Systematic review with meta-analysis: rifaximin is effective and safe for the treatment of small intestine bacterial overgrowth

Background Small intestinal bacterial overgrowth (SIBO) is a heterogeneous syndrome, characterised by an increased number and/or abnormal type of bacteria in the small bowel. Over the past decades, rifaximin has gained popularity for this indication despite its use is not evidence based. Aim To perform a systematic review and meta-analysis to summarise evidence about the efficacy and safety of rifaximin to eradicate SIBO in adult patients. Methods MEDLINE, EMBASE, CCRCT, Scopus and Web of Science were searched from inception to March 16, 2015 for RCTs and observational studies. Furthermore, abstract books of major European, American and Asian gastroenterological meetings were also examined. Results Thirty-two studies involving 1331 patients were included. The overall eradication rate according to intention-to-treat analysis was 70.8% (95% CI: 61.4-78.2; I-2 = 89.4%) and to per protocol analysis 72.9% (95% CI: 65.5-79.8; I-2 = 87.5%). Meta-regression identified three covariates (drug dose, study design and co-therapy) independently associated with an increased eradication rate. The overall rate of adverse events was 4.6% (95% CI: 2.3-7.5; I-2 = 63.6%). In the subset of studies (n= 10) allowing the analysis, improvement or resolution of symptoms in patients with eradicated SIBO was found to be 67.7% (95% CI: 44.7-86.9; I-2 = 91.3%). Conclusions Rifaximin treatment seems to be effective and safe for the treatment of SIBO. However, the quality of the available studies is generally poor. Well-designed RCTs are needed to substantiate these findings and to establish the optimal regimen.