Abstract: The effect of mixed probiotic cultures on the intestinal microbiota of male Kunming mice was analyzed by
high-throughput sequencing in this investigation. An animal model of intestinal microflora imbalance was established
by intragastric administration of sodium penicillin to 40 mice, and these animals were randomly divided into natural
recovery group and three groups orally treated with mixed probiotic cultures at low, medium and high doses. Besides, a
blank group consisting of 10 normal mice was set up for control. After 14-d administration, feces were collected and the
intestinal microbiota were detected by high-throughput sequencing. The results showed that the high dose group had the
highest diversity of intestinal microbiota (ACE-index = 22 101.63; Chao1-index = 13 791.40) and the intestinal microbiota
in the natural recovery group exhibited the lowest species diversity. In addition, the results showed that the proportions of
beneficial and pathogenic bacteria in the mouse intestine differed significantly among the five groups; the proportions of
beneficial bacteria were higher in the three treatment groups than in the natural recovery group, and the highest proportion
of pathogenic bacteria (56.36%) was observed in the natural recovery group, suggesting that mixed probiotic cultures could
regulate intestinal microbiota imbalance in mice.

Key words: probiotic, intestinal microbiota, high-throughput sequencing