Characteristic Gut Microbiota in PCOS-IR Patients and Its Association with Endocrine Features

The aim of this study is to explore the changes of gut microbiota, the metabolic characteristics and sex hormones in polycystic ovary syndrome with insulin resistance (PCOS-IR), and to clarify the role of gut microbiota in the occurrence of this condition.

We established a rat model of PCOS-IR using dehydroepiandrosterone (DHEA) combined with a high-fat diet, and recruited patients who met the clinical diagnostic criteria for PCOS-IR. We measured metabolic parameters and sex hormone profiles, and analyzed gut microbiota characteristics via high-throughput 16S rRNA sequencing. We also conducted microbial transplantation experiments to verify the causal relationship between gut microbiota and PCOS-IR.

In PCOS-IR rats, we observed significant endocrine-metabolic disturbances and alterations in gut microbiota β-diversity, characterized by an enrichment of Fusobacterium. Transplantation of this dysbiotic microbiota to healthy rats reproduced key PCOS-IR features, confirming a causal role. In people with PCOS-IR, we found a distinct gut microbial profile compared to both healthy individuals and those with PCOS without IR, with Fusobacterium consistently identified as a key genus across species.

Our findings show that gut microbiota disturbance leads to endocrine and metabolic features resembling PCOS-IR. The gut microbiota, particularly Fusobacterium, could serve as a clinical marker and potential therapeutic target for people with PCOS-IR. This study provides mechanistic insights into how gut microbiota contributes to PCOS-IR pathogenesis.