SCIENTIFIC AMERICAN – A recent study finds varying combinations of microbes in the vaginal microbiome may influence health outcomes such as risk of sexually transmitted disease and preterm birth.
While increased diversity is key to microbiomes such as those in the gut or mouth, the vagina has been thought to thrive when it has fewer bacterial species overall and more of one particular species crucial to vaginal health, Lactobacillus crispatus.
But a new analysis published last week in Microbiome shows a more complex picture.
“Of the 28 bacterial species common to the vagina, scientists identified 135 unique combinations of strains of those species, each of which has different functions and cohabits with other strains.”
“So the diversity exists; we just never had a chance to appreciate it,” says study co-author Jacques Ravel, a professor of microbiology and immunology at the University of Maryland School of Medicine and acting director of the Institute of Genome Sciences at the university.
The findings show what the different strain combinations may do in the body—and how they could play a role in a person’s susceptibility to sexually transmitted diseases and risk of preterm birth and their overall health.
The microorganisms that colonize the vagina protect against infection.
An imbalance of these microbes are associated with certain infections and medical conditions, such as bacterial vaginosis (BV), a painful condition that affects about 30 percent of women between the ages of 14 and 49 in the U.S. Bacterial vaginosis is very ill-defined, Ravel says.
While one individual’s infection might present similar symptoms to another’s, including itching and an odorous discharge, “Microbiologically it could be very different,” Ravel says.
Past research has identified two specific imbalances of the vaginal microbiota that commonly lead to bacterial vaginosis.
In the new study, Ravel’s team sequenced almost 2,000 vaginal metagenomes—the genetic material of all the microorganisms in an environment. This revealed nine communities of bacteria that were specifically linked to bacterial vaginosis …