Microbiol Spectr. 2025 Oct 20:e0214425. doi: 10.1128/spectrum.02144-25. Online ahead of print.
ABSTRACT
This study aimed to characterize the vaginal microbiota in women with vulvovaginal candidiasis (VVC) across nonpregnant states and different stages of pregnancy, to explore gestation-specific patterns of microbial dysbiosis. Vaginal samples were collected from nonpregnant and pregnant women with clinically diagnosed VVC, including cases in early, mid-, and late pregnancy. Microbial composition was assessed using 16S rRNA gene sequencing targeting the V3-V4 region. Alpha and beta diversity metrics were calculated to evaluate microbial richness, evenness, and structural differences. Linear discriminant analysis effect size (LEfSe) analysis and microbial co-occurrence network modeling were performed to identify differentially abundant taxa and examine community connectivity. VVC-associated microbial communities exhibited distinct diversity and structural features across gestational stages. Notably, increased Shannon and Simpson indices were observed in early and mid-pregnancy VVC cases. Beta diversity analysis revealed significant differences between VVC and healthy controls within each trimester. LEfSe analysis consistently identified a decrease in Lactobacillus in VVC patients. Microbial co-occurrence networks in VVC groups showed higher modularity in early pregnancy, whereas networks in mid- and late pregnancy exhibited reduced connectivity and lower average degree compared with healthy controls. Lactobacillus showed reduced network connectivity in early and late pregnancy, but its integration was markedly increased in mid-pregnancy VVC cases. This study demonstrates that vaginal microbial dysbiosis in VVC exhibits distinct, gestational stage-specific features. While Lactobacillus reduction is a consistent hallmark, microbial diversity and network structure vary notably across trimesters, with Lactobacillus connectivity also showing significant changes. These findings highlight the importance of gestational age-specific perspectives in both diagnosis and clinical management of VVC.
IMPORTANCE: Vulvovaginal candidiasis (VVC) is highly prevalent in reproductive-age women and poses unique challenges during pregnancy. While previous studies have explored the vaginal microbiota in healthy pregnancies or in VVC-affected nonpregnant women, few have comprehensively evaluated how VVC-associated dysbiosis evolves across gestational stages. In this study, we revealed that microbial diversity, taxonomic composition, and ecological network structures differ significantly across trimesters in women with VVC. Notably, we found that the topological role of Lactobacillus-central to vaginal health-changes dynamically during pregnancy, indicating gestational stage-specific vulnerabilities in microbial resilience. These findings offer new insight into how pregnancy shapes the vaginal ecosystem under pathological conditions and highlight the need for trimester-tailored strategies in the management and prevention of VVC to better protect maternal and neonatal outcomes.
PMID:41114499 | DOI:10.1128/spectrum.02144-25
