In a healthy mouth, the diverse communities of microbes collectively known as the oral microbiome live in harmony with one another. They exist in a state of balance, or homeostasis. When that balance is disturbed—through smoking cigarettes, or eating lots of sugary foods, for example—some microbes capitalize on the chaos and use it to gain an upper hand. They multiply rapidly and grow out of control.
Luckily, our bodies have ways of keeping these opportunistic pathogenic bacteria in check. Dr. Xuesong He, Associate Member of Staff at The Forsyth Institute, has developed a hypothesis to explain one of these potential defense mechanisms. His prior research suggests that human epithelial cells produce specific molecules to prevent overgrowth of an opportunistic pathogen in the oral cavity known as Fusobacteria. He and his co-investigators recently received a 5-year Research Project Grant (R01) from the NIH’s National Institute of Dental and Craniofacial Research to investigate this host-microbial interaction.
Fusobacteria are commonly found in healthy mouths, living in harmony within the oral microbial community. But in patients with gum disease, Fusobacteria have been found to grow out of control. They become pathogenetic, or harmful to their human host, and throw off the balance of the oral microbiome. To combat this overgrowth of Fusobacteria, He believes the host’s epithelial cells produce specific molecules called tsRNAs to modulate the growth of Fusobacteria.
“Epithelial cells are the first layer of the mucosal surfaces in both the oral cavity and the gut, providing a first line of defense against infectious agents,” says He. “These cells have direct and constant contact with the outside environment, including the bacteria, so it makes sense for them to respond and make sure those bacteria behave. This could potentially be another weapon used by the host to keep those bacteria in check.”
This research could ultimately provide scientists with another tool for treating oral diseases, including periodontal disease, which afflicts up to half of the global population and currently has no cure. The work will also reveal new insights about how microbes interact with their host and influence the human oral microbiome. Co-Investigators for the grant include Drs. Hatice Hasturk, Batbileg Bor, George Chen, and Chung-Jung Chiu from The Forsyth Institute, and Dr. Jiahe Li from Northeastern University.
Dr. He’s lab now has an open postdoctoral position. Learn more and apply.
