The effects of probiotic compounds on the composition of gut microbiota. (A) Microbial distribution at the phylum level. (B) Microbial distribution at the genus levels. (C,D) Relative abundances of the genera Lactobacillus and Bifidobacterium. Statistical significance between groups is indicated by a–c: different letters indicate that there is a difference between groups (p < 0.05, ANOVA, Tukey test). (E) Treatment with different concentrations of probiotic compounds altered the gut microbiota at the Lactobacillus species level. (F) Effects of low-dose probiotic compounds on the gut microbiota of mice at different times. (G) Effects of high-dose probiotic compounds on the gut microbiota of mice at different times. Normal group, BK; low-dose group, CD; high-dose group, CG; the first gavage, 00; the last gavage, 01; one week after stopping gavage, 07; two weeks after stopping gavage, 14.