Microbiome associated with recurrent vulvovaginal candidiasis: key characteristics and potential therapeutic targets

Recurrent vulvovaginal candidiasis (RVVC) is one of the most complex forms of urogenital infection in terms of its clinical burden, impact on quality of life, and difficulty in preventing relapses. The aim of this study was to comprehensively characterize the taxonomic composition and functional potential of the vaginal microbiome associated with RVVC. This case-control study included patients with RVVC and conditionally healthy women. Vaginal samples were analyzed using shotgun metagenomic sequencing, followed by taxonomic and functional annotation of the microbiome using data quality control, taxonomic classification (Kraken2, MetaPhlAn4), and functional annotation (HUMAnN 3.9). At the community structure level, the RVVC microbiome exhibited pronounced interindividual variability and did not represent a uniform microbiota configuration. The taxonomic profile of the microbiome in RVVC was characterized by an increased relative abundance of Lactobacillus iners and anaerobic taxa (Prevotella bivia, Dialister microaerophilus), forming a compact "core" of intergroup differences. Functional analysis revealed a limited but reproducible set of metabolic pathways associated with RVVC; these included pathways of purine metabolism, central carbohydrate metabolism, and biosynthesis of cofactors and cell wall components. RVVC is associated not only with changes in the taxonomic composition of the microbiota but also with a stable reconfiguration of its functional potential. The identified shifts in metabolic pathway patterns reflect a transition of the vaginal microbial community to an alternative functional state, thus highlighting the need to develop new therapeutic strategies alternative to traditional antifungal-based approaches.