Study offers new insights into periodontal disease and body’s protective response
SEATTLE, U.S.: Biofilm buildup can lead to many oral health issues, including gingivitis, periodontitis and tooth loss, as well as other serious health consequences, such as heart disease, diabetes, cancer, arthritis and bowel disease. To better understand individual variation in gingival inflammation, researchers have recently identified and classified human host and microbial responses to the accumulation of dental plaque. The study may help explain why some people are more susceptible to inflammation-associated health problems.
The study included 21 participants, and the researchers performed clinical evaluation and sampling of the oral bacteria at early and late time points. After analyzing the data, they found that the participants showed a range of inflammatory responses to bacterial accumulation in the mouth, including a previously unidentified variation in host response. Previously, there were two known major oral inflammation phenotypes, namely a high clinical response and a low clinical response. In the study, the researchers identified a third phenotype, which they called “slow,” since it displayed a delayed strong inflammatory response after bacterial buildup.
Additionally, the study revealed that participants with low clinical response demonstrated a low inflammatory response to various inflammation signals: “Indeed, this study has revealed a heterogeneity in the inflammatory response to bacterial accumulation that has not been described previously,” co-author Dr. Richard Darveau, professor of periodontics and of oral health sciences at the University of Washington School of Dentistry in Seattle, said in a press release.
“We found a particular group of people that have a slower development of plaque as well as a distinct microbial community makeup prior to the start of the study,” explained co-author Dr. Jeffrey Scott McLean, associate professor of periodontics at the university.
According to the researchers, understanding variation in gingival inflammation could help better identify those who are at elevated risk of developing periodontitis. In addition, the researchers believe that variation in the inflammatory response may be associated with susceptibility to other chronic bacteria-associated inflammatory conditions, such as inflammatory bowel disease.
Finally, the researchers also identified a novel protective response by the body that was triggered by biofilm accumulation and that can help save soft tissue and bone during inflammation. According to the study, the mechanism uses neutrophils to regulate the bacterial population in the mouth in order to maintain healthy homeostasis.
Discussing the importance of good oral hygiene, Darveau commented: “The idea of oral hygiene is to in fact recolonize the tooth surface with appropriate bacteria that participate with the host inflammatory response to keep unwanted bacteria out.”
The study, titled “Human variation in gingival inflammation,” was published online on July 6, 2021, in the Proceedings of the National Academy of Sciences of the United States of America.