Dietary Supplementation with the Probiotic Bacillus velezensis BV379 Decreases Abdominal Bloating Without Perturbing the Commensal Gut Microbiota: A Randomized, Double-Blind, Placebo-Controlled Trial in Healthy Adults.

Abstract

Objective: Various bacterial Bacillaceae and Bacillus strains have demonstrated health benefits, but less is known about probiotic characteristics of strains of Bacillus velezensis. In this randomized, double-blind, placebo-controlled clinical trial, we investigated the safety and efficacy of B. velezensis BV379 supplementation for 8 weeks (2 × 10⁹ colony-forming units (CFU)/day).

Methods: During the baseline and final weeks, GI symptoms were recorded daily using the 8-item Gastrointestinal Tolerance Questionnaire (GITQ). The primary outcome was the proportion of participants showing an improvement from baseline to week 8 in the 7-day, 3-item composite score for abdominal distention/bloating, burping, and gas/flatulence. Plasma chemistry, hematology, intestinal permeability, and fecal metagenomes were also investigated.

Results: Eighty participants (54% female; age: 50.3 ± 10.1 years) were randomized to BV379 (n = 39) or placebo (n = 41). At end of study, no significant difference was observed in the percentage of participants with improvement in the 3-item composite GITQ score (BV379: 36.1%; placebo: 28.2%; p = 0.46). Analysis of individual GI symptoms showed that more participants experienced improvement in abdominal distention/bloating with BV379 compared to placebo (38.9% vs 17.9%; p = 0.044). There were no clinically meaningful changes in plasma chemistry, hematology, or intestinal permeability between groups. Fecal metagenomic analyses showed no overall shifts in microbial composition between groups. In addition to B. velezensis, a few commensal species such as Lacticasei bacillus casei were significantly enriched in the BV379 group.

Conclusion: Despite not significantly improving the composite GITQ score of distention/bloating, burping, and gas/flatulence, BV379 supplementation was a well-tolerated approach to specifically lower abdominal bloating.