Diabetes causes a shift in the oral microbiome which may lead to an increased risk of developing periodontitis, also known as gum disease, which causes inflammation around the teeth as well as bone loss, researchers say.
The study, conducted in mice, revealed that when diabetic mice developed high blood sugar levels or were hyperglycemic, their microbiome became distinct from their normal littermates, with a less diverse community of bacteria.
These diabetic mice also had periodontitis, including a loss of bone supporting the teeth, and increased levels of IL-17 -- a signalling molecule associated with periodontal disease in humans.
"The diabetic mice behaved similar to humans that had periodontal bone loss and increased IL-17 caused by a genetic disease," said Dana Graves from the University of Pennsylvania in the US.
For the study, published in the journal Cell Host and Microbe, the team of researchers transferred microorganisms from the diabetic mice to normal germ-free mice, animals that have been raised without being exposed to any microbes.
These recipient mice also developed bone loss.
However, a micro-CT scan revealed they had 42 per cent less bone than mice that had received a microbial transfer from normal mice.
Further, mice that received microbiomes from diabetic mice treated with an anti-IL-17 antibody had much less severe bone loss.
The findings "demonstrate unequivocally" that diabetes-induced changes in the oral microbiome drive inflammatory changes that enhance bone loss in periodontitis, the researchers said.
Though IL-17 treatment was effective at reducing bone loss in the mice, it is unlikely to be a reasonable therapeutic strategy in humans due to its key role in immune protection.
The study highlights the importance for people with diabetes of controlling blood sugar and practicing good oral hygiene.
"Diabetes is one of the systemic disease that is most closely linked to periodontal disease, but the risk is substantially ameliorated by good glycemic control. And good oral hygiene can take the risk even further down," Graves noted.