Small Intestinal Bacterial Overgrowth – A Common Cause of IBS

The human microbiome – the bacteria and other microbes that we carry within our bodies and on our skin - is a hot topic of research lately.  It is increasingly clear that good health is associated with having a healthy and diverse population of bacteria.  While this is particularly true regarding the microbes within the large intestine, problems can arise when too many bacteria reside and grow within the small intestine.  We call this Small Intestinal Bacterial Overgrowth (SIBO), and it is a common cause of Irritable Bowel Syndrome (IBS), indigestion, diarrhea, and constipation.

Excessive bacteria in the small intestine creates problems because it produces gas and inflammation in a part of your body that is not adequately equipped to handle it.  This leads to discomfort, bloating, and can cause constipation and/or diarrhea.  The overgrowth can create damage to the lining of the intestine, thereby interfering with nutrient absorption, potentially leading to other health problems.  The damage also reduces your ability to break down some kinds of carbohydrates, which then feed the bacteria, further contributing to the problem.

Diagnosing SIBO is typically done using a relatively simple breath test.  Once the diagnosis is made, a person can use either an herbal or a pharmaceutical antibiotic regimen, in conjunction with very specific dietary strategies, to eliminate the overgrowth.  According to studies comparing the two, the herbal and pharmaceutical regimens are equally effective.  Diets for SIBO, such as the low FODMAP diet and the GAPS diet, help by minimizing the specific kinds of carbohydrates that feed the bacteria.  After the 2-4 week treatment regimen, symptoms typically improve or resolve completely, but continued close attention to diet is critical to preventing a recurrence.  

Greg Burkland, ND