Shah · Alimentary pharmacology & therapeutics 2013 · systematic review and meta-analysis · n=10 studies

Meta-analysis: antibiotic therapy for small intestinal bacterial overgrowth.

Cited 204 times in the scientific literature.

Level 1 - systematic review of randomized trials

Systematic review and meta-analysis of clinical trials

PubMed 24004101 · doi:10.1111/apt.12479 · record verified 2026-08-27

What was done

Four databases were searched for clinical trials evaluating antibiotic effectiveness in symptomatic patients with documented small intestinal bacterial overgrowth (SIBO). Studies compared different antibiotics, different doses of the same antibiotic, or antibiotics versus placebo. Study quality and data were extracted independently. The primary outcome was normalization of post-treatment breath testing; the secondary outcome was post-treatment clinical response.

What was found

Ten of 1,356 identified articles met inclusion criteria. Rifaximin was evaluated in 8 studies, yielding a breath test normalization rate of 49.5% (95% CI 44.0–55.1%). Across all evaluated antibiotics, the combined normalization rate was 51.1% (95% CI 46.7–55.5%) compared with 9.8% (95% CI 4.6–17.8%) for placebo. A meta-analysis of 4 placebo-controlled studies favored antibiotics over placebo for breath test normalization (OR 2.55, 95% CI 1.29–5.04). Clinical response was heterogeneously evaluated across 6 studies but tended to correlate with breath test normalization.

Why it matters

This meta-analysis demonstrates that antibiotic therapy, most notably rifaximin, is superior to placebo for normalizing breath tests in SIBO, with test normalization generally tracking clinical symptom improvement.

Limits

The included trials were constrained by modest methodological quality, small sample sizes, and heterogeneous designs. Clinical response was evaluated inconsistently across studies, only 4 trials were eligible for the placebo-controlled meta-analysis, and the total participant count was not reported in the abstract.

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