Characterization of the vaginal microbiota in women of childbearing age with different Nugent scores.

The present study investigated the richness and diversity of vaginal microbiota among a cohort of 60 childbearing-age women. The samples were classified into three groups: healthy control (HC), bacterial vaginosis (BV), and BV intermediate (BVI). The number of Operational Taxonomic Units (OTUs) per sample ranged from 50 to 212, with three groups having 469 (HC), 482 (BVI), and 456 (BV) OTUs. Alpha diversity analysis (p < 0.05) showed that HC had lower diversity than the BV and BVI groups, whereas richness indices did not differ significantly across the groups. Beta diversity analysis (p < 0.05) indicated significant differences in species composition between groups, and specific biomarker taxa were identified for each group. Compared to HC, the BVI and BV groups showed an increase in Actinobacteria and Bacteroidetes, and a relative decrease in Bacillota. Overall, the vaginal microbiota of healthy women of childbearing age was in a state of absolute predominance of Lactobacillus, dominated by Lactobacillus crispatus or Lactobacillus iners alone, or both equally, and coexisted with a wide range of bacteria. However, patients in BVI group, Lactobacillus is reduced, dominated by L. iners, with an increased proportion of anaerobic bacteria (e.g., Gardnerella). While BV patients have predominantly Gardnerella with commensal bacteria, such as Prevotella and Fannyhessea, which collectively contribute to the development of BV. This study's findings provide insight into the dynamics of vaginal microbiota in women of childbearing age.