The bacteria in the vagina play an important role in maintaining health, yet studies on the vaginal microbiota have mainly focused on women of European ancestry.

Writing in Trends in Microbiology, Sandra Condori-Catachura at the University of Antwerp in Belgium and her colleagues emphasize the need for a better understanding of what a ‘healthy’ vaginal microbiota looks like across different populations. 

“Conditions related to the female reproductive tract are among the most pressing health issues that women face and include non-communicable gynecological and reproductive conditions and infections,” the authors say. “Many of these conditions have been associated with the vaginal microbial community or microbiota inhabiting the reproductive tract.”

The authors also highlight the importance of conducting studies in diverse geographic regions while considering social and environmental factors, rather than relying on ethnicity.

Health conditions

Previous research has linked the composition of the vaginal microbiota to various conditions, including pregnancy complications, sexually transmitted infections and bacterial vaginosis. A decrease in lactobacilli, particularly Lactobacillus crispatus, is associated with increased health risks, while an overgrowth of anaerobic bacteria is linked to bacterial vaginosis. However, there is no global gold standard for diagnosing bacterial vaginosis, and standard treatments such as metronidazole and clindamycin often don’t work long-term.

Some studies suggest that Black and Latin American women have a higher prevalence of bacterial vaginosis and lower lactobacilli levels than Asian or European women. However, most of these studies do not account for factors such as diet and socioeconomic status, which could influence microbiota composition. 

Research from Nigeria and South Africa highlights the need to consider regional differences rather than ethnicity only. However, increasing diversity in microbiota research remains a challenge, as most studies are conducted in high-income countries.

Lack of diversity

To address the lack of diversity in microbiota research, several initiatives collect microbiota data from multiple nations, but data from many regions — including parts of Asia, Africa and South America — remain underrepresented. 

Citizen science has emerged as a promising approach to increase participation and representation in vaginal microbiota research. For example, the Isala project in Belgium engaged more than 3,000 people to map the vaginal microbiota and now supports global collaborations.

However, many studies still attribute microbiota differences to ethnicity without considering social and economic factors, the authors say. For instance, factors such as vaginal douching, which is a common practice among certain groups in the United States, can influence microbiota health. 

Moving forward, more research is needed to define what constitutes a healthy vaginal microbiota across different populations, the authors say. By addressing biases and increasing diversity in microbiota studies, they add, researchers can develop more accurate and inclusive health strategies for women of different backgrounds.