In recent years, there has been a lot of research on the bacteria found in our gut, from how certain species appear to be associated with depression to how the gut microbiome (the genetic material of all the microbes – including bacteria – found in the gut) could shape our personalities. There are also other microbiomes in our bodies whose regulation is important for our health.
The vaginal microbiome likely plays a key role in conditions such as bacterial vaginosis, sexually transmitted infections, and problems in pregnancy, such as preterm birth. To better our understanding, and therefore treatments of these health concerns, a team from the University of Maryland School of Medicine (UMSOM), has created the first catalog of genes from the microbes that inhabit the human vagina. The publically released information, called human vaginal non-redundant gene catalog (VIRGO), will act as a convenient reference database for researchers looking into women’s health issues.
“The value of VIRGO is that it functions as both a central repository and a highly scalable tool for fast, accurate characterization of vaginal microbiomes,” lead author Dr Bing Ma, research associate in the Department of Microbiology and Immunology at the Institute for Genome Sciences (IGS) at UMSOM, said in a statement. “VIRGO is particularly useful for users with limited computational skills, who want to analyze a large volume of sequencing data and with access to limited computing infrastructure.”
From hundreds of vaginal “metagenomes” (samples containing the genetic material belonging to humans, bacterium, viruses), the team isolated almost 1 million genes belonging to around 300 species of bacterium. The researchers estimate that their database contains around 95 percent of all genes found in vaginal microbiomes, and is particularly applicable to populations from North America, Africa, and Asia.
As described in a study published in Nature Communications, Dr Ma and her colleagues applied their comprehensive catalog to a further 1,507 vaginal metagenomes to characterize the gene content of commonly found species of bacteria in the vagina. Surprisingly, they found that bacteria was more genetically diverse than originally thought, with each woman carrying her own personalized version of the microorganisms.
One group of importance is Lactobacillus. Species of the bacterium, such as Lactobacillus crispatus, L. gasseri and L. jensenii, produce large amounts of lactic acid that protects the vagina against harmful infections. An optimal microbiome has been known by scientists to involve a combination of these different Lactobacillus species. But what this study has shown is that an optimal microbiome not only contains different species, but also several strains of the same species. The strength comes from the unique functions of the different strains working together in a little community.
“This finding is a paradigm changing discovery, as it moves the field away from the idea that a single strain of Lactobacillus is responsible for an optimal microbiome,” Jacques Ravel, professor of Microbiology and Immunology at the Institute for Genome Sciences (IGS) at UMSOM, said.
Alongside the help for other women’s health issues, the question of rebalancing microbiomes that have gone awry could also be addressed by the team’s VIRGO tool.
“Important efforts are underway by UMSOM faculty to translate our growing understanding of human-associated microbial communities into clinical biomarkers and treatments,” UMSOM Dean E. Albert Reece explained. “This groundbreaking research provides powerful, publicly available tools to researchers who are addressing key health issues for women.”