Differential enrichment of bacteria and phages in the vaginal microbiomes in PCOS and obesity: shotgun sequencing analysis.

Introduction: Previous research has linked vaginal bacteria to polycystic ovary syndrome (PCOS) and obesity in women, yet the specific disparities in vaginal microbiota between these conditions remain unclear. Methods: In this study, we aimed to elucidate the contribution of dysregulated vaginal microbiota to PCOS and obesity by analyzing the vaginal microbiota in reproductive-aged women with and without PCOS, as well as obese and non-obese women, using shotgun sequencing. Results: Swab specimens were collected from four groups of subjects: PCOS and obese, PCOS and non-obese, non-PCOS and obese, and non-PCOS and non-obese. A total of 333 bacteria and 24 viruses/phages were identified to the species level. Clustering analysis revealed that non-PCOS and non-obese individuals exhibit a similar "healthy" vaginal microbiome, while both obesity and PCOS were associated with microbial dysbiosis. Significant differences in abundance were observed for 26 bacterial species and 6 phages/viruses between groups. Notably, pathobionts such as Discussion: This study confirms that PCOS and obesity are associated with differing enrichment of bacteria and viruses/phages, with both conditions linked to microbial dysbiosis. Moreover, our findings suggest that vaginal phage diversity is associated with a healthy vaginal microbiota, while dysbiosis is associated with a decrease in phages alongside increased bacterial diversity.