[Influence of different fecal microbiota transplantation cycles on the recovery of intestinal microbiota in the antibiotic cocktail-pretreated mice]

Objective: To explore the effects of different transplantation frequencies and time of fecal microbiota transplantation on mice.

Methods: Twenty-four C57BL/6J mice were randomly divided into control group, fecal microbiota transplantation group 1(FMT1), fecal microbiota transplantation group 2(FMT2), and fecal microbiota transplantation group 3(FMT3). The control group was used as the donor of fecal microbiota transplantation, and the FMT1, FMT2, and FMT3 groups were intervened with mixed antibiotics(200 μL/d) for 2 weeks, and received fecal bacterial suspension(200 μL/d). The transplantation time of the FMT1 group frequency was 1 time/d for 1 weeks, the FMT2 group was 1 time/d for 2 weeks, and the FMT3 group was 3 times/week for 2 weeks. At the end of the experiment, the feces of the mice were collected to analyze the gut microbiota.

Results: Compared with the control group, there were more independent Amplicon Sequence Variants in the intestinal microbiota of mice in FMT1 group, FMT2 group and FMT3 group, and the ACE index and Chao1 index were significantly reduced(P<0.05). Beta diversity showed differences between fecal microbiota transplantation and control groups, with FMT2 and control groups being the closest. At the phylum level, there were two species in FMT1 group and one species in FMT3 group showed statistically significant differences compared with control group(P<0.05). However, there was no significant difference between the FMT2 group and the control group. At the genus level, there were 6 species in the FMT1 with statistically significant differences from the control group(P<0.05), and 2 species in the FMT2, 5 species in the FMT3 respectively. Among which FMT2 group has the least number of species that differed from the control group, suggesting that the compitsition of its intestinal microbiota is closet to that of the control group.

Conclusion: Fecal bacteria transplantation helps to restore the intestinal microbiota structure of mice cleaned by antibiotics, and different transplantation frequencies and transplantation times have different recovery effects on the intestinal microbiota of mice pretreated with antibiotics, and the fecal bacteria transplantation effect is better with 1 time/d lasting 2 weeks.