Effects of Bacillus subtilis BS-Z15 on Intestinal Microbiota Structure and Body Weight Gain in Mice

In our previous study, we identified a metabolite of Bacillus subtilis BS-Z15 (a strain with probiotic characteristics) that could improve immunity in mice. In the present study, we examined the effects of B. subtilis BS-Z15 and its metabolites on body weight gain and the intestinal microbiota of mice. Sixty 25-day-old male Kunming white mice were selected and randomly divided into four groups: control group (A), daily saline gavage; B. subtilis -treated group (B), single gavage (1 × 10 9 CFU/time/animal/day); group D, 14 consecutive gavages (1 × 10 9 CFU/time/animal/day); and B. subtilis metabolite-treated group (E), 30 consecutive gavages (90 mg kg −1 /time/animal/day). High-throughput sequencing technology was used to analyze intergroup differences in the mouse intestinal microbiota. The results showed that the three treated groups had significantly slower body weight gain compared with the control group, which lasted until the 45 days ( P