The efficacy of Lactobacillus reuteri ATCC 55730 in the treatment of patients with irritable bowel syndrome—a double blind, placebo-controlled, randomized study

Background It was suggested that the intestinal microflora may play a role in the pathogenesis of irritable bowel syndrome (IBS). Probiotics may ease symptoms in IBS patients by changing gut microflora, reducing mucosal inflammation and exerting antibacterial effects. Aim To assess the short- and long-term effects of Lactobacillus reuteriadministration on clinical symptoms of IBS. Methods This is a double blind, placebo-controlled 6-month trial. Subjects consumed 1×108 cfu/tablet twice a day. The clinical severity of the IBS symptoms was evaluated by the Francis Severity score and the IBS quality-of-life score at study entry and then monthly. Results In total, 54 subjects were randomized for treatment and 39 concluded the study. Both groups (treatment and placebo) improved significantly in all the studied parameters with no significant differences between groups. Two parameters, constipation and passing gasses, were marginally different between the main groups (P=0.0714 and 0.0971, respectively). Conclusions IBS symptoms did not improve with probiotic treatment with L. reuteri. A strong placebo effect and a lack of uniformity of the IBS population may have hindered a clearer demonstration of the effect.