Metagenomics study on taxonomic and functional change of gut microbiota in patients with obesity with PCOS treated with exenatide combination with metformin or metformin alone.

Objective: To investigate the effect of exenatide treatment on the composition of intestinal flora and metabolic pathways in patients with obesity with polycystic ovary syndrome.
Methods: Patients with obesity with polycystic ovary syndrome (PCOS) were distributed to two groups: one received exenatide combined with metformin (COM group, n  = 14) and the other used metformin alone (MF group, n  = 15). Fresh fecal specimens from the participants, including 29 patients with obesity with PCOS and 6 healthy controls, were collected for metagenomic sequencing. The effect of exenatide combination with metformin or metformin alone on the composition and function of intestinal flora in patients with obesity with PCOS were compared by bioinformatics analysis.
Results: The level of BMI, TT, HbA1c, and HDL-c was significantly improved in both groups. The MF and COM groups were abundant in Firmicutes, Bacteroidetes, Uroviricota, Actinobacteria, and Proteobacteria. Abundance of Bacteroidetes, Proteobacteria, Hungatella, and certain probiotics like Phocaeicola and Anaerobutyricum significantly increased in both groups after treatment. Enriched microbial species in the MF and COM group were different. Clostridium, Fusobacterium, and Oxalobacter were the main bacteria in the post-MF group, while Lactococcus_garvieae , Clostridium_perfringens , and Coprococcus _sp_AF16_5 were the main bacteria in the post-COM group. The post-COM group had more probiotic species including Bifidobacterium, Prevotella, and Anaerobutyricum after treatment.
Conclusion: Both exenatide combined with metformin and metformin monotherapy can improve metabolic and endocrine markers, and the diversity and abundance of gut microbiota in patients with obesity with PCOS. The effects of the combination and monotherapy agents on intestinal flora were consistent to some extent but also unique respectively.