A Spore-Based Probiotic Containing Five Strains of Bacillus Had No Notable Effect on the Recovery of the Activity and Composition of the Baby Gut Microbiota Following Antibiotic Treatment in an In Vitro Model

Antibiotic use causes dysbiosis; probiotic treatment may mitigate these effects by promoting the growth of beneficial bacteria and restoring a healthy gut microbiota. The effects of a probiotic formulation (MegaSporeBiotic™; Bacillus indicus [HU36], Bacillus subtilis [HU58], Bacillus coagulans [SC208], Bacillus licheniformis [SL307], and Bacillus clausii [SC109]) on the microbial community activity and composition of the baby gut microbiome were evaluated using the in vitro gut model, the mucosal simulator of the human intestinal microbial system (M-SHIME®), and fecal samples from four babies aged 6–24 months. Established Baby-Quad-M-SHIME® proximal colon vessels (control period) were treated with 75 mg amoxicillin:clavulanic acid (2:1) for five days (antibiotic period) and then with/without daily MegaSporeBiotic™ (2 weeks; follow-up period). Antibiotic-induced dysbiosis was confirmed by significantly decreased SCFA levels and changes in the microbial community composition in the antibiotic vs. the control periods. SCFA levels recovered for both untreated and treated chambers during the follow-up period; recovery was similar among donors. There were few differences in microbial community composition between untreated and treated chambers during the follow-up period. MegaSporeBiotic™ supplementation following antibiotic-induced dysbiosis had little effect on the recovery of the microbial community activity or composition of the baby gut microbiota. Future studies evaluating simultaneous antibiotic and probiotic treatment may be of interest.