Systematic review and meta-analysis: Efficacy of patented probiotic, VSL#3, in irritable bowel syndrome

Abstract

Background: VSL#3 is a patented probiotic for which several clinical trials suggest benefits on motor function, bloating and symptoms of irritable bowel syndrome (IBS). Objectives: To quantify effects of VSL#3 on abdominal pain, stool consistency, overall response, abdominal bloating, and quality of life (QOL) in IBS through meta-analysis. Methods: MEDLINE (OvidSP and PubMed), EMBASE, Web of Science, and Scopus were searched up to May 2017. Using a fixed effects model, we pooled data from intention-to-treat analyses of randomized trials (RCTs) comparing VSL#3 to placebo in IBS. Data were reported as relative risk (RR), overall mean difference (MD) or standardized MD (SMD) with 95% confidence intervals (CI). Quality of evidence was rated using the GRADE approach. Key Results: Among 236 citations, five RCTs (243 patients) were included. No significant differences were observed for abdominal pain (SMD = −0.03; 95% CI −0.29–0.22), bloating (SMD = −0.15; 95% CI −0.40–0.11), proportion of bowel movements with normal consistency (overall MD = 0; 95% CI −0.09–0.08), or IBS-QOL (SMD = 0.08; 95% CI −0.22–0.39). VSL#3 was associated with a nearly statistically significant increase in overall response (RR=1.39; 95% CI 0.99–1.98). Conclusions & Inferences: In this systematic review and meta-analysis, there was a trend towards improvement in overall response with VSL#3, but no clear evidence effectiveness for IBS. However, the number and sample sizes of the trials are small and the overall quality of evidence for three of the five outcomes was low. Larger trials evaluating validated endpoints in well-defined IBS patients are warranted.