The Female Genital Tract Microbiome: a review

Abstract

The human microbiome, a complex ecosystem consisting of microorganisms and their genetic material, profoundly impacts physiological processes crucial for human health. Among various niches within the human body, the female genital tract harbours a diverse microbial community, known as the vaginal microbiota, which plays a pivotal role in maintaining vaginal health and preventing infections. This review explores the intricate relationship between the vaginal microbiota and gynaecological conditions, including bacterial vaginosis, human papillomavirus (HPV) infection, cervical neoplasia, endometrial cancer, ovarian cancer, preterm birth, and infertility. Changes in the composition of the vaginal microbiota, known as dysbiosis, have been associated with a higher risk of these conditions. Notably, dysbiosis characterized by a reduction in protective Lactobacillus species and an increase in anaerobic organisms is associated with bacterial vaginosis, HPV infection persistence, and neoplastic development. Furthermore, alterations in the vaginal microbiota during pregnancy have implications for gestational outcomes, with a low frequency of lactobacilli predisposing women to preterm birth. Moreover, abnormal vaginal flora has been implicated in female infertility, affecting embryo implantation, tubal factors and pregnancy outcomes. Although there has been progressing in understanding the role of the vaginal microbiome in gynaecological health, additional research, particularly randomized controlled trials, is necessary to clarify the underlying mechanisms and devise targeted therapies.