Gardnerella vaginalis


With Isala, we found 359 women in whom this bacterium was dominant in their vagina. That is about 11% of all Isala participants.

Gardnerella vaginalis

What does this bacterium look like?

This is a cocobacillus. The shape is something between a sphere and a rod with a not so clearly delineated cell wall. This bacterium is no larger than 1 micrometre. And that is small because 1000 micrometres fit in one millimetre.


What does science already know about this bacterium?

A little more every day. Recently, for example, it was discovered at Ghent University that this is not just one species but four types of Gardnerella. This bacterium is related to the bifidobacterial group; these are the first bacteria in the gut of a small baby.

Gardnerella vaginalis has an average genome size of 1.7 million base pairs and has about 1,300 genes. This bacterium can therefore produce more than 1,300 different substances, including lactic acid.

Komt ze nog ergens anders voor?

What is this bacterium doing in my vagina? 

Gardnerella vaginalis can make lactic acid in your vagina. But we also know that this bacterium breaks down many proteins, which sometimes cancels out the positive effect of the lactic acid. And it’s the acidity that is important to better protect your vagina against infections and inflammation.

Some types of Gardnerella vaginalis have venomous spikes and enzymes. The biggest risk is that they can break down cells of the vaginal wall and disrupt the acidity in your vagina so that you may be more susceptible to infections or inflammation.

But don’t panic. Not all types of Gardnerella have these worse properties. Unfortunately, the technique used at Isala does not allow us (at this moment) to find out which Gardnerella type is in your vagina: a favourable or less favourable one.

Very often, we find this bacterium together with different types of lactobacilli. Those lactobacilli can help keep Gardnerella in check. As we have previously explained, your vaginal microbiome is somewhat dynamic. It could well be that the dominance of the Gardnerella has already disappeared. There are even indications that there is a connection with the course of your cycle. We suspect that Gardnerella is more common just after your period because this bacterium likes the presence of iron in your blood.

The most important advice we can give you is to contact your doctor if you experience complaints or worry about your vaginal health. Within Isala, we even have a separate page with more background information, especially for doctors, so you can certainly refer to that.

Waar komen ze nog voor?

Does this bacterium occur elsewhere?

Gardnerella is most commonly found in the vagina. Still, this bacterium can also sometimes be found in blood or urine samples, in the pharynx or lungs, and when examining wounds or abscesses.