Personalized and Precision Medicine Journal

Abstract The vaginal microbiome is a dynamic mucosal ecosystem that plays a crucial role in female reproductive health. Unlike the gut microbiome, where high diversity is often considered beneficial, a healthy vaginal microbiome in reproductive-age women is commonly recognized by low microbial diversity and dominance of Lactobacillus species, particularly Lactobacillus crispatus. These communities help maintain an acidic vaginal environment, inhibit pathogen growth, support epithelial barrier integrity, and regulate mucosal immune responses. Growing evidence links vaginal microbial composition and function to fertility, assisted reproductive technology outcomes, pregnancy complications, and gynecological disorders. Lactobacillus-dominant communities are generally associated with favorable reproductive outcomes, whereas high-diversity anaerobe-rich communities have been implicated in bacterial vaginosis, pelvic inflammatory disease, HPV persistence, cervical dysplasia, recurrent infections, preterm birth, and potentially impaired fertility. However, the traditional concept of dysbiosis is insufficient to explain the biological complexity of vaginal microbial ecosystems. Similar taxonomic profiles may differ in microbial gene content, metabolic activity, biofilm formation, inflammatory potential, ecological stability, and clinical impact. Therefore, multi-omics approaches, including metagenomics, metatranscriptomics, metabolomics, proteomics, and host-response profiling, provide a more comprehensive framework for understanding host–microbiome interactions. This review summarizes current evidence on the vaginal microbiome in fertility, pregnancy outcomes, and gynecological disorders, while emphasizing the transition from descriptive dysbiosis models toward functional, ecological, and personalized perspectives. Emerging strategies such as microbiome-based biomarkers, targeted probiotics, live biotherapeutics, vaginal microbiome transplantation, and AI-driven prediction models may support future precision gynecology. Nevertheless, clinical translation requires standardized methods, longitudinal studies, diverse cohorts, validated biomarkers, and careful ethical oversight.