Systematic review with meta‐analysis: the efficacy of probiotics in inflammatory bowel disease

Summary Background Ulcerative colitis (UC) and Crohn's disease (CD) are inflammatory bowel diseases (IBD). Evidence implicates disturbances of the gastrointestinal microbiota in their pathogenesis. Aim To perform a systematic review and meta‐analysis to examine the efficacy of probiotics in IBD. Methods MEDLINE, EMBASE, and the Cochrane Controlled Trials Register were searched (until November 2016). Eligible randomised controlled trials (RCTs) recruited adults with UC or CD, and compared probiotics with 5‐aminosalicylates (5‐ASAs) or placebo. Dichotomous symptom data were pooled to obtain a relative risk (RR) of failure to achieve remission in active IBD, or RR of relapse of disease activity in quiescent IBD, with 95% confidence intervals (CIs). Results The search identified 12 253 citations. Twenty‐two RCTs were eligible. There was no benefit of probiotics over placebo in inducing remission in active UC (RR of failure to achieve remission=0.86; 95% CI=0.68‐1.08). However, when only trials of VSL#3 were considered there appeared to be a benefit (RR=0.74; 95% CI=0.63‐0.87). Probiotics appeared equivalent to 5‐ASAs in preventing UC relapse (RR=1.02; 95% CI=0.85‐1.23). There was no benefit of probiotics in inducing remission of active CD, in preventing relapse of quiescent CD, or in preventing relapse of CD after surgically induced remission. Conclusions VSL#3 may be effective in inducing remission in active UC. Probiotics may be as effective as 5‐ASAs in preventing relapse of quiescent UC. The efficacy of probiotics in CD remains uncertain, and more evidence from RCTs is required before their utility is known.