Bacteria are key to vaginal health, say UArizonaona health scientists

Bacterial vaginosis is the most common and recurring gynecological disease that affects nearly 30% of women between the ages of 15 and 44, according to the U.S. Centers for Disease Control and Prevention. A study conducted by the University of Arizona Health Sciences recently identified a specific family of bacteria and revealed how they contribute to bacterial vaginosis, paving the way for new insights into disease prevention and treatment.

Led by Melissa Herbst-Kralovetz, PhD, a member of the BIO5 Institute and Associate Professor of Basic Medical Science at the College of Medicine – Phoenix, researchers found that members of the Veillonellaceae bacterial family contribute to increases in inflammation and cell death, and the Alter the acidity of the cervical microenvironment. These changes support bacterial vaginosis and create favorable conditions for subsequent gynecological diseases such as sexually transmitted diseases and cancer.

“Bacterial vaginosis is a mystery,” said Dr. Herbst-Kralovetz, who is also the director of the Women’s Health Research Program. “We know that many factors contribute to this disease, but little is known about the functional effects of the key players and how they change the local landscape.”

The July 6 article “Veillonellaceae Family Members Uniquely Alter the Cervical Metabolic Microenvironment in a Human Three-Dimensional Epithelial Model” published July 6 in the journal npj Biofilms and Microbiomes found that members of the Veillonellaceae family contribute to disease by reducing inflammation and metabolism in the cervix change region.

The female reproductive tract is typically colonized by beneficial bacteria such as Lactobacillus. Although these bacteria are considered friendly, an imbalance can lead to the formation of a biofilm – a consortium of many different harmful microbes – that promotes disease.

Last year, Dr. Herbst-Kralovetz and colleagues developed a hypothetical model in which the interactions between microbes and human cells alter the vaginal microenvironment and ultimately affect the balance between health and disease. This study is the first to define a definitive role for this family of bacteria in bacterial vaginosis.

Using a 3D human model, Dr. Herbst-Kralovetz investigated the effects of three bacteria – Veillonella atypica, Veillonella montpellierensis, and Megasphaera micronuciformis – on the cervical microenvironment.

They found that two species – V. atypica and V. montpellierensis – decreased lactate, an acid typically produced by beneficial bacteria that protects against harmful infections. These two species also increased substances that play a role in bacterial vaginosis-associated vaginal odor.

They also found that M. micronuciformis fueled disease progression by increasing inflammation and promoting cell death through the production of certain fat molecules.

The findings from this study lay the foundation for polymicrobial or “multi-bug” studies that can determine the complex interaction effects of several bacterial species on female reproductive health.

“Using this study and our 3D model as a basis, we hope to determine if and how other species are changing the environment to contribute to bacterial vaginosis,” said Dr. Autumn Kralovetz. “We have found that different species make different contributions, so we also hope to categorize a wide variety of bacterial vaginosis-associated microbes based on their unique effects on the female reproductive tract.”

Ultimately, Dr. Herbst-Kralovetz that these and other studies can help inform treatment and intervention strategies.

“It is important to know who the main players are, but also how they affect physiological processes and diseases so that we can develop targeted strategies to treat bacterial vaginosis and prevent secondary infections and cancer,” she said.


The co-authors of Dr. Herbst-Kralovatz from the College of Medicine – Phoenix are Jason Maarsingh, PhD, a postdoc in the Department of Obstetrics and Gynecology, and Pawel Laniewski, PhD, a research fellow in the Department of Basic Medical Sciences. Other co-authors include undergraduate students Camryn Garza and Mary Salliss, who participated in Bath University’s internship / exchange program.

Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of press releases sent to EurekAlert! by contributing institutions or for the use of information via the EurekAlert system.

Related Articles