In a recent article, I talked about new research linking alterations in our gut microbiota to Parkinson’s Disease (PD). Since then, I was approached by one of the members in the Fast Tract Diet Discussion Group on Facebook asking “my dad has PD. What I don’t understand from the article is: are people with SIBO (small intestinal bacterial overgrowth) at higher risk of PD or do people with PD get SIBO?”

Although the exact cause and effect relationship between SIBO and PD is still being worked out, here’s what we know:

  1. Gastrointestinal issues including constipation often precede the onset of PD
  2. Several studies have found that people with PD are much more likely to test positive for SIBO
  3. Treating SIBO appears to improve PD symptoms

SIBO in Parkinson’s Disease

A study titled “The role of small intestinal bacterial overgrowth in Parkinson’s disease” led by one of the top celiac researchers, Dr. Alfonso Fasano found that SIBO was significantly higher in patients (54.5%) than in controls (20.0%). Eradicating SIBO resulted in an improvement in motor fluctuations.

Another study titled “Prevalence of small intestinal bacterial overgrowth in Chinese patients with Parkinson’s disease” also found a significantly higher SIBO positive rate in patients with PD (30.2%) compared to healthy controls (9.5 %). SIBO positive PD patients suffered worse gastrointestinal symptoms and worse motor function.

A third study in 2014 titled “Small intestinal bacterial overgrowth in Parkinson’s disease” found that 25% of PD patients were SIBO positive. In this case, SIBO was not associated with worse gastrointestinal symptoms, but was associated with worse motor function.

In summary, these studies found that between 25 and 50% of PD patients tested positive for SIBO. This is significantly higher than healthy controls in every case. And this connection is strong enough for the University of Cincinnati to launch a clinical study called “Treating Bacterial Overgrowth in Parkinson’s Disease (SIBO-PD)” to determine if treating SIBO will improve motor function in SIBO-positive PD patients.

Fast Tract Diet for SIBO and Parkinson’s Disease

Caltech researchers (refer to my last article) proposed that imbalances in short chain fatty acids (SCFAs) produced by gut bacteria contribute to the motor dysfunction in the mouse model of Parkinson’s Diseases (PD) and potentially in people with PD. And I suggested in my last article that SCFAs including butyrate may be healthy in moderation. But we may be getting too much of a good thing, and the Fast Tract Diet that limits all types of fermentable dietary carbohydrates may turn out to be preventative for PD.

The SIBO studies presented in this article provide definitive evidence that SIBO is common in PD patients. Therefore, a strategy to limit all types of fermentable carbohydrates in the small intestine makes perfect sense not only for people with SIBO but also for people with PD or people at risk for this disorder.