When we think of bacteria, we often associate them with illness or infection. However, the human body is home to millions of microorganisms that play essential roles in our health and wellbeing. One of the most important examples is the vaginal microbiota: a community of bacteria that acts as a natural protective barrier, helping to maintain vaginal health.
What is the vaginal microbiota and what role does it play?
Under healthy conditions, the vaginal microbiota is predominantly composed of bacteria of the genus Lactobacillus. These bacteria play a crucial role in maintaining an acidic vaginal pH, generally below 4.5. This acidic environment inhibits the growth of potentially harmful microorganisms and helps preserve the natural balance of the vaginal ecosystem. A healthy vaginal microbiota also contributes to the regulation of the immune system’s response and helps maintain a low-inflammation environment.
When this balance is disrupted and the levels of Lactobacillus decrease, the pH tends to rise above 4.5. This creates conditions that favour the proliferation of other microorganisms and can alter the interaction between the vaginal microbiota and the immune system. These changes may contribute to vaginal health disorders such as bacterial vaginosis and vulvovaginal candidiasis, and have been associated with a range of reproductive health problems.
How does the vaginal microbiota change throughout the menstrual cycle?
The vaginal microbiota is not a static system. It is a dynamic ecosystem that naturally changes over time, and the menstrual cycle is one of the factors that can influence its composition. The microbiota undergoes changes throughout the different phases of the cycle, including the follicular and luteal phases and menstruation.
This natural variability presents an important challenge for researchers. While some general markers of vaginal health are already known, experts believe that further research is needed to establish reliable reference ranges and accurately distinguish between a healthy and an altered microbiota. What is considered normal for one woman may not be exactly the same for another. Understanding this natural variation is therefore crucial to advancing more personalised approaches to medicine.
Why is it important to study the vaginal microbiota?
Research in recent years has also suggested that the vaginal microbiota may play an important role in various aspects of women’s health, from preventing infections to supporting reproductive health. Gaining a better understanding of the characteristics of this microbial ecosystem help pave the way for more accurate diagnostic methods and preventive strategies tailored to each woman. Commercial testing kits are already available for this purpose, however their results can be difficult to interpret as reference values are still lacking.
It is in this context that the DIVA project was established. This research initiative, led by the Microbiome Unit within the Microbiology Department, aims to deepen our understanding of the vaginal microbiota and identify patterns that can be considered normal. To achieve this, the study is recruiting women with regular menstrual cycles who do not have any factors that could significantly alter their microbiota, such as recent hormone treatments, antibiotic use or certain gynaecological and metabolic conditions. By collecting samples at different stages of the menstrual cycle, the researchers hope to gain a better understanding of the natural fluctuations in this ecosystem and to establish reference values for healthy vaginal microbiota in our population.
The vaginal microbiota: an ally for women’s health
The vaginal microbiota is much more than just a collection of bacteria: it is a living ecosystem that plays a vital role in maintaining vaginal and reproductive health.
Despite the progress made in recent years, there is still much to learn about how the vaginal microbiota changes throughout life and which factors influence its composition and function. Research projects such as DIVA are therefore essential to developing a better understanding of this ecosystem and establishing patterns of normal variation. This could help pave the way for more accurate diagnostic tools, new prevention strategies and increasingly personalised treatments. A better understanding of the vaginal microbiota not only helps to improve the management of various gynaecological conditions, but also contribute to a more preventive, precise and personalised approach to women’s health.
INFORMATION DOCUMENTED BY:
Dr Andrea Aira, Dr Elisa Rubio and Dr Mª Mercedes Montero, Biomedical Diagnostic Centre, Hospital Clínic Barcelona.
