The gut microbial composition in polycystic ovary syndrome with insulin resistance: Findings from a normal-weight Population

Abstract Background A few studies have reported on the relationship between intestinal flora dysbiosis and clinical characteristics in polycystic ovary syndrome (PCOS). But the structure and characteristics of gut microbiota in PCOS have not been fully elucidated. Objective To analyze the composition of the Intestinal flora population in normal-weight women with PCOS and insulin resistance(IR) compared to PCOS alone and healthy women. Methods The study included 14 PCOS patients with insulin resistant(PCOS-IR) and 12 PCOS alone༈PCOS-NIR༉,and 10 age- and body mass index-matched healthy control women. BMI: 18.5–23.9 kg/m2. The bacterial 16S rDNA V3-V4 fragment was amplified and sequenced. The sequencing data were analyzed for species annotation, community diversity, inter-group differences, to explore the composition characteristics of gut microbial of the subjects and their correlation with clinical parameters. Results No significant difference in diversity was observed between PCOA and sample cluster analysis among the three groups (Beta-diversity) and Alpha-diversity. The relative abundance of Rothia, Ruminococcus, and Enterococcus were significantly higher in the PCOS-IR group than in the other two groups (P < 0.05), whereas the abundance of the Prevotella was dramatically decreased (P < 0.05). The abundance of Enterococcus was positively correlated with waist circumference, hip circumference, diastolic blood pressure, and insulin resistance index. Meanwhile, Rothia abundance was positively associated with waist circumference and free fatty acids. Conclusion The gut microbial composition of PCOS patients with insulin resistance is different from that of PCOS alone and healthy women. The difference is correlated with the clinical characteristics of PCOS, with regards to insulin resistance, abdominal obesity, free fatty acids, and other indicators. PCOS-IR patients have an increased abundance of Enterococcus. It may affect the intestinal environment of the host by enriching the metabolic pathways related to insulin resistance, leading to the occurrence and development of PCOS.