More than a year ago, we asked for your help to make history with Isala. And we definitely did all that together! As researchers at the University of Antwerp, we are extremely proud of what we have achieved with Isala. We now have a unique set of data to further investigate the vaginal microbiome of healthy women in Flanders. Today we are happy to share the very first results with you. 


Who took part in Isala? 

Nearly 89% are sometimes or always bothered by their periods

As a participant in Isala, you are in good company, more than 4684 provided data to Isala via a large questionnaire, among which 3300 women donated a swab! The youngest woman was 18 years old, the oldest no less than 98. 1921 participants were pregnant at least once, and all women from Isala together identify with no fewer than 99 different cultures. Naturally, we as scientists are very careful with the interpretation of all research data. Citizen science will remain something in 2021 that will not be able to reach the entire population. But Isala is also actively working on progress there because we are involved in removing possible barriers for future citizen science projects. So, we write history with that too! 

What happened to all the swabs?  


At Isala, we use high-tech DNA analysis. For example, suppose you have a smear taken at the gynaecologist. In that case, this is usually only thoroughly examined under the microscope to look for abnormal cells. We have gone a step further to fully map the vaginal microbiome of women. The blue swab you took has helped us identify the most numerous types of bacteria in your vagina. We used the pink swab to grow the bacteria we found in our lab. This way, we can see which positive properties they have for female health. For example, we think that some bacteria could eventually help as an alternative to antibiotics in women who suffer from infections, inflammations or other discomforts. 

 This high-tech DNA analysis is quite a complex form of research. In exceptional cases, the analysis of the submitted swab was therefore not entirely successful. If this is the case with you, you can read more about this on your personal page. 

Has anything been discovered yet? 

How healthy are our vaginas?

Yes! As you know, it was the first time that vaginal samples were collected from healthy women on such a large scale. Of course, we already knew a lot about the composition of the vaginal microbiome. Still, most of the samples we had so far were taken in a medical context by women with health complaints. 

For the first time, we finally have a large set of samples from a general population. Thanks to Isala, we found that around 80% of the participants had a vaginal microbiome dominated by lactic acid bacteria, with lactobacilli being the most common. These bacteria are associated with a healthy vagina based on current scientific literature. 

Healthier than expected based on previous results

To present this large amount of information clearly, we have chosen to focus on the eight most common bacteria in all participants. The researchers included each woman into one of these eight types, which means that this bacterium is the most common in your swab.   

But usually, that’s not the only bacteria we found in your swab because the composition of your microbiome is unique. That is why, in addition to the dominant type, each Isala participant also receives a table in which we give the percentages of the eight most common bacteria. 

There is more to tell for many women than just those eight bacteria, so there is also a category ‘other bacteria’. Women who see a high percentage in that group should definitely not panic. The makeup of the vaginal microbiome of these women is simply more unique than the average participant in our study. Since more than 3000 women participated in Isala, we were unable to name and discuss all bacteria in detail. Still, we will certainly take this into account for further research. 

These are the eight most common bacteria that the researchers found in the participants of Isala: 

Lactobacillus crispatus
Lactobacillus iners
Lactobacillus jensenii
Lactobacillus gasseri

Lactic acid bacteria or lactobacilli, Do I know those bacteria from somewhere?

80% has mainly lactic acid bacteria

Yes, probably because they are related to the bacteria, you can find in yoghurt. Lactic acid bacteria are those bacteria that convert the natural sugars in milk into lactic acid through fermentation. As a result, yoghurt has a more acidic taste and is thicker in texture. 

In more than 80% of the swabs we analysed at Isala, a lactic acid bacterium, in particular a Lactobacillus, was dominant. In your vagina, these bacteria actually do the same thing as in yoghurt. Because they will use glycogen, a type of sugar that is also in the wall of your vagina and uterus, as a nutrient and convert it into lactic acid. Therefore, thanks to the lactobacilli, a healthy vagina has a low acidity, which is extremely important in the fight against pathogenic bacteria or viruses. 

Science also discovered a link between the female hormone estrogen and the number of lactobacilli. After all, estrogen ensures a higher presence of sugars, which is the most important nutrient for the lactobacilli. The amount of estrogen changes during your menstrual cycle, and your age also plays a role. It might be nice to know that during pregnancy, estrogen rises sharply, which has a positive impact on the number of lactobacilli in your vagina. In this way, nature ensures that you are extra well protected against infections and inflammations during pregnancy. 

Lactobacilli are found not only in your vagina. They are also often found in your intestines, on your skin or even in your nose. The four most common types of lactobacilli found in Isala are Lactobacillus crispatusLactobacillus jenseniiLactobacillus gasseri and Lactobacillus iners – are also found on our skin, for example in the groin area. 

How many different bacteria were actually found? 

Too many to mention. :)  

Because even within the same Lactobacillus species, there can still be a lot of variations in their genetic code. We then call these variants different strains or isolates of the same species. Every vagina, including yours, contains a unique combination of different strains, together making up billions of cells. We have mapped all the results on large graphs, and this is how we try to see patterns. Each participant is one anonymous line or dot and forms a small piece of the whole puzzle. The analysis of all swabs gives a nice graph with a kind of continuum. It is not a question of whether that bacterium or another, rather a story of more and less. There is no single vagina that contains only one type of bacteria. It is always a combination of different types that determine your unique vaginal microbiome. The researchers made a thoughtful selection of the eight most common types of vaginal bacteria.  

We then determined the percentages for each participant that we found in the analysis of the swabs. This graph summarizes the whole of Isala; each vertical line is one woman who has taken a swab for Isala:

Distribution of bacteria types
Click here for a larger version of the graph.

 Will the same bacteria remain dominant in my vagina once and for all? 

That is an exciting research question for Isala. With what we already know, we can say no. A baby’s vaginal microbiome is very different from a girl’s puberty. We know that pregnancy and menopause also have a significant impact. Your vagina evolves with you through different phases of your life.  

There is growing evidence that the composition of your vaginal microbiome is even more dynamic. We think it can also change under the influence of your cycle, hormonal fluctuations, diet, smoking, sexual activity, the type of soap you use when washing,… To further investigate this, in the autumn of 2020, 275 women were selected from the large group of Isala participants. They were asked to take six different vaginal swabs during two menstrual cycles. By further analyzing these samples, we hope to better understand the natural changes in a healthy vagina in the coming months. 

Therefore, it is important to realize that your personal result for Isala – if it seems a little less favourable, for example – does not immediately mean that you still belong to the same type today. And vice versa, if you were dominated by very healthy bacteria in the summer of 2020, something may have changed in the meantime. That is why our most important message is always: if you experience complaints, contact your trusted doctor so that you can be helped. 

Not sure when you might need to make an appointment with your doctor? This is a list of common complaints that may indicate a (small-scale) problem with your vaginal health:  

o Redness 
o Swelling 
o Pain (general) 
o Itching 
o Burning sensation 
o Increase in vaginal discharge (different from normal monthly discharge) 
o Change in vaginal discharge (different colour, unpleasant odour) 
o Pain during sexual contact 
o Bladder infection and others  

Is the investigation over now? 

No, it is actually just getting started. 

As researchers at the University of Antwerp, we are already very satisfied with the first results of Isala. We did not expect that no less than 80% of the examined vaginas would be dominated by healthy lactobacilli. Because based on the literature, we estimated this to be lower, about 70%. 

In the coming years, we want to learn a lot more about the health of the female microbiome based on all the research data and the extensive questionnaires that you all have completed. We will first examine which factors exert the most influence on the health of your vagina. We hope to develop a series of recommendations and tips to promote health in your vagina based on our research. For example, if we discover that women with a very healthy microbiome remarkably often have the same diet, we would like to investigate further whether there is a clear connection. Because then women could also have a very positive influence on their female microbiome by simply eating differently. 

In addition, we are truly convinced that it should be possible to develop therapies based on the bacteria present and their protective molecules in a healthy vagina. In this way, we hope to contribute even more to the fight against bladder infections, infections, infertility, etc… These kinds of new therapies can also become very important in the search for alternatives to antibiotics, as more and more bad bacteria and fungi are becoming resistant, causing the treatment of such infections is becoming increasingly difficult.  

So, while we’re repeating this, we’d like to end with a big, heartfelt thank you! Because with your participation in Isala, you have made a difference. And we are very grateful to you for that.