SIBO is conventionally treated with certain classes of antibiotics that are poorly absorbed — unlike systemic antibiotics, which easily enter circulation — so they act primarily in the intestines. This leads to fewer side effects and lower chances of antimicrobial resistance, which leads to potentially deadly microbes becoming unaffected by antibiotics.[1] SIBO is generally considered to be cured (often referred to as being eradicated or decontaminated) based on normal breath test results.[2][3]
Antibiotics such as rifaximin, neomycin, and metronidazole have an eradication rate of 50 to 70%, making them an effective treatment option in many cases.[1] One pilot study found that antibiotics reduced SIBO-related flatulence incontinence (uncontrollable gas) more effectively than an over-the-counter gas pill containing simethicone and activated charcoal.[4]
Fecal microbiota transplants (FMT) aren’t an established treatment yet, but the results of a recent clinical study were promising. In the double-blind, placebo-controlled, randomized study, 55 patients with SIBO were assigned to take 16 oral FMTcapsules (from five healthy donors) or a placebo every week for 4 weeks. SIBO symptoms — abdominal pain, acid reflux, indigestion, diarrhea, and constipation — were lower after one month of FMT and remained lower than baseline until the final follow-up at 6 months; the placebo group experienced no change in symptoms.
Breath tests at 6 months were normal in the FMT group but not the placebo group. Fecal analysis also showed that the microbiota of the recipients changed after FMT, becoming more similar to the donors’ (who had greater microbial diversity than the recipients).
Larger studies are needed to confirm these findings, but the study design, confirmation of SIBO eradication via breath testing, and fecal analysis provide strong evidence that FMT changes the microbiota and may effectively treat SIBO.[5]