How does a healthy vaginal microbiome make us stronger, and why are we more susceptible to dysbiosis before menstruation?

(5 minutes of reading)

One of our meta topics at Syster is resilience. This is also one of the topics of this article, albeit in a slightly unusual attire. The vaginal microbiome. A healthy and happy vaginal microbiome is one of the basic pillars of a strong immune system of a healthy and happy woman. And a woman with a strong immune system is a resilient woman. In this article you will learn in what ways a healthy vaginal microbiome makes us more resilient and why some of us are more susceptible to such ailments as bacterial vaginosis around our period. At the end, we will share some tips for supporting your microbiome. 

PS: If you tend to blush when you read the word vagina, you’re in for a wild ride. You have been warned! :)

The vaginal microbiome

The vaginal microbiome is a population of microorganisms (bacteria, viruses, yeast) that live in a vagina. These microorganisms communicate with each other using something called quorum sensing. You can imagine it as a sort of “Internet for bacteria”. It allows them to perceive their environment, readily adapt to every situation and regulate their numbers and behaviour as needed (1). The vaginal microbiome is a unique kingdom that differs greatly from the gut microbiome. The gut microbiome loves diversity. It can be made up of up to 200 different species of bacteria. The vaginal microbiome, on the other hand, is somewhat of a minimalist. It prefers fewer species - usually only 1 to 5 different bacteria species (although in a small number of women, it can be as many as 25). Most of the time, they live in harmony. Everyone knows their role, and in a healthy European woman’s vagina, Lactobacilli are in charge.

Dysbiosis - Now I am in command!

The vaginal microbiome continually evolves and fluctuates in accordance with the changes in other aspects of our life. I refer you to Kristie’s article, where she describes such ups and downs in the life of a vagina. A healthy vaginal microbiome cannot really be defined, as it means something different to every woman. However, in most cases, there should be a Lactobacillus on the throne. Lactobacilli cooperate with the immune system and check continually if there is any threat of health complications. Their speciality are sexually transmitted diseases or complications related to pregnancy, such as miscarriage or ectopic pregnancy. It is also their responsibility to defend their leading position to prevent dysbiosis. There is an incessant game of thrones going on in the vaginal microbiome. The Lactobacilli are not the only ones interested in governing, and if such unwanted intruders as Streptococcus, Atopobium, Gardnerella, or Prevotella become overabundant, dysbiosis ensues (2). This can lead to a bacterial vaginosis or candidiasis. Whew. (We will look at the various symptoms of dysbiosis in another article.)

What makes the ruler happy?

So it is very important to us that our vaginal microbiome be happy. You definitely know the saying “good food, good mood”. Well, sure, but what does the vaginal microbiome eat? The vaginal microbiome feeds on cervical mucus. Cervical mucus is produced all the time, but its consistency and amount change depending on the phase of the menstrual cycle. I am sure you have noticed that sometimes the consistency resembles egg whites, it is transparent and stretchy, sometimes the mucus is thick and creamy. The hormone oestrogen contributes significantly to the production of cervical mucus and - what is important - makes it rich in glycogen. Glycogen is especially popular with the rulers of the Lactobacillus genus, and in processing it, they produce metabolites (something like by-products), for example, lactic acid and hydrogen peroxide (H2O2) (3, 4). “Acid? Peroxide? What?!” Now you might be thinking about the peroxide your hairdresser uses to bleach your hair. If you have ever found bleached spots on your favourite underwear, it is precisely due to the peroxide contained in our cervical mucus. We should forgive the bleached underwear, though, because the presence of this compound together with lactic acid in our cervical mucus is very important. It helps to maintain an acidic environment in the vagina, prevents microbial invasion, supports the immune system, reduces inflammation, maintains tissue homeostasis, and boosts our ability to resist certain infections (3, 4).

Revolt - Susceptibility to dysbiosis before menstruation

So in great part, a healthy acidic vaginal environment (pH ideally 4-4.5) in women of reproductive age is governed by Lactobacilli, oestrogen and glycogen. And now, Systers, hold on tight because this is going to get super interesting!

Just before menstruation, the oestrogen levels decline → we know that oestrogen is very important to the production of mucus and its glycogen content → the decrease of oestrogen therefore creates a short supply outage during which our good bacteria do not get as much food → less food = less power, and the otherwise mighty genus of Lactobacillus can be weakened (ayayay!) → this affords a wonderful opportunity for other bacteria that have so far been a minority; they start reproducing and - “Woohoo, now it’s time for us to party!” → this party is no fun for us, though, as it may lead to dysbiosis and the onset of an infection or inflammation (5). Menstruation can also cause an imbalance when the usually abundant Lactobacilli are reduced due to bleeding. Some Lactobacilli can agglutinate to red blood cells and leave the vagina with them (6, 3). The bacteria lurking nearby now have an opportunity to seize the throne. And a bacterial vaginosis will soon follow. 

How can I know that a revolt is afoot?

Even though dysbiosis can occur out of the blue, it is usually not without a cause. Learn to recognise what normal cervical mucus means to YOU. If you feel that something is not quite right, observe, note down the changes, and ask questions. Your body will tell you. The natural resilience of your vaginal microbiome may be weakened or disrupted by a number of factors. We can look for the triggers in our everyday habits (intimate hygiene practices, contraception, smoking) or biological variables (hormones, the resilience of our immune system). Tracking the symptoms, especially if they are just starting, will help you and your gynaecologist identify the triggers. 

The basic questions may be as follows:

How can you describe the change?

• Do you experience uncomfortable itching?
• Where and with what intensity?
• Did you notice an unusual smell of your cervical mucus?
• Did you notice an unusual consistency of your cervical mucus?
• Pain during or after sex?

What are the circumstances?

• Have you started taking new medication or antibiotics?
• Do you use scented soaps or shower gel for your intimate hygiene?
• Do you have a new sexual partner?
• New sexual practices or unprotected sex?
• New underwear? Sexy lingerie can really irritate our vaginal microbiome. 
• Change of diet?
• Are you a diabetic and have to watch your blood sugar levels?
• What phase of your menstrual cycle are you in?
• Do you feel stressed or anxious, which may have weakened your immune system?

As I mentioned at the beginning, a healthy happy microbiome is a part of a resilient woman. The game of thrones is a tough game. You can either debilitate or support your army in its battle. Assume responsibility, observe and record. Take active care of your vaginal microbial inhabitants. How? You will find out in the next article!

PS: Do not underestimate the signals of your body and talk to your trusted gynaecologist about any unusual changes.

Bibliography: 

1. Yang, M. et al., 2020. Effects of natural products on bacterial communication and network-quorum sensing. BioMed Research International, 2020, pp.1–10. 
2. Chen, X. et al., 2021. The female vaginal microbiome in health and bacterial vaginosis. Frontiers in Cellular and Infection Microbiology, 11. 
3. Amabebe, E. & Anumba, D.O., 2018. The vaginal microenvironment: The physiologic role of Lactobacilli. Frontiers in Medicine, 5. 
4. Kovachev, S., 2017. Defence factors of vaginal lactobacilli. Critical Reviews in Microbiology, 44(1), pp.31–39. 
5. Aldunate, M. et al., 2015. Antimicrobial and immune modulatory effects of lactic acid and short chain fatty acids produced by vaginal microbiota associated with eubiosis and bacterial vaginosis. Frontiers in Physiology, 6. 
6. Farage, M.A., Miller, K.W. & Sobel, J.D., 2010. Dynamics of the vaginal ecosystem—hormonal influences. Infectious Diseases: Research and Treatment, 3.