Host and Microbiome Interplay Shapes the Vaginal Microenvironment

Abstract

The female reproductive tract harbors a unique microbiome, especially the vagina. The human vaginal microbiome exhibits a low diversity and is dominated by Lactobacillus species, compared to the microbiome of other organs. The host and vaginal microbiome mutually coexist in the vaginal microenvironment. Host cells provide Lactobacillus glycogen as an energy source, and Lactobacillus produce lactic acid, which lowers vaginal pH thereby preventing growth of other bacteria. Bacterial vaginosis can modulate host immune systems, and is frequently associated with various aspects of disease, including sexually transmitted infection, gynecologic cancer, and poor pregnancy outcomes. Because of this, numerous studies focused on the impact of the vaginal microbiome on women`s health and disease. Furthermore, numerous epidemiologic studies also have demonstrated various host factors regulate the vaginal microbiome. The female reproductive tract undergoes constant fluctuations due to hormonal cycle, pregnancy, and other extrinsic factors. Depending on these fluctuations, the vaginal microbiome composition can shift temporally and dynamically. In this review, we highlight the current knowledge of how host factors modulate vaginal microbiome composition and how the vaginal microbiome contributes to maintaining homeostasis or inducing pathogenesis. A better understanding of relationship between host and vaginal microbiome could identify novel targets for diagnosis, prognosis, or treatment of microbiome-related diseases.

Effects of emergency/nonemergency cervical cerclage on the vaginal microbiome of pregnant women with cervical incompetence

“…The analysis can be conducted more clearly by further stratification based on expanding the sample size. Additionally, this study was limited to the vaginal microbiota, lacked multifactor integration analysis, and did not consider the interaction between vaginal microorganisms and the host immune response ( Fettweis et al., 2019 ; Al-Nasiry et al., 2020 ; Marangoni et al., 2021 ; Kwon and Lee, 2022 ).…”

Vitamin D deficiency increases the risk of bacterial vaginosis during pregnancy: Evidence from a meta-analysis based on observational studies

“…By elevating calcium concentration, vitamin D may stimulate insulin secretion and increase glycogen synthesis, which induces glycogen deposition in the vagina ( 36 , 55 ). A higher concentration of free glycogen in the lower genital tract promotes Lactobacillus species colonization, decreases vaginal pH, and inhibits the growth of other bacteria ( 56 ). A pilot study including black adolescent women also showed that higher vaginal glycogen levels were positively related to the dominance of Lactobacillus ( 57 ).…”

The Molecular Gut-Brain Axis in Early Brain Development

“…The adult gut microbiota are relatively stable but retain some tractability in response to internal and external environmental factors. Food, antibiotics, infections, and anxiety affect the gut microbiota and other human body parts [ 16 ]. The association between genetic manipulation, immune system regulation, and aging requires additional research to obtain a more detailed understanding [ 17 ].…”