Diabetes and gum disease

People with diabetes are susceptible to periodontitis, a gum infection that can resultin tooth loss. New research helps explain why…

A new study led by University of Pennsylvania researchers unequivocally demonstrates the population of oral microbes (microbiome) is affected by diabetes.  Diabetes causes a shift to increase the pathogenicity of the microbiome.

Researchers characterized the oral microbiome of diabetic mice compared to healthy mice. They found diabetic mice had a similar oral microbiome to their healthy counterparts when sampled prior to developing high blood sugar levels, or hyperglycemia. But, once the diabetic mice were hyperglycemic, their microbiome became distinct from their normal littermates, with a less diverse community of bacteria.

The diabetic mice also developed periodontitis, including a loss of bone supporting the teeth, and increased levels of a signaling molecule important for immune response and inflammation (IL-17). 

To drill into the connection, researchers then transferred microorganisms from the diabetic mice to normal germ-free mice, animals (these were raised without being exposed to any microbes). These recipient mice also developed bone loss - 42% less bone. Markers of inflammation also went up in the recipients of the diabetic oral microbiome.

With the microbiome now implicated in causing the periodontitis, researches wanted to know how. Suspecting that inflammatory cytokines, the researchers repeated the microbiome transfer experiments and this time also injected the diabetic donors with an anti-IL-17 antibody prior to the transfer.

Mice that received microbiomes from the treated diabetic mice had much less severe bone loss compared to mice that received a microbiome transfer from untreated mice confirming the role of IL-17 in bones loss.

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," he said. "And good oral hygiene can take the risk even further down." , said Dana Graves, senior author on the new study and vice dean of scholarship and research at University of Pennsylvania School of Dental Medicine.


For the full article see: ScienceDaily, 12 July 2017,

Journal Reference:

E Xiao, Marcelo Mattos, Gustavo Henrique Apolinário Vieira, Shanshan Chen, Jôice Dias Corrêa, Yingying Wu, Mayra Laino Albiero, Kyle Bittinger, Dana T. Graves. Diabetes Enhances IL-17 Expression and Alters the Oral Microbiome to Increase Its Pathogenicity.

Cell Host & Microbe, 2017; 22 (1): 120 DOI: 10.1016/j.chom.2017.06.014