P-672 Vaginal microbiome changes in women with polycystic ovary syndrome: a large cross-sectional study

Abstract

Abstract Study question How the vaginal microbiome changes in women with polycystic ovary syndrome? Summary answer The PCOS women had a higher diversity in the vaginal microbiome and showed an enhanced level of heterogeneity. What is known already PCOS is a common reproductive endocrine disorder with a highly heterogeneous clinical presentation. Recently, few studies with limited sample size have reported that the inconsistent vaginal microbiota composition changes in PCOS. Study design, size, duration The cross-sectional study conducted at a single academic university-affiliated center. A total of 1,446 subjects, including 713 PCOS cases and 733 controls, were recruited. Participants/materials, setting, methods Vaginal swabs were collected for subsequent 16S rRNA gene sequencing. The microbiome diversities, community distances, vaginal bacterial relative abundances, and microbial interactions network were compared between the PCOS group and control group. Main results and the role of chance The PCOS group had a higher alpha diversity in the vaginal microbiome than the control (P < 0.05), while higher intra-group variability was observed in PCOS (P < 0.05). At the genus level, the abundance of Lactobacillus in the PCOS group decreased, while the abundance of Gardnerella and Ureaplasma increased (FDR<0.2). Gardnerella vaginalis, Prevotella buccalis, and Prevotella timonensis were identified as differential species and were significantly associated with clinical parameters of PCOS, like AMH. The microbial interaction network analysis revealed that Prevotella and Lactobacillus could be key drivers for network rewiring in PCOS. Notable alterations of predicted pathways, which significantly differed between PCOS and control women, mainly enriched in amino acid metabolism. Limitations, reasons for caution The study only included Chinese Han population data. Due to the structure of the vaginal flora may vary between ethnic groups, generalizing the results of this study to other populations should be taken caution. Wider implications of the findings This study with large samples could enhance our understanding of the PCOS vaginal microbiome, and provide a basis for future research on the potential mechanism by which pathogenic bacteria are involved in PCOS vaginal microbial imbalances. Trial registration number Not applicable