Small Bowel Bacterial Overgrowth

What is Small Bowel Bacterial Overgrowth?
Small intestine bacterial overgrowth (SIBO) is a dysfunction of the small bowel that allows bacteria to proliferate above normal levels. Unlike the colon, which should contain a lot of highly active bacteria, a healthy small intestine is not heavily colonized. Bacteria can accumulate in the small intestine if there is damage from inflammation or any obstruction that prevents food from being moved through the intestine with ease. Nerve or muscle damage, scarring, abnormalities in the intestinal lining, and certain medications can all affect the small bowel in this way.

Gut flora is influenced by external factors such as genetics, diet, medications, geography, stress, lifestyle, and alcohol use. Other conditions that are associated with SIBO are short bowel syndrome, chronic pancreatitis, intestinal fistula, immunodeficiency, obesity, and liver disease. A lactulose breath test can help identify SIBO.

If you have SIBO, you may notice a number of symptoms including:

Bloating (a feeling of uncomfortable fullness or visible distension of your abdomen)
Stomach pain
Excessive flatulence (passing gas)
Excessive eructation (burping)

If there is an associated disease that may be contributing to the SIBO, treatment of the underlying disease can help. A high fat, low carbohydrate, low fiber diet can help decrease SIBO, as carbohydrates and fiber take longer to absorb, which creates a nutrient-rich environment for the bacteria to thrive. It is not recommended to follow this diet long-term, however. If a patient with severe SIBO is losing weight or has nutrient deficiency, vitamin supplementation is important. Most patients with SIBO require treatment with antibiotics to reduce the amount of extra bacteria. Usually antibiotic treatment for SIBO is a short course for 1-2 weeks. Sometimes symptoms recur and patients require intermittent courses of antibiotics to keep the SIBO suppressed.