Page last updated: December 2, 2011
Moderate alcohol consumption is associated with small intestinal bacterial overgrowth


Moderate alcohol could lead to small intestinal bacterial overgrowth (SIBO) and subsequently cause gastrointestinal symptoms like bloating, gas, abdominal pain, constipation and diarrhea, according to the results of a study unveiled at the American College of Gastroenterology’s (ACG) 76th Annual Scientific meeting in Washington, DC.
The retrospective review, “Moderate Alcohol Consumption is Associated with Small Intestinal Bacterial Overgrowth,” looked at the charts of 198 patients who underwent lactulose hydrogen breath testing (LHBT) to determine the presence of SIBO, and found that any current alcohol consumption was significantly associated with the presence of SIBO. (Neither smoking nor use of heartburn drugs were associated with an increased risk of SIBO).
Small intestinal bacterial overgrowth is a condition where abnormally large numbers of bacteria grow in the small intestine. Normally the small intestine contains a relatively low number of bacteria in contrast to the large intestine, which should contain a larger number of bacteria. In patients with SIBO, the abnormally large numbers of bacteria in the small intestine use for their growth many of the nutrients that would otherwise be absorbed.
As a result, a person with small bowel bacterial overgrowth may not absorb enough nutrients and become malnourished. The breakdown of nutrients by the bacteria in the small intestines can also produce gas as well as lead to a change in bowel habits.
While previous studies have focused on alcoholics, who were found to have high rates of SIBO, this study by Scott Gabbard, MD and colleagues at the Dartmouth-Hitchcock Medical Center and the Mayo Clinic, is one of the first to look at the relationship between moderate alcohol consumption and SIBO.
Dr. Gabbard, noted that  “These findings are significant because we now know that any bit of alcohol consumption--not just the amount consumed by alcoholics -- is a strong predictor of a positive lactulose hydrogen breath testing and small intestinal bacterial overgrowth,” he said. “While typical treatment for SIBO has been antibiotics, probiotics or a combination of the two, the question now becomes what is the exact association between moderate alcohol consumption and SIBO and whether alcohol cessation can be used as a treatment for this potentially harmful condition.”
Source: American College of Gastroenterology (2011, October 31). Moderate alcohol consumption is associated with small intestinal bacterial overgrowth.

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