Press review #1: Vaginal Microbiota

The role of the vaginal microbiota in women’s health

The human body hosts trillions of microorganisms, collectively known as the microbiome, residing in various locations and coexisting in a complex symbiotic partnership. Importantly, the vaginal microbiota influences women’s reproductive and overall health. Understanding this ecosystem could revolutionise the prevention and treatment of these conditions.

This review highlights the links between dysbiosis of the vaginal microbiota and gynaecological disorders, as well as pregnancy-related complications. Specifically, reductions in lactobacilli and an increased vaginal microbiota diversity are associated with human papillomavirus (HPV) infection, the formation of cervical lesions, and cervical cancer. A loss of vaginal Lactobacillus dominance can create a proinflammatory environment that compromises successful embryonic implantation, leading to infertility. An imbalance in the vaginal microbiome can trigger inflammation leading to pregnancy complications. Having fewer Lactobacillus species in the vaginal microbiome increases the risks of premature rupture of membranes, preterm birth, miscarriage, and ectopic pregnancy. Vaginal dysbiosis may contribute to insulin resistance, a hallmark of gestational diabetes mellitus, and greater diversity in bacterial composition has been found in severe preeclampsia. Testing for Prevotella bivia colonisation during pregnancy may help to predict and mitigate against hypertensive disorders during pregnancy.

This review underscores the key relevance of the vaginal microbiome in women’s reproductive and overall health. The composition of this microbiome can impact everything from fertility and pregnancy outcomes to infection susceptibility. The article covers various aspects of vaginal microbiota, including its relationship with immune system function, inflammation, and pathogen defence, and thereby offers a broad, holistic understanding of its role with generalisable insights into women’s health at large. Enhanced knowledge around how the vaginal microbiome influences health presents an important advance for early disease detection and prevention, instead of treating infections or conditions after they appear. However, long-term study data are needed to clarify the long-term effects of vaginal microbiome imbalances. Moreover, while probiotics and other microbiomebased interventions show promise for maintaining a healthy vaginal microbiome, probiotic strains, dosages, and delivery mechanisms have yet to be standardised for clinical application. Much work remains to be done.

In sum, having fewer vaginal Lactobacillus species and increased vaginal microbial diversity is associated with obstetric and gynaecological complications. This review highlights the possibility of using microbiome-based diagnostics to detect imbalances in vaginal flora, potentially before symptoms manifest. Early intervention may prevent adverse consequences.