Cedars Sinai - Medically Associated Science and Technology Los Angeles, California
Introduction: Small intestinal bacterial overgrowth (SIBO) is characterized by an increase in proteobacteria in the small intestine and is associated with gastrointestinal symptoms. Antibiotics are used to treat this condition and previous meta-analyses have shown that antibiotics can successfully eradicate SIBO. Currently, there have been no high-quality, multicenter trials evaluating the efficacy of antibiotics in improving symptoms. Here, we performed a systematic review and meta-analysis to assess the efficacy of antibiotics to relive symptoms in patients with SIBO.
Methods: Following the PRISMA protocol a systematic review and meta-analysis was conducted. From inception to March 2021, MEDLINE, EMBASE, Web of Science, and Cochrane database were searched. Randomized controlled trials and prospective studies were included. Studies were included if SIBO was diagnosed based on breath test or small bowel aspirate. The rate of no improvement in symptoms were compared between antibiotics and no antibiotics. To assess study bias, the Cochrane Risk of Bias Tool was used. Studies with all categories with low risk of bias were deemed good quality. If 1 category had high or unclear risk of bias, they were deemed fair, the rest were deemed as poor quality.
Results: Of 694 citations, 647 were excluded based on the title or abstract. After a full manuscript review, 6 studies met inclusion criteria and were included (Table 1). There was a total of 196 patients, out of which 101 received antibiotics and 95 received placebo or no antibiotics. Two studies compared rifaximin to placebo, 1 compared rifaximin with bran to placebo with bran, 1 compared norfloxacin to placebo, 1 compared neomycin to placebo, and another compared rifaximin to no antibiotics. Overall, the RR (95% CI) of no improvement was 0.63 (0.43-0.91) with antibiotics compared to no antibiotics or placebo (Figure 1). The NNT for antibiotics in relieving symptoms was 2.8. There was significant heterogeneity with I2 = 69.3%. There was no publication bias based on Egger’s test (t = -1.5936, df = 4, p = 0.1863). Four studies were deemed to be of poor quality and 2 studies were deemed to be of fair quality.
Discussion: This is the first systemic review and meta-analysis to evaluate the efficacy of antibiotics in relieving symptoms in patients with SIBO. Our data suggests that antibiotics provide symptomatic relief for patients with SIBO. A large multicenter randomized control trial is needed to validate these findings.
