the side effects of drugs and supplements that block starch digestion.

Consistent with these observations, reports of GI side effects from RS (not RUMPS specifically) include: flatulence, bloating, stomach aches, cramps and diarrhea.[7],[8] Though both studies were conducted in healthy people, the reported side effects are consistent with SIBO or a general imbalance of gut microbes – dysbiosis. I would expect the side effects to be worse, not better, in people who already had established SIBO or dysbiosis.

While most people supplementing with RUMPS report varying amounts of flatulence, some report additional side effects including: abdominal pain, diarrhea, constipation, gas, bloating, acid reflux, nausea, cramps fatigue, and even intestinal blockage. These reports come from the comment sections under the many RUMPS blogs. Keep in mind they are anecdotal (n=1) reports so we shouldn’t read too much into them, but we also can’t ignore them.

These reports of side effects mirror my own experiences over the years with RS in general. Though I don’t supplement with RUMPS, I suffer from acid reflux when I consume pasta or certain rices and breads with high levels of RS. My gut can tell the difference between basmati rice (high RS) and jasmine rice (no RS) with a fairly high degree of certainty.

Tim Steele recounted to me his own experience when he consumed additional RUMPS in response to a bout of indigestion. I his words: “I felt some indigestion coming on, and took 4TBS of RUMPS in a glass of water. Almost instantly, the heartburn was unbearable, nearly doubled me over. I ate at least 6 TUMS and got a bit of relief, but the discomfort actually lasted all night and into the next day.”

Richard Nikoley also recounted to me a report of someone having to stop supplementing with RUMPS: “because after a while it gave him perpetual heartburn for days.”

A post from Mark’s Daily Apple recently stated: “A note for those experiencing heartburn from the PS, it has taken over a week off the PS to get the HB under control.”

A post on Facebook, though not specifically about RUMPS, noted: “Several of us in The Paleo Approach Group have problems digesting plantains. I had issues for over a week, severe stomach pain and psychological issues, worse than anything I’ve eaten in a long time. I’m thinking it has to do with the large amount of resistant starch feeding bad bacteria.”

RUMPS AI Side Effects

Others have complained that RUMPS exacerbated their preexisting autoimmune conditions such as rheumatoid arthritis (RA) and ankylosing spondylitis (AS). Symptoms included joint pain in the hip, knee, extremities and back. Despite the side effects, some people continue to supplement hoping to gain benefit even though their own bodies are telling them to stop. Before assuming that RUMPS is the appropriate course of action for AI conditions, a thorough review (beyond this article) of bacterial involvement in specific AI conditions is in order. For instance:

  • K. pneumonia (capable or degrading RS) overgrowth and antibodies to the same have been linked to AS and possibly Crohn’s disease, and dietary starch restriction has been proposed as a treatment strategy[9].
  • RA has been linked to increased intestinal populations of Prevotella copri and a decrease in Bacteroides strains,[10] Yet Prevotella is associated with carbohydrate-based diets while Bacteroides is associated with animal-based diets.[11]

Note: RA has also been linked to urinary tract infections caused by the bacterium Proteus mirabilis.[12] How these two very different bacterial strains, one growing in the gut (Prevotella. copri) and one causing UTI infections (Proteus mirabilis), contribute to RA has yet to be determined.

Given the complexity of AI and SIBO-related conditions, can we assume (as has been commonly stated) that people with these conditions will always benefit by improving their “good” and reducing their “bad” gut microbes with RUMPS? In reality this strategy has not been proven and does not seem to be working, at least for some people who may be ignoring the risks in pursuit of perceived benefit. I remain open, but continue to believe that RUMPS has the potential to invoke symptoms in people who have SIBO or are susceptible to SIBO or dysbiosis, particularly if they consume higher doses.

The connection between gut microbiota, SIBO and diet

We know that our gut microbiota can be significantly influenced by diet and disease. But understanding what this means will take some time. Studies show that people with IBS (IBS is definitively linked to SIBO) have increases in Firmicutes type bacteria Dorea, Ruminococcus, and Clostridium spp., and decreases in Bacteroidetes, Actinobacteria (Bifidobacterium), and one specific Firmicutes –Faecalibacterium spp.[13],[14] A study by Malinen and colleagues,[15] found that a predominance of Ruminococcus type bacteria (related to R. torques) was associated with severity of bowel symptoms in IBS subjects. However, within this high group, several species of Clostridia were significantly reduced. A study looking at microbiota changes in IBSD and IBSC found that R. torques was more prevalent in IBS-D and R. bromii (recall the “keystone species” in RS fermentation) was associated with IBS-C patients in comparison to control subjects.[16] Another study showed that the microbiota in IBS-D patients was enriched in Proteobacteria and Firmicutes (particularly Lachnospiraceae and sometimes R. torques), but reduced in Actinobacteria and Bacteroidetes compared to controls.[17]

 Table 1. Microbiota characteristics and population changes in IBS

Microbiota typeRelative change in IBSGas producingStarch degrading



  • Ruminococcus



  • R. torques



  • R. bromii



  • Rosburia



  • E. rectale
No change



  • Clostridium spp.[18]
Increased or decreased



  • Dorea (Clostrid.)



  • Lachnospiraceae (Clostrid.)



  • Faecalibacterium spp.


ProteobacteriaNo change or increased


Actinobacteria (bifidobacterium)[13]Decreased






While there are many contributing factors for SIBO and IBS covered in Fast Tract Digestion IBS that may alter microbiota composition, and different studies yielded some variability in results, the microbiota profiles of people with IBS show an important trend. Two things struck me immediately after putting the data into a table:

  • IBS involves increases in many Firmicutes type bacteria, which are most adept at degrading polysaccharides such as resistant starch, and a decrease in more nutritionally versatile Bacteroidetes and certain Clostridia. Actinobacteria were also lower in IBS.
  • The Firmicutes type bacteria that are increased, are most proficient at producing (mostly hydrogen and carbon dioxide) gas.

The connection between IBS and increases in bacterial species that preferentially ferment complex carbs and produce gas is consistent with the success of diets that limit fermentable carbs for IBS, acid reflux and other SIBO related conditions – covered in my first article.

Irritable Bowle Syndron (IBS) and Obesity

The microbiota profile of people with IBS is consistent with a diet rich in fermentable carbs. The same is true for obese individuals, which may explain the connection between obesity and GI symptoms including bloating, diarrhea, and an even stronger connection with acid reflux.[22],[23]

In a study of overweight men, a diet supplemented with RS yielded significant increases in Ruminococcaeae, Roseburia and E. rectale, which decreased significantly when subjects were switched to a lower carb weight-loss diet.[24]  Similar results were obtained in study on the effects of reducing dietary carbohydrates (high carb 399g/day, moderate carb 164g/day, low carb 24g/day) on microbiota in obese men.[25]  As dietary carbs were lowered, the researchers observed a decrease in Roseburia and E. rectale related (clostridial cluster XIVa) species as well as bifidobacteria (Actinobacteria). Bacteriodes group and Clostridium coccoides group bacteria as well as clostridial cluster IX group bacteria were not significantly affected by reducing dietary carbs.

In general, obesity is associated with a significant decrease in microbiota diversity with fewer Bacteroidetes (associated with more diversity) and more Firmicutes and Actinobacteria (associated with less diversity).[26] The authors found that the obese human gut microbiome (microbiome refers to gut microbe genes, whereas microbiota refers to the actual bacteria) is genetically enriched for phosphotransferase systems involved in microbial processing of carbohydrates. They likened the obese gut microbiota more to fertilizer runoff, where abnormal energy input creates blooms of less diverse microorganisms, compared to a lean gut microbiota that is actually more like a rain forest. These findings are in agreement with other microbiota studies on obesity.[27],[28],[29],[30]  The reason may have to do with the ability of Bacteroidetes type bacteria, as well as some Clostridia species, to use a variety of both animal and plant based nutrients making them less dependent on complex carbohydrates.

Note: Two notable differences between obesity and IBS: Both Actinobacteria and E. rectale levels were observed to be increased in obesity but decreased or unchanged respectively in IBS.

What is the best diet for SIBO and obesity?

RUMPS is believed to promote the growth of “good bacteria” and increase gut microbiota diversity. This intuitively makes some sense as RUMPS and other complex fermentable carbs feed or cross-feed many types of bacteria in the gut, most of which reside in the large intestine. RUMPS would therefore be expected to increase the numbers and possibly the diversity of organisms that can participate in carbohydrate breakdown.

But the studies cited above indicate that complex polysaccharides result in more Firmicutes, Actinobacteria and certain Clostridia but less diversity overall due to a decrease in Bacteroidetes and several other Clostridia species. Similar changes are associated with the symptoms of IBS.

The diet that continues to make the most sense for people with SIBO (and obesity?) in my view, is one that limits (not eliminates) fermentable carbs putting the polysaccharide loving microbes on a diet so to speak. Animal-based foods in combination with moderate / reduced levels of fermentable carbs promote bacterial species that metabolize amino acids and other animal-based macronutrients as well as a moderate level of Firmicutes and Clostridia that prefer complex carbs.

Even Dr BG from Animal Pharm says “For SIBO and intestinal permeability, it’s actually healing to minimize fermentation if it is occurring pathologically in the small intestines… where it shouldn’t be.”

How many complex carbs is the right amount?

The best mix of complex carbs to animal-based proteins and fats will depend on the age, health, and gut microbiota makeup of each individual. There are three basic types of diet in terms of fermentable carb levels. At one end is the elemental diet which provides zero fermentable carbs. In the middle are moderate fermentable carb diets which include: low starch, low carb, low FODMAP, and my own Fast Tract Diet. At the other extreme are diets that contain an excess of fermentable carbohydrates including the Standard American Diet (SAD), Vegetarian diets and diets that include fermentable carb supplements such as inulin, fructose oligosaccharide, fiber or RUMPS.

Diets with no fermentable carbs

While elemental diets (predigested carbohydrates, proteins and fats) are very effective at normalizing SIBO symptoms in IBS,[31] going too low on fermentable carbs may not be a great long term strategy. People who are very ill with conditions such as active Crohn’s disease can benefit dramatically (supporting remission) from the elemental diet, however eliminating all fermentable carbohydrates does decrease microbiota diversity which may have negative consequences long term.

One example is the connection between enteral tube feeding with the elemental diet and C. diff infection.[32] The risk of C diff. may be from the diet reducing protective bacteria or their metabolic end products, but there are many other risk factors that may also be responsible including: People in the study were very sick to begin with and often hospitalized where C diff infections are commonly acquired. Patients were often on antibiotics or PPI drugs which both increase the changes of C diff. Also, tube feeding increases the chances of C diff exposure. Regardless, common sense indicates that including some level of fermentable carbs in the diet is the healthy thing to do. In addition to a variety of health benefits from a robust microbiota, we get up to 20 – 25% of our calories from the fats that gut bacteria make.

Diets with high levels of fermentable carbs

Hi fermentable carb diets include vegan, Standard Amer. Diet or SAD, and diets supplemented with high fiber, prebiotics or RS. Feeding our gut microbes with plenty of fermentable carbs on the surface sounds like a great idea. But we can see that Firmicutes and certain Clostridia bacteria may take advantage of this high fermentation burden in people susceptible to bacterial overgrowth. It’s easy to ignore the many other sources of fermentable material gut bacteria have available including: Unabsorbed proteins, mucus, nucleic acids and other macromolecules.

To make matters worse, people with SIBO often have malabsorption issues – it’s a double whammy. Carbohydrate malabsorption theoretically makes the effective GI of carb-containing foods lower. Therefore people with SIBO likely end up with more fermentable carbs in their intestines after the same meal compared to people that don’t suffer from malabsorption. Also, people with IBS may have an additional source of fermentable carbs, mucin. IBS patients overexpress the gene for mucin production, Muc20.[33] Mucin is a fermentable substrate. Top mucin degraders include Rumminococcus, particularly R. torques, but also bifidobacteria.

Since most people already agree with the monumental problems with the SAD diet, I won’t comment further and limit the discussion to diets that have lots of resistant starch or add RUMPS or other fermentable carb supplements. I have no issue with young healthy people, or older healthy people for that matter, consuming lots of fermentable carbs and there is even some evidence that RS may help with infectious diarrhea. If you’re supplementing with RUMPS and suffering no negative consequences, you have my blessing by all means. But as you have seen in the side effects section, not everyone escapes the negative consequences of excessive fermentation if they include too many fermentable carbs.

Diets moderate in fermentable carbs

Microbiologists estimate that our gut microbes ferment approximately 60-80 grams of fermentable carbs per day to account for one typical day of fecal output accounting for metabolic loss.[34] But how many fermentable carbs are in our diet? To answer this, I developed a formula called Fermentation Potential:

FP = (100-GI)(NC)/100 + DF + SA

GI = Glycemic index, NC = Net Carbs, DF = Dietary Fiber, SA = Sugar Alcohols. Values are in grams/per serving.

Using this formula, I have estimated that typical Western diets actually contain well over 100 grams / day of fermentable carbs. As little as 30 grams of carbs allow gas-forming gut bacteria to produce 10 liters of hydrogen gas. Also, recall the many sources of fermentable material listed above which are available to gut bacteria. Several moderate fermentable carb diets mentioned above reduce the fermentative burden and improve symptoms of SIBO-related conditions. For a review of these diets along with the elemental diet, check out this article on SIBO Diets.

Because I don’t think these other diets go far enough, I created the Fast Tract Diet, and FP system. My goal was to quantitatively reduce hard to digest fermentable carbs to 45 grams per day or less to “quite the gut” so to speak and allow the body’s control mechanisms  including motility, acidity and immune system to clean house reducing the overall number of microorganisms to restore some order from chaos.

Concluding Remarks

We have been endowed through evolution with a huge variety of helpful gut microbes that perform a variety of important functions supporting our health and nutrition. We are just beginning to understand specific growth patterns of gut bacteria in response to diet, particularly fermentable carbs. These patterns will likely be different for different people, especially people who are obese or suffer from SIBO-related conditions. Developing an extensive image of gut bacterial types (phylum/enterotype, genus and species) able to participate in the breakdown of various fermentable carbs and their connection with digestive and autoimmune diseases as well as obesity will help.

While keeping an open mind to the benefits of RUMPS, my own view still leans towards the concept that RUMPS, though potentially less threatening, belongs in the group of hard-to-digest but fermentable carbs, which also include: lactose (for lactose-intolerant), fructose, other forms of RS, fiber and sugar alcohols. I believe limiting all five types is key to getting control of symptoms of IBS, acid reflux and other SIBO-related conditions. But there needs to be balance. I don’t think diets that eliminate fermentable carbs or diets with excessive amounts of fermentable carbs are healthy diet for people with SIBO. I recommend some skepticism concerning RUMPS for people with SIBO or autoimmune-related conditions based on the following:

  • Reported GI side effects from many supplementing with RUMPS that are constant with the GI side effect of RS published in the scientific literature.
  • Anecdotal reports of autoimmune side effects with RUMPS.
  • Early research on gut bacterial enterotypes suggests that overgrowing, carb-loving, gas producing bacteria may be a factor in IBS and obesity.
  • Complex polysaccharides including RS may be reducing, not increasing, the diversity of our gut microbes, feeding blooms of gas-producing bacteria and driving symptoms.

But I don’t want to completely close the door on using RUMPS for treating SIBO for a number of reasons:

  • A few people with SIBO, IBS or acid reflux have reported improvement supplementing with RUMPs – I can’t argue with that if it works. Given the complexity of SIBO and dysbiosis, there may be certain individuals with SIBO who may benefit from RUMPS.
  • There are is a plausible mechanism, particularly in the case of diarrhea-predominant IBS – RS is like a bus.
  • The low relative fermentability of RUMPS suggests it may be less symptom-provoking than other fermentable carbs (I learned something new).
  • Careful dosing (reductions) for people with SIBO has not been tried / studied and could provide benefits with fewer side effects.

Of course only time and actual studies in people with SIBO-related conditions will tell us for sure if RUMPS is therapeutic for treating SIBO.

General recommendations

People with SIBO-related conditions suffer from a variety of underlying issues including: intestinal scarring, motility problems, gastroenteritis (infection or food poisoning), malabsorption due to intestinal villi, (needed for absorbing nutrients) damage, digestive enzyme deficiency, immune deficiency, low stomach acid, antibiotic use, or even genetic susceptibility based on Crohn’s, Celiac or other autoimmune conditions.

If you have signs or symptoms of SIBO or dysbiosis, I recommend the following:

  1. Reduce excessive gut fermentation by adopting the Fast Tract Diet that quantitatively limits all difficult-to-digest fermentable carbs.
  2. Work with your own health practitioner to explore, and where possible correct, potential underlying causes of SIBO listed above.
  3. Once you reach a baseline where excessive inflammation, SIBO and symptoms are under control, you can begin to experiment with gradually adding back more fermentable carbs including RUMPS (start with ½ teaspoon with lots of water) and see how it goes.
  4. Your gut microbiota can recover over time provided you don’t overfeed it, avoid antibiotics and address any underlying issues identified in step 2. You can experiment with adding probiotics (lactic acid, bifidobacteria or even soil-based probiotics), but to date, probiotics have not been shown to be very effective for IBS (the exception being some possible benefit for diarrhea) likely because most don’t become established in the gut. The gut is a highly specialized ecosystem in which bacteria have actually evolved the tools to colonize it. Though some probiotics might remain transiently and a few may even become established, rebuilding your microbiota occurs gradually overtime with fecal-oral transfer from house mates likely being one of the most significant sources of gut bacteria that can become established.


  1. Hard-to-digest “fermentable carbs” are quite different from “fermented carbs”. Fermented carbs have already been fermented outside the body in an incubator- think yogurt. Fermented carbs are mostly used up and replaced with short chain fatty acids. Fermented foods (unsweetened) are low carb / low fermentation potential and are safe to eat and encouraged on the Fast Tract Diet.
  2. You can always have your own microbiota tested to see what’s going on.
  3. The next wave of understanding will likely come when we understand how microbiota changes in luminal or unattached bacterial enterotypes relate or not to changes in mucosal or attached bacterial enterotypes in digestive health and illness.
  4. The Fast Tract Digestion books have a whole chapter on identifying and addressing the many underlying causes of SIBO.


[1] Ramakrishna BS1, Venkataraman S, Srinivasan P, Dash P, Young GP, Binder HJ. Amylase-resistant starch plus oral rehydration solution for cholera. N Engl J Med. 2000 Feb 3;342(5):308-13.

[2] Gancz H1, Niderman-Meyer O, Broza M, Kashi Y, Shimoni E. Adhesion of Vibrio cholerae to granular starches. Appl Environ Microbiol. 2005 Aug;71(8):4850-5.

[3] Rabbani GH1, Teka T, Zaman B, Majid N, Khatun M, Fuchs GJ. Clinical studies in persistent diarrhea: dietary management with green banana or pectin in Bangladeshi children. Gastroenterology. 2001 Sep;121(3):554-60.

[4] Olesen M1, Rumessen JJ, Gudmand-Høyer E. Intestinal transport and fermentation of resistant starch evaluated by the hydrogen breath test. Eur J Clin Nutr. 1994 Oct;48(10):692-701.

[5] Heijnen ML1, Deurenberg P, van Amelsvoort JM, Beynen AC. Replacement of digestible by resistant starch lowers diet-induced thermogenesis in healthy men. Br J Nutr. 1995 Mar;73(3):423-32.

[6] Vonk RJ1, Hagedoorn RE, de Graaff R, Elzinga H, Tabak S, Yang YX, Stellaard F.Digestion of so-called resistant starch sources in the human small intestine. Am J Clin Nutr. 2000 Aug;72(2):432-8.

[7] Heijnen ML, van Amelsvoort JM, Deurenberg P, Beynen AC.Neither raw nor retrograded resistant starch lowers fasting serum cholesterol concentrations in healthy normolipidemic subjects. Am J Clin Nutr. 1996 Sep;64(3):312-8.

[8] Muir JG1, Lu ZX, Young GP, Cameron-Smith D, Collier GR, O’Dea K Resistant starch in the diet increases breath hydrogen and serum acetate in human subjects. Am J Clin Nutr. 1995 Apr;61(4):792-9.

[9] Rashid T1, Wilson C, Ebringer A. The link between ankylosing spondylitis, Crohn’s disease, Klebsiella, and starch consumption. Clin Dev Immunol. 2013;2013:872632.

[10] Scher JU1, Sczesnak A, Longman RS, Segata N, Expansion of intestinal Prevotella copri correlates with enhanced susceptibility to arthritis. Elife. 2013 Nov 5;2:e01202.

[11] Wu GD1, Chen J, Hoffmann C, Bittinger K, Chen YY, Linking long-term dietary patterns with gut microbial enterotypes. Science. 2011 Oct 7;334(6052):105-8.

[12] Ebringer A1, Rashid T.  Rheumatoid arthritis is caused by a Proteus urinary tract infection. APMIS. 2013 Aug 29. doi: 10.1111/apm.12154.

[13] Rajilić-Stojanović M1, Biagi E, Heilig HG, Kajander K, Kekkonen RA, Tims S, de Vos WM. Global and deep molecular analysis of microbiota signatures in fecal samples from patients with irritable bowel syndrome. Gastroenterology. 2011 Nov;141(5):1792-801.

[14] Jeffery IB1, O’Toole PW, Öhman L, Claesson MJ, Deane J, Quigley EM, Simrén M. An irritable bowel syndrome subtype defined by species-specific alterations in faecal microbiota. Gut. 2012 Jul;61(7):997-1006.

[15] Malinen E1, Krogius-Kurikka L, Lyra A, Nikkilä J. Association of symptoms with gastrointestinal microbiota in irritable bowel syndrome. World J Gastroenterol. 2010 Sep 28;16(36):4532-40.

[16] Lyra A1, Rinttilä T, Nikkilä J, Krogius-Kurikka L, Kajander K, Malinen E, Mättö J, Mäkelä L, Palva A. Diarrhoea-predominant irritable bowel syndrome distinguishable by 16S rRNA gene phylotype quantification. World J Gastroenterol. 2009 Dec 21;15(47):5936-45.

[17] Krogius-Kurikka L, Lyra A, Malinen E, Aarnikunnas J, Microbial community analysis reveals high level phylogenetic alterations in the overall gastrointestinal microbiota of diarrhoea-predominant irritable bowel syndrome sufferers. BMC Gastroenterol. 2009 Dec 17;9:95.

[18] McKay LF, Holbrook WP, Eastwood MA. Methane and hydrogen production by human intestinal anaerobic bacteria. Acta Pathol Microbiol Immunol Scand B. 1982 Jun;90(3):257-60.

[19] Walker AW1, Ince J, Duncan SH, Webster LM, Dominant and diet-responsive groups of bacteria within the human colonic microbiota. ISME J. 2011 Feb;5(2):220-30.

[20] McKay LF, Holbrook WP, Eastwood MA. Methane and hydrogen production by human intestinal anaerobic bacteria. Acta Pathol Microbiol Immunol Scand B. 1982 Jun;90(3):257-60.

[21] Walker AW1, Ince J, Duncan SH, Webster LM, Dominant and diet-responsive groups of bacteria within the human colonic microbiota. ISME J. 2011 Feb;5(2):220-30.

[22] Delgado-Aros S1, Locke GR 3rd, Camilleri M, Talley NJ, Fett S, Zinsmeister AR, Melton LJ 3rd. Obesity is associated with increased risk of gastrointestinal symptoms: a population-based study. Am J Gastroenterol. 2004 Sep;99(9):1801-6.

[23] Hagen J, Deitel M, Khanna RK, Ilves R. Gastroesophageal reflux in the massively obese. Int. Surg. 1987 Jan-Mar;72(1):1-3. Fisher BL, Pennathur A, Mutnick JL, Little AG. Obesity correlates with gastroesophageal reflux. Dig Dis Sci. 1999 Nov;44(11):2290-4. Austin GL, Thiny MT, Westman EC, Yancy WS Jr, Shaheen NJ. A very low-carbohydrate diet improves gastroesophageal reflux and its symptoms (Obese patients). Dig Dis Sci. 2006 Aug;51(8):1307-12.

[24] Walker AW1, Ince J, Duncan SH, Webster LM, Dominant and diet-responsive groups of bacteria within the human colonic microbiota. ISME J. 2011 Feb;5(2):220-30.

[25] Duncan SH, Belenguer A, Holtrop G, Johnstone AM, Flint HJ, Lobley GE. Reduced dietary intake of carbohydrates by obese subjects results in decreased concentrations of butyrate and butyrate-producing bacteria in feces. Appl Environ Microbiol. 2007 Feb;73(4):1073-8.

[26] Turnbaugh PJ1, Hamady M, Yatsunenko T, Cantarel BL, Duncan A, Ley RE, Sogin ML, Jones WJ, Roe BA, Affourtit JP, Egholm M, Henrissat B, Heath AC, Knight R, Gordon JI. A core gut microbiome in obese and lean twins. Nature. 2009 Jan 22;457(7228):480-4.

[27] Ley RE1, Turnbaugh PJ, Klein S, Gordon JI. Microbial ecology: human gut microbes associated with obesity. Nature. 2006 Dec 21;444(7122):1022-3.

[28] Turnbaugh PJ1, Ley RE, Mahowald MA, Magrini V, Mardis ER, Gordon JI An obesity-associated gut microbiome with increased capacity for energy harvest. Nature. 2006 Dec 21;444(7122):1027-31.

[29] Turnbaugh PJ1, Bäckhed F, Fulton L, Gordon JI. Diet-induced obesity is linked to marked but reversible alterations in the mouse distal gut microbiome. Cell Host Microbe. 2008 Apr 17;3(4):213-23.

[30] Schwiertz A, Taras D, Schäfer K, Beijer S, Bos NA, Donus C, Hardt PD. Microbiota and SCFA in lean and overweight healthy subjects. Obesity (Silver Spring). 2010 Jan;18(1):190-5.

[31] Pimentel M1, Constantino T, Kong Y, Bajwa M, Rezaei A, Park S A 14-day elemental diet is highly effective in normalizing the lactulose breath test. Dig Dis Sci. 2004 Jan;49(1):73-7.

[32] O’Keefe SJ. Tube feeding, the microbiota, and Clostridium difficile infection. World J Gastroenterol. 2010 Jan 14;16(2):139-42.

[33] Aerssens J, Camilleri M, Talloen W, Thielemans L, Alterations in mucosal immunity identified in the colon of patients with irritable bowel syndrome. Clin Gastroenterol Hepatol. 2008 Feb;6(2):194-205.

[34] Topping DL1, Clifton PM.Short-chain fatty acids and human colonic function: roles of resistant starch and nonstarch polysaccharides. Physiol Rev. 2001 Jul;81(3):1031-64.

By |2018-02-20T08:38:48+00:00March 24th, 2014|Diet and Digestive Health|153 Comments

About the Author:

Norm Robillard received his Ph.D. in microbiology from the University of Massachusetts, Amherst studying Bacillus anthracis and other Bacillus species. His post-doctoral training at Tufts University focused on antibiotic resistance and gene transfer between the gut microbes Bacteroides fragilis and E. coli. During his career in pharma / biotech, Dr. Robillard studied the genetics of antibiotic resistance, septic shock, viral illnesses and antimicrobial and antibody-based therapies prior to founding the Digestive Health Institute. Dr. Robillard is the creator of the Fast Tract Diet, author of the Fast Tract Digestion book series and publisher of the Fast Tract Diet mobile app. He was the first to propose excess intestinal fermentation as the underlying cause of acid reflux and explained the connection between intragastric pressure from gas-producing bacteria in our intestines, nutritional malabsorption and the symptoms of acid reflux. His latest book series, Fast Tract Digestion provides a safe and effective dietary tool and behavioral strategy as an alternative to proton pump inhibitors (PPIs), H2 blockers, IBS drugs or antibiotics for heartburn, acid reflux, GERD, laryngopharyngeal reflux disease (LPR), IBS and other SIBO related conditions.


  1. Tatertot March 24, 2014 at 11:14 pm

    How fitting, I get to be first!

    Thank you so much for the in-depth look, this will be a very valuable article for a long time and hopefully assist many people in making wise decisions.

    As I relayed, RUMPS on an inflamed, dyspeptic stomach is not comforting in the least! My dyspepsia seemingly caused by a slight overdose of ibuprofen. If this were a chronic condition and not just temporary as in my case that night, I feel for anyone who has it.

    So many different problems associated with digestion. RUMPS has actually turned into somewhat of a litmus test for broken guts. Instant discomfort would seem to indicate a problem in the stomach. Discomfort from 30-60ish minutes after would be in the small intestine, and discomfort after 3-4+ hours would be an issue with large intestine.

    It seems the average Joe with no history of digestive troubles is generally able to digest 3-4TBS with no problems, but still may end up with a bit more flatulence that he likes. In this case, the “Soil-based organisms” seem to help most as they are the primary and secondary degraders of the RS. The end result being a boost in butyrate production and thriving colonies of bifidobacteria that stay put and do what they are supposed to do.

    But, digestive issues aside, this has been quite a learning experience for all of us and it has been great exchanging ideas with you, Norm. Everyone deserves the best gut possible for quality of life, and anything that gets people off PPIs and antibiotics is great in my book.


    • Norm Robillard March 25, 2014 at 12:00 am

      Hey Tim, Thanks for your perspective. Yes, it has been, and continues to be, quite a learning experience indeed.

  2. Cooper Mor March 25, 2014 at 4:52 am

    Hey Norm, thanks so much for the thoughtful post. I’m particularly interested in your thoughts (and all others willing to weigh in!) regarding AS, klebsiella, and their relation to RS.

    I’m HLA-B27+, with psoriatic arthritis that includes spinal involvement. In addition I tested positive for high amounts (“potentially pathogenic”) amounts of klebsiella pneumoniae on a Genova stool test. Given this, I consider it to be a pretty close relative to AS.

    Now I’ve been on a no starch, no sugar, no refined carbs diet for going on a year now. I’ve had slight symptom reduction (I also started LDN during the year), but not the success I’m looking for (or that other people have reported). I personally started the protocol Art Ayers is recommending (RS + probiotic cocktail) a couple days ago.

    So personal history aside, the meat of my question is: if we look at Tim’s n=1 American Gut data we see his proteobacteria band is considerably smaller than average. Am I right that klebsiella is a Gammaproteobacteria which would fall under the proteobacteria band?

    If we pretend that Tim’s results are standard and not just an n=1, wouldn’t this be evidence of RS helping other bacteria overtake the klebsiella? And then assuming the link between the AS and kp is causative, that it might help the condition?

    Thanks again for the incredibly well researched post!

    • Norm Robillard March 25, 2014 at 12:00 pm

      Hi Cooper,
      Thanks for the post and a really great question. At the macro level, having less Proteobacteria would seem to be a good thing if you were worried about being colonized with one of it’s members (Kleb), but I think the micro level is much more important in your case. Bacteria within a given enterotype often have very different metabolic capabilities. Klebsiella pneumoniae has excellent starch degrading capabilities. And you have actually tested positive for it. I think your strategy of limiting starch and sugar is a good one. If you don’t get results, I recommend you try the Fast Tract Diet which focuses not on “refined” carbs, but rather carbs that are most likely to escape absorption and provide fuel for organisms like K. pneumonia. As for using LDN, Art is the expert here, but just keep an eye out for the most common side effects: “gastrointestinal complaints such as diarrhea and abdominal cramping.”

      ps: You may have read this review, but just in case, here’s a link.

      • Christy March 25, 2014 at 5:40 pm

        Thanks for this great info. I also came looking for AS and klebsiella information and was shocked and pleased to see that you mentioned them specifically. I think for now I’ll stick with my low carb, no starch diet as that’s the only way I’ve gotten relief from my IBS symptoms.

  3. Reub March 25, 2014 at 11:33 am

    So where are the scientific studies on resistant starch? I’m particularly interested in any proof of a positive effect (if any) on fasting blood sugar. Everything that I’ve read seems to be anecdotal.

  4. PhilT March 25, 2014 at 12:42 pm

    The glycemic index of RUMPS looks to be effectively zero (or less) at Fig 1.

  5. DuckDodgers March 25, 2014 at 1:49 pm

    It’s easy to ignore the many other sources of fermentable material gut bacteria have available including: Unabsorbed proteins, mucus, nucleic acids and other macromolecules

    True, but aren’t those other fermentable materials generally ignored because they aren’t all that great at fermenting into SCFAs like butyrate? I thought that’s what the “carbohydrate gap” is all about. It’s hard to imagine getting much butyrate production without fermentable carbs. Additionally, I’d imagine feeding gut bugs mucus would just diminish the gut barrier, so wouldn’t it be best to keep that at a minimum?

    • Norm Robillard March 25, 2014 at 3:09 pm

      Good thoughts Duck. Don’t have all the answers, but I recall looking at some (boring) metabolic pathways awhile back showing that bacteria can make butyrate along with some isomers of butyrate (utilizable by enterocytes) from various amino acids. So you might not make as much from protein, but you still do make it. As for nucleic acids, don’t know for sure, but you might check check out the Kegg pathway Mucus is 3/4 carbohydrate side chains that I would imagine is fine for making butyrate but only bacteria with glycosidases can free up the carbs for use. Many bacteria can’t do this, but interestingly, Bifidobacteria bifidum and Ruminococcus torques can. As for using up mucus, that is pretty speculative. You could also speculate that feeding key gut microbes is a function of mucus during fasts/starvation or when consuming mostly animal based diets. What do wolves do? Perhaps mucus helps ensure that the mucosal (adherent microbes) are taken care of.

      • DuckDodgers March 25, 2014 at 3:14 pm

        As for using up mucus, that is pretty speculative

        Really? I thought a lack of mucus is a significant contributor to leaky gut?

        I would think that the more mucus you have, the more intact the gut barrier is.

      • DuckDodgers March 25, 2014 at 4:48 pm

        What do wolves do?

        Obligate carnivores consume lots of raw, fresh, whole animals that are rich in prebiotic glycans. Researchers call it “Animal Fiber” and the fresh skin, cartilage, collagens and prebiotic glycans get fermented into SCFAs.

        The problem with modern “wolf” diets is that they lack these fresh postmortem prebiotic glycans and they lack the raw enzymes (lipase for digesting fat, just to name one) that make digestion of these components easier. In other words, the wolf doesn’t need to waste energy creating a lot of enzymes since the enzymes are already present in the fresh postmortem animal.

        And as some of these glycans are easily assimilated into the wolf’s body (collagens, mucins, etc) they appear to excuse the body from having to produce their own versions of those compounds, thus freeing up energy to produce the much needed glycans, like mucin. Interestingly, this appears to be what the Inuit and Masai did when they consumed their prey raw.

        So, I don’t see why we would equate a Western low carb diet with that of an obligate carnivore. They are totally different.

        • Norm Robillard March 25, 2014 at 5:36 pm

          Very interesting perspective Duck. What do you consider a Western low carb diet in grams of carbs per day?

          • DuckDodgers March 25, 2014 at 5:49 pm

            I was under the impression that studies tend to classify “low carb” as anything under 100g of carbs/day. And “very low carb” as anything under 50g carbs/day. Moderate carb would be just above that.

            From reading about highly-carnivorous humans — even cannibals for that matter — was that they always ate their meats raw. Even homo erectus, who was well known for relying heavily on meat, was not believed to have cooked its foods.

            There had to be a reason that every highly-carnivorous culture ate so much raw meat.

            And it gets even weirder. Here’s an individual that kills and butchers his own animals and has been eating raw animals for five years. He says it fixed his gut problems and makes him feel great. The anthropological evidence suggests that’s how “low carb” cultures always did it.

            In fact, I can’t find a single low carb culture that ate lots of cooked meat!

          • DuckDodgers March 25, 2014 at 5:57 pm

            Also worth noting that when Jeff Leach visited the Hadza, he observed one of the hunters kill an animal and within minutes the hunter was inviting him to consume the raw stomach and lightly singed colon of an impala. Both would have been particularly rich in prebiotic and pre-formed glycans. In other words, he would have been consuming preformed mucins had he eaten it.

            So, I just can’t see how we can use these cultures or obligate carnivores as an excuse to eat lots of aged and cooked steak. Doesn’t seem to be in the same ballpark from my perspective.

  6. DuckDodgers March 25, 2014 at 2:26 pm


    In terms of lowering Firmicutes and increasing Bacteroides, one needs to consider glycobiology. Most of the known prebiotics are glycans. There are millions of different glycans (together known as the “glycome”) with millions of different roles, but all they really are are just carbohydrates attached to proteins or fats or other macromolecules. As I’m sure you know, mucin-2 is a key glycan in the body — it’s a protein that is 80% sugar by weight. Many glycans are polysaccharides or oligosaccharides linked to a protein or fat molecule — so you can see why they are a prime target for gut bugs. When the link between the glycans and their parent fat or protein is cleaved in the digestive tract, the glycan (which tends to be indigestible) becomes freed. It turns out that Bacteroides secrete a lot of glycan-degrading enzymes. Firmicutes don’t have as many.

    The glycome is enormous. There is a human milk glycome, with over 200 different glycans. There is a food glycome, where millions of glycans exist in our food supply.

    Interestingly, raw animal skin, cartilage, raw intestines and raw muscles contain a lot of prebiotic glycans. Raw animal parts, particularly those ingested immediately after postmortem, are a very good source of glycans. However, the meats we buy in supermarkets and from butchers are missing many of these glycans since lactic acid producing bacteria quickly degrade them during the long chilling process, which tenderizes the meats we eat. Cooking also tends to degrade any remaining glycans as well. This shouldn’t be surprising since you can’t really cook prebiotics without destroying most of them.

    It’s worth noting that every carnivorous animal and every highly-carnivorous indigenous culture that ever walked the face of the Earth ate lots of raw animals and raw meats. This suggests that the evolutionary low carb diet is actually a raw meat diet, which the Inuit and Masai were well known to have consumed.

    At any rate, it turns out that polyphenols tend to be glycans as well. And it turns out that eating polyphenol-rich foods seems to bloom Bacteroides and suppresses Firmicutes.

    From: High polyphenol, low probiotic diet for weight loss because of intestinal microbiota interaction by Rastmanesh R.:

    The relative proportion of Bacteroidetes to Firmicutes is decreased in obese people. This imbalance in gut microbiota generates signals controlling the expression of genes by the epithelial intestinal cells. Both dairy and non-dairy probiotics increase body weight, reportedly through Lactobacillus species growth in the gut. On the other hand, daily intake of some fruits and drinks such as three apples or three pears or grapefruit, or green tea, which all are rich in polyphenols, can significantly reduce body weight in obese people. Metabolism of polyphenols by microbiota involves the cleavage of glycosidic linkages. Glycans, which are the product of glycosidic cleavage, are necessary for survival of the intestinal microbiota as a nutrient foundation. There are two pivotal points: (i) Firmicutes possess a disproportionately smaller number of glycan-degrading enzymes than Bacteroidetes, (ii) Firmicutes are more repressed than the Bacteroidetes by phenolic compounds’ antimicrobial properties. The Bacteroidetes community prevails following dietary polyphenol intake and its fermentation to phenolic compounds, due to having more glycan-degrading enzymes, so this may thus be a mechanism by which dietary polyphenols exert their weight lowering effect.

    You will note that Grace has recommended high ORAC foods/supplements for treating SIBO. High ORAC foods are rich in polyphenols — which makes them prime prebiotic targets for Bacteroidetes which are particularly adept at degrading glycans.

    So, some of those glycans just become prebiotic food for the Bacteroidetes, and some of those glycans become other end products of colonic metabolism that can be assimilated by the body. So, when the polyphenol glycosidic linkages are cleaved by the microbiota, the ones that aren’t eaten by the gut bugs become “phenolic compounds” that can be absorbed by the body. It’s another example of our a symbiotic relationship with our mirobiota.

    As I said before, there are millions of different kinds of glycans in the glycome. And again, some of them are just absorbed directly by the body. For instance, glycosaminoglycans (or “GAGs”) are found in all sorts of foods. Collagen hydrolysate, skin and cartilage are all good sources of GAGs. Wild blueberries have GAGs in them as well. The GAGs from wild blueberries appear to be cleaved by Bacteroidetes and seem to get assimilated into aortic tissues.

    What this also means is that dark chocolate, raw mushrooms, tea leaves, vinegars, lemons, red wine, cocoa, flax seeds, olives, dark berries and raw herbs all have prebiotic targets and microbial metabolites in them. Do a search on virtually any of those foods and you’ll find a “surprising” article about researchers discovering prebiotic targets in them. But, it’s really not so surprising when you understand that these foods contain lots of prebiotic glycans.

    When it comes to prebiotics and polyphenols, keeping them raw and undenatured is helpful for preserving their glycans. The problem seems to be that it’s a challenge to eat significant quantities of these glycan-rich foods, particularly in their raw form. And therein lies the conundrum in the Western world.

    It’s worth noting that including some polyphenol-rich ingredients (particularly natural acids/vinegars) with carbohydrates have been shown to significantly lower the GI of those foods (sounds like a prebiotic effect, doesn’t it?).

    Additionally, some keen thinkers have often suspected that polyphenols have prebiotic properties, but now you know why. Other than the career glycobiologists, there seem to be only a few handful of people on the planet who are aware of this glycans-as-prebiotics concept. See, you learned something else new! 😉

    Kidding aside, I think the conversation should probably be less about “RUMPS” and more about how to maximize SCFA production and modulate microbiota composition. That’s the real goal here, isn’t it? “RUMPS” is just an easy/cheap way to maximize SCFA production. To my knowledge, obligate carnivores and carnivorous cultures produced their SCFAs by consuming lots of raw glycans from eating whole raw animals. That’s why they don’t have a “carbohydrate gap.” If you have any other good ways to achieve good SCFA production, we’re all ears!

  7. Norm Robillard March 25, 2014 at 4:12 pm

    Thanks for the info on glycobiology Duck. Need to read up on that. As for needing more SCFAs in my gut, I’m not sure about that at all. I was looking over some of the literature on in-vivo levels and found it quite confusing. Do you know what the typical levels are / should be? I understand there is quite a bit of variation depending on where in the intestine you sample and also the problem of them being metabolized or transported as soon as they’re made. Some in-vitro studies talk about straight up mM concentrations where some in-vivo studies used mM per day or mM per kg. Also, I read one study where dietary changes that altered the microbiota showed no change in SCFA levels. Honestly, I would like to learn more about why we need to actively eat specific types of foods or take supplements to increase SCFA levels.

  8. Tatertot March 25, 2014 at 4:32 pm

    I would love to pin down our exact need for butyrate, too. Lots and lots being written on butyrate lately–enhancing MUC gene expression and all sorts of stuff.

    The thing that gets me, in the US and western diets, normal fermentable fiber intake (traditional sense, not FP sense) is less than 10g per day. All the studies that increase it to around 40g per day show lowering or pH, increase of SCFA (particularly butyrate), and growth of beneficial bifidobacteria.

    I’ve looked at quite a few stool sample reports lately, and hardly anyone has any bifidobacteria. A couple studies say it comprises less than 4% of adults microbiome, but mostly what I see is zero%.

    Seems to me a gut that favors the growth of bifidobacteria is a healthy gut. Only a few things really make it grow well…RS, inulin, momma’s milk.

    Many other foods can make it thrive once established: FOS, dark chocolate, coffee, polyphenols/glycans of all sorts.

    But it seems to me that so many people have a gut that is just plain hostile to bifidobacteria.

  9. Norm Robillard March 25, 2014 at 5:22 pm

    Agreed Tim. Much work to be done. The one thing I do like about Bifidobacteria is most species are homolactic fermenters producing only lactic acid and no gas from carbs which translates into fewer GI symptoms.
    But some of the other claims have me wondering – colon cancer for instance. Don’t we need to firm up the connection before we go off in what could be the wrong direction? My last article included this: Two species of bifidobacterium (B. longum and B. angulatum), as well as Bacteroides were “significantly associated with high risk of colon cancer.” (Moore WE1, Moore LH. Intestinal floras of populations that have a high risk of colon cancer. Appl Environ Microbiol. 1995 Sep;61(9):3202-7.).
    So here we have two very important groups being found at the scene of the crime – innocent by-standers perhaps? Interesting that both groups were reduced in IBS. Does that mean people with IBS will have a lower rate of colon cancer? I tend to doubt it. They also found that bacteria that produce lactic acid (not butyrate) were associated with low cancer risk. Maybe we should go after lactic acid bacteria?
    And this: A study that specifically looked at the protective effect of resistant starch in carriers of hereditary colorectal cancer found that resistant starch had no detectable effect on cancer development (Mathers JC, Movahedi M, Macrae F, Mecklin JP, Long-term effect of resistant starch on cancer risk in carriers of hereditary colorectal cancer: an analysis from the CAPP2 randomised controlled trial. Lancet Oncol. 2012 Dec;13(12):1242-9.)
    – Too many questions, not enough answers.

  10. Johnny March 25, 2014 at 5:45 pm

    My n=1 experiment w/ PS was no bueno. RA quickly came out remission and wrecked havoc. Crazy vivid dreams were the only positive but my sleep sucked and these dreams were not always pleasant.

  11. Tatertot March 25, 2014 at 6:16 pm

    Too bad you don’t have a reader/commenter who knows more about Bifidobacteria than any human alive and even wrote a book about it, huh Bill L. ?

    I just looked over a uBiome report for a friend, it showed that the average sample had less than 2% bifido. The American Gut project showed similar–and these represent thousands of samples.

    Babies have nearly 90% bifido until weaned. Ancient coprolite 16S rRNA samples showed high levels of bifido from 10,000 years ago and as recently as 100 years ago.

    Seems like the only way to get levels above 5% is to eat a ton of inulin or RS. Jeff Leach had 5% on high inulin diet, I had 12% on high RS diet. Just saying this for ‘interesting insight’. No hidden agenda. The RS studies predicted a high concentration of bifido on an RS supplemented diet.

    I’m hoping it’s a clue to better health for people. Lots of folks spending money on bifido supplements, yet not getting large bifido populations. I’m betting that ancestral populations all had high bifido counts and that the bifido in some way contributes to better guts, or is at least a canary in the coal mine.

    I wonder what a famous Bifido author would say?

    • Bill Lagakos March 26, 2014 at 5:23 pm

      For starters, 12% is officially the highest bifido count I’ve ever encountered!

      When it comes to colon cancer, it’s hard to say, but I’m leaning toward: no strong relationship. As Norm mentioned: in the Moore study, bifido was ‘caught at the scene of the crime,’ and Mathers showed no effect of long-term RS2 supplementation (HAMS, Novelose)… and this Gueimonde study showed *less* bifido in colon cancer ( So it’s all over the board, which to me suggests no relationship.

      I think the best evidence for prebiotics is in IBS and related conditions; the focus should be on identifying which subgroups stand to benefit from supplementation.

      • Bill Lagakos March 26, 2014 at 5:50 pm

        edit: it appears as though a 1:1 blend of Novelose 240 (RS2) and Novelose 330 (RS3) was used in the Mathers study.

    • caessence March 28, 2014 at 9:47 pm

      Perhaps the way to get bifidobacterium in the diet is to ingest it through sauerkraut and other fermented foods daily. Increase the numbers with good soil.

  12. Paleophl March 26, 2014 at 12:52 am

    Nice work, Norm. Good to see you working with Tim and Richard to help people. Resistant starch has been beneficial for me and I’m grateful for the efforts of you guys.

  13. Gemma March 26, 2014 at 10:10 am

    Thank you, great article and even greater comment section with Duck The Eyeopener!
    Btw, Duck, as a tip for a next topic worth some deep exploration: what about some truffles?

    • DuckDodgers March 28, 2014 at 3:38 am

      Gemma. Great find! I had no idea that truffles stored their energy as glycogen. That’s pretty cool. Too bad they cost so much. I also remember reading that the inferior chinese truffle has tainted the European truffle market.

      • Gemma March 28, 2014 at 8:32 am

        Glycogen: any mushroom, not only truffles. Have you read The Lord of the Rings? “It is said that Hobbits have a passion for mushrooms, surpassing even the greediest likings of Big People.” 🙂

  14. Bill Lagakos March 26, 2014 at 5:33 pm

    Also, just have to admit: I’m very excited about Tim Dinan’s work on the gut-brain axis (eg, PMID 23910373 & 23759244).

  15. Eileen @ Phoenix Helix March 29, 2014 at 9:36 pm

    I love this article and the educated discussion in the comments. It is by far the most objective assessment I have seen. I totally get why everyone is excited about the potential for RS, but true scientific research is slow work, and it will be years – maybe decades – before we really understand its effect on the diverse microbiome out there. I’m someone with RA who finds RS inflammatory. I do a combination of GAPS and AIP and have been flare-free for over a year, with no need for immunosuppressant or steroid medication, so I’m very happy with the results of diet and quite comfortable living without RS in my life.

    I noticed at the start of your article you said that one of the claims of RS is that it’s an immune stimulant. I wonder if that’s one reason it harms some of us with AI, whose immune systems are prone to overactivity to begin with?

    I’m also fascinated that you found some studies calling into question the universal benefits of bifidobacteria. Since I’m also casein-intolerant, I’m aware my bifido count must be quite low, so I bought some bifido-only probiotics and had an inflammatory response to them, similar to a food intolerance reaction. It caused joint stiffness and a negative gut-brain response where I felt a cloud of depression descend, which simply doesn’t happen to me. I’m one of the lucky people with positive emotional mindset as my norm. So that was completely unexpected and makes me wonder if the reason I have trouble with RS isn’t just that it feeds pathogens, but that it feeds bifido, which my body for some reason reacts against. Again….more questions than answers.

    One note: just because I have a negative response to RS doesn’t mean I think all people with AI disease should avoid it. I have lots of friends in the Paleo AI community and some of them do quite well with RS. The more I learn about dietary healing, the more I see how unique we all are. I’m a big believer in n=1, and wary of n=everyone.

    • Norm Robillard March 30, 2014 at 12:26 am

      Thanks Eileen for your thought provoking comments. I noted the claim that RS is an immune stimulant, but don’t personally know of evidence supporting this. But your idea is plausible. One of the best groups of bacteria for maintaining tolerance is the Bacteriodes, B. fragilis for instance, with it’s miraculous zwitterionic polysaccharide A. And it seems to do well on an animal-based diet. Also check out the link I just posted above on RA and Prevotella copri.

  16. Christoph Dollis April 10, 2014 at 5:38 am


    I first left this on William Lagokas’ post: Gluten vs. gut bacteria, Op. 78, and I’ll add a bit to it now. The post, which is spectacular, is about how increasing bifodobacteria reduces inflammation caused by gluten; in part:

    “Crackpot theory of the week: could inulin/GOS increase gluten tolerance? He and colleagues (2008) gave lactose-intolerant patients supplemental bifidobacteria in the form of capsules (1.8×10^9 cfu B. longum) and yogurt (3×10^10 cfu B. animalis) which significantly improved their lactose tolerance (it nearly cured them). In this study, yogurt provided the prebiotics necessary to ensure survival of the supplemental bifidobacteria. I imagine inulin or GOS would’ve had a more profound effect.

    “Celiac disease, lactose-intolerance, IBS, and veganism are all associated with reduced bifidobacteria and could theoretically benefit from inulin/GOS supplementation. …”

    My experience:

    Wow, this is an amazing find.

    About five or six weeks ago, I started raw potato starch 2 Tbsp/day, then dropped it to 1.

    Two or three weeks ago, I went from the SAD to an on-purpose, high-wheat diet so that I could test for gluten sensitivity. My mom had celiac proper and a doctor I recently saw thought I might be sensitive to it because my heartburn did not respond to pantoprazole, a protein-pump inhibitor, but does respond to large doses of ranitidine (or famotidine), a histamine H2-receptor antagonist, which she says has some antihistamine properties. Further, the usual triggers for GERD—tomatoes, other acidic food, spicy food including hot spices, coffee, etc.—don’t seem to bother me (indeed these are my favourite foods). I’ve also noticed that my heartburn gets worse when I eat more carbohydrates and my worst ever nights with it were after eating very high-wheat meals (such as the better part of a large pizza).

    The doctor put this all together and thought gluten sensitivity.

    And yet, my blood glucose has quite significantly improved over the last two to three weeks despite eating wheat at every single meal and my heartburn is certainly no worse, probably better. I’m taking less ranitidine—last night I took none at all.

    “How could this be?” I puzzled.

    Well, it could be the case that the resistant starch upped my bifidobacteria and as a result I’m lest sensitive to the gliadin in gluten. It seems more than just plausible, doesn’t it?

    P.S. Well gee, this is going to complicate getting tested for gluten sensitivity, now isn’t it? LOL

    Further, commenter George Henderson posts a link to this paper:

    Bifidobacteria reduce gliadin-induced toxicity

    Laparra J.M. and Sanz Y.*
    Microbial Ecophysiology and Nutrition Group. Instituto de Agroquímica y Tecnología de Alimentos (CSIC), Apartado 73, 46100, Burjassot (Valencia), Spain.

    Running title: Bifidobacteria attenuate gliadin-induced inflammation

    “The peptides from gliadin digestions inoculated with bifidobacteria did not exhibit the toxic amino acid sequences identified in those non inoculated (a/ß-Gld [158-164] and a/ß-Gld [122-141]). The RT-PCR analysis evidenced a down-regulation in mRNA expression of pro-inflammatory biomarkers. Consistent with these results the production of NF-?B, TNFa and IL-1ß was reduced (18.2-22.4%, 28.0-64.8% and abolished, respectively) in cell cultures exposed to gliadin digestions inoculated with bifidobacteria. Therefore, bifidobacteria change the gliadin-derived peptide pattern and, thereby, attenuate their pro-inflammatory effects on Caco-2 cells.”


    How do you like dem apples?

    – – – – –

    To sum up: I’ve eaten wheat at every single meal for at least three weeks precisely to test if, as a doctor and I suspected, it was giving me the heartburn, since the worst episodes of that were after eating high-wheat meals; I didn’t respond to a PPI but did to an histamine H2-receptor (ranitidine) in large (up to 600 mg/day!) doses (which the doctor says has anti-histamine properties, and led her to suspect that’s why it was effective, but the PPI not); the traditional GERD triggers such as caffeine, acidic food, and the like didn’t affect me; and my mom had celiac disease proper.

    The plan was at the end of a month, to test for gluten sensitivity.

    But the plan has gone awry—stymied by resistant starch. My heartburn is much reduced as is my antacid dose—yesterday none again, not for the first time. After. Eating. Wheat. In. Quantity. At. Every. Single. Meal. For. Weeks.

    About six weeks ago, I’d begun the raw potato starch, just a tablespoon on average per day. (I’ve since bumped it up as of two days ago, and added other things to my “Essential Slurry”.)

    It appears the prebiotic has upped my Bifodobacteria and made me much, much less sensitive to gluten … as, unknown to me at the time, science has shown Bifodobacteria does.

    So I will probably get a false negative result if and when I test for gluten sensitivity.

    Further: Food cravings have gone away … for the first time ever.

    P.S. My operating theory is as above, but alternatively, perhaps it helped with SIBO, hence the betterment of symptoms. Either way, there’s little doubt to my mind that RUMPS and other prebiotics can, for many people, help their microbiota in profound ways. I’m increasing my dosage, for what it’s worth.

    • Norm Robillard April 10, 2014 at 12:00 pm

      Great post Christoph, There may just be more than one way to skin this cat. I do believe prebiotics are a double edged sword. In one study I talk about in Fast Tract Digestion, fructose oligosaccharide (FOS) actually triggered acid reflux in healthy subjects. I will take a look at the refs you posted for sure. It is interesting that Bifidobacteria are one of the bacterial types observed to be reduced in IBS subjects. I’m interested to see how your experiment unfolds in the coming weeks.

      • Christoph Dollis April 11, 2014 at 4:30 am

        For the record, I was not diagnosed with SIBO. But definitely needed ranitidine for years. And haven’t taken it for a few days now. So that’s interesting.

  17. Susan April 10, 2014 at 4:13 pm

    I didn’t know where to ask this. The forum doesn’t seem to be working.
    On the first day of the diet, the lunch is caesar salad and calls for 1 small head of romaine per person. About how many grams would this be ?

    On day 5 for dinner, you recommend only 1/2 cup rice until symptoms are under control. Is that cooked or uncooked ?

    And generally, in the fermenation tables, are those values for cooked or uncooked foods ?


  18. Norm Robillard April 11, 2014 at 1:00 am

    Hi Susan,
    The lettuce has almost no FP – maybe 1 to 1.5 grams. The rice refers to 1/2 cup cooked. The idea is to really watch the starch early on – even the low FP variety until SIBO is more under control. Even easy to digest starch can be malabsorbed with aggressive SIBO.

  19. Hcallahann44 April 15, 2014 at 3:10 pm

    Thanks for your great work Norm…you are on the cutting edge. I wonder if you have considered the work of Andrew Kim and Ray Peat….both of these guys support your contention that fermentation should be minimized…..exactly the opposite of what Mr. Leach seems to be saying. Very confused. And no one seems to be looking at the problem of “persorbtion” as it applies to RS. From Kim –

    • Paleophl April 16, 2014 at 12:30 am

      Hi Hcallahann44, Tatertot Tim Steele addressed the persorption topic here:

      Both Norm and Jeff Leach have provided interesting contributions toward explaining the big picture. I have also read some of Andrew Kim and Ray Peat’s writings and also found some of their work quite interesting. One of the more interesting things was that when I increased my consumption of prebiotic foods to closer to ancestral levels, my body temperature and resting heart rate moved toward the numbers that Ray Peat advocated, with my body temperatures now matching Ray’s ideal range. Resistant-starch-rich foods did more than any other prebiotic source or other type of food I’ve tried so far to give me Peat-recommended results, including tropical fruits. I actually wish it had been yummy tropical fruits, of which I still eat more than most people do (and I often have to tell the cashiers what some of them are). 🙂

      Of course, YMMV, and I take Norm’s cautions seriously.

      • Hcallahann44 April 16, 2014 at 3:54 pm

        Thanks Paleophil…I have been scouring the internet trying to find an answer to this so your response was extremely helpful!! I was on a VLC diet for many years and developed unconquerable diarrhea. I kept cutting the carbs even lower in an attempt to address it…following the Life Without Bread guys. Finally I caved and tried potato starch…and within a week had perfect poop. Of course the Peat crowd rained on my parade. You seem to be one of the most informed authorities out there on these issues…would you consider a private paid consult?? Curious to hear that you are using Prescript Assist probiotics…some say these are harmful due presence of Bacillus Subtillus…and organism that can be difficult to eradicate in the immunocompromised. Would love to pick your brain on the RS stuff sometime. Thanks again for your post!

        • Paleophil April 18, 2014 at 11:40 am

          Hi Hcallahann44,

          I used 1 bottle of Prescript Assist and now am trying Primal Defense Ultra. Haven’t noticed anything from them.

          I’m not an authority. Tatertot knows more about the topic than me and he answers questions for free, thus killing my chances for a profitable consultancy. 😉 He has answered questions in the past at the Mark’s Daily Apple Forum and you could also PM me (Paleophil) there if you like.

        • Paleophil June 27, 2014 at 9:56 pm

          I have noticed a small benefit from Primal Defense Ultra – eyebrow dandruff that I’ve had for decades disappeared since I’ve been taking it. I still have some scalp dandruff, though.

  20. Hcallahann44 April 16, 2014 at 7:38 pm

    The real question that remains unanswered is— do we need to eat as many types of fermentable fiber as possible to optimize gut function….or do we need to minimize consumption of fermentable fiber to reduce endotoxin and achieve optimal gut health. Ray Peat and Andrew Kim and I assume Norm R. falls in the latter camp. Jeff Leach and Tatertot in the former? Frustrating that these two positions are diametrically opposed. Would be nice to know the answer!

    • Duck Dodgers April 16, 2014 at 8:04 pm

      do we need to eat as many types of fermentable fiber as possible to optimize gut function

      Lots of ways to phrase the last part of that sentence:

      …to feed our microbiome?
      …to create more SCFAs and improve acidity?
      …to crowd out pathogens?
      …to produce a vitamin factory in our guts?
      …to improve nutrient absorption?
      …to improve neurotransmitters?

      But if you have a bad gut and your goal is to minimize endotoxins, then those benefits may not be first on your list.

    • Norm Robillard April 16, 2014 at 9:24 pm

      Good question Hcal. Curiosity and effort to find answers may help replace some of the frustration. I do think the answer will be different for different people. This study for instance ( is a good tip of the iceberg story on how the amazing diversity of our gut microbiota matches and adjusts to the changes in our diet. And it includes a few surprises, for instance these hunter-gathers have almost no bifidobacteria and their bacteriodes have not been characterized.

      • Duck Dodgers April 16, 2014 at 10:50 pm

        And it includes a few surprises, for instance these hunter-gathers have almost no bifidobacteria and their bacteriodes have not been characterized.

        I wouldn’t get too excited. Unfortunately, the researchers stored the samples in alcohol. So, the bacterial proportions are likely invalid.

        The article elaborates:

        There is one problem with the study: the team stored their Hadza stool samples in alcohol, which can seriously affect the proportions of different species found within them. This may explain why both the Hadza and Italian samples were dominated by bacteria from the Firmicutes group—a trend that has been linked to obesity in past studies. Maria Gloria Dominguez-Bello from New York University has run into this problem before, and had to repeat a lot of past work to correct for it. She has looked at the microbiomes of hunter-gatherers in Venezuela (as yet unpublished) and rural kids in Mexico, and neither group were dominated by Firmicutes.

        “The conclusions about relative proportions of bacteria are likely not valid,” says Rob Knight, a microbiome scientist with expertise in technical issues. “Unfortunately there is no published reference for this yet; we’re working on one.” It’s not clear if this problem affects the study’s other conclusions, like the lack of Bifidobacteria.

        • Norm Robillard April 17, 2014 at 2:54 am

          Interesting Duck. I would agree if they were trying to preserve viable organisms. Instead they were preserving the genetic material from the samples (16s ribosomal DNA) and SCFAs for extraction and analysis. They validated the methodology with human fecal samples (Germans). Check out the methods section at the end of the paper.

          • tatertot April 17, 2014 at 3:29 am

            I hope it’s true, or if not, the re-do the tests. These are invaluable.

            If it’s true they have no bifido, it makes me wonder if their babies do…surely they do? I wonder when they lose it.

            Also, if the graphs in the study are accurate, maybe we should be looking at the massive blue bands at the bottom of the charts that both groups share and search for commonalities that we all share and then see if those are missing in people with say, GERD, IBS, AI diseases, etc..

            The fact that they had no bifido wasn’t all that shocking to me, many, many Americans don’t have it, either. It must be a very temperamental species.

          • Duck Dodgers April 17, 2014 at 3:43 am


            You would know better than I, so I just thought it was interesting. Though, the quote from Rob Knight that the data isn’t valid should be a warning flag. Rob Knight sure seems to know a lot about DNA:


            Nevertheless, Jeff Leach’s frozen poo samples, which are still being analyzed should give us more clues.

            I also suspect that the pH of their guts allows them to have a wider variety of potential pathogens. As fermentation drops (as in a low-fermenting Western gut) alkalinity rises and there are species that are known to proliferate and turn pathogenic in an alkaline gut, but are generally benign in an acidic gut. So, when we talk about the species they have, the context of the gut, in terms of pH probably matters a lot.

          • Gemma April 17, 2014 at 7:43 am

            I think it should be looked upon from a broader perspective. Read the study till the end. Interesting quotations:

            “The Hadza neither domesticate nor have direct contact with livestock animals. Thus, as they lack exposure to livestock bifidobacteria, this raises the question of whether the necessary conditions for interspecies transfer and colonization of bifidobacteria do not occur for the Hadza.

            It is important to note that while bifidobacteria are considered a beneficial bacterial group in western GM profiles, their absence in the Hadza GM, combined with the alternative enrichment in ‘opportunistic’ bacteria from Proteobacteria and Spirochaetes, cannot be considered aberrant. On the contrary, the Hadza GM probably represents a new equilibrium that is beneficial and symbiotic to the Hadza living environment.

            In our study, more than 33% of the total Hadza GM genera remain unidentified. Such taxonomic uncertainty holds exciting prospects for discovering yet unknown microbial genetic arrangements.

            We expect that detailed study of the function of this GM community will expose a greater number of genetic specializations for degrading polysaccharides than what is currently found in other human populations.

            The functional redundancy found in bacterial communities indicates that microbial activity, rather than composition, is conserved. However, the ability of novel genes to propagate through environmental transfer into common gut bacteria complicates the enterotype–function paradigm.

            Even if taxonomic similarities do exist between human populations, at finer scales their GM communities may exhibit dramatic metabolic differences tailored to suit disparate environmental constraints. “

  21. Norm Robillard April 17, 2014 at 11:13 am

    Excellent points Gemma. It’s really all about the microbiome and metabolic functionality as described in several other studies as well.

    Tim (Tater) “search for commonalities that we all share and then see if those are missing in people with say, GERD, IBS, AI diseases, etc..”

    That would be interesting for sure. I would also be looking for what drives those changes. Genetic and physiological differences can alter our microbiota. One example is lactose intolerance (undigested lactose feeds more bacteria in the small intestine). Another example is the recent finding that obesity is linked to low copy numbers of amylase enzyme genes needed to digest starch. That would lead to more undigested starch and more starch-fermenting gut microbes. Since obesity is linked to GERD, we might expect to find the same low amylase gene copy number (and matching microbe changes) in people with this condition.

  22. Norm Robillard April 17, 2014 at 12:42 pm

    “I also suspect that the pH of their guts allows them to have a wider variety of potential pathogens”
    Interesting idea, but their findings seem to be the opposite of current thinking associating plant consumption to lower intestinal pH and fewer pathogenic species. In this case, they observed high plant consumption, presumably lower pH and yet found species considered to be pathogenic.

    • Duck Dodgers April 17, 2014 at 5:35 pm

      Norm. What I’m saying is that these guys eat raw uncleaned impala colons and raw stomach contents for breakfast and they don’t wash their hands. They are exposed to waaay more pathogens than we are. But they are presumably fermenting more SCFAs and their pH should be lower too.

      A lower pH seems to prevent pathogens from multiplying like crazy. For instance, Candida is benign in an acidic gut. But in an alkaline gut, Candida’s growth gene gets switched on and it morphs into its filamentous form. It’s like two completely different organisms. The plethora of research that shows this mechanism is listed here:

      And when we look at staphylococcus (staph infection), streptococcus (strep throat), pneumococcus (pneumonia), h. influenza (the flu), meningococcus (meningitis), corymbacterium diptheria (diptheria), clostridium tetani (tetanus), and others — they all thrive and grow optimally on alkaline media of pH 7.4 and above. That’s the kind of pH you would only see in someone who doesn’t ferment.

      When you put it all together, what it probably means is that you can have an acidic gut, with a more diverse microbiome, and eat poo-smeared impala colon without much trouble. But, give that same poo-smeared impala colon to a Westerner and I bet they’ll get diarrhea in an hour.

      In a nutshell, I think their guts allow them to have pathogens that don’t multiply into infections.

      • Norm Robillard April 17, 2014 at 8:56 pm

        Hey Duck. Thanks for the clarification. Your comment makes more sense to me now. I read an old paper some time ago showing that hydrogen production by gut bacteria (in-vitro work) was inhibited lowering pH. So lower pH could likely reduce gas in-vivo. But your body is also adding bicarbonate as chyme moves from the stomach to the small intestine, potentially overriding the effect at least in the small intestine. I like the way you think though. Good ideas.

  23. Bill Lagakos April 17, 2014 at 1:42 pm

    The authors speculated that Hazda infants would have had bifido early on, but lose them after weaning because they don’t drink any other kind of milk. Still, though, I’d like to see the data because I’m sure there are a lot of differences between breast milk from Western and Hazda women… HMOs, microbes, fatty acid composition, etc., etc.

    • Norm Robillard April 18, 2014 at 1:30 pm

      Good point Bill. We have great data on this in the West. Would be very interesting to compare.

  24. Hcallahann44 April 17, 2014 at 2:45 pm

    Great comments all. Funny that some of the most groundbreaking work on health may be being performed by some of the folks posting here…with little public acclaim. I have had amazing success with RUMPS…but the “persorbtion” issue continues to frighten me. Picturing my arteries and organs clogged up with Potato Starch particles is a little scary. I saw someone posting that the nightshade/lectin issues associated with RUMPS consumption might be mitigated by taking RUMPS via enema. It occurred to me that doing this might mitigate the persorbtion concerns as well….as it appears most “persorbtion” occurs as a consequence of small intestinal transit. If RUMPS was taken by enema….wouldn’t the bacteria in the colon immediately consume most of it leaving little to be “persorbed”??? Thanks for all your excellent posts!

    • Tatertot April 17, 2014 at 3:56 pm

      I wish some really smart person would dig up all the references on persorption and do a huge piece on it, because I think it is important, but not as a reason to avoid raw starch, but as a reason to eat healthy, pesticide/chemical free, and non-manmade foods. Remember Jack Lalanne? He loved to say, “If man made it–don’t eat it!” If he knew about persoorption, he would have said it louder.

      Persorption of raw starches is as natural as persorption of HMOs in breast milk. We persorb bits of anything we eat that is the right size to be persorbed. We even persorb particles of the meat we eat, is that a reason to not eat meat? It seems to serve an important function.

      An article was written in the 90’s that persorption of starch may be a cause of senile dementia, the article concluded that persorption was a normal event, but could introduce contaminates.

      Here’s another, with some more search terms for those interested:

      The Herbst-Volkheimer effect

      More than 150 years ago the foundations were laid for the so-called HERBST effect which was subsequently forgotten. In the sixties the phenomenon was rediscovered by VOLKHEIMER at the Charité Hospital in Berlin and then reviewed through many experiments and publications. What is meant by the HERBST effect? If an experimental animal or even human being is given a larger amount of maize starch or also biscuits or some other products containing starch, starch bodies can be detected rapidly in venous blood already after minutes or half an hour later and in the urine after one hour and later. The term “persorption” has been coined for this interesting phenomenon. It is indeed surprising that it has met with so little attention. As a matter of fact, it constitutes the basis for our understanding of peroral immunization and of allergies. In the same way, feeding of carbon particles results in their appearance and detection in blood, kidney and urine. The same result is obtained by the intake of diatoms and what is even more important with meat fibres. I hope you are aware of the implications. When Professor NAGAI stayed in Berlin, we tried to receive the phenomenon. Since only a few cell nuclei are necessary for “genetic fingerprinting” we thought that after intake of 200 or 400 g of raw meat the type of food eaten could be determined from the urinary sediment by means of the fingerprint method which would be of forensic significance. Therefore, we eat meat and raw liver and examined the urinary sediment.(ABSTRACT TRUNCATED AT 250 WORDS)

      Persorption of Metal Particles

      Persorption of Latex

      Persorption of polymer-derived microspheres

      The problem I see is when we persorb particles that are man-made, such as microcrystal cellulose or particles covered with chemicals, colors, or nano-particle contaminates.

      • Norm Robillard April 17, 2014 at 9:08 pm

        What about persorption of starch particles with bacteria attached?

      • Norm Robillard April 17, 2014 at 9:27 pm

        Here’s another article with reference to starch.

        • Duck Dodgers April 17, 2014 at 9:44 pm

          I’m not sure I understand the concern. Is eating green bananas/plantains known to be harmful in any way?

          If persorption was so terrible, wouldn’t we expect to see side effects from long term Horchata (the ancient raw starch beverage) consumption? Horchata has been studied rather extensively in Spain—where it has been consumed as long as they’ve been recording words on paper—and it’s widely considered there to be an extremely healing tonic, with no known side effects. Many people drink Horchata de Chufa every day.

          If we’re just going to throw around the word “persorption” and ignore millions of years of raw starch consumption (tiger nuts), it just strikes me as fear mongering unless we can find good evidence that the rich history of raw starch consumption has ever been shown to be harmful.

          • Duck Dodgers April 17, 2014 at 11:05 pm

            And don’t get me wrong, Norm. I want to know if there is a hazard with persorption. But, I just have a hard time believing that the Hadza are killing themselves when they eat their raw or barely cooked ekwa, shumuko, or panjuko tubers — all which are available year round, and make up a significant part of their diet.


            And lets not forget the kūmara tubers (Ipomma chrysorrhisa, Forst.) a revered sweet potato tuber of the Māori people of New Zealand that is often consumed raw/dried. I have a hard time believing that their favorite tuber was causing them harmful persorption.

            It appears that we evolved with significant raw starch consumption — with significant “tiger nut” consumption in Africa going back millions of years.

            On the other hand, I understand the concern with persorption, and it’s certainly worth looking into. My guess is that people with leaky guts probably allow more persorption than someone with a healthy gut lining — and perhaps it’s people with leaky guts that need to worry about it. (Ironically, RS granules may help repair their gut lining).

            I just think that there’s been millions of years of persorption, so I just find it hard to believe that it’s all bad. But, I agree it’s worth exploring to leave no stone unturned.

          • Norm Robillard April 18, 2014 at 1:46 am

            I’ll give you this much Duck. I would gladly suffer heartburn if it meant not starving to death. But I’ve found a way to avoid heartburn and not starve to death. That’s what I’m doing ten years and counting.

          • Duck Dodgers April 18, 2014 at 2:07 am

            Well, I’m pretty sure the Hadza and Māori don’t get heartburn from their daily raw tubers.

            But sure, if you get heartburn from eating RUMPS, you probably have bigger problems than wondering what’s for dinner.

          • Norm Robillard April 18, 2014 at 2:21 am

            Funny Duck, I don’t think I have a problem and that too many fermentable carbs are the problem – for me. I feel completely healthy. I guess it’s all perspective. And I don’t think I would have heartburn either in Paleo times for a number of reasons I covered in my AHS 13 presentation.

        • tatertot April 17, 2014 at 11:56 pm

          Here’s a crazy thought.

          Up here in Alaska, we have this 1,000 mile long pipe full of oil. It grows scale and biofilms and slows down the flow of $$.

          To clean it out, they have a thing called a “pig” that they stick in the pipeline and it is the perfect size to be pushed by oil pressure ahead of the oil as it goes to the Exxon shipyard in Valdez.

          Now, supposedly the site of persorption is in Peyer’s Patches. These aren’t just any old epithelial cells, they are part of the Gut Associated Lymphoid Tissue, a place where T Cells are born and get put into circulation and taken out of circulation.

          What if the Peyer’s Patches are using starch, pollen, and any other thing of just the exact right size to act as “pigs” for our blood vessels? Makes sense.

          Everytime you eat raw starch, like in a carrot, granola bar, piece of multi-grain bread, sunflower seeds, etc… you WILL get starch in your blood. Fact of life.

          An hour later, it’s gone. What did it take with it?

          I think it is a fabulous, amazing phenomenon. Makes me think I should go to church more.

          • Norm Robillard April 18, 2014 at 1:43 am

            I agree Tater, it’s a crazy thought.

          • Duck Dodgers April 18, 2014 at 2:39 am

            I agree Tater, it’s a crazy thought.

            Hardly. Other scientists have wondered the exact same thing:

            From: Persorption Of Plant Microparticles After Oral Plant Food Intake

            The question of potential benefits or harm of starch granules in human serum is obvious. Answers remain purely speculative. The existence of starch granules in human blood could change our knowledge concerning the function of plant food. It is possible that these particles have beneficial health effects not only in the intestinal lumen but directly in the blood stream and on the endothelial surface of vessels. According to recent studies, small particles are better persorbed than large particles. This suggests that plant food with small starch granules could have better health promoting effects than plant food with large granules. Of course this allegation has no actual scientific explanation. Another interesting question is whether malabsorption syndromes like celiac disease, ulcerative colitis or Crohn´s disease have a higher extent of persorbability and this may influence the disease activity.

            RS is pretty good at lowering blood cholesterol. Perhaps that’s why.

            Interestingly, the study was the first to use electron microscopy, but it could not detect the hypothesized smaller particles in the blood. Most of the persorbed starch granules were 5-30µm.

          • Norm Robillard April 18, 2014 at 10:36 am

            “Hardly. Other scientists have wondered the exact same thing:”
            I’ll wait for the evidence on this one Duck.

          • Gemma April 20, 2014 at 8:22 am

            “I think it is a fabulous, amazing phenomenon. Makes me think I should go to church more.”

            Now I see what you meant, Tim. The body as an intelligent filter. Take it in, use it, build it in, remember it or expel it.
            Do they still feed people with the altar-bread in churches?

          • Gemma April 20, 2014 at 2:31 pm

            I have just finished my spring cleaning and realized something 🙂 Do you know the best window cleaner recipe? Starch, what else.

          • Duck Dodgers May 2, 2014 at 6:44 pm

            Norm said:
            I’ll wait for the evidence on this one Duck.


            You might find this interesting. It seems likely that the mechanism/purpose of persorption may have something to do with the widespread act of geophagy (eating dirt) across the animal kingdom. Geophagy is extremely common in humans and over 180 species of animals — often used for detoxification and to cure gastrointestinal upset. Pregnant mothers take part in Pica (eating dirt) particularly in African cultures.

            From: Consuming The Inedible: Neglected Dimensions of Food Choice

            “When an African female senior government physician in Malawi was asked if village women ate clay in pregnancy, she smiled: ‘It would be very surprising if pregnant women in Malawi did not eat clay. That’s how you know when you are pregnant! (Hunter 1993).”

            Some researchers believe that it may have more to do with detoxification and to settle the stomach rather than to alleviate nutritional deficiencies (studies have shown that the urge for pica/geophagy typically do not resolve when nutritional deficiencies are solved).

            Soil has a wide range of particle sizes. Medicinal clays are technically defined as having particles that are less than 2 microns.

            And the good ‘ol medicinal standby, activated charcoal, has a particle size range of 1-150 microns.

            Given what we know about persorption, it appears that medicinal clays and activated charcoal enter the bloodstream. In fact, Volkheimer specifically mentions “charcoal particles” as being found in the blood in his results (see page 11).

            People who consume zeolite actually seem to want persorption to take place. Although, the marketers of zeolite seem to think that it can’t be absorbed into the bloodstream unless it is 0.3 microns or less.

            Perhaps the ability for these particles to enter the bloodstream is how medicinal clays, zeolite and activated charcoal do their job so well. If so, then that implies the body has a mechanism in place to absorb and eliminate these detoxification particles.

            I think persorption becomes fascinating when you look at it from a geophagy standpoint!

  25. Gemma April 17, 2014 at 3:26 pm

    Re Hadza study: Have you opened the supplementary Fig.1? It mentions a tuber that they chew but not eat.

    The name of the plant is misspelled, it is probably Eminia antennulifera (Rhynchosia antennulifera ).

    Why do the Hadza do it? To obtain amylolytic enzymes! This story is getting even more complicated 🙂

    Skelton, G. S.; Matanganyidze, C., 1978: Amylolytic activity in a rhodesian legume eminia antennulifera. Transactions of the Rhodesia Scientific Association 59(2): 6-11
    The roots of a Rhodesian legume, E. antennulifera, were found to contain considerable amylolytic activity, which appears to be due to several distinct enzymes. A partial purification of the amylase system has resulted in an almost 60-fold increase in specific activity. A root extract readily hydrolyzes soluble starch to hydrolysis products that give no coloration with I, in addition to maltose as the only sugar. The amylases are particularly thermostable. The concomitant presence, in the same organ, of free starch and a potent .beta.-amylase (EC system seems paradoxical but such a situation is not uncommon in plants. Marked phosphorylase (EC activity in the root extract was detected and assayed.

    More here: How to live and survive in Zambezian open forest

    • Norm Robillard April 17, 2014 at 4:34 pm

      Very interesting Gemma. Good job digging into this. I have read common potatoes also contain amylase, but I wonder how the levels and types of amylase differ between starchy veggies.

  26. Gemma April 17, 2014 at 4:00 pm

    Repeated posting (without the url links)

    Re Hadza study: Have you opened the supplementary Fig.1? It mentions a tuber that they chew but not eat.
    The name of the plant is misspelled, it is probably Eminia antennulifera (Rhynchosia antennulifera ).

    Why do the Hadza do it? To obtain amylolytic enzymes! This story is getting even more complicated 🙂

    Skelton, G. S.; Matanganyidze, C., 1978: Amylolytic activity in a rhodesian legume eminia antennulifera. Transactions of the Rhodesia Scientific Association 59(2): 6-11
    The roots of a Rhodesian legume, E. antennulifera, were found to contain considerable amylolytic activity, which appears to be due to several distinct enzymes. A partial purification of the amylase system has resulted in an almost 60-fold increase in specific activity. A root extract readily hydrolyzes soluble starch to hydrolysis products that give no coloration with I, in addition to maltose as the only sugar. The amylases are particularly thermostable. The concomitant presence, in the same organ, of free starch and a potent .beta.-amylase (EC system seems paradoxical but such a situation is not uncommon in plants. Marked phosphorylase (EC activity in the root extract was detected and assayed.

    More here: How to live and survive in Zambezian open forest

    • Tim "Tatertot" April 17, 2014 at 5:12 pm

      I think you will find that just about every ancient society had their own raw starch concoctions. The ancient Egyptians cultivated Cyperus esculentus (also called chufa sedge, nut grass, yellow nutsedge, tiger nut sedge, or earth almond) and ate them raw. The Spanish turned these starchy sedge nuts into “Horchata” a starchy drink made with extracted starch of the tiger nuts, but now more commonly with rice starch. The Andean Indians had Chufa, freeze-dried potato starch.

      There are fossils of a long-lived ancient human called Nutcracker man who appeared to have subsisted mainly on starchy underground tubers like tiger nuts for millions of years.

      • Norm Robillard April 17, 2014 at 8:59 pm

        Ok Tim, You’ve got me. I will buy your book. Very interesting stuff.

      • Gemma April 18, 2014 at 5:47 am

        Exactly, Tim. Makes me wonder this Eminia root because similarly a Liquorice, for instance, is a legume and it has been used since ages for its medicinal properties, chewed etc. Surely the Eminia has more purpose in Hadzas diet – they do not dig it out only for its sweetness. They might have noticed that adding some digestive enzymes in their diet via Eminia chewing can stop fermentation in their upper GI (just kidding).

  27. Hcallahann44 April 17, 2014 at 7:48 pm

    Thanks Tater…really appreciate all your work on this. I wholeheartedly agree that we should only eat what nature intended….but shouldn’t we also eat it in the “WAY” nature intended?? Thats what concerns me about RUMPS…we were never intended to eat potatoes in this fashion…i.e….large doses of raw starch seperated from the vegetable itself. It seems to me that might pose risks given the persorbtion study showing mice organs and blood vessels clogged with starch particles. Do you have any thoughts about whether using an enema to deliver the starch to the colon might mitigate the persorbtion risks? It would seem the starch would be quickly consumed there and would be less likely to end up in the blood stream. Appreciate your input on this as you are the pre-eminent authority on these matters. BTW…did you notice improvements in the way you feel from consuming the RUMPS. Were there tangible health improvements?

    • Tatertot April 17, 2014 at 8:12 pm

      H44 – I’m probably not the pre-eminent authority, but King of RUMPS has a nice ring to it.

      Here’s my take on 4TBS of RUMPS. This is the amount found in one medium sized potato, a double handful of tiger nuts, one green plantain, a big chunk or wild yam. It’s not like inulin, where in order to get 40g you’d need to eat several pounds of raw onion or garlic. Of all the prebiotics, RS is the one found in the highest concentrations in nature, but we prepare the food in a way that destroys it. Tweaks in cooking can bring it back, if someone doesn’t want the accompanying calories or just want to really boost RS intake, RUMPS is available.

      I will be the first to say that a low-plant diet revolving around RUMPS is a bad idea. RUMPS should be used in a way that mimics a natural intake, ie. alongside other foods as in a smoothie or mixed in with mashed potatoes. I like to mix it in sour cream and put on a slightly cooled baked potato for instance. It should always be consumed with some natural fibers…psyllium husk and plantains have both been shown to increase the distal GI effects of RUMPS.

      I personally have no fear of taking 4TBS of RUMPS on an empty stomach with regards to persorption. The Horchata I mentioned previously is one of those Westin A Price traditional preparations that people have been drinking forever, when we look to the past, we see evidence of straight-up raw starch consumption. That said, I don’t think anyone needs to take RUMPS in isolation on an empty stomach, better to take with food and fiber to allow it to spread and ferment slowly through the colon.

      As to an enema, if I had a bowel disease that required more butyrate distally, I’d do it in a heartbeat. There is an RS suppository on the market being used on people with diversion colitis, an IBD in a portion of bowel that has been re-directed and receives no food from eating, so they give it an RS suppository and keep it healthy until it’s re-connected or removed. I would not recommend an RS enema just because you were afraid to eat RS, no more than I would recommend a baked potato enema (OK, sorry, just kidding). But, really, if you want prebiotics and are afraid of RUMPS, there are all kinds of others out there…inulin, FOS, pectin, gums, mucilages, arabinogalactins, chitins, and BIMUNO.

      But, starch in the bloodstream is as natural as air in the lungs, I’m afraid. Babies get human starch in bloodstream after first sip of milk.

      For me, personally, I saw rapid drop in FBG, better sleep, normalization of bowel movements, decrease in smelly flatulence, and long-term weight stability. I’ve been doing a high RS diet for well over a year now, weight has stayed +/- 5 pounds during that time without any effort or conscious dieting.

      I’m not trying to take anything away from Norm here, people with dyspeptic gut have a long road ahead of them and limiting RS and high fermentation potential foods may be a lifesaver for them if it means getting off PPIs and being able to live normally.

  28. Gemma April 18, 2014 at 6:55 am

    Seems off topic, but: I have been recently interested in Polly Matzingers Danger Model of the immune system (as opposed to an old model of self/nonself). As it was published in 1994 or so, the gut microbiota was not considered. Seems now that the immune system is more complicated than the simple model of Danger and Damage (Dr. Matzinger admits as well) and new understandings and theories extend her Danger Model. The geek can read for instance “Towards a liquid self: how time, geography, and life experiences reshape the biological identity” at Frontiers.

    Concerning the enemas, persorptions, etc.: it has to be considered that the food should primarily come in through the mouth. And there is something called oral tolerance which has an important immune function. Makes me wonder if people with strong reactions to SBO probiotics via capsules should better open them, mix the powder with their food and let the SB organisms contact their mouth tissue, salivas, etc. Should the message be: eat your (dirty) food, the body knows how to deal with it? Do not bring the dirt directly in your GI, bypassing the stomach and mouth. More reading:
    “Food components and the immune system: from tonic agents to allergens” (Frontiers)

  29. Gemma April 18, 2014 at 9:15 am

    Re starch persorption / adsorption / insorption:
    Could this food (starch) scientist’s knowledge be exploited?

    • Norm Robillard April 18, 2014 at 12:15 pm

      Great article Gemma. Who knew? Given what we know about the body’s reaction to foreign substances such as undigested food or bacteria (allergy, autoimmune, etc.), it’s hard to put a positive spin on these observations. On the other hand, the human body has evolved some pretty powerful detox mechanisms potentially mitigating negative effects.

  30. Gemma April 18, 2014 at 12:59 pm

    Dr. Robillard,
    yes, the Frontiers articles are great (did you mean those?) The science is only scratching the surface. Life is fascinating.

    Re starch persorption: Seems that ANYTHING of certain size (who knows what man-made nanoparticles perform in our bodies) can penetrate /translocate / persorp (?) the endothelial and other membranes, not only starch granules. Really scary. However almost all the links on starch persorption go back to Ray Peat or Volkheimer.

    I found an interesting article from 1993 on uncooked cornstarch therapy for patients with a disease called glycogenosis Ia:
    “Oral cornstarch therapy: Is persorption harmless?” at Springer (readable by “Look inside”).

    • Norm Robillard April 18, 2014 at 1:50 pm

      Gemma, I was referring to this great review/blog article:

      • Gemma April 18, 2014 at 3:39 pm

        Okay I was not sure since I only linked to the main blog page. I agree the information provided there is valuable. Definitely more research is needed and it is surely possible that high/continuous dosing of RS can cause some health risks for certain people.
        The conclusion for me, in the moment, is “More is not better” (I can easily imagine that some people overdose) and aim for real foods, not supplements. I think that is what Tatertot and Co. promote as well.

      • tatertot April 18, 2014 at 3:50 pm

        Yes, that was a very informative article, I also read the 3-4 other blog posts he’s made on the new blog, they are also great. The blog owner appears to be some sort of food chemist, a bit jaded at the industry. His thoughts are very enlightening for sure.

        As to persorption, who knows? In a jacked-up modern, dyspeptic gut all bets are off. If someone is looking for a reason to avoid raw starch granules, this is as good a reason as any, but please don’t stop at potato starch and please look really hard at man-made stuff you may be eating as well. That part really does concern me, even from a healthy gut stand-point.

        At this point, it’s not really a digestive issue, but an issue of systemic problems that could be attributed to toxins entering the bloodstream on the back of starch granules or microparticles. What a mess we’ve made of ourselves!

      • Duck Dodgers April 18, 2014 at 5:22 pm

        It should probably be clarified that when Volkheimer showed embolisms in 1974, he used 200g of starch to create the embolisms.

        Nobody eats 200g of starch. Nobody even eats 200g of dietary fiber for that mater. It’s a pretty ridiculous experiment in terms of real-world practicality.

        Amazing how we can read a study about the harmful effects of fat, cholesterol or protein with similar outrageous parameters and we can dismiss them without a second thought. But a study with those same ridiculous parameters comes along about raw starch and suddenly we have a double standard? You gotta be kidding me.

        Honestly, if eating hunter gatherer levels of raw starch is harmful, we should expect to see those harmful effects in hunter gatherer societies.

        • Tatertot April 18, 2014 at 5:29 pm

          Not to beat a dead horse, but is it possible that a piece of starch got stuck in an already present embolism?

          I just can’t get it out of my head that if we have a digestive process in place that puts raw starch into our bloodstream, it serves an evolutionary purpose.

          Do human milk oligosaccharides cause embolisms in babies?

        • Gemma April 18, 2014 at 7:52 pm


          thanks you noticed the high dose, I missed it. This Volheimer was obsessed with any small particles. He even fed 200 g of iron powder to dogs to demonstrate persorption:
          Persorption of metallic iron particles

          He simply discovered the mechanism of persorption of any micro/nano particles.

        • Norm Robillard April 19, 2014 at 12:45 am

          That is a lot of starch! Good point Duck.

          • Duck Dodgers April 19, 2014 at 9:40 pm

            It’s funny, Norm. Volkheimer easily could have come to a different conclusion from the persorption observed with 200g of starch. He could have marvelled at how the human body was able to tolerate a ridiculous amount of starch without killing all the subjects! 🙂

          • Norm Robillard April 19, 2014 at 9:52 pm

            Yes, they should really report on what they find using physiological amounts of starch. That’s a whopping dose.

      • tatertot April 19, 2014 at 11:49 pm

        Here’s the full text of a study where they looked at persorbed starch particles from regular meals.

        “Sober [fasted] subjects did not present any starch particles in their blood samples. Contrary to our expectations we could not detect any starch particles by means of scanning electron microscopy in sober subjects. The number of starch particles was equal in the light microscopy and the electron microscopy line (paired student t: p<0.05). It seems that smaller starch granules (0,2 – 5µm) cannot be persorbed better than bigger ones. Most of the starch particles detected had a size from 5-30µm."

        "The highest starch granule content could be found in the muesli group. There was no sex difference concerning particle number and particle size. There was a significant difference of particle number between several individuals. Younger subjects had better persorption capacity than older. Neither light microscopy nor scanning electron microscopy was able to detect any plant derived cell fragments."

        • Paleophil April 20, 2014 at 2:35 pm

          “Younger subjects had better persorption capacity than older”

          Interesting. What does “better persorption capacity” mean precisely? Is it greater ability to absorb the non-dissolving microparticles?

          Things that young people are able to do better than older people tend to be regarded as signs of good health and vitality. For example, Ray Peat points to the higher resting heart rates of young people vs. old as a sign that higher RHR’s in otherwise normal people are healthier.

          Tatertot, re: “chemical-free,” were you referring to this article’s pointing to chemically modified RS4, rather than raw unmodified resistant RS1, as the culprit in persorption problems:

  31. Gemma April 18, 2014 at 1:05 pm

    Okay one more on long term cornstarch therapy:
    Type I glycogen storage disease: nine years of management with cornstarch (1993)

    Long-term effects of cornstarch (CS) therapy on biochemical values and physical growth in children with type I glycogen storage disease (GSD I) were compared to those of children receiving continuous nocturnal nasogastric glucose feedings (CNG). Only patients who had received more than 5 years of dietary therapy (either CS or CNG) were evaluated. Six patients (five female, age 13.5 years +/- 1.3, range 11.7-16.5 years) received CS (1.75-2.5 g/kg, four times daily) and seven patients (five female, age 9.6 +/- 2.5 years, range 7.3-14.8 years) received CNG. Blood glucose, lactate, cholesterol and triglyceride levels were not significantly different between the two methods of treatment. All patients maintained linear growth rates normal for their age. The standard deviation score of height after 6.7 +/- 1.6 years (range 5-9 years) of CS treatment was -1.29 +/- 0.59 and after 8.8 +/- 2.4 years (range 7-14 years) of CNG was -1.24 +/- 0.63. These values did not differ significantly from each other or from the target height, an estimate of genetic potential for height as determined from parental heights. With the exceptions of diarrhea, increased flatulence and excess weight gain, there were no adverse effects of CS after 9 years of treatment. Our data suggests that cornstarch is a simple, effective and safe therapy for GSD I.

  32. Hcallahann44 April 18, 2014 at 5:07 pm

    Thanks so much Tater…would you mind if I repost your stuff on this Ray Peat board I participate on. It will be considered blasphemy by those folks. I was reading a study on a bunch of folks who were on an elemental diet for various digestion reasons….after a period of time it was found that their health began to decline. Ironically they were returned to health with doses of Resistant Starch. If Peat and Andrew Kim are correct….everyone should thrive on an elemental diet because it minimizes fermentation which Peat beleives to be inflammatory and endotoxin generating. But they didnt thrive and needed to be rescued with Resistant Starch. I was trying to heal my gut with the SCD. I even went hardcore and reduced fruit to near zero…eating only meat, fish shellfish and nonfodmap veggies….I developed unconquerable diarrhea….after 6 months of daily sprints to the bathroom…I read your stuff on RS and was quickly cured in a day with 4 TBS of RUMPS. This was after worthless gastros did colonoscopies and endoscopies and threw up their hands telling me they didnt know what was wrong. The work you are doing is comparable to the work of Semmelweis and Barry Marshall. People think you are crazy….but they will come around in time!!

    • Tatertot April 18, 2014 at 5:25 pm

      ‘People think you are crazy….but they will come around in time!!’

      Who thinks I’m crazy? I want names.

      Glad to hear RUMPS is helping you, feel free to post wherever you like. I think a subset of people respond very well to RUMPS because it feeds established, but under represented colonies of beneficial gut bacteria. However, I’ve seen enough RUMPS failures to make me realize that if one has overgrowths of pathogens or out-of-place commensals, ie. SIBO, then RUMPS is no good and the other stuff needs dealt with ASAP.

      • Bill Lagakos April 19, 2014 at 1:06 am

        “Who thinks I’m crazy? I want names.”

        Me! …just kidding, especially because of statements like this:

        “I’ve seen enough RUMPS failures to make me realize that if one has overgrowths of pathogens or out-of-place commensals, ie. SIBO, then RUMPS is no good and the other stuff needs dealt with ASAP.”

        Ignoring people who respond negatively is unhelpful (and possibly harmful?). Happy to see you openly considering all cases… the negative ones are the ones we need to really be focusing on.

        • Charles Richardson September 9, 2014 at 5:07 am

          Bill: I generally agree with everything you say, but I have to disagree here. The negative cases are important, sure. But the positive ones, which, from what I can tell, significantly outnumber the negative ones, are very important. That’s where we discovered a very positive approach to gut (and many other systems) health. We still have to figure out what to do about the serious gut problems, where the gut microbiota is seriously damaged. But we don’t want to discount a very helpful approach to health, an approach that has really illuminated the importance of feeding the microbiota what they really need, and how powerful that can be.

          • Bill Lagakos September 9, 2014 at 3:04 pm

            Fwiw, I think the “neutral” anecdotes significantly outnumber both the positives & negatives.

          • Johnn September 9, 2014 at 5:03 pm

            :Fwiw, I think the “neutral” anecdotes significantly outnumber both the positives & negatives.:

            I’ve heard Tatertot mention on the Latest in Paleo podcast awhile back that people on VLC seem to have the least favorable RUMPS anecdotes. Perhaps those who don’t regularly ingest starch don’t have much or any of the flora to capitalize on it? And maybe whichever circle you happen to run in will skew the kinds of anecdotes you hear?

          • Charles Richardson September 9, 2014 at 6:21 pm

            Bill: My experience has been the opposite. In 40 years of being around this kind of thing, I’ve not seen the breadth and depth of positive responses. That doesn’t mean everyone by any means. But I’ve seen hardly any neutral responses. It’s only a lot of individual anecdotes, but still an interesting sample

          • Paleophil September 11, 2014 at 9:10 pm

            Charles wrote: “In 40 years of being around this kind of thing, I’ve not seen the breadth and depth of positive responses.”

            Same here, Charles. I’ve been following the Paleo/Ancestral community since 2004 and haven’t seen anything like it since Paleo first took off. I was one of the skeptics until I looked into it more deeply and then gave resistant starch a try.

        • Norm Robillard September 9, 2014 at 6:32 pm

          Not sure about who would do better on RUMPs – low carbers or high carbers, but I can tell you this. We stopped attending the Low Carb Cruises because there were too few people with gut issues in the audience. I think we would do better if we could find a Carb Lovers Cruise.

  33. Norm Robillard April 19, 2014 at 1:42 am

    “Who thinks I’m crazy? I want names.”
    I think you’re crazy Tater, but are you crazy enough?

  34. Hcallahann44 April 21, 2014 at 7:27 pm

    thanks again to all contributing here. I wish we could get to the bottom of this. I suppose the safest route is to pursue the low fermentation diet that Norm has espoused. But its a little troubling to me that you have to become a slave to this diet in order to avoid the likes of SIBO, reflux and the like. Norm has admitted that a simple serving of Basmati rice can still give him symptoms after 10 years of following the low FP diet. Doesn’t that indicate that the low FP diet is simply a bandaid and not a real cure?? Surely if our intestinal tracts were optimized as the intestines of the Hadza allegedly are, a periodic meal of Basmati rice would not cause symptoms. The Hadza can apparently get away with eating fecal material afterall. The real cure may be fecal transplant from someone who has not been subjected to antibiotics….followed by a diet along the lines of what Jeff Leach is recommending. As soon as I gave up RUMPS due to my persorbtion concerns my diarrhea returned. But I suppose diarrhea is preferable to the risk of arterial embolism.

    • Norm Robillard April 22, 2014 at 1:16 am

      I can relate to your frustration and you may have a point about our depleted gut microbiota in the modern world filled with preservatives, chemicals and antibiotics. For some reason, not everyone is affected. Many people don’t have IBS, acid reflux etc. at all. They are able to tolerate more fermentable carbs without symptoms. The same thing is true of carbs and blood sugar. Some people can consume lots of carbs and not suffer from insulin sensitivity or metabolic disease, while others can’t.

      For us that do become sensitive to fermentable carbs, I think the wide availability of so many high FP foods which we can binge on whenever we feel the slightest bit hungry or even bored is a big part of the problem. It’s the total amount that we consume (excess) that often does us in. I’ll bet the Hadza’s diet is a lot less excessive than the American diet, no Snickers bars for instance.

      I mentioned basmati rice giving me symptoms, and it does, but generally I am more susceptible to fermentable carbs in general when I am less careful on my overall FP levels for two or three days. That’s when I notice breakthrough symptoms. After big holidays for instance. Picture a pan of soup boiling over. So one serving of basmati rice would likely not be a problem if I was otherwise observing a low FP diet.

      ” The real cure may be fecal transplant from someone who has not been subjected to antibiotics….followed by a diet along the lines of what Jeff Leach is recommending. ”

      This would be great. It’s worth a try. But we will need to be careful about modern food items, preservatives and antibiotics and be sure to address any underlying conditions that helped lead to the problem in the first place.

      • Elle December 14, 2015 at 10:56 pm

        Norm’s Fast Track Diet saved me from perishing from SIBO and LPR. Then Fecal Transplant and MCT oil largely cured my SIBO. But I did not return to my vegan high fiber diet that I had been on for 17 years- I’ve stayed on a very low LCHF method of eating (10-35 net carbs a day) because I think the research is more compelling that it conveys long term cardiovascular and brain health that surpasses that of a vegetarian diet. (Provided of course that you eat grass fed, organic and wild products) etc. Small intestine healed first but my large intestine only healed after the Fecal Transplant.

  35. Hcallahann44 April 24, 2014 at 1:19 pm

    Thanks Norm…interesting that you should mention that some people can consume lots of carbs with limited metabolic response. I am not one of those people. My concern about your protocol is that is based on lots of high glycemic foods. Makes sense if you want to reduce fermentation….but what about the blood sugar effects? I still think you provide the best option for controlling Sibo and reflux. I am not convinced that trying to kill bad bugs with antibiotics or herbs (like my own gastro is trying to do) makes a lot of sense. We know that the gut environment can change quickly in response to diet so your program seems like the best and most harmless approach. For a week now I tried Jeff Leach’s approach and tried to eat as many fermentable fibers as I could…to see if I could improve my gut function. I got much much worse….so for now will stick to your protocol. I think Jeff’s approach may be a good one for someone whose flora have not been dramatically altered…but I was on antibiotics for years ….some quack doctor put me on them because I had a few pimples in high school….I don’t think I can ever come back from that without fecal transplant. There is a clinic in London that is having great success with IBS…they have developed a method for transplanting anaerobic bacteria. I may pursue treatment there.

    • Norm Robillard April 24, 2014 at 3:02 pm

      I’m not at all surprised that you experienced symptoms from adding fermentable carbs. This connection is pretty solid and why I continue to write books on the subject.

      I agree with your assessment that antibiotics in any form – synthetic, natural (recall that penicillin was originally derived from a mold, and aminoglycosides, vancomycin and erythromycin are produced by bacteria) and even herbal should not be the first line treatment for functional gut disorders. All antibiotics will result in collateral damage to our microbiota. Diet is, in my view, the least invasive and most effective way to modulate gut microbiota.

      As to your question on high GI carbs, I have written about this issue on this blog and in other places. I recognize that too many carbs, particularly high GI carbs can contribute to increases in blood sugar levels which can present problems for people with diabetes or other insulin-related or metabolic issues. But the best way to combat these issues is controlling the actual levels of dietary carbs – by far, superior to low GI approach. Fast Tract Digestion recipes average around 75 grams of overall carbs per day, significantly less than the 300 carbs per day in the SAD diet and closer to carb levels recommended by the American Diabetes Association. Still, people with diabetes or other metabolic issues may want to limit carbs even further. Here is a paragraph from Fast Tract Digestion IBS:
      “Both week one and week two meal plans contain some higher carb foods such as rice, parsnips, dextrose, etc. Higher carb foods can be unhealthy for people with metabolic disorders, diabetes or other problems relating to high blood sugar levels. If you fall into one of these groups or simply prefer a lower carb lifestyle, replace the higher carb foods with lower carb options. The purpose of this book is to control SIBO and IBS symptoms for as many people as possible supporting the widest possible range of dietary preferences. But the diet is flexible for a variety of eating styles as long as FP levels are controlled.”

  36. Greg April 24, 2014 at 11:41 pm

    Dr. Robillard—I congratulate you on a thoroughly entertaining and educational article. I have been reading the blog of Mr. Heisenbug who has also looked at these issues in some detail. He posted a quote from a microbiologist from Stanford that stated as follows:
    “Eat as many high-fiber fruits and vegetables and legumes as you can,” says Stanford University’s Justin Sonnenburg, a microbiologist who studies how diet impacts bacteria in the gut. “Our hypothesis is that a variety of plant fibers supports a diversity of gut microbes.”
    This individual seems to be arguing for consumption of large and varied doses of fermentable fiber to ensure gut health. I saw others posting on this apparent contradiction earlier on this thread. I understand that you are a microbiologist as well.
    How does this square with your analysis? Would you advocate a wide variety of low FP fruits and veggies. Heisenbug argues that large amounts of fermentable fiber are needed to bulletproof the gut. But I think you have made a strong case for minimizing fermentable fiber. Is this a simple case that one of you is right and one is wrong and time will tell us which in your opinion? Thank you for your thoughts!

    • Norm Robillard April 25, 2014 at 2:12 pm

      Hi Greg,
      I have been reading Mr. Heisenbug’s excellent blog as well. My own studies and experience treating my own acid reflux issues lead me to conclude that limiting the overall amount of fermentable carbs (any carbs that escape immediate digestion and absorption) to 45 grams/day or less is therapeutic for people with SIBO/dysbiosis. But I certainly don’t advocate eliminating these carbs and I do agree that the most varied diet along Paleo lines is the likely the healthiest long term. The more diverse our microbiota the better so providing more varied carbs types is helpful as is eliminating things that reduce diversity. The early studies on IBS and obesity suggest (the picture could change as more research is done) that too many fermentable carbs may actually be reducing diversity though increasing overall numbers of certain carb loving microbes.

  37. Greg April 25, 2014 at 12:03 am

    P.S. the FP score for Dark Chocolate is not listed in your book. I eat a lot of this stuff and saw that milk chocolate was high FP. Trust Dark is even worse? Maybe need to dial down on that.

    • Norm Robillard April 25, 2014 at 2:05 pm

      Yes, I have not found a GI for dark chocolate to use in the FP calculation, but it has more fiber. I would use a bit of caution with it. I love dark chocolate myself, bu try not to overdue it.

  38. Mike April 25, 2014 at 12:37 am


    There is some documented use of lactulose as an energy source for SCFA-producing microbes. I read about this, some of the documentation of which is below, and did a course of lactulose. It exacerbated my digestive complaints. Like RS, lactulose might be beneficial for some and harmful for others.

    Here’s a letter that used to be freely available on the web, but which I can no longer find:

    J Gastroenterol 2005; 40:767–770

    Letters to the editor

    Culture-proven small intestinal bacterial
    overgrowth as a cause of irritable bowel
    syndrome: response to lactulose but not
    broadspectrum antibiotics

    To the Editor:

    Much recent debate, to which we have contributed,
    has centered on whether small intestinal bacterial overgrowth
    (SIBO) may be a cause of the irritable bowel syndrome (IBS).1–6
    This possibility had been raised by Pimentel et al.,5 who reported
    a double-blind, randomized, placebo-controlled study in which
    normalization of the lactulose breath hydrogen test (LBHT) following
    antibiotic treatment was found to correlate with symptom
    improvement in patients with IBS. The same group had earlier
    reported that 78% of patients with IBS had an abnormal LBHT,
    a finding interpreted to indicate that SIBO is common in IBS
    patients.5 We and others have expressed concern at the reliability
    of the LBHT for diagnosing SIBO,1,2,4,7 and suggested that further
    studies using a more reliable diagnostic test for SIBO, such as
    culture of small intestinal aspirate, should be performed so that
    the important issue of whether SIBO may contribute to IBS
    symptoms can be clarified.1,2

    We report the case of a 48-year-old man who presented with a
    27-year history of chronic diarrhea and intermittent abdominal
    pain, fulfilling Rome I criteria for IBS. There was no history of
    steatorrhea, weight loss, gastrointestinal bleeding, or previous
    gastrointestinal surgery. Previous investigations, including stool
    analyses for enteric pathogens and colonoscopy with colorectal
    and ileal biopsy, had revealed no abnormality. Upper gastrointestinal
    endoscopy with small intestinal biopsy was performed and
    demonstrated normal small intestinal mucosa and disaccharidase
    levels. Large duodenal diverticula were evident. A computerized
    tomography scan of the abdomen revealed extensive diverticulosis
    of the duodenum and jejunum. No pancreatic abnormality was
    apparent. Results of a full blood count, serum vitamin B12 and
    folate levels, iron studies, thyroid function tests, assays for hormonal
    causes of chronic diarrhea, and a 24-h fecal fat level were
    all within the reference range. Small intestinal aspirates for microbiological
    analysis were separately obtained from a duodenal
    diverticulum and the true duodenal lumen, using a sterile endoscopic
    technique.7 SIBO (total viable bacterial count 10^12 colony
    forming units/ml [CFU/ml]; normal <10^5CFU/ml (7) was confirmed
    in aspirates from both sites. The overgrowth flora consisted of a
    mixed population of aerobes and facultative anaerobes, including
    Streptococcus spp and coliforms.

    The patient was treated with Augmentin Duo (amoxycillin
    500mg and clavulanic acid; GlaxoSmithKline, Boronia, Victoria,
    Australia), 125mg b.d. orally, and metronidazole (Aventis
    Pharma, Lane Cove, New South Wales, Australia), 400mg t.d.s.
    orally for 4 weeks. Symptoms persisted at the end of treatment. A
    repeat small intestinal aspirate, obtained from the same duodenal
    diverticulum that had been sampled initially, demonstrated an
    unchanged total viable bacterial count (10^12CFU/ml). The patient
    was then treated with the nonabsorbable disaccharide, lactulose
    (b-d-galactopyranosyl-d-fructose; Solvay Pharmaceuticals,
    Sydney, Australia), 10 g b.d. orally for 4 weeks, on the premise
    that fermentation of lactulose by small intestinal overgrowth flora
    to short chain fatty acids8 would acidify the small intestinal lumen
    and thereby reduce the small intestinal total viable bacterial
    count. Treatment was associated with resolution of diarrhea and
    abdominal pain within 3 days. A repeat small intestinal aspirate,
    obtained as above, yielded a markedly reduced total viable bacterial
    count (10^7 CFU/ml). An increased daily dose of lactulose (20g
    b.d. orally for 4 weeks) did not lead to a further reduction in the
    small intestinal viable bacterial count. Treatment was then suspended
    for 2 weeks, during which time symptoms rapidly
    recurred. A progress small intestinal aspirate demonstrated that
    the total viable bacterial count had increased to 10^11CFU/ml.
    Lactulose treatment was reinstituted (10g b.d. orally) and symptoms
    again rapidly resolved, in association with a reduction in the
    small intestinal total viable bacterial count to 10^7 CFU/ml (Fig. 1).
    The patient has remained asymptomatic over a 6-month period
    while receiving continued lactulose therapy.
    Our case is noteworthy in two respects. Firstly, the trend in our
    patient’s clinical status in relation to the total viable bacterial
    count in serial small intestinal aspirates provides compelling evidence
    that SIBO, in our patient presumably related to intestinal
    stasis associated with extensive small intestinal diverticulosis, may
    be a cause of IBS, at least in some patients. Secondly, this case
    indicates that broadspectrum antibiotic treatment may not always
    be effective for the treatment of SIBO. A possible alternative
    approach is the use of lactulose, the metabolism of which by gut
    flora to short chain fatty acids, thereby acidifying the gut lumen in
    the region of the bacterial overgrowth, may provide a form of
    “targeted” antibacterial therapy in the small intestine. The
    marked reduction in small intestinal total viable bacterial counts
    and rapid resolution of our patient’s chronic symptoms in association
    with lactulose treatment, along with the ongoing clinical response
    now, 6 months later, suggest that the value of this novel
    approach to the treatment of SIBO should be assessed in appropriate
    randomized, placebo-controlled studies.
    Jelica Kurtovic, Isidor Segal, and Stephen M. Riordan
    Gastrointestinal and Liver Unit, The Prince of Wales Hospital,
    Barker Street, Randwick 2031, New South Wales, Australia

    • Norm Robillard April 25, 2014 at 4:07 am

      Thanks for posting the case study and reference Mike. This kind of work really does strike at the crux of this issue – is it better to remove or add fermentable substrate for SIBO? The partial case study you posted seems to indicate that, at least in some cases, you can drive a durable symptomatic improvement with lactulose. This is interesting since lactulose is more typically credited with causing symptoms – as you experienced. The idea of lowering the pH in the small intestine makes some sense though the number of bacteria in the small intestine was still in the SIBO range (10e7/mL) after lactulose treatment. Interestingly, the symptoms returned when the lactulose was removed.
      It’s important to note that this case study focuses on one person diagnosed with extensive diverticulosis of the duodenum and jejunum which is atypical of IBS and even most people with diverticulosis (these are most common in the large intestine). This condition likely allowed for the unusual growth of very high number of bacteria in the small intestine – “10^12CFU/ml”. These large diverticuli might also explain why the antibiotics did not work – less access to the bacteria. None the less, interesting food for thought.

  39. tatertot April 25, 2014 at 3:47 pm

    Hey, Norm!

    Regarding microbe diversity and such, I would love to see you get an American Gut Project test and see your results, and others following the Fast Tract plans. The report they send is mind-blowing, it shows genus level taxa for all detectable microbes. Mine had about 90 genera, with about 50% of them being just like .01 or less percent of the total.

    It’s only $99, cheaper if you buy more. I just sent off for two more kits to do some experimenting. I’m afraid they will close the project to the public soon.

    Just go here: requires a PayPal account. They make it sound like you need to keep a detailed food log, which turns many off, but all they ask when you send your kit in is a few questions about your diet, they don’t want a detailed food log, just a rough idea of carbs/fat/protein. The sample collection is simple, swipe a q-tip looking swab over some used toilet paper.

    The level of detail that AmGut is using is vastly superior to the other companies offering similar services…it won’t show parasites or fungi, but it will show you exactly what microbes and percentages.

    • Norm Robillard April 25, 2014 at 5:49 pm

      I’ve thought about that Tim. I am sure there will be more opportunities in the future. I have not done it yet for few reasons. To begin with, I feel completely healthy and would not expect any bad news. My body doesn’t tolerate large amounts of fermentable carbs. Now that I know that, problem solved. Also, no one even knows what this all means yet. Add to that the limited sampling – only fecal samples which are not representative of the small intestine or adherent bacteria in either the small or large intestine. I am content to read, study and learn for the time being.

      • Paleophil April 25, 2014 at 9:50 pm

        If your results were to prove excellent (based on current knowledge), because of your excellent health, that would also be useful information, and something you could tout and show to anyone who questioned the approach you’re advocating. Maybe they would be better than Tim’s and Jeff Leach’s and you could tease Tim about it. 🙂 I for one would be interested to see the results.

        • Norm Robillard April 25, 2014 at 11:05 pm

          Nice try Phil, but I choose to make my decisions based on my own thought process.

          • Paleophil April 25, 2014 at 11:27 pm

            Glad to hear that, Norm. I wouldn’t want anyone do anything just because I suggested it. Dealer’s choice. Good luck with whatever you do.

            I’m looking forward to seeing whatever the American Gut Project future results reveal. I’m considering doing one of the gut tests myself.

          • Paleophil April 25, 2014 at 11:40 pm
    • Paleophil April 25, 2014 at 9:56 pm

      Tatertot wrote: “The level of detail that AmGut is using is vastly superior to the other companies offering similar services…”

      Tim, So is the American Gut test better than the Metametrix test?

      • tatertot April 26, 2014 at 12:15 am

        Can’t really say ‘better’ just different. The Metametrix will show pathogens, SCFA %, yeast, and several other biomarkers of gut health. The AmGut and UBiome just show taxa of microbes.

        I just find this kind of data at our fingertip unbelievable, I am a total geek for numbers, charts and trends. Snapshots mean very little, but are interesting. It was very rewarding doing an AmGut at the same time as my wife and comparing our results.

        I’m getting ready to do all 3 tests on the same turd. I have a suspicion that UBiome is not so great.

        I really don’t see what anyone’s hesitation is, we spend $99 on dinner when we eat out. My biggest motivation was that I’m afraid these tests will soon be off-limits to the public and I wanted to get a baseline for future tests. Simply for curiosity. I also did a 23and Me DNA test.

  40. Andrew King May 3, 2014 at 11:04 am

    Hi Norm,

    Great information here thanks.

    I’m in the UK and have AS. I’ve been using RUMPS for 7-8 weeks now. At first I had bad gas so I got some of the primal defence probiotics and kept on going. The gas has gone now. Interestingly though it hasn’t affected my AS at all. And in fact I’m more tolerant to sweet potatoes now in relation to flare ups. I’ve also found a product in the UK called bimuno which is a GOS second generation prebiotic. Other than the gas at first I have been ok, however haven’t seen all the other benefits like vivid dreams and improved sleep. Bowel movements are more frequent and softer though.

    Just thought I would add my n=1 for reference.

    Thanks again

  41. Ann May 5, 2014 at 2:52 pm

    Hi – My SIBO is back after kicking it with diet and herbal antibiotics. I have to admit I got caught up in the RS mania and overdid it with that and adding too much fiber back and now am back to square one:( In retrospect, I believe I have neural damage to the intestinal cells in charge of the cleansing waves due to history of Hoshimoto’s, Celiac and a couple of bouts of food poisoning. Therefore adding resistant starch to my newly healed gut was not a good idea. I got so focused on building the good bacteria I lost site of the basics of the root cause which I think is really important for everyone to try to figure out before experimenting. Unfortunately the herbal antibiotics are not working as well this time so will probably try a round of rifaximin. The diet I am currently on is no starch except the Jasmine rice, low fodmap and the elimination of diet of Aglaee Jacob of Digestive Health with Real Food – basically limiting veggies to carrots, zucchini, some green beans and spinach, berries and some citrus. Thank you Norm, Tim etc, for all for your efforts – it takes a village of smart people to try to solve this!

  42. Lori Ann May 19, 2014 at 3:31 pm

    Hi Norm,
    This is my first post. Nice to meet you and great article. I am starting to read your book and have a question that pertains to this post. My functional medicine doctor has recommended a few items along with diet to help with my gut issues. One is this rice protein called GI sustain by Metagenics. I have talked with the manufacture and cannot get a GI number so am at a loss to whether it is ok or not. I have Lyme disease so I want to stay low on the FP numbers until I get better 🙂 I would appreciate your help and thanks again for such a great book. I realized pretty fast that my coconut flour was causing me a lot of distress even though I loved it so much.

    Here is a link to the product by Metagenics:

    Take care and hope to hear from you.


    • Norm Robillard May 19, 2014 at 4:14 pm

      Hi Lori Ann,
      Interesting question. I have not looked at this product closely so thanks for the link. According to Wiki, “Isomaltooligosaccharide (IMO) is a mixture of short-chain carbohydrates which has a digestion-resistant property.” If they listed this separately, I would count all the carbs grams as FP. Since they don’t we need to make some assumptions to arrive at an estimated FP. The other ingredients with FP are fiber with the balance of carbs likely being the rice flour ingredient. For a rough estimate, you could add the fiber grams as straight FP and take half (50%) of the remining carbs (29 grams) as FP since there is no indication that the rice flour comes from a high GI rice. A relatively conservative FP estimate would therefore be about 17.5 grams. With more information, this could be refined.

    • Norm Robillard May 19, 2014 at 4:20 pm

      You might also be interested in the FDAs take on claims that this product addresses leaky gut.

  43. Lori Ann May 19, 2014 at 5:12 pm

    Thanks Norm. This is very helpful and I too researched and saw that article. I know my doctor recommends a lot of good things, but I usually research everything he does just to make sure.

    I guess in short, if the rice protein has zero carbs like a lot do, it should be ok but this one is not like that.

    I really appreciate the quick reply and the book is very interesting.

    I am hoping to see some positive changes.

    Take care,


  44. Lori Ann May 19, 2014 at 7:25 pm

    Well I wanted to follow up for you and for anyone else interested. Metagenics has excellent customer service. They researched and called me back with GI and it’s 55. So that is one I will avoid for now.

    Take care

  45. Norm Robillard May 19, 2014 at 7:30 pm

    Fascinating. Thanks for checking that out Lori. Did they have it tested themselves? I wonder if they have any data or reference material on this. I would gladly add it to the tables with some source info to substantiate the results.

  46. Lori Ann June 5, 2014 at 6:46 pm

    Good question, and I assume they did the testing themselves because it was their lab team that got back to me the next day. Although its not a product I can use right now , I still am happy to have called. The knowledge was helpful.

    I have another question, please. I don’t see anything about Jicama in the book ( Unless I am missing it). Is this a food you have a GI on?

    Fingers crossed because I love it so much.

    Take care,


    • Paleophil June 27, 2014 at 9:58 pm

      Jicama, a legume tuber that contains some inulin, is one of my favorite foods (though I’m careful to select only small, fresh, sweet ones and avoid large or blistered mature ones that tend to taste bitter, presumably from higher plant toxin levels).

  47. Norm Robillard June 5, 2014 at 9:07 pm

    Interesting tuber. I found one nutritional facts source that lists about 5 grams net carbs and 5 grams of fiber for a 100 gram serving (a little over 3 ounces). Without a measured GI, I would assume GI 50 and estimate the FP at about 7-8 grams for that serving amount.

  48. Asia July 10, 2014 at 7:21 pm

    Please somebody help me with this question – is non-organic potato starch safe or not?
    Potatoes go through many rounds of pesticides, herbicides and fungicides, sop them up in the ground, and are one of the Dirty Dozen. Does the process of separating the starch molecules offer some protection or none?

    My chronic constipation has improved dramatically since adding SBOs, RS, and psyllium. I did not notice any improvement/change in the SIBO/SIFO, however, except if I drink this concoction at night, I bloat horribly.

    And is there any hope for broken migrating motor complex? Prokinetic herbs like the bitters don’t seem to be doing much.

  49. Stella December 8, 2014 at 9:06 pm

    Do you like l-glutamine for gastritis? recently took antibioitcs for a skin infection and now have gastritis. Also what probioitc do you recommend?

    anything else Ii can do for gastritis?

  50. Zoe Langley September 5, 2015 at 4:53 pm

    I just found this site while looking for information to help me overcome severe drug-induced GI problems via diet. I puree a lot of my food. To increase my intake of resistant starch, is it safe to throw in some raw potato? My greens must be cooked to tolerate them but i’m unsure about potatoes. Thanks for all the good information!

    • Norm Robillard September 23, 2015 at 12:56 pm

      Hi Zoe, Of course, determining the nature of the problem is important before initiating any kind of intervention. But as you might infer from the article, for SIBO / dysbiosis, I recommend first reducing the number of fermentable carbs. Raw potatoes go against this recommendations.

  51. Zoe Langley September 29, 2015 at 7:39 pm

    Hi Norm,

    Can you clarify some confusion regarding resistant starch? The quote below is from the UC Davis integrative medicine page. Wouldn’t excess fermentation harm the large intestine as well as the smooth?

    “Resistant Starch resists breakdown in the stomach and small intestine, arriving to the large intestine intact. When it arrives in the large intestine, resistant starch acts as ‘food’ for your gut flora. It is fermented by bacteria, producing short chain fatty acids, which lower the pH level of your colon contents encouraging the growth of healthy bacteria in the gut.”

  52. Shane March 19, 2016 at 5:31 pm

    Would re-heating jasmine rice or “sticky” rice cause them to contain resistant starch at levels that are not recommended on the Fast Tract diet?

    I’ve bought both books and the app but can’t seem to find an answer, other than directions for freezing and re-heating sticky rice. Does this prevent the formation of RS and, if so, would the same directions work for jasmine rice?

    I’m trying to find a way to be able to use the leftover rice in a small household.

    Thank you for all of your important work!

    • Norm Robillard March 19, 2016 at 11:58 pm

      Hi Shane, Fresh is best. All starchy foods will develop some level or RS upon cooling. Reheating helps reduce the levels. The problem is worse with high amylose starches. You are better off with sushi and jasmine rice all the way around, but again, fresh is best.

  53. Bette Isacoff June 25, 2016 at 7:04 pm

    Dr. Mark Hyman, of the Cleveland Institute and The Ultrawellness Center, recommends two tablespoons of potato starch daily, but warns against its use with SBBO. That’s a far cry from the “cure” some suggest.

  54. Kerry June 30, 2017 at 3:59 am

    Hi Norm, I’m having some success with red skinned potatoes as recommended in your book (and I limit the quantity) so I thought I’d try potato juice from the same source as it’s supposed to be good for gastritis (I have pernicious anemia). I also use the potato starch from the separated mixture for pancakesso effectively I’m eating RS but one which is less fermentable. Could this be a beneficial way of getting RS without the associated high fermentability?

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