PCOS and BV: why PCOS raises your bacterial vaginosis risk

Author: Jessica Lloyd
Senior Vulvovaginal Specialist Naturopath | BHSc(N) | ISSVD, ISSWSH, BSSM, ATMS

Last reviewed: July 6, 2026

People with polycystic ovarian syndrome (PCOS) get bacterial vaginosis (BV) more often than people without it. The link between PCOS and BV runs through hormones, insulin and inflammation, which together thin out protective Lactobacillus and make room for BV-linked bacteria. Below is how those pieces connect, and where the most useful leverage sits.

Polycystic ovarian syndrome (PCOS) is one of the most commonly diagnosed conditions in premenopausal women and people with a functional female reproductive tract. The main features of PCOS are excess androgen production by the ovaries or androgen sensitivity, lack of ovulation, infertility and insulin resistance.¹

PCOS is also linked with menstrual disorders, infertility, excess hair growth (hirsutism), acne, weight management and metabolic disturbances,¹ with far-reaching impacts beyond irregular periods and into advancing age.²

PCOS and the gut and vaginal microbiomes

Research shows changes to the gut and vaginal microbiome in people with PCOS, with differences compared to those without PCOS. Studies suggest changes in microbial diversity and possible dysbiosis (microbial imbalances).³

PCOS and inflammation

Low-grade chronic inflammation can occur due to microbiome disturbances, particularly when an excess in certain bacterial species contributes to metabolic disorders.^2,4

Does PCOS cause BV?

The vaginal microbiome and its relationship to PCOS symptoms is not fully understood, but some studies show reductions in Lactobacillus species, particularly L. crispatus, and increases in Prevotella and other atypical pathogens such as Mycoplasma and Chlamydia.⁵

Pathogen growth is favoured, promoting the growth of bacterial vaginosis (BV)-causing microbes such as Gardnerella vaginalis.⁶

In one study on the vaginal microbiome and women with PCOS, BV was suspected in 64% of the PCOS group, with an increase in G. vaginalis found in 57%. The researchers suggested a higher rate of BV in PCOS patients than in the general population.⁷

The mouth, gut and vagina are all affected by inflammation from PCOS

Studies on the gut, oral cavity and vaginal microbiome in people with PCOS indicate an increased propensity to inflammation, and with it a destabilisation of the microbial environment.^8,9 High triglycerides, fasting glucose and insulin levels, and metabolic disturbances are all known to affect the microbiome.^10–12

Managing the microbiome in PCOS

Achieving a balanced microbiome by addressing the various imbalances inherent in PCOS matters for managing both the inflammation and the dysbiotic microbiomes, while also working from the microbiome backwards. It is well observed that the gut microbiome influences sex hormones.¹³

When the vaginal microbiome is disrupted and there is systemic inflammation, IL-8 and tumour necrosis factor alpha rise, affecting the hypothalamic-pituitary-ovarian axis (HPO axis) via blood and lymph.^5,14,15

Hormonal impacts on the vaginal microbiome from PCOS

Interruptions to normal levels of oestrogen and progesterone due to irregular cycles affect the vaginal epithelial lining of the vagina and reproductive tract. This plays an important role in the vaginal microbiome.³

Androgens have been shown to affect the gut microbiome in women with PCOS and androgen excess.^13,16,17

Women with high testosterone levels have higher gut microbiome diversity, with increased levels of G. vaginalis and effects on lactobacilli.^2,3,6 The length of menstrual cycles affects lactobacilli levels,^5,10 giving disruptive microbes greater access.

Natural and functional support for the PCOS microbiome

Because so much of the PCOS and microbiome link runs through insulin and androgens, the most useful natural approaches work on those root drivers rather than on the vagina alone. Steady the metabolic picture and the vaginal environment usually has a far better chance of holding a protective, Lactobacillus-led balance.

Insulin and blood sugar: the central lever

Insulin resistance sits underneath much of PCOS, and a low-glycaemic-index way of eating improves insulin sensitivity and menstrual regularity, in one randomised trial independent of weight loss.¹⁸ Because insulin and glucose disturbances feed the inflammation that destabilises the microbiome, this is often the highest-value place to start. Our guide to managing insulin resistance in PCOS goes into the practical side.

Inositol

Inositol, in its myo- and D-chiro-inositol forms, acts as an insulin sensitiser. A systematic review and meta-analysis of randomised trials, carried out to inform the international evidence-based PCOS guidelines, found improvements in insulin measures, testosterone and menstrual cycle regularity, with a good safety profile.¹⁹

Gut microbiome and probiotics

Since the gut microbiome influences sex hormones, treating from the gut backwards is a legitimate route. Meta-analyses of randomised trials find that probiotics and synbiotics improve fasting insulin, insulin resistance and testosterone in PCOS.²⁰ Rebuilding protective bacteria, supported by the lactic acid they produce, is the same principle applied locally to the vagina.

Anti-androgen botanicals

Some botanicals act on the androgen side directly. Spearmint tea has significant anti-androgen effects in PCOS, lowering free and total testosterone in a randomised controlled trial.²¹ Because raised testosterone is one of the levers that tips the vaginal microbiome towards G. vaginalis, easing it can help the environment settle.

None of these replace medical care, and they work best matched to your particular PCOS picture. Our specialist naturopaths can help build a plan around the drivers that are actually active for you, and a comprehensive vaginal microbiome test shows what is really happening before you treat.

Frequently asked questions

Does PCOS make you more likely to get BV?

Yes. Studies consistently find lower protective Lactobacillus and more BV-linked bacteria in people with PCOS, and in one study BV was suspected in 64% of the PCOS group, a higher rate than in the general population.⁷ The link runs through hormones, insulin and inflammation rather than hygiene.

Why do I keep getting BV with PCOS?

Recurrent BV in PCOS usually reflects the underlying drivers still being active: raised androgens, insulin resistance and low-grade inflammation all make it harder for protective bacteria to hold their ground.^2,13 Treating the vagina alone, without addressing those drivers, tends to give short-lived results.

Can improving insulin resistance help my vaginal microbiome?

It is a sound target. Insulin and glucose disturbances feed the inflammation that destabilises the microbiome, and approaches that improve insulin sensitivity, such as a low-glycaemic-index diet and inositol, also improve testosterone and cycle regularity.^18,19 A steadier metabolic picture gives protective bacteria a better environment to recover in.

Does treating BV improve PCOS symptoms?

The relationship looks two-way: vaginal dysbiosis and systemic inflammation can feed back to the hypothalamic-pituitary-ovarian axis,^5,14,15 so restoring the microbiome may support the wider hormonal picture. It is best thought of as one part of managing PCOS rather than a standalone fix for the syndrome.

This article is general information and not a substitute for personalised medical advice. If you are worried about PCOS or recurrent vaginal symptoms, please see an experienced practitioner.