Researchers from North Carolina State University have discovered that different types of Gardnerella bacteria, which are often linked to bacterial vaginosis (BV) and pre-term birth, can exist together in the same vaginal microbiome. This new information contributes to the growing understanding of the impact of Gardnerella on human health.The article discusses the presence of bacteria in the vaginal microbiome, particularly Gardnerella, and its association with bacterial vaginosis (BV) and pre-term birth risk. The study aims to understand the diversity within Gardnerella and its potential health effects. Ben Callahan, an associate professor at NC State, highlights the need to explore the ecology of Gardnerella and the impact of different species on women’s health.One of the main challenges of sequencing the vaginal microbiome is that the majority of samples will be made up of the host’s DNA, which makes it more costly and time-consuming to extract microbial data. The first task for the research team was to develop a method that would allow them to differentiate between different species of Gardnerella from the microbiome data.
“The existing tools for studying the vaginal microbiome would categorize all Gardnerella as the same species,” explains Hanna Berman, postdoctoral research scholar at NC State and the lead author of the study. “In order to even be able to conduct this research, we had to create our own database of Gardnerella genomes and come up with our own methods for analysis.”A method for distinguishing between different species of Gardnerella was developed, with the hope that this would enable more researchers to investigate the diversity of Gardnerella. The research team examined sequencing data from three groups: two random groups of pregnant women, and one group with a history of pre-term birth. They studied the genetic sequences of Gardnerella from the samples to determine if there was a link between a specific Gardnerella species and pre-term birth. Although they did not find definitive evidence, they did make two unexpected discoveries. First, they uncovered a possible 14th species of Gardnerella.that the presence of multiple species of Gardnerella was associated with a higher abundance of the bacteria, suggesting that coexistence may provide benefits to the microbes.”
The team also found that certain species of Gardnerella were more likely to be present in samples taken from women with bacterial vaginosis, a common vaginal infection. This suggests that different species of Gardnerella may play unique roles in the development and progression of this condition. This discovery could have important implications for the diagnosis and treatment of bacterial vaginosis in the future.
Overall, this study provides valuable insights into the diversity and coexistence of Gardnerella species in the vaginal microbiome, shedding light on the complex interactions between different bacterial species and their potential implications for human health.
It has been observed that when there is a higher overall microbial load, Gardnerella makes up a larger proportion of the microbial load.
Research suggests that Gardnerella is linked to pre-term birth, but the details of this relationship are complex. This study did not identify one harmful species of Gardnerella – they may all be harmful. This is just the beginning of the story.
The researchers are looking to further investigate questions about species coexistence and microbiome composition in future studies.
“The vaginal microbiome has not been extensively studied,” Callahan explains. “For instance, it is often dominated by a single species of Lactobacillus, which creates an environment that excludes other bacteria. When it’s not present Gardnerella is. So how do the bacteria interact?
“Answering these questions may lead to more effective treatments for BV, and for ways to predict and avoid pre-term birth. This work is an important step in that process.”
The research appears in mSystems and is supported by funding from the Eunice Kennedy Shriver National Institute of Child Health and Human Development under Award Numbers 5F31HD104353 and 730 K99HD090290, the National Institutes of Health NIGMS under award R35GM133745, and the March of Dimes. NC State student Megan Anderson, Daniela Aliaga Goltsman from Metagenomi, Inc., and David Relman from Stanford University also participated in the research.
