Randomised clinical trial: a liquid multi‐strain probiotic vs. placebo in the irritable bowel syndrome – a 12 week double‐blind study

Summary Background The importance of interactions between the host and gut microbiota in the pathogenesis of irritable bowel syndrome ( IBS ) is becoming increasingly apparent. Probiotics offer a potential new treatment for IBS , but current results are conflicting, largely as a result of poorly designed trials and nonstandardisation of outcome measures. Aim To assess the efficacy of a liquid, multi‐strain probiotic (Symprove) in IBS . Methods A single‐centre, randomised, double‐blind, placebo‐controlled trial of adult patients with symptomatic IBS . Patients received 12 weeks of treatment with the probiotic or placebo (1 mL/kg/day). The primary efficacy measure was the difference in change in the IBS symptom severity score ( IBS ‐ SSS ) between probiotic vs. placebo at week 12. Secondary outcome measures included change in the IBS quality of life ( IBS ‐ QOL ) score and change in the IBS ‐ SSS symptom component scores. Results A total of 186 patients were randomised and 152 patients completed the study. The mean change in IBS ‐ SSS was −63.3 probiotic vs. −28.3 placebo. The mean difference in the IBS ‐ SSS was statistically significant [−35.0 (95% CI ; −62.03, −7.87); P  = 0.01]. There was no significant improvement in the IBS ‐ QOL . No serious adverse events were reported. Conclusions The multi‐strain probiotic was associated with a statistically significant improvement in overall symptom severity in patients with IBS , and was well tolerated. These results suggest this probiotic confers benefit in IBS and deserves further investigation (ISRCTN identifier: 77512412).