Constant itching or burning in the genital area, discharge and sometimes an unpleasant odour: an infection with harmful bacteria or fungi in the vaginal area is painful and very unpleasant for affected women, especially if it recurs regularly. In addition, many sufferers find it difficult to talk openly about these problems, which is why they often put off going to the doctor.

However, in order to be able to treat the symptoms in an acute case, it is crucial to determine the pathogen, as it can either be a fungal infection (vaginal candidiasis), an infection of the vagina with the bacterium Gardnerella vaginalis and related bacteria (vaginosis) or an infection with bacteria such as Escherichia coli or B streptococci (aerobic vaginitis).

Beyond the acute treatment of the pathogens, however, doctors have long been helpless: millions of women in the UK have had to accept the fact that their symptoms, whether caused by bacteria or fungal infections, keep recurring and need to be treated. Relapse rates of up to 75 percent are the sad reality.

However, German researchers have now made a groundbreaking discovery that could have a lasting impact on the lives of those affected: They have succeeded in identifying the true cause of the fact that harmful bacteria and fungi can colonise again and again. Based on this, they have now come up with a completely new approach that could give millions of affected women new hope. In this article, we take a closer look at it, explain what you need to bear in mind and what this revolutionary idea could mean for you.

Recurrent itching or burning in the genital area, discharge and sometimes unpleasant odours are often due to one of the following three diseases, which are caused by different pathogens and are very common in the UK:

But why are millions of women repeatedly affected by these symptoms, while others never suffer from them? In order to understand this, it is first necessary to shed light on how the body can actually protect itself against the possible triggers of candidiasis, vaginosis and vaginitis. This is where the latest research results come into play, which have identified the same body's own defence mechanism against all three diseases.

The secret lies in the vaginal microbiome, i.e. the natural community of beneficial bacteria found in a healthy vagina. What many people don't realise: Even though the term microbiome is often associated with the bacterial landscape in the gut, there are also beneficial bacteria in many other places in our body that play a crucial role in our well-being. Examples include the skin, mucous membranes and the intimate area.

Like the gut microbiome, the healthy vaginal microbiome consists of different strains of bacteria that colonise the vaginal epithelial cells (i.e. the skin). These bacteria have been the subject of intensive research in recent years.

Using state-of-the-art methods such as 16S rRNA-based gene sequencing, researchers analysed the vaginal microbiomes of thousands of women. They discovered that each vaginal microbiome is as unique as a fingerprint. While some bacterial species are found in the vaginal microbiome of the vast majority of women, others are found in less than one percent of the samples examined!

When various research groups worldwide finally investigated the connection between the vaginal microbiome and complaints such as candidiasis, vaginosis or aerobic vaginitis, they came to groundbreaking results: While the vaginal microbiome of healthy women usually consists predominantly of lactobacilli (i.e. lactic acid bacteria), particularly of the genera Lactobacillus crispatus, Lactobacillus gasseri or Lactobacillus jensenii, the microbiome of women suffering from candidiasis, vaginosis or anaerobic vaginitis often has a completely different composition.

A research group led by David N. Fredericks from the University of Washington/Seattle (USA) found that over 83% of the microbiome of women who do not suffer from vaginosis is dominated by lactobacilli. In contrast, these were largely replaced by Gardnerella vaginalis in women affected by vaginosis and are therefore in the minority. The same applies to aerobic vaginitis, except that aerobic bacteria such as streptococci displace the lactobacilli.

However, the vaginal microbiome is also significantly altered in vaginal candidiasis: A research team led by Emily McKloud and Christopher Delaney from the University of Glasgow was able to prove that the proportion of the crucial lactobacilli in patients with vaginal candidiasis is almost 40% lower than in the comparison group!

Science was electrified: The vaginal microbiome apparently plays a crucial role in preventing a wide range of vaginal complaints, from vaginosis and aerobic vaginitis to candidiasis. However, in order to develop effective new approaches, it was first necessary to understand how exactly the beneficial lactobacilli counteract the invasion of harmful bacteria such as Gardnerella vaginalis, streptococci or fungi (e.g. Candida albicans).

Researchers on all continents have eagerly set to work to shed more light on this connection. In recent years, this has resulted in a large number of studies that prove that various specific lactobacilli strains suppress harmful bacteria and fungi through several mechanisms.

A team led by Marnie L. Peterson from the University of Minnesota (USA) has reached an important milestone in research into how the vaginal microbiome can prevent the development of bacterial-induced complaints such as vaginosis or vaginitis.

Their idea: The vaginal flora of healthy women is characterised by an acidic environment, as the lactobacilli that predominate there produce a lot of lactic acid as part of their glycogen metabolism (pH value of 3.8-4.5). However, many harmful bacteria cannot survive in such an environment. They surmised that this would also apply to the pathogen that causes vaginosis, Gardnerella vaginalis.

To put their hypothesis to the test, the researchers exposed Gardnerella vaginalis to two different environments: One acidic and one with a neutral pH of 5.5. The result of their experiments: The pathogen was unable to grow in an acidic environment, such as that produced by lactobacilli, but was able to grow in an environment with a neutral pH value. They were thus able to show that the acidic environment created by the lactobacilli in the healthy vagina is crucial for the prevention of vaginosis.

Incidentally, a team from Washington University in St. Louis (USA) was able to show the same for the harmful fungus Candida albicans, the most common pathogen of candidiasis: even though an acidic environment, such as that produced by lactobacilli, does not kill the fungus, it was able to significantly curb the growth of the harmful fungus Candida albicans.

In addition, as Italian researcher Irene Vacca was able to show, the fungus has to change in an acidic environment (chitin and β-glucan are more exposed). This in turn helps the immune system to recognise and fight the invader.

Another mechanism by which lactobacilli strains counteract bacterial infections such as vaginosis has been discovered, thanks in part to the work of Caroline Mitchell's research group in Boston (USA).

Mitchell and her team were able to show that the beneficial bacteria produce hydrogen peroxide, which also inhibits or even stops the growth of many pathogenic bacteria such as Gardnerella vaginiensis. Other researchers had previously discovered this with regard to bacteria that cause aerobic vaginitis.

The reason for hydrogen peroxide production lies in the type of beneficial bacteria: Because lactobacilli are so-called anaerobic bacteria, i.e. they do not need oxygen to live; on the contrary, it can even be harmful to them. The unique process of many lactobacilli strains: they "detoxify" oxygen via enzymes and use it to produce hydrogen peroxide (chemically H₂O₂).

As hydrogen peroxide inhibits the growth of harmful bacteria, the lactobacilli use this completely natural process to create a further mechanism that protects against vaginosis and vaginitis. Incidentally, the production of hydrogen peroxide is particularly pronounced in strains of the Lactobacillus crispatus family, as a separate study by Pirje Hütt and Eleni Lapp from the University of Tartu (Estonia) was able to show.

The bacteria that produce hydrogen peroxide are also useful for the treatment of candidiasis. After colonising the vagina, the harmful fungus Candida albicans produces a biofilm that protects it from threats. As Yijun Li and Jingyun Du from Fujian University in China have shown, hydrogen peroxide damages this protective shield of the invader so that both treatments and the body's own defences can better attack it and thus combat candidiasis.

A third aspect of why intact vaginal flora, which consists primarily of beneficial lactic acid bacteria, can protect against vaginosis and aerobic vaginitis as well as candidiasis has been demonstrated by international researchers, including German specialists from Leibnitz-HKI Jena and the University of Cologne:

Lactobacilli have a strong adhesive force, i.e. they adhere very strongly to the vaginal epithelial cells. They therefore form a dense bacterial turf that is almost impenetrable to harmful germs if they dominate the vaginal microbiome to a sufficient extent. The number of lactobacilli can reach up to 10 billion bacteria per millilitre of vaginal secretion. In this way, they take away the habitat of harmful bacteria such as Gardnerella vaginalis or B streptococci, but also fungi such as Candida albicans, so that they cannot colonise.

As vaginosis and aerobic vaginitis are often very unpleasant and painful, doctors are often forced to prescribe antibiotics. These are also very effective in the short term, because despite increasing resistance, they usually succeed in killing the trigger, i.e. the harmful bacteria.

The problem with this is that antibiotics not only kill harmful bacteria such as Gardinerella vaginalis or B streptococci, but also the good bacteria such as lactobacilli in the vaginal flora. The result: a clear-cutting of the bacterial landscape, which significantly weakens the resistance of the vaginal microbiome to newly invading bacteria or fungi and makes it easier for them to colonise and cause a new infection.

It is therefore no wonder that, as mentioned at the beginning, we are dealing with a high proportion of recurrent diseases. As the most important therapeutic approach, antibiotics, can actually increase the risk of recurrence in the case of a bacterial infection, many researchers have asked themselves how the knowledge gained in recent years on the importance of the microbiome in vaginosis or aerobic vaginitis, but also in candidiasis, can be utilised.

On this basis, a research team from the German company SYNformulas aimed to find a long-term solution for the aforementioned recurring infections. Three important hypotheses for a corresponding preparation have emerged: