Vaginal Microflora: Beneficial organisms living down there?

There’s a dynamic ecosystem down there ladies! The vaginal microflora in woman’s genital comprises microbial ecology and is responsible for many physiological and biological functions of the vagina. The different microbiota typically associated with the human body have a significant impact on human development, physiology, immunity, and nutrition. This is particularly true in the vagina, where mutualistic bacteria communities serve as the host’s first line of defence. Thus it eliminates invading, nonindigenous species that might cause illness. However. the dynamics of human vaginal flora are still not well understood.

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Vaginal Microflora

A Balanced Vaginal Ecosystem

A somewhat balanced vaginal microecological system promotes female health. An imbalance in the flora ratio might increase the risk of infection or reproductive issues. The study of vaginal microecology and its involvement in genesis is critical for preventing, diagnosing, and treating obstetric and gynaecological diseases. Sex hormone production is regarded as an important extrinsic variable influencing the female genital tract’s vulnerability to bacterial colonization.

  • Some research hypotheses suggest that the dynamics of vaginal ecosystems are highly influenced by menstruation and human activities. These activities include intercourse, douching, and other habits and practices. Although a functional balance offers stability to the ecosystem, which is considered critical to preserving vaginal health.
  • New technologies enable molecular investigations of the vaginal microbiota, to reveal a spectrum of functional microbial equilibria depending on the relevant host and microbial parameters.
  • Hormonal changes that characterize a woman’s reproductive cycle have a major impact on her vaginal microbiome. The vaginal environment is especially sensitive to estrogen, a hormone that creates distinct changes in the vaginal ecosystem.

The  Microbial Community at Vagina

The vaginal microbiota is dominated by lactic acid-producing strains of the genus Lactobacillus in most women. In addition to lactic acid, lactobacilli in the vaginal microenvironment create hydrogen peroxide and bacteriocins. This suppresses the growth of possible infections. Women often go through four different stages during their reproductive and late reproductive years: puberty, menstruation, pregnancy, and menopause. Estrogen and progesterone have the greatest influence on the composition and quantity of the vaginal microbiota. This begins at puberty and continues in a dynamic equilibrium with small oscillations throughout the reproductive years. Oestrogen stimulates vaginal epithelial cell proliferation and glycogen storage, whereas progesterone lyses vaginal epithelial cells, allowing for glycogen release.

Vaginal Microflora

Image source: Auriemma, R. S., Scairati, R., Del Vecchio, G., Liccardi, A., Verde, N., Pirchio, R., … & Colao, A. (2021). The vaginal microbiome: a long urogenital colonization throughout woman life. Frontiers in cellular and infection microbiology, 11, 686167.

Vaginal Microflora During Menstruation Period

During menstruation, the contact of menstrual blood with the vagina neutralizes the acidic vaginal milieu. Also, the rise in vaginal PH causes a considerable increase in the number of anaerobic microorganisms that function as symbionts. Furthermore, during menstruation, iron in iron-containing heme from broken blood cells quickly becomes the principal source of food for a variety of bacteria. To acquire iron deposits on the vaginal mucosal surface, vaginal bacteria such as Streptococcus and Gardnerella release iron chelator complexes (Scholl et al., 2016).

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Vaginal Microflora During Pregnancy Period

The organization, nature, and quantity of microbial communities that colonize distinct body regions change continuously, particularly during pregnancy. The relative abundance of the thick-walled phylum increased with each gestational week in the pregnancy cohort. Also, a completely new group of microbiota was discovered in the vaginal microenvironment during early pregnancy. By the middle of pregnancy, the amount of this new vaginal microbiota has significantly decreased, while Lactobacillus has increased in abundance.

During the early stages of pregnancy, the immune system weakens to allow for embryo implantation, the diversity of vaginal flora increases, and the number of Lactobacillus decreases. As a result, Lactobacillus lactis can colonize and multiply in the vagina, lowering the pH and inhibiting the colonization and development of other bacteria. This kind of stable vaginal flora in late pregnancy limits the growth of dangerous bacteria in the reproductive system, lowering the incidence of reproductive tract infections and so encouraging the healthy development of the gestational sac or fetus (Shen et al., 2021).

Vaginal Microflora

Image source: Günther, V., Allahqoli, L., Watrowski, R., Maass, N., Ackermann, J., von Otte, S., & Alkatout, I. (2022). Vaginal microbiome in reproductive medicine. Diagnostics, 12(8), 1948.

  • An imbalance of vaginal bacteria can cause inflammatory illnesses and problems in women, such as bacterial vaginosis, EMs, and STDs. Colonization is substantially connected with premature birth before 28 weeks of gestation.
  • In the female vagina, imbalances in the microbial community are thought to cause symptoms associated with bacterial vaginosis.
  • Understanding the structure and diversity of the reproductive tract microbiome in healthy and pathological conditions is important for identifying disease risk factors and developing treatments.

Tips for Healthy Vaginal Microflora

  1. Research suggests that the use of feminine hygiene products may be the result of a ‘harmful cycle’ whereby women wash to reduce perceived itching, odour, and discharge. This develops more significant or additional symptoms resulting from increased washing and the associated disturbance of the normal microbiome. Knowledge surrounding feminine hygiene products, the vaginal microbiome, and adverse vaginal health conditions need to be increased.  Women will then be able to make an informed choice about their use of these products to optimize their reproductive health(Holdcroft et al., 2023).
  2. While diet is a good source of nutrients, taking supplements is another alternative for maintaining optimal vaginal health. If you’re searching for a probiotic supplement, choose one labelled “cold chain,” which implies it needs to be refrigerated. In addition, seek probiotics that contain the three vaginal-specific bacteria strains: Lactobacillus acidophilus, Lactobacillus rhamnosus, and Lactobacillus reuteri.


  1. Shen, L., Zhang, W., Yuan, Y., Zhu, W., & Shang, A. (2022). Vaginal microecological characteristics of women in different physiological and pathological period. Frontiers in Cellular and Infection Microbiology, 12, 959793.
  2. Scholl, J., Nasioudis, D., Boester, A., Speleotes, M., Grunebaum, A., Witkin, S. S. (2016). Group b streptococcus alters properties of vaginal epithelial cells in pregnant women. Am. J. Obstet. Gynecol. 214 (3), 383.e1–383.e5. doi: 10.1016/j.ajog.2015.12.053
  3. Holdcroft, A. M., Ireland, D. J., & Payne, M. S. (2023). The Vaginal Microbiome in Health and Disease—What Role Do Common Intimate Hygiene Practices Play? Microorganisms, 11(2), 298.

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Team MBD

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