Vaginal microbiome genetics explained

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

Last reviewed: June 24, 2026

A large new study in Nature Genetics has found that your own DNA helps shape your vaginal microbiome – the community of bacteria, viruses and fungi that lives in the vagina. In other words, part of why some people settle into a protective, Lactobacillus-rich community while others tip towards disruptive bacteria is written into our genes, not just down to behaviour or environment.¹

The researchers built the largest genomic map of the vaginal microbiome assembled so far, then looked for links between human genetic variants and the bacteria living there. They found seven genetic signals that held up across separate groups of people.¹

For anyone who has battled recurrent bacterial vaginosis (BV) and quietly blamed themselves, this is worth sitting with. Some of the deck may have been stacked before you did a single thing.

The vaginal microbiome has long been treated as something we can control if we just do the right thing. This work, alongside a growing body of research, paints a more nuanced picture: it is a living ecosystem shaped by hormones, immunity, the gut and now, demonstrably, the genes you were born with.¹

What the vaginal microbiome genetics study found

A team led by researchers at BGI Research pulled together vaginal samples from more than 13,000 people across China, the USA, France and several other countries.¹ They used shotgun metagenomic sequencing, which reads all the genetic material in a sample rather than just a single bacterial marker gene, so it can pick up bacteria, viruses and fungi at once and tell closely related species apart.^1,3

From this they built the Global Vaginal Metagenome-assembled Genomes catalogue (GVMG): 65,055 microbial genomes covering 890 bacterial and archaeal species, 11 fungal species and 6,577 viral groups.¹ That is nearly double the size of the previous big reference set, the multi-kingdom catalogue of 33,804 genomes published in 2024, which we covered here.^1,2

The headline finding is the genetic one. Because vaginal swabs contain a lot of human DNA, the team could read each participant’s own genome and their microbiome from the same sample, then run what is called a metagenome-genome-wide association study (M-GWAS) – a hunt for points in the human genome that line up with which bacteria are present.¹

Your genes are one of several dials

Testing 5.46 million human genetic variants against 54 common vaginal species, the researchers found 18 spots in the genome linked to the microbiome, and seven of those reached their strictest significance bar and were repeated in independent groups.¹

The strongest and most reliable link was between a gene called OPRK1 and bacteria called Ureaplasma urealyticum, which can act as a potential pathogen in the genital tract.¹ OPRK1 codes for the kappa-opioid receptor and has previously been tied to stress responses, so the authors suggest a possible gene-stress-microbiome thread worth pulling on in future work.¹

None of this means your genes single-handedly decide your microbiome. The authors are clear that environmental and lifestyle factors still do most of the shaping; host genetics is one dial among several.¹ But it is a real dial, and it helps explain why two people doing everything the same can end up with very different vaginas.

Why geography and ancestry showed up too

The study also found that where a person’s microbiome came from left a genetic fingerprint on the bacteria themselves. Among the species common enough to test, most showed meaningful genetic differences between populations.¹

Interestingly, the protective species Lactobacillus crispatus was the most genetically stable across the globe, while Lactobacillus iners, Lactobacillus jensenii and several BV-associated bacteria varied much more by region.¹

The mix of community types also differed: a high-diversity community dominated by bacteria known as BVAB1 was far more common in the US samples than the Chinese ones.¹

This matters for testing and research. Earlier attempts to link host genes to the vaginal microbiome were smaller and used lower-resolution methods, so this larger, higher-resolution map is a real step forward.⁴ Much of what we know about the vaginal microbiome has also come from Western cohorts, and this study shows that reference data built on one population may not translate cleanly to another.^1,5

A sharper picture of the bacteria that cause trouble

Beyond the genetics, the catalogue gives a much higher-resolution view of the bacteria involved in dysbiosis, which is where the practical value sits for anyone dealing with BV.¹

The team confirmed that L. crispatus, one of the most protective species, carries plenty of lactate-producing genes but very few of the genes for sialidases and cytolysins – the enzymes that strip the protective mucus layer and damage vaginal cells.¹ In plain terms, L. crispatus earns its keep without harming the tissue it lives on.

By contrast, the disruptive bacteria told a messier story. The group formerly lumped together as Gardnerella turned out to be a cluster of distinct genomospecies, and these – along with Prevotella species – were far more likely to carry the mucus-degrading and cell-damaging enzymes that drive BV symptoms.¹

The amount of these enzymes varied a lot even between closely related strains, which helps explain why two people with a ‘BV’ result can have quite different experiences.¹

This is the kind of detail that makes future testing sharper. The more precisely we can name the species and even the strains involved, the better targeted any plan can be.

The study also mapped the vaginal virome – the viruses, mostly bacteria-infecting phages, living alongside the bacteria. Most of the viral groups it found were new to science, and disease-linked phages tended to avoid Lactobacillus and instead target the disruptive bacteria.¹ It’s early, but it hints at another layer of the ecosystem we have barely begun to understand.

What this means for you

If you have struggled with recurrent dysbiosis, the takeaway is permission to drop some of the self-blame. BV, aerobic vaginitis and their relatives are not a moral failing or a hygiene problem, and this work adds genetics to the long list of reasons the microbiome can be hard to hold steady.

Every day in our clinic, we see people who have done everything ‘right’ and still cannot keep a protective community in place, and the reasons are multitudinous – which is why our specialist naturopaths are so sought after. They understand the nuances and drivers of the vaginal microbiome, and know it’s more than just an ‘infection’.

This study is a useful reminder of why: the vaginal microbiome is the end result of many forces – hormones, immune function, the gut, stress and now demonstrably your genes – not simply a reflection of what you did or did not do.

It also reinforces something we say often here at My Vagina: vaginal dysbiosis is frequently the result of an underlying process in the body, not the root cause on its own. Knowing genetics plays a part does not change the day-to-day plan – good information, accurate testing and targeted, systemic support – but it can change how you feel about needing one.

One limitation of this study is that the largest part of this dataset came from Chinese cohorts, with smaller US and European groups, and it studied women.¹ That is actually a strength for diversifying the field, which has leaned heavily Western, but it also means the exact genetic signals may not map identically onto every person or population. The broad principle – that host genetics is in the mix – is the message.

What genetics does not give us is any reason to accept vaginal symptoms. A genetic leaning is a starting point, not a verdict. Understanding your own vaginal microbiota community – ideally through a thorough test – is still the most useful first step.

What to do next

If recurrent BV, unexplained symptoms or a stubborn microbiome are part of your life, the most practical move is to find out what is actually growing in your vagina. A detailed test tells you which species dominate and whether protective lactobacilli are present, which is the foundation any sensible plan is built on.

You can read our guide on how to get a thorough PCR or NGS test, and see what a protective vaginal microbiome looks like so you know what you are aiming for.

If you would like to talk something through, Aunt Vadge’s Assistant – the chat widget in the bottom left of your screen – is a good place to start, and our practitioners are here if you want tailored, one-to-one help.

This is general information, not a substitute for personalised medical advice. If you have ongoing symptoms, please see a qualified practitioner.

Frequently asked questions

Does this mean BV is genetic?

Not exactly. The study shows host genetics is linked to which bacteria live in the vagina, and to risk of carrying certain disruptive species.¹ It is one contributing factor, not the whole story – environment and lifestyle still do most of the shaping.¹

If my genes are involved, is there any point treating my microbiome?

Yes. A genetic leaning makes some communities harder to hold steady, but it does not lock anything in place. The practical plan – accurate testing, then targeted and systemic support – is the same, and many people do shift their microbiome with the right approach.

What is OPRK1 and why does it matter?

It is a human gene that codes for the kappa-opioid receptor, best known for its role in stress responses.¹ In this study its strongest link was with the genital bacteria Ureaplasma urealyticum, hinting at a possible connection between stress biology and the microbiome that future research will need to test.¹

Why does ancestry or geography matter for my microbiome?

The same bacterial species carried genetic differences between populations, and the mix of community types varied by region.¹ Practically, it means reference data built on one population may not perfectly fit another, so broad, diverse datasets like this one make testing more accurate over time.¹

Can a test tell me my genetic risk?

No. A standard vaginal microbiome test shows which bacteria are present right now, not your genetic make-up. It is still the most useful thing to do, because it tells you what is actually growing and guides what to do about it.