Scientists and clinicians know that oral health and inflammation, which is a part of many diseases, are connected. Not a lot is known about exactly what underlies this relationship, however. Researchers have now shown that gum disease triggers overactive immune cells. The findings have been reported in the Journal of Dental Research.
"There are statistically significant correlations between periodontitis (oral inflammatory disease) and systemic diseases ranging from diabetes to cardiovascular diseases," noted study co-author Howard Tenenbaum, professor at the University of Toronto's Faculty of Dentistry, and chief dentist at Sinai Health Systems in Toronto.
In this study, the researchers examined neutrophils, a type of immune cell that is activated by gum disease. When a person has gum disease, their body generates an abundance of these cells to fight the bacteria causing the gum problems.
The researchers determined that when periodontal inflammation starts, abnormally high levels of neutrophils that are ready to attack begin to circulate. The immune system is on high alert, and any it reacts to any other infection with excessive force.
"It's almost as if these white blood cells are in second gear when should be in first," explained study senior author Michael Glogauer, a Professor at the University of Toronto's Faculty of Dentistry.
The body is then vulnerable to inflammatory conditions. The primed-for-attack neutrophils can start to destroy tissues and organs after a secondary event.
a secondary event causes those immune cells to destroy affected tissues and organs.
"The [neutrophils] are much more likely to release cytokines much more quickly, leading to negative outcomes," added Glogauer.
While the researchers began the study with in vivo work, they conducted a clinical trial to confirm the findings, showing how important oral health is to overall wellness.
"We believe this is the mechanism by which oral hygiene can impact vulnerability to unrelated secondary health challenges," said the lead study author Noah Fine, a postdoctoral fellow at the University of Toronto's Faculty of Dentistry. "Neutrophil priming throughout the body can connect these seemingly distinct conditions."
There may also be a COVID-19 connection.
"There is evidence out there that patients with periodontal disease may be much more likely to have negative outcomes with COVID-19," said Glogauer. "Neutrophils are the cells that are at prime risk of causing cytokine storms. That's the exact cell we show is primed with people with periodontal disease."