What do you know about the vaginal microbiome?

Undoubtedly one of the greatest achievements in human biology and medicine is the sequencing of the human genome, which was announced in 2001. However, it gave us only a partial image of who we are! The studies of the human microbiome (i.e. the small communities of microorganisms that coexist in the human body) but also of the genetic profile of all these microorganisms, certainly promise to complete who we are.

Until recently, studies on the human microbiome focused mainly on pathological conditions, but current data indicate that native microorganisms have an important role in the maintenance of human health. A prime example of a highly coordinated relationship is the human vagina and the associated bacterial communities that live there - also known as the vaginal microbiome.

The vaginal microbiome is just a complex and important ecosystem of microorganisms in the female reproductive system and has an important role in the health of every woman. At the same time, these microorganisms have a protective role in the prevention of the colonization of potentially harmful microorganisms, such as those which are responsible for fungal infections, bacterial vaginosis, sexually transmitted infections, and urinary tract infections.

How does it work?

Bacterial balance

Just like in the intestine, so in the vagina, trillions of microorganisms, mainly bacteria along with fungi and viruses coexist synthesizing the vaginal microbiome. The main bacteria in a healthy vagina are called lactobacilli and they are responsible for maintaining an acidic environment, which in turn impairs the growth of other bacteria, fungi, and viruses.

However, achieving a balance is complicated as there are specific categories of lactobacilli that enhance the spread of sexually transmitted diseases. Conversely, women who do not have a sufficient amount of lactobacilli in their microbiome are at increased risk of contracting sexually transmitted diseases and other bacterial vaginoses.

Microbiome imbalance

In the vaginal environment, all experiences affect the microbiome. For example, sexual activity, the use of lubricants, semen, hormonal contraceptives, menstruation, and antibiotics affect the composition of the vaginal microbiome. Even the diet or the age of a woman can affect the vaginal microbiome but it is still not clear how this happens.

Disruption of the microbiome can cause an imbalance of its bacterial symbiosis and consequently bacterial vaginosis. Respectively, it can lead to the overgrowth of fungi e.g. Candida.

Is the vaginal microbiome associated with gynecological diseases and a woman's fertility?

The truth is that the vaginal microbiome is associated with the risk of contracting sexually transmitted diseases and other disorders. As mentioned before, the presence or absence of specific lactobacilli is associated with STDs and inflammatory pelvic disease.

Similarly, certain pathogens are associated with pregnancy loss or adverse health effects on the fetus. What has not yet been confirmed is the degree of influence of the vaginal microbiome on the smooth or non-smooth course of a pregnancy.

However, studies on IVF indicate that the presence of specific microorganisms in the uterus during embryo transfer affects the outcome of each effort.