Research on the Vaginal Microbiome

In recent years, researchers at Karolinska Institutet have conducted studies to better understand the dynamics of the vaginal microbiome and its impact on women’s health. A particularly notable study, published in August 2024, provides new insights into how just a few carefully selected samples can help predict imbalances in vaginal health.

What is the vaginal microbiome?


The vaginal microbiome consists of billions of microorganisms, primarily bacteria, that reside in the vagina. A healthy microbiome is dominated by Lactobacillus species, which produce lactic acid and hydrogen peroxide to maintain a low pH and protect against harmful microbes. Imbalances in the microbiome, known as dysbiosis, can lead to issues such as bacterial vaginosis, increased risk of sexually transmitted infections, failed fertility treatments, preterm birth, and certain gynecological cancers. Dysbiotic conditions allow harmful bacteria to thrive, whereas a eubiotic microbiome is healthy and stable, typically dominated by Lactobacillus species.

Karolinska Institutet study


In the study, researchers monitored 49 healthy women daily throughout an entire menstrual cycle using metagenomic sequencing—a technique that allows scientists to identify all microbes present in a sample (e.g., from the vagina) without the need for laboratory culturing. This provides a complete picture of the microbiome and how these microbes influence health.

The researchers identified four main patterns of vaginal microbiome dynamics (VCD):


🌿 Constant eubiotic – a stable and healthy microbiome


🌿 Constant dysbiotic – a persistent imbalance


🌿 Menstruation-related – changes linked to the menstrual cycle


🌿 Unstable dysbiotic – periods of imbalance

The study also found that higher levels of bacteriophages (viruses that infect bacteria) and certain bacterial genes were associated with instability in the microbiome. This led to the development of VALODY, a new tool that uses these insights to assess vaginal health. VALODY can analyze the composition and dynamics of the microbiome to identify long-term risks for imbalance and related health issues. With just a few carefully selected samples, the tool can provide a personalized view of vaginal health and potentially guide preventive measures and self-care.

Implications for self-care and women’s health


This research opens new avenues for monitoring and understanding the vaginal microbiome. In the future, women may receive more precise, personalized recommendations for self-care based on their unique microbiome profile, enabling them to prevent problems before they arise.

Karolinska Institutet’s work deepens our understanding of the complexity of the vaginal microbiome and its influence on overall health. By combining advanced technology, carefully selected samples, and tools like VALODY, we can develop more effective and individualized strategies to promote vaginal health and prevent related disorders.