Small intestinal bacterial overgrowth (commonly abbreviated to SIBO) is a condition involving the overgrowth of commensal bacteria normally found in the large bowel up into the small intestine. It can also less commonly be caused by an increase in the population of the bacteria that naturally reside in the small intestine. SIBO can have a negative impact on both the structure and function of the gastrointestinal tract, contributing to leaky gut and the myriad of health issues that may ensue from this all too common presentation. SIBO can also adversely affect the absorption of key nutrients in the small intestine, which can also have knock on effects throughout other organ systems of the body.
What causes SIBO?
Small intestinal bacterial overgrowth can be caused by a number of factors. Low stomach acid is one of the big drivers, particularly when the individual has been on stomach acid reducing medication for reflux over a number of months or even years (something I often see). This creates a more desirable environment for the population of bugs that normally would not be found in the small intestine. Slowed intestinal transit time (ie constipation) is also a very strong driver, and inflammatory bowel disease and IBS seem to also predispose and individual to developing SIBO. Overuse of antibiotics is definitely a strong causative factor, as is diabetes (both type 1 and 2). Moderate to high alcohol consumption increases the risk for developing SIBO, as does prolonged use of many prescription medications and the oral contraceptive pill.
How do you know if you have SIBO?
One of the most common symptoms that I see in my patients is significant bloating and discomfort in the upper digestive region after eating. This is in contrast to bloating and discomfort in the lower digestive region that is more indicative of general dysbiosis of the large bowel or IBS/IBD. Diagnosis is usually confirmed by a combination hydrogen / methane breath test which measures the volume of these gasses that have diffused into the blood for expiration by the lungs. The amount of gas is measured over a 2 to 3 hour period which correlates with small intestinal transit time. Elevations of these gasses outside of the normal reference range indicate a proliferation of undesirable bacteria in the SI and thus SIBO. Note that both glucose and lactulose may be used as the ingested agent for measuring a SIBO reaction, however in my practice I prefer the use of lactulose as it is better able to ascertain SIBO impacting the distal portion of the small intestinal tract (which is a far more common presentation).
Treatment options for SIBO
Conventional treatment of SIBO involves the use of antibiotics, however studies have shown this to be only moderately effective. My preferred method of treatment is to use natural botanical antimicrobial agents, along with dietary modifications to reduce the foods that feed these undesirable bacteria in the small intestine. After eradication, rebuilding a healthy gut flora through appropriate probiotic therapy and functional foods is crucial. Most important, however, is to address the underlying cause/s to eliminate the possibility of the SIBO recurring (as so often is the case in conventional treatment).
If you suspect you may have SIBO I strongly recommend seeking advice from a qualified naturopath or functional medicine practitioner to create a plan that can address your individual presentation and get you back on the path to good digestive health.
In wellness,
James
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