In recent years, there has been growing interest in understanding the role that the vaginal microbiome plays in women's health and wellbeing. One aspect of this is the production of lactic acid by the vaginal wall cells, which helps to maintain a low pH environment within the vagina. This acidity acts as a barrier against potentially harmful bacteria, including those that cause BV (bacterial vaginosis) and STIs (sexually transmitted infections). However, researchers are still investigating how exactly lactic acid is produced and regulated by the body, as well as its potential effects on fertility and pregnancy outcomes. In this article, we will explore what is known about the production and functions of lactic acid in the vaginal environment.
Lactic acid production
The vaginal epithelium produces lactic acid through fermentation of glycogen, a form of sugar stored in cells. Lactobacilli, a type of bacteria that reside in the vaginal microbiome, play an important role in this process, breaking down glucose into lactate. The exact mechanisms behind this are not yet fully understood, but it is thought that lactobacilli produce enzymes that help convert glucose into lactate. Lactobacilli also secrete hydrogen peroxide, which can further increase the acidity of the vaginal environment.
Acidity and bacterial balance
The normal vaginal pH range is between 3.8 and 4.5, and this acidic environment creates a hostile environment for many types of bacteria. This includes species such as Gardnerella vaginalis, which causes BV, and Chlamydia trachomatis and Neisseria gonorrhoeae, both of which can cause sexually transmitted infections. Lactobacilli have been shown to be protective against these pathogens, producing lactic acid and other metabolites that create a barrier against them. However, there is evidence that changes in the microbial community can lead to reduced levels of lactate and increased pH, potentially increasing risk of infection.
Fertility and pregnancy outcomes
Some studies suggest that low levels of lactic acid may be associated with infertility and miscarriage. For example, women who have had recurrent miscarriages often have higher pH levels than those with successful pregnancies. It has been hypothesized that lactic acid production may play a role in implantation of the embryo, although more research is needed to confirm this. Other studies have suggested that lactate may affect sperm motility and fertilization rates, but again, more research is necessary to fully understand how it fits into reproductive health.
Research into lactic acid regulation and its potential effects on fertility and pregnancy outcomes is still in early stages, so much remains to be learned about this important part of the vaginal microbiome. Nevertheless, understanding the mechanisms behind lactic acid production and its impacts on the body will help us better understand female health and wellbeing.