Geographic-specific Diversification of Vaginal Microbiota in China

The vaginal microbiota is pivotal to womens reproductive health, with significant geographic and ethnic heterogeneity suggesting evolutionary adaptations to environmental, climatic, and lifestyle factors. In this multi-centric study, we analyzed vaginal microbiome samples from women across five provinces in China, each characterized by distinct climatic, ethnic, and lifestyle traits. Our results indicate that the vaginal microbiota among Chinese women is characterized by low alpha diversity, with Lactobacillus crispatus being the dominant species in Community State Type (CST) I, especially in the northern regions. While most participants exhibited stable CSTs throughout their menstrual cycles, fluctuations were observed in some individuals. We also detected low-abundance bacterial species such as Fannyhesea vaginae and Sneathia vaginalis. Comparative genomic analysis of high-quality metagenome-assembled genomes of L. crispatus revealed minimal single nucleotide polymorphism (SNP) variations within individuals but substantial diversity between individuals, delineating a distinct separation between vaginal-associated populations (VAP) and gut-associated populations (GAP). These findings highlight the intricate dynamics of the vaginal microbiome, which are markedly influenced by geographic and individual determinants. This study offers an in-depth phylogenetic and genomic analysis of the vaginal microbiota among Chinese women, underscoring the imperative for further research into the impact of regional and individual variations on microbial community composition. Such knowledge could facilitate the development of personalized vaginal health management strategies that accommodate the unique microbiome profiles specific to different geographical regions. ImportanceThis study provides a groundbreaking analysis of the vaginal microbiota among Chinese women, offering insights into the population structure and evolutionary dynamics of this critical component of womens reproductive health. The research reveals that Lactobacillus crispatus, a key species in vaginal health, has a recent evolutionary emergence and exhibits significant geographic variation in prevalence, being more common in northern China. This discovery, along with the identification of distinct vaginal-associated and gut-associated populations, underscores the importance of understanding the vaginal microbiotas complexity. The findings have profound implications for developing personalized strategies to manage vaginal health, tailored to regional microbiome characteristics. This work not only advances our understanding of the vaginal microbiotas role in health and disease but also sets the stage for future research into the factors that shape microbial community structures across diverse populations.