Abstract:The effects of selenium-enriched bacterium C5, Live Combined Bifidobacterium, Lactobacillus and Enterococcus Capsules, and Bacillus licheniformis Capsule on intestinal flora in mice were investigated. The mice were divided into the probiotics group A (Live Combined Bifidobacterium, Lactobacillus and Enterococcus Capsules group), the probiotics group B (Bacillus licheniformis Capsule + Live Combined Bifidobacterium, Lactobacillus and Enterococcus Capsules group), the experimental group C (selenium-enriched bacterium C5 group) and the blank group D. Mice feces were collected after 4 weeks of feeding. The V3-V4 region of 16S rDNA gene was amplified by PCR. Illumina Hiseq 2500 high-throughput sequencing was performed. The species abundance table at different taxonomic levels was generated by QIIME2 software, and the alpha-diversity index was evaluated and beta diversity was analyzed. Selenium-enriched bacterium C5 could regulate the abundance and diversity of intestinal flora in mice, which was comparable to the regulation produced by Live Combined Bifidobacterium, Lactobacillus and Enterococcus Capsules as well as Bacillus licheniformis Capsule. The alpha-diversity of ACE, Chao1 and Shannon were all increased (P<0.05). Selenium-enriched bacterium C5 could increase the relative abundance of Firmicutes and Lactobacillus in the intestinal flora of mice, reduce the Staphylococcus and increase the relative abundance of Agathobacter in Lachnospiraceae(P<0.05). Selenium-enriched bacterium C5 could improve the intestinal microecology of body and therefore it has certain application value in microbial agents to improve the health of intestinal flora.