What is SIBO?

Better understanding the far reaching effects of small intestinal bacterial overgrowth (SIBO) requires us to be reminded by a quote from Hippocrates, the father of medicine, “All disease starts in the gut.” GI dysbiosis, which is simply defined as an imbalance within the gut microbiome that leads to illness for the host, is at the root of SIBO. Like irritable bowel syndrome (IBS), SIBO is another form of GI dysbiosis. In fact GI dysbiosis has been linked to over 40 different chronic diseases, including depression, arthritis, cancer, etc. (draxe.com).

ome of the symptoms of SIBO, overlap with IBS. They can include not only gastrointestinal symptoms such as nausea, bloating, constipation, diarrhea, abdominal pain but also systemic symptoms such as malnutrition, weight loss or gain, joint pain, fatigue. Suffering from chronic skin conditions such as a non specific rash, eczema, acne, or rosacea can also be a clue that you may be suffering from SIBO. As a result of these far reaching symptoms and their impact to our overall quality of life, we need to at least consider that taken together these symptoms may be SIBO. Unfortunately, and too often, this battery of symptoms lend to fragmented care that does not always lead to getting to the root of the problem, and but rather lead to using prescription drugs long term, which at best masks the symptoms and at worse contributes to worsening the problem and/or creating new problems.

In matter of fact, chronic use of proton pump inhibitors (PPIs), such as Prevacid, Nexium, Prilosec, just to name a few, is a risk factor for developing SIBO as demonstrated in a metaanalysis conducted by Lo and Chan and later published in Clinical Gastroenterology Hepatology Journal in 2013. This analysis showed PPI users had a sevenfold higher incidence of SIBO. Other risk factors include consuming the Standard American Diet (SAD), which is high in carbohydrates, refined sugars, and has less total and insoluble dietary fibers. Other causes and risk factors include having diabetes, celiac disease, and even aging. Food poisoning has also been associated with SIBO, especially when infected with Shigella, E. coli, Campylobacter, and Salmonella. Antibiotic use, especially recurrent use, has also been implicated in predisposing individuals to SIBO. And finally, toxic heavy metals such as lead can also put one at risk.

Unlike IBS, objective testing can help diagnose SIBO. Unfortunately, the gold standard test is invasive and not routinely accessible in clinical practice. The test requires collecting aspirate from the small intestines and sending to lab for a bacterial plate count. Short of doing this, the Glucose Breath Test (GBT) is the most accurate hydrogen breath test for non-invasive diagnosis of SIBO according to leading authorities. But even this test has its shortcomings because it is dependent on pretesting dietary restrictions and proper test methods which can either underestimate or overestimate the SIBO diagnosis. As a result, the best tool to diagnose SIBO remains the constellation of symptoms one is experiencing, and history of previous and current risk factors.

If diagnosis is suspected, and if possible confirmed, best to start treatment with dietary changes. That is a low carbohydrate diet, avoiding refined and processed foods, such as chips, fast food. Also, it is extremely important to avoid fructose all together, as well other sweeteners such as a mannitol, sorbitol, corn syrup, and even xylitol and fruit juice. Avoiding gluten and dairy is crucial. If simple dietary changes are not fruitful, one can utilize a low FODMaP diet, which stands for fermentable oligosaccharides (found in fructans), disaccharides (found in lactose), monosaccharides (found in fructose), and polyols (found in sweetners such as sorbitol, xylitol, mannitol, etc). Specific charts including foods to avoid while following the low FODMaP diet can be found online. These specific type of carbohydrate molecules have the propensity to not be well absorbed in certain individuals. As a result of these FODMaPs not being well absorbed, they allow the bacteria present within the colon to ferment these sugars which then contributes to some of the hallmark symptoms of SIBO, specifically excess foul smelling gas, abdominal pain, and bloating.

If dietary measures are not enough, more and more gastroenterologist are prescribing antibiotics to help eradicate SIBO. Specifically, they are treating with the antibiotic Rifaximin. From my own clinical experience, I find that some individuals are not able to tolerate this medication, and if they do it can help but only short term. The take home message here is that though this antibiotic can help, if the lifestyle changes have not improved, and the diet remains unaltered the symptoms will continue to comeback. Less noxious natural antibacterials are also available such as grapefruit seed extract and natural plant oils that include concentrated forms of thyme, oregano, and clove oil have been found to be useful.

Finally, because many folks who suffer from SIBO have malabsorption contributing to nutrient deficiencies it is important to supplement with nutrients. Fat soluble vitamins are routinely low, such as Vitamin A, D, E, and K, as well are B complex vitamins. One way to help improve the digestion and absorption of nutrients is by taking digestive enzymes. Also supporting the gut lining with nutrients that include glutamine, aloe vera, licorice root, zinc, lactoferrin may be helpful. The use of probiotics as an adjunct to the treatment in SIBO has been controversial. Primarily because probiotics can theoretically contribute to the fermentation process that creates the symptoms of SIBO. However, probiotics can also help support our immune system, aid in digestion, and decrease inflammation within our GI tract. As a result, and from my own clinical experience, probiotics are useful and should be used. In some case, certain individuals with suspected SIBO cannot tolerate high doses initially, such as 100 billion plus, but are able to tolerate lower doses, such as 20 billion or less. In this case, start probiotics at the lowest dose tolerable and increasing the dose slowly is useful to help maximize all the benefits of probiotics as it pertains to helping specifically with SIBO, and gut health in general.