Diverse vaginal microbiomes in reproductive-age women with vulvovaginal candidiasis

Vulvovaginal candidiasis (VVC) is one of the most prevalent vaginal infectious diseases with controversial reports about the vaginal microbiota diversity. We determined the vaginal microbial community in patients with VVC, bacterial vaginiasis (BV), and mixed infection of VVC and BV using the Illumina sequencing of 16S rRNA tags. Our results revealed for the first time the highly variable patterns of the vaginal microbiome from VVC patients. In general, the alpha-diversity results of species richness and evenness showed an increased order from normal control, VVC only, mixed infection of BV and VVC, to BV. The beta-diversity comparison of community structures also showed an intermediate composition of VVC between the control and BV. Detailed comparison showed that while the control and BV communities had typical patterns, the vaginal microbiota of VVC is complex. The mixed BV and VVC infection group showed a unique pattern with relatively higher abundance of Lactobacillus than the BV group but higher abundance of Prevotella, Gardnerella, and Atopobium than the normal control. The VVC-only group, however, could not be described by any single profile. They spanned from a community structure similar to the normal control (predominated with Lactobacillus) to BV-like community structures (abundant with Gardnerella and Atopobium). Treatment of VVC showed inconsistent changes of vaginal microbiota, with four BV/VVC samples recovered to a higher Lactobacillus level while many VVC-only patients did not. These results will be useful for future study about the role of vaginal microbiota in VVC and related infectious diseases.