We hear a lot about the gut microbiome, but what about the vaginal microbiome?
The vagina has its own complex microbial ecosystem, and its composition can influence vaginal health, susceptibility to certain infections and local immune function.
And unlike the gut, where greater microbial diversity is generally associated with health, a healthy reproductive-age vaginal microbiome is often characterised by the dominance of a relatively small number of beneficial bacterial species.
What Is the Vaginal Microbiome?
The vaginal microbiome refers to the community of microorganisms living within the vaginal environment.
In many healthy reproductive-age women, this community is dominated by bacteria belonging to the genus Lactobacillus.
These bacteria produce lactic acid, helping maintain the naturally acidic vaginal environment.
A typical vaginal pH during the reproductive years is approximately 3.8–4.5, although this varies with factors such as menstruation, menopause and individual physiology.
This acidic environment can help limit the growth of certain potentially harmful microorganisms.
Meet Lactobacillus crispatus
One species of particular interest is Lactobacillus crispatus.
Research has associated L. crispatus-dominant vaginal communities with a relatively stable, low-pH environment and a reduced risk of certain vaginal infections.
Other species, including L. jensenii and L. gasseri, can also contribute to a healthy vaginal environment.
Not every Lactobacillus species behaves identically.
For example, L. iners is found in both healthy and disrupted vaginal microbial communities, and researchers continue to investigate its role.
Importantly, microbiome composition alone doesn't establish whether someone has an infection.
Symptoms, examination and appropriate testing all matter.
What Happens When the Microbiome Becomes Disrupted?
A shift away from Lactobacillus dominance towards increased concentrations of certain anaerobic bacteria may occur in bacterial vaginosis (BV).
BV can cause symptoms such as thin vaginal discharge and a noticeable fishy odour, although some women experience no symptoms.
It is not the same condition as vaginal thrush, which usually involves Candida species.
These conditions require different assessment and treatment approaches.
Recurrent vaginal symptoms should not automatically be assumed to be caused by the same microorganism each time.
What Can Influence the Vaginal Microbiome?
Several factors can affect vaginal microbial communities, including:
Hormonal changes
Menstruation
Sexual activity
Antibiotic exposure
Vaginal douching
Menopause and changes in vaginal oestrogen exposure
One important protective habit is avoiding internal vaginal cleansing.
The vagina is self-cleaning, and douching can disrupt its normal environment.
Gentle external washing is generally sufficient.
Do Vaginal Probiotics Actually Work?
This is an area of considerable interest, but the evidence is still developing.
Certain Lactobacillus strains have been studied for their potential to support vaginal microbial recovery and reduce bacterial vaginosis recurrence.
However, results vary depending on the strain, formulation and treatment approach.
Not all products marketed as vaginal probiotics have demonstrated clinical benefits, and probiotics should not be assumed to replace recommended treatment for an active infection.
When Should You Investigate?
Persistent odour, unusual discharge, burning, itching, discomfort or recurrent symptoms warrant appropriate assessment.
Testing may include examination, microscopy or targeted molecular testing, depending on the clinical situation.
At Flora Whole Health, we take an individualised approach to vaginal concerns, considering symptoms, history, potential contributing factors and relevant pathology.
Because when it comes to the vaginal microbiome, understanding which organisms are present — and whether they're actually causing symptoms — matters far more than simply trying to introduce more bacteria.