The human vaginal microbiota is a critical determinant of vaginal health. These communities live in close association with the vaginal epithelium and rely on host tissues for resources. Although often dominated by lactobacilli, the vaginal microbiota is also frequently composed of a collection of facultative and obligate anaerobes. The prevalence of these communities with a paucity of Lactobacillus species varies among women, and epidemiological studies have associated them with an increased risk of adverse health outcomes. The mechanisms that drive these associations have yet to be described in detail, with few studies establishing causative relationships. Here, we review our current understanding of the vaginal microbiota and its connection with host health. We centre our discussion around the biology of the vaginal microbiota when Lactobacillus species are dominant versus when they are not, including host factors that are implicated in shaping these microbial communities and the resulting adverse health outcomes. We discuss current approaches to modulate the vaginal microbiota, including probiotics and vaginal microbiome transplants, and argue that new model systems of the cervicovaginal environment that incorporate the vaginal microbiota are needed to progress from association to mechanism and this will prove invaluable for future research.
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This Review was supported by the National Institute of Allergy and Infectious Diseases (NIAID) and the National Institute of Nursing Research (NINR) of the National Institutes of Health (NIH) under awards number U19AI158930, R21AI162006 and R01NR01549. M.A. acknowledges support from the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) of the NIH under award number T32DK067872.
J.R. is co-founder of LUCA Biologics, a biotechnology company focusing on translating microbiome research into live biotherapeutics drugs for women’s health. All other authors declare that they have no competing interests.
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France, M., Alizadeh, M., Brown, S. et al. Towards a deeper understanding of the vaginal microbiota. Nat Microbiol 7, 367–378 (2022). https://doi.org/10.1038/s41564-022-01083-2