Vaginal microbiome: the cornerstone for women’s health

This is a post by Mariya Petrova, PhD:

What is the human microbiome?

We do not live alone; We are more microorganisms than human cells. This bacterial population known as the human microbiome is found in our skin, mouth, nose, gastrointestinal tract, and the urogenital tract. Both we and the microorganisms that our body harbors benefit from this collaboration, we provide to them the nutrients that they need to grow, and in return, they help us defend ourselves against pathogens, digest complex foods, or synthesize vitamins. The amount and diversity of microorganisms differ per location, but it is fascinating to discover that microbes inhabit most parts of the healthy human body. The spotlight is on the gut microbiome since this is the biggest microbial population residing in our body. However, after years of research focusing on the gut microbiome, scientists today are increasingly interested in the microbiome that contributes to the reproductive health of women. In truth, we are faced with mounting evidence that the microbial population in the vaginal niche is an important cornerstone not only for women’s health but also for the health of the newborn baby.

What are the characteristics of vaginal microbiota?

The vaginal microbiota is one of the best studied female microbial niches. This women’s specific microbiota is characterized by low bacterial diversity, unlike other more complex niches such as the gut. This low bacterial diversity in the vagina is linked to health. We know now that Lactobacillus species are the most common bacteria in the vaginal microbiome, and are referred to as key species associated with health.

But why are lactobacilli so crucial for a healthy vagina? In the first place, lactobacilli are essential lactic acid producers, which lowers the vaginal pH to 4-4.5, thus keep the vaginal niche acidic. This low pH and high levels of lactic acid help to keep pathogens in check since they cannot survive and grow in an acidic environment. Different types of lactobacilli also have additional ways to fight pathogens and help to keep the vagina healthy. For example, they can produce other anti-pathogenic molecules, attach to the vaginal epithelium or affect signaling pathways that control the immune system. Certainly, Lactobacillus bacteria, part of the vaginal microbiome are essential for women’s intimate health and able to protect them against all bacterial, fungal and viral infections.

Just like a fingerprint, the vaginal microbiota of each woman is unique. The vaginal microbiota is shaped and influenced by hormones, environmental factors, pregnancy and even behavior, such as the use of antibiotics, sexual activity, smoking, washing lavishly with soap or being stressed. Remarkably, not only is the vaginal microbiome of every woman is unique, but it is also a very dynamic and continuously changing. It changes throughout women’s lives, but also in the shorter term. For example, during the menstrual cycle, hormone changes affect the composition of the vaginal microbiota.

What happens when the number of lactobacilli decreases?

A lack of lactobacilli and an overgrowth of pathogenic microbes cause an imbalance in the vaginal microbiome and the development of disease states. Bacterial vaginosis (BV) is the most common dysbiosis state. One in three women gets BV at some point in their lives. During BV, the number of lactobacilli decreases and anaerobic pathogens such as Gardnerella vaginalis, Prevotella, and Atopobium increase, which cause the pH of the vaginal milieu to elevate above 4.5. BV is recognized by fishy odor, a milky or grey vaginal discharge, and vaginal burning. Until today, the exact cause of BV is unknown. Researchers have discovered that hormone changes, the number of sexual partners, smoking, personal hygiene, and antibiotic use are risk factors for the development of BV. BV is also associated with other vaginal and urinary tract infections, increased risk of infertility, fallopian tube inflammation, preterm birth, and sexually transmitted infections such as HIV, HPV, herpes infections, chlamydia, or gonorrhea. Regular checkups to your gynecologist will ensure that the vaginal niche stays healthy. However, if you experience, itching, burning, fishy odor and/or unusual discharge make an appointment immediately.

Let’s cut to the chase: How to take care of my vaginal microbiota?

The vagina is a self-regulating ecosystem equipped with various defense mechanisms. Usually, the vagina can protect itself, but not always. This is why it is vital to take care of the vaginal microbiota.

• Be careful with too much hygiene.The vagina is a self-cleaning system, so washing daily with water is enough, the vagina does the rest.
• Do not use soap. Soap disrupts the acidic environment of the vagina and therefore, the natural protection. Ask your pharmacy for a soap-free product that respects the acidic pH of your vagina.
• Stop vaginal showers. Intravaginal shower products can cause chemical damage to the vaginal microbiota and easily wash away the good Lactobacillus

Do not overuse antibiotics. Antibiotics destroy not only the harmful bacteria but also the good ones, which may lead to the development of BV or other vaginal infections. >>> Read more about antibiotics

• Do not smoke. Women who smoke have a lower number of vaginal lactobacilli and a higher chance of overgrowth of pathogenic bacteria.
• Safe sexual practice. During sex, we exchange bacteria, which brings the vagina in contact with "unknown" bacteria. Use a condom to prevent sexually transmitted infections.