Small intestine bacteria unresponsive to treatment

DEAR DR.ROACH >> I have been suffering with small intestine bacterial overgrowth syndrome for five years. It started when I was treated for H. pylori with omeprazole.

I’ve had two endoscopies, a colonoscopy and lab tests.

I’m negative for celiac disease. I had a positive breath test four years ago. I’ve taken five courses of antibiotics, including rifaximin and neomycin with brief relief each time. I’ve followed gluten free and low FODMAP diets and tried several acupuncture sessions to no avail. I’m now taking “herbal antibiotics” without any relief so far.

I have well-controlled diabetes. There does not seem to be consistent or reliable information or treatment recommendations other than antibiotics and diet. Can you guide me toward reliable literature? Do you have any advice for this ailment? I worry about longterm effects like malnutrition and emaciation.

DEAR READER >> Small intestine bacterial overgrowth syndrome is when there are more bacteria in the small intestine than normal. It is uncommon but not rare, although its exact prevalence is unknown. The major symptoms are bloating, gas, abdominal discomfort and diarrhea. It can be complicated by weight loss and vitamin deficiencies.

The diagnosis is made by a breath test, and this ideally looks at both methane and hydrogen in the breath after consuming a test meal of sugar. Whether the breath test result is methane-predominant or hydrogen-predominant affects the likelihood of success of treatment.

The first thing to consider after making the diagnosis is why the SIBO is there. The small bowel has a “transit” time of intestinal contents fast enough that the bacteria normally present in the colon do not have time to go up into the small bowel. Conditions that slow the small intestine, including irritable bowel syndrome, opiate drugs and diabetes affecting the gut all can predispose a person to SIBO, and treatment will not be effective if the underlying cause isn’t attended to. Omeprazole and other proton pump inhibitors prevent the stomach from making acid: Without acid to kill bacteria, SIBO can occur, so these drugs need to be stopped in a person with SIBO. Celiac disease is associated with SIBO and is often undiagnosed.

In hydrogen-predominant SIBO, rifaximin for two weeks usually is effective; however, in methanepredominant SIBO, a combination of rifaximin and neomycin will be more effective. Both regimens are usually two weeks long.

Keith Roach