International Collaboration Maps Vaginal Microbiome Diversity

The vaginal microbiome is a complex ecosystem of bacteria and yeasts that fluctuates over time. Despite its crucial role in health, research on these microbial communities remains limited, with most studies focusing on participants from a single continent. This geographical imbalance leaves significant gaps in our understanding.

A recent study published in Trends in Microbiology highlights findings from a global network of citizen scientists, demonstrating how international collaboration can bridge these gaps. By examining vaginal microbiomes across diverse populations, researchers are identifying beneficial and harmful bacteria while deepening their understanding of microbial variations worldwide.

“Women’s health is fundamental to societal and economic well-being, yet disparities persist. For centuries, women’s bodies and health knowledge have been overlooked, controlled, and even persecuted, resulting in ongoing inequities,” stated the study’s authors, a group of scientists from four continents and nine countries, including lead author Sarah Lebeer of the University of Antwerp, Belgium.

The researchers are part of citizen science initiatives like the Isala Sisterhood, which seeks to advance global research on women’s health and microbiomes by mapping vaginal microbiota. Initially launched in Belgium as the Isala Project with over 6,000 participants, the initiative has grown into a worldwide effort involving microbiologists, healthcare professionals, governmental organizations, and the public across multiple continents.

Lebeer and her team combined data from the Isala Sisterhood with nearly a century of research, uncovering key insights:

• There are five commonly recognized categories of "healthy" vaginal microbiota, classified based on the dominant bacterial species: Lactobacillus crispatus, Lactobacillus gasseri, Lactobacillus iners, Lactobacillus jensenii, and a fifth category consisting of a mix of other species.

• However, the Isala Project found that over 10% of Belgian participants did not fit within these classifications, leading researchers to advocate for a more nuanced approach that considers the full complexity of vaginal microbiota composition and functionality.

• The composition of vaginal microbiota has been linked to various clinical conditions. A reduction in lactobacilli, for instance, can result in an overgrowth of anaerobic bacteria, which is associated with preterm birth, urinary tract infections, endometritis, and sexually transmitted infections.

• Bacterial vaginosis, a common condition caused by decreased lactobacilli, is typically treated with antibiotics. However, these treatments have limited success, with symptoms recurring in up to 60% of cases.

• Vaginal live biotherapeutic products, which are FDA-approved treatments using live microorganisms, may offer more effective solutions for managing bacterial vaginosis and other vaginal health conditions.

• Cultural hygiene practices, such as vaginal douching, have been linked to an increased risk of vaginal dysbiosis. These findings underscore how health disparities can arise from both biological and social factors.

Beyond bacteria, the vaginal microbiome also contains yeasts, viruses, and other microbes, though their roles remain largely unexplored. Notably, lower- and middle-income countries are underrepresented in microbiome research, with disparities in infrastructure, technology, and funding contributing to this imbalance. The authors recommend fostering international collaborations to share resources and bridge these gaps.

Initiatives such as the Isala Project and the Vaginal Human Microbiome Project, which focuses on mapping the microbiomes of individuals from diverse ethnic backgrounds in the United States, are working to close the vaginal microbiome data gap. These efforts are gaining momentum worldwide.

The authors emphasize the urgent need for research that prioritizes geographical and socioeconomic diversity while accounting for social and cultural influences. “To develop better preventive, diagnostic, and therapeutic strategies for conditions linked to the vaginal microbiota, more research is needed across different regions. This will allow us to better define what a healthy vaginal microbiome looks like in various geographical contexts,” they stated.