Clare Fleishman MS RDN

Your vagina teems with microbes, most of them worthy of their role in creating human life. They deserve more attention.

A healthy vaginal microbiota is simple compared to the diversity found elsewhere in the body such as the gut. Yet it is dynamic, changing throughout the life of a female.

Genetic analyses have afforded a good picture the vaginal microbial ecosystem. Not surprisingly, age impacts the type of microbes present in a healthy vagina.

Microbiota shifts across the lifecycle

Perinatal development

Maternal estrogen thickens the vaginal epithelium. Glycogen settles into cells; the epithelial cells shed glycogen which favors microbes which ferment glucose.


The vaginal mucosa thins out as estrogen recedes which then promotes different microbes.


Microbiota is now mostly populated by Gram-negative anaerobes, some Gram-positive anaerobes and facultative anaerobic bacteria.


Estrogen increases lead to further thickening, selecting for glucose-fermenting microorganisms. Lactobacillus, Gardnerella vaginalis, and Prevotella bivia are in low abundance.


Microbiota evolves and becomes similar to the vaginal microbiota of adult women as follows.


Most healthy women host these predominant species: Lactobacillus crispatus, Lactobacillus gasseri, Lactobacillus iners, and Lactobacillus jensenii. These species create a barrier against pathogen invasion; products of their metabolism secreted in the cervicovaginal fluid can inhibit bacterial and viral infections.


Estrogen levels plummet during menopause leading to a change in composition. The microbiome at this stage is mainly characterized by Lactobacillus crispatus, Lactobacillus iners, Gardnerella vaginalis, and Prevotella and a lower abundance of Mobiluncus, Staphylococcus, Bifidobacterium, Gemella, and yeasts, such as Candida.

The natural shifts fashioned by estrogen depend on a healthy ecosystem. Dysbiosis is essentially an imbalance where pathogens take over and create problems. Bacterial vaginosis, sexually transmitted diseases and reproduction complications can ensue.

Taking care of vaginal microbes

  • Never douche.
  • Use mild soaps.
  • Modulate vaginal pH (a more acidic environment facilitates growth of Lactobacillus species and inhibits pathogens).
  • Eat lots of prebiotic fibers to nourish probiotic bacteria.
  • Eat fermented foods including yogurt, kombucha, kefir and fermented cheeses.
  • Consider a supplement that may repopulate the bacteria known to exist in a healthy ecosystem.

Other great reads:

Women and Their Microbes: The Unexpected Friendship

Cervicovaginal Microbiota and Reproductive Health: The Virtue of Simplicity