Supplementary Material for: Effect of a multistrain probiotic on leaky gut in patients with diarrhea-predominant irritable bowel syndrome (IBS-D): a pilot study

Background: A probiotic mixture prevented epithelial barrier impairment in various experimental models. The objective was to evaluate its effects in patients suffering from IBS-D with confirmed leaky gut. Methods: IBS D patients with increased intestinal permeability measured by radionuclide tracers were enrolled in this pilot, open-label, prospective, interventional, single-center, Phase IV study. Patients received two capsules of a multistrain probiotic a day for 30 days and were evaluated by repeated intestinal permeability test, the Bristol Stool Scale, and patient-perceived quality of life and satisfaction. Results: Of the 30 enrolled patients (mean age: 42.1 [SD: 13.1] years; female: 60%), 27 completed the study (Full Analysis Set [FAS]), 18 had no major protocol violation (Per Protocol Set [PPS]). On D30, an improvement of intestinal permeability was observed in 81.5% of patients in FAS, normalization being observed in 37% of the participants (44% in PPS). Mean intestinal permeability was significantly decreased: baseline minus D30, 3.4 (95%CI: 1.7, 5.2); IBS-QOL Total score was significantly increased: D30 minus baseline, 8.0 (95%CI: 3.0, 12.9); stool consistency was significantly improved. On D15 and D30, 96.3% of patients claimed that their IBS symptoms had been satisfactory alleviated, and a significant improvement was reported for the following VAS-IBS items: Abdominal pain, Diarrhea, Impact of gastrointestinal problems in daily life. Compliance and tolerance were satisfactory. Conclusion: The multistrain probiotic tested may reduce intestinal permeability in a considerable proportion of patients and may improve abdominal pain, stool consistency, and quality of life. These results pave the way for larger, placebo-controlled clinical studies.