Characterization of vaginal microbiota diversity by 16S rRNA high-throughput sequencing

Introduction This study employed high-throughput sequencing to analyze the diversity of vaginal microbiota in healthy women of reproductive age, thereby establishing a foundational dataset that may inform future forensic applications such as individual identification. Methods A cohort of 100 healthy reproductive-age women meeting the inclusion criteria was enrolled. Vaginal secretion samples were collected, after which microbial DNA was extracted and assessed for quality using agarose gel electrophoresis. The V3-V4 region of the 16S rRNA gene was subsequently amplified with universal primers and subjected to Illumina high-throughput sequencing for comprehensive microbial analysis. Results Sequencing analysis revealed that the five most predominant genera in the female vaginal microbiota were Lactobacillus , Gardnerella , Prevotella , Serratia , and Atopobium . Cluster analysis of the 100 samples classified them into five major clusters, further delineated into eight subtypes, ranging from absolute dominance of Lactobacillus to dominance of non- Lactobacillus bacteria. Analysis of influence factors showed that microbial diversity was positively associated with age, higher in urban compared to suburban participants, and lower in pregnant versus non-pregnant women. The 16S rRNA high-throughput sequencing of vaginal microbiota exhibited distinct inter-group clustering, with Lactobacillus identified as a core candidate marker for vaginal secretions. Discussion The compositional profile of the vaginal microbiota exhibited variations associated with individual characteristics such as age range and geographic region. This study provides a foundational description of vaginal microbiota composition in this cohort. Such foundational data are a necessary first step toward exploring potential future applications in forensic science, though direct inference of individual characteristics is not supported by the current dataset.