Vaginal microbiota

The vaginal microbiome in healthy individuals is characterized by low bacterial diversity, which contrasts with the more diverse gut microbiome (Ravel et al. 2011 Proc. Natl Acad. Sci. USA 108: 4680–4687; Collins et al. 2018 Appl Environ Microbiol 84: e02200-e02217). Studies have shown that a Lactobacillus-dominated community is prevalent in healthy vaginas. This dominance of Lactobacillus is crucial as it helps lower the vaginal pH to approximately 3.5 (O’Hanlon et al. 2013 PLoS ONE 8: e80074), creating an environment that is less conducive to disease. A higher vaginal pH is often associated with various health issues (Ravel et al. 2011 Proc. Natl Acad. Sci. USA 108: 4680–4687; Ceccarani et al. 2019 Sci Rep 9: 14095; Brooks et al., 2017a; Zheng et al., 2019; Drell et al., 2013)

Observational studies provide valuable insights into the composition and dynamics of the vaginal microbiome. These studies explore:

• The links between the vaginal microbiome and infections, inflammation, and reproductive issues.


• The interaction of the vaginal microbiome with urinary and mucosal areas.

These findings help establish a framework that connects the structure of microbial communities to health and disease.
Dillen et al. 2026 Cell Host & Microbe 34(4): 567-587

The vagina is a microecosystem with billions of microorganisms. They protect the female reproductive tract and reduce gynecological infections
Nori & H-Hameed 2023 World J Clin Cases 11: 2119-2122

Disruption of this ecosystem leads to pathogen overgrowth with complicated Vaginal infections / Vaginitis. Factors like menses, pregnancy, and sexual practices contribute. Uncontrolled antibiotic use and vaginal douching also alter the microbial community
Chee et al. 2020 Microb Cell Fact 19: 203

The majority of bacteria in the the female reproductive tract (FRT) reside in the vagina
Łaniewski et al. 2020 Nature Reviews Urology 17: 233-250

Newborn gut microbiota is similar the mother's vaginal flora (rich in lactobacilli)

In addition to bacteria, the vaginal microbiome includes fungi, collectively known as the "vaginal mycobiota” (Drell et al. 2013 PLoS ONE 8: e54379). Candida albicans is the dominant species within this mycobiota and is present in about 20% of women without symptoms. However, it is also a common cause of infectious vaginitis (Bradford & Ravel 2016 Virulence 8: 342-351). Other non-albicans Candida species, such as Candida glabrata / Nakaseomyces glabratus, Candida tropicalis, and Candida parapsilosis, are also present but less prevalent (Barousse et al. 2004 Sex Transm Infect 80: 48-53).

From the eight phyla that we observed in the vaginal ecosystem, Firmicutes constituted the vast majority of vaginal microbiota in healthy women, while Bacteroidetes, Actinobacteria and Fusobacteria were strongly associated with Bacterial vaginosis
Ling et al. 2010 BMC Genomics 11: 488

see also:
Bacterial vaginosis
Chlamydia trachomatis
Development of Gut Microbiota
Female reproduction tract (FRT) & Gut microbiota
Lactobacillaceae & Vaginal Microbiota
Postmenopause / Menopause
Urogenital infections & Drugs/Treatments