In recent years, there has been much talk about the importance of the gut microbiome for our overall health. Consequently, we now systematically associate the terms microbiome and microbiota with communities of microorganisms inhabiting our digestive system while forgetting that humans do not host one, but several microbiotas including the skin, the oropharyngeal and the vaginal microbiota. Often overlooked, the vaginal microbiota performs several important functions and deserves some TLC, so let us learn about our friendly bacteria and how to take care of them!
Discovering the Vaginal Microbiota
The composition and proper functioning of the vaginal microbiota contributes to the protection of this fragile ecosystem associated with the overall health of women. It is believed that the microorganisms inhabiting the vaginal cavity act, among other things, as the first line of defense for the urogenital tract.
When the vaginal microbiota is healthy and balanced, there are between 100 million and 1 billion microorganisms per milliliter of vaginal secretions. Although the ‘normal’ composition of the microbiota is as unique as our fingerprints, the healthy vaginal cavity contains mainly bacterial groups (or phyla) belonging by and large to Firmicutes, with a strong predominance of Lactobacilli. Analysis show that in 70% of women of reproductive age, the dominant Lactobacilli come from one of the following four subgroups: L. crispatus, L. gasseri, L. jensenii and L. iners. A last group presents few Lactobacilli but rather different proportions of anaerobic bacteria including Gardnerella, Atopobium, Mobiluncus, Prevotella as well as bacteria of the Clostridium type.
However, the composition of the vaginal microbiota is dynamic and can change within 24 hours! The estrogen level seems to favor the predominance in Lactobacilli via the accumulation of glycogen, serving as a nutrient in the epithelium of the vaginal mucosa. The composition also varies according to ethnicity and is generally more stable during pregnancy.
The ecological vaginal niche is favorable to the predominance of Lactobacilli because they are resistant to oxygen as well as to the acidity of the vagina. The high concentration of Lactobacilli contributes to the delicate balance of the flora, thanks to their production of lactic acid which keeps the vaginal pH around 4.5.[i] Lactic acid also appears to play a role in innate and acquired host immunity via the activation of anti-inflammatory cytokines and helper T cells, as well as the potentiation of interleukin-23.
Lactobacilli use other means to prevent the colonization of pathogenic species such as the production of biosurfactants. These natural ῀detergents” prevent the adhesion of pathogens to the vaginal mucosa. Our friendly bacteria also metabolise bactericidal substances such as bacteriocins and hydrogen peroxide, in addition to competing with the not-so-friendly ones for nutrients. Aren’t they impressive?
Our Friends’ Enemies
Several factors affect the quantity of Lactobacilli including: hormonal imbalance, taking antibiotics, antifungals, corticosteroids or oral contraceptives, sexual activity, excessive or inadequate hygiene, stress, smoking, vulvovaginal Infections, excessive consumption of sugar or alcohol, etc. When the vaginal environment becomes less acidic, other microorganisms such as the anaerobic bacteria that make up the vaginal flora can proliferate to the point of imbalance or what is called dysbiosis.
The absence or insufficient relative amount of Lactobacilli in the vaginal microbiota is associated with an increased risk of bacterial vaginosis, yeast vaginitis, urinary tract infections and obstetric complications such as miscarriages, premature rupture of membranes, premature delivery, respiratory distress of the baby at birth, etc.[ii]
The use of antimicrobial treatments such as metronidazole has been the preferred conventional approach for some 40 years. Their effectiveness is variable (as low as 61%) due mostly to bacterial resistance, and relapses are frequent. In addition, these treatments induce a dysbiosis favoring the subsequent proliferation of pathogenic bacteria and yeasts. As for antibiotics, they also destroy our beneficial bacteria and induce dysbiosis.
Probiotics, Our Allies
Oral supplementation with Lactobacilli helps rebalance the vaginal microbiota since bacteria can migrate from the colon to the vagina via the perineum. There are also various natural products in the form of vaginal suppositories available in stores or to prepare yourself. Administering vaginal probiotics to reseed the vaginal microflora in lactobacilli has been shown to reduce the risk of recurrent vaginosis.[iii]
However, when we use a probiotic for prevention or to relieve the symptoms of discomfort in the genitourinary tract, we must keep in mind that not all Lactobacilli have the same properties. We must therefore favor products containing strains which have been shown to colonize the vagina such as L. gasseri. In addition, the number of bacteria per capsule and the amount of strains present in a product do not guarantee its effectiveness. We must select supplements which have been tested and clinically proven for their effectiveness. Many supplements do not survive our internal conditions and certain strains may simply not be compatible with each other.
Taking Care of Our Friends
In addition to taking oral or vaginal probiotics, there are other natural ways to promote a healthy vaginal microbiome:
Consume fermented foods. They provide good bacteria which participate in digestive and intestinal health, as well as in the production of lactic acid. Even if these bacteria are not found in the vagina, the state of the intestinal microbiota influences that of the vaginal microbiota. Incorporate sauerkraut, kombucha, kefir, miso and tempeh into your diet.
Reduce your sugar intake. Harmful vaginal and intestinal microorganisms love sugar! Reducing the intake of sugar in all its forms (including alcohol) and ensuring its proper use through the practice of physical activity and the taking of supplements such as a vitamin B complex, chromium and magnesium are key factors to maintaining a healthy microbiota and good health.
Balance your hormonal cycle. The drop in estrogen levels and natural hormonal variations natural or associated with the use of oral contraceptives or of IUD directly affect the ecology of the pelvic and vaginal area. Do not hesitate to consult a naturopathic doctor or other healthcare professional to assist you in the process.
Limit assaults against the vaginal microbiota. Despite the temptation to succumb to scented cleansing products including douching, it should be remembered that the vagina is a self-cleaning organ. If a soap must be used, prefer unscented soaps, with neutral pH and specially designed for the vagina. Thoroughly wash sensitive skin around the vaginal orifice and let the water flow cleanse the genital area. Dry well and leave to “air dry’ as often as possible! A healthy vaginal microbiota does not give off bad odors. It might reassure you to know that it is even immensely popular with some – indeed, the Polish company The Order of Yoni markets a beer based on vaginal bacterial culture![iv]
Choose organic menstrual products. We know that tampons and sanitary pads are treated with various chemicals. A report from the National Agency for Food, Environmental and Occupational Health Safety (ANSES) reveals the presence of the herbicide glyphosate and the pesticides lindane and quintozene, which are very harmful to our microbiota and our health. According to the researchers, the rate would not pose a risk, but it must be remembered that the effect of the chemicals is cumulative. Choose products that are safe for you and the planet.
The vaginal microbiota is of paramount importance for the health of women and it greatly influences our fertility, the smooth progress of our pregnancies and even the health of our infants! Since our good bacteria are living beings sharing a symbiotic relationship with us, everything that affects us will also have an impact on our microbiota, and vice versa. When our bacterial flora is in poor shape, it is usually a reflection of systemic or even emotional imbalances that we must address globally. It is not surprising that conventional drugs usually only provide temporary symptomatic relief! Good, healthy relationships are built over time! It’s time to get to know your friendly bacteria and to take good care of them!
- Finn DA. (2020). The Endocrine System and Alcohol Drinking in Females. Alcohol Res. 40(2):02
- Hartman TJ, Sisti JS, Hankinson SE, et al. (2016). Alcohol Consumption and Urinary Estrogens and Estrogen Metabolites in Premenopausal Women. Horm Canc. 7:65-74
- Shufelt C, Merz CN, Yang Y, et al. (2012). Red versus white wine as a nutritional aromatase inhibitor in premenopausal women: a pilot study. J Womens Health (Larchmt). 21(3):281-4
- Sepkovic DW, Stein J, Carlisle AD, et al. (2009). Diindolylmethane inhibits cervical dysplasia, alters estrogen metabolism, and enhances immune response in the K14-HPV16 transgenic mouse model. Cancer Epidemiol Biomarkers Prev. 18(11): 2957-64
- Im A, Vogel VG, Ahrendt G, et al. (2009) Urinary estrogen metabolites in women at high risk for breast cancer. Carcinogenesis. 30(9):1532-5
- Powell CL, Bradford BU, Craig CP, et al. (2010). Mechanism for prevention of alcohol-induced liver injury by dietary methyl donors. Toxicol Sci. 115(1):131-9.
- Frydenberg H, Flote VG, Larsson IM, et al. (2015). Alcohol consumption, endogenous estrogen and mammographic density among premenopausal women. Breast Cancer Res. 17(1):103
- Anwar MY, Marcus M, Taylor KC. (2021). The association between alcohol intake and fecundability during menstrual cycle phases. Hum Reprod. 36(9):2538-2548
[i] Cassard, A-M. et Thomas, M. Les microbiotes humains : des alliés pour notre santé. https://www.encyclopedie-environnement.org/sante/les-microbiotes-humains-des-allies-pour-notre-sante/
[ii] Thomas, A. The Vaginal Microbiota and Influence of Select Probiotic Lactobacilli Strains. From the Townsend Letter. February / March 2018. http://www.townsendletter.com/FebMarch2018/vaginal0218.html
[iii] Larsson PG et al. Human lactobacilli as supplementation of clindamycin to patients with bacterial vaginosis reduce the recurrence rate ; a 6-month, double-blind, randomized, placebocontrolled study. BMC Womens Health. 2008 jan 15;8:3. Brevet Français N°1256569 – Souche de Lactobacillus crispatus IP 174178.