What is it?
SIBO is an overgrowth of bacteria in the small intestine. Normally, less than 10,000 organisms/mL are found in the upper small intestine. SIBO is defined as a bacterial population exceeding 10,000,000 organisms/ml.
What problems does it cause?
Gas, belching, bloating, diarrhea, constipation, bad breath, nutrient deficiencies. Symptoms occur daily, regardless of dietary intake and rank moderate to severe intensity. The type of symptoms will depend on the type of bacterial overgrowth. For example, methane-producing bacteria will create chronic, severe constipation. Klebsiella species may produce toxins that damage the mucous lining of the small intestine, causing malabsorption and ‘leaky gut’.
Who is at high risk for SIBO?
- Maintenance of healthy acid levels discourages bacterial growth in the small intestine. Those taking acid-blocking medications will be at higher risk for SIBO. In one study, bacterial overgrowth was found in 53% of patients taking omeprazole (proton pump inhibitor).
- Age. The older we get, the less stomach acid we produce. For example, the prevalence of SIBO in young and middle-aged healthy adults is estimated at 5%. In older adults, approximately 15%.
- Those with structural abnormalities of the GI tract are at high risk, particularly those with strictures, or history of intestinal surgery.
- Those with a history of Irritable Bowel Syndrome, Inflammatory Bowel Syndrome and poorly controlled diabetes are at higher risk.
- Chronic alcohol use. An estimated 90% of alcoholics also have SIBO.
- Chronic Antibiotic use will increase risk.
How is it diagnosed?
The diagnosis of SIBO is controversial. There is no consensus for a gold standard test. Breath testing is now the predominant method to evaluate patients. The patient is given a readily metabolized carbohydrate and their exhaled gases are analyzed. However this test is expensive and is subject to false negatives so symptom presentation always plays a dominant role in diagnosis.
How is it treated?
At HealthSpan we use a modified FODMAPS approach which accounts for a person’s unique food intolerances (which we test for). This aims to ‘starve’ the displaced bacteria and control symptoms as antimicrobial agents and therapeutic probiotics work to eradicate populations of problem flora. Prescription antibiotics are also used in stubborn cases, though at least 1 study has shown herbal therapy to be more effective than the prescription agent, Rifaximin, in treating SIBO. The road to treating SIBO can be long and unpredictable. The same qualities that help these bacteria invade a new environment, are also the qualities that make them difficult to treat. While we aim to control and kill the ‘bug’, we also aim to change the ‘terrain’ in the small intestine to avoid overgrowth in the future.