Probiotics, also referred to as "living microorganisms," are mostly present in the genitals and the guts of animals. They can increase an animal's immunity, aid in digestion and absorption, control gut microbiota, protect against sickness, and even fight cancer. However, the differences in the effects of different types of probiotics on host gut microbiota composition are still unclear. In this study, 21-day-old specific pathogen-free (SPF) mice were gavaged with Lactobacillus acidophilus (La), Lactiplantibacillus plantarum (Lp), Bacillus subtilis (Bs), Enterococcus faecalis (Ef), LB broth medium, and MRS broth medium. We sequenced 16S rRNA from fecal samples from each group 14 d after gavaging. According to the results, there were significant differences among the six groups of samples in Firmicutes, Bacteroidetes, Proteobacteria, Bacteroidetes, Actinobacteria, and Desferribacter (p < 0.01) at the phylum level. Lactobacillus, Erysipelaceae Clostridium, Bacteroides, Brautella, Trichospiraceae Clostridium, Verummicroaceae Ruminococcus, Ruminococcus, Prevotella, Shigella, and Clostridium Clostridium differed significantly at the genus level (p < 0.01). Four kinds of probiotic changes in the composition and structure of the gut microbiota in mice were observed, but they did not cause changes in the diversity of the gut microbiota. In conclusion, the use of different probiotics resulted in different changes in the gut microbiota of the mice, including genera that some probiotics decreased and genera that some pathogens increased. According to the results of this study, different probiotic strains have different effects on the gut microbiota of mice, which may provide new ideas for the mechanism of action and application of microecological agents.
Keywords: 16S rRNA gene amplicon sequencing; B. subtilis; E. faecalis; L. acidophilus; L. plantarum; probiotics.