Probiotic Blend of Lactobacillus acidophilus LA-5 and Bifidobacterium animalis ssp. Lactis BB-12 in Non-constipated Irritable Bowel Syndrome: A Double-Blind Randomized Placebo-Controlled Trial

Abstract

Background: As dysregulated gut microbiota is known in irritable bowel syndrome (IBS) and probiotics may improve it, we investigated the efficacy and safety of a combination probiotic, Lactobacillus acidophilus LA-5 and Bifidobacterium animalis ssp. lactis BB-12 in non-constipated IBS. Methods: Two hundred non-constipated IBS patients were randomized to the above-mentioned probiotic and placebo for 84 days. The outcome measures included IBS–Global Improvement Scale (IBS-GIS), IBS–Quality of Life (IBS-QoL), EAR3Q, IBS–Severity Scoring System (IBS-SSS), and patient-reported improvement. Fecal microbiota was evaluated in a subset. Results: Response in IBS-GIS was higher with probiotics than with placebo at days 28 (19.3% vs. 8.9%; p = 0.048), 56, and 84. Total and abdominal pain, distension, and QoL scores of IBS-SSS decreased at day 28 with probiotics that persisted till days 56 and 84. The percentage of patients with “severe” symptoms reduced from 20.8% at baseline to 3.9% at day 84, and the median IBS-QoL score decreased significantly at day 28; the beneficial effect on QoL was sustained till days 56 and 84 (p < 0.001). Improvement in abdominal pain, distension, urgency of defecation, bowel habit satisfaction, and stool frequency was noted earlier with probiotics than with placebo; 4.0% in the probiotic group and 0.9% in the placebo group had mild/moderate adverse events (p = 0.167). Symptom recurrence occurred in 3.0% in the probiotic group and 3.9% in the placebo group during follow-up of 180 days (p = 0.718). No difference was observed in the fecal microbiota between the two groups, but healthy genera were enriched with probiotics. Conclusions: The probiotic blend studied was more effective than placebo in non-constipated IBS in adults.