Metagenomic Analysis Identified Microbiome Alterations and Pathological Association between Intestinal Microbiota and Polycystic Ovary Syndrome

Background: Polycystic ovary syndrome (PCOS) is the most common metabolic and endocrinal disorder in women of childbearing age. Although some studies have investigated the microbiota of women with PCOS, the functions and underlying mechanisms of microbes associated with PCOS have not yet been identified. Methods: Subjects were recruited at the Centre for Reproductive Medicine. We collected faecal samples from women in the control group (n = 14) and women with PCOS (n = 14) and performed shotgun metagenomic sequencing. Clinical parameters, including body mass index, endocrine hormone, and blood glucose level, were gathered for correlation analysis. Findings: In this study, we found several microbial strains were significantly more abundant in the PCOS group, including Parabacteroides merdae, Bacteroides fragilis, and strains of Escherichia and Shigella, whereas Faecalibacterium prausnitzii was enriched in the control group. Metagenomic species (MGS) analysis revealed that the microbes which enrich the PCOS group were negatively correlated with those of the control group. Of note, we observed a positive correlation between MGSs relevant to PCOS and endocrine disorder, including elevated levels of serum testosterone (T), luteinising hormone (LH), anti-MA¼llerian hormone (AMH), and body mass index (BMI). Functional alterations, reflected by KEGG orthologues, could imply potential mechanisms of microbial involvement in the developmental progress of PCOS. Interpretation: Our findings suggest an intimate association and potential mechanisms linking microbial dysbiosis and pathophysiology changes of PCOS. We address the importance of monitoring and modulating microbial composition and functional shifts in future clinical practice. Funding Statement: This work was partly supported by grants from the National Key Research and Development Program of China (No. 2017YFC1001002 and No. 2018YFC1003202), the National Natural Science Foundation (No.81671414 and 81490743), and Shanghai Commission of Science and Technology (No.17DZ2271100). Declaration of Interests: The authors declare that they have no competing interests. Ethical Approval Statement: The Ethics Committee of the Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, reviewed and approved all procedures (number: 2015030307).