Impact of Heyndrickxia (Bacillus) coagulans GBI-30, 6086 (BC30) probiotic on gastrointestinal function in healthy adults: a randomised controlled trial

Many healthy people complain of functional gastrointestinal (GI) tract symptoms that do not fit diagnostic criteria for established diseases. Disrupted intestinal microbiomes are associated with these functional conditions, thus the use of beneficial bacteria shown to restore the protective microbiome may be useful. Our aims were to determine if Heyndrickxia (Bacillus) coagulans GBI-30, 6086 (BC30) would improve GI functions in healthy adults living in China and to determine its effect on the GI microbiome. Healthy adults ( n = 111, 18-65 years old) with functional GI complaints were enrolled in a prospective, double-blind trial and randomised (by random number table) to either BC30 (1 × 109/day) or placebo for four weeks. Outcomes were analysed by ANOVA or the Wilcoxon tests or with mixed regression models. Functional GI symptoms improved significantly in adults given BC30 compared to placebo: increase in number of stools/week ( P = 0.036), improved fecal consistency ( P < 0.001) and fewer participants had constipation ( P < 0.001). Four weeks of BC30 increased intestinal Bacteroides levels and reduced Clostridium, Blautia, Ruminococcus levels but did not otherwise alter the general microbiome. BC30 significantly improved GI functions in healthy adults in China, with minor modifications of the fecal microbiome and was well-tolerated. The trial was registered at ClinicalTrials.gov (NCT06644001).