Diabetes shifts the oral microbiome
Les chercheurs ont constaté que le diabète déplace le microbiome oral, transformer en un environnement plus inflammatoire et favorisant la perte osseuse, caractéristiques de la maladie de gomme la parodontite.

Une nouvelle étude menée par des chercheurs de l’Université de Pennsylvanie a trouvé que le microbiome oral est affecté par le diabète, provoquant un décalage augmenter son pouvoir pathogène.

La recherche, publié dans la revue Cell Host & Microbe cette semaine, non seulement a montré que le microbiome oral des souris diabétiques décalée mais que le changement a été associé à une inflammation et la perte osseuse.

“Jusqu'à présent, il n’y avait eu aucune preuve concrète que le diabète affecte le microbiome oral,” ladite Dana Graves, auteur principal sur le nouveau étude et vice doyen de bourses d’études et de recherche à l’Ecole de médecine dentaire de Penn. “Mais les études qui avaient été effectués n’étaient pas rigoureuses.”

Il y a quatre ans, the European Federation of Periodontology and the American Academy of Periodontology issued a report stating there is no compelling evidence that diabetes is directly linked to changes in the oral microbiome. But Graves and colleagues were skeptical and decided to pursue the question, using a mouse model that mimics Type 2 diabète.

My argument was that the appropriate studies just hadn’t been done, so I decided, We’ll do the appropriate study,” Graves said.

Graves co-authored the study with Kyle Bittinger of the Children’s Hospital of Philadelphia, who assisted with microbiome analysis, along with E Xiao from Peking University, who was the first author, and co-authors from the University of São Paulo, Sichuan University, the Federal University of Minas Gerais and the University of Capinas.

The authors consulted with Daniel Beiting of Penn Vet’s Center for Host-Microbial Interactions and did the bone-loss measurements at the Penn Center for Musculoskeletal Diseases.

The researchers began by characterizing the oral microbiome of diabetic mice compared to healthy mice. They found that the diabetic mice had a similar oral microbiome to their healthy counterparts when they were sampled prior to developing high blood sugar levels, or hyperglycemia. Mais, 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 had periodontitis, including a loss of bone supporting the teeth, and increased levels of IL-17, a signaling molecule important in immune response and inflammation. Increased levels of IL-17 in humans are associated with periodontal disease.

The diabetic mice behaved similar to humans that had periodontal bone loss and increased IL-17 caused by a genetic disease,” Graves said.

The findings underscored an association between changes in the oral microbiome and periodontitis but didn’t prove that the microbial changes were responsible for disease. To drill in on the connection, the 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. A micro-CT scan revealed they had 42 percent less bone than mice that had received a microbial transfer from normal mice. Markers of inflammation also went up in the recipients of the diabetic oral microbiome.

We were able to induce the rapid bone loss characteristic of the diabetic group into a normal group of animals simply by transferring the oral microbiome,” said Graves.

With the microbiome now implicated in causing the periodontitis, Graves and colleagues wanted to know how. Suspecting that inflammatory cytokines, and specifically IL-17, played a role, the researchers repeated the microbiome transfer experiments, this time injecting 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.

Les conclusions “demonstrate unequivocallythat diabetes-induced changes in the oral microbiome drive inflammatory changes that enhance bone loss in periodontitis, the authors wrote.

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. But Graves noted that 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,” Il a dit. “And good oral hygiene can take the risk even further down.

In addition to Graves and Bittinger, co-authors included E Xiao, Marcelo Mattas, Shanshan Chen and Yingying Wu of Penn Dental Medicine; Gustavo Henrique Apolinário Vieira of the University of São Paulo; Joice Dias Correa of the Federal University of Minas Gerais; and Mayra Laino Albieiro of the University of Campinas.

The study was supported by grants from the National Institute of Dental and Craniofacial Research (DE017732 and DE021921) with assistance from Penn Vet’s Center for Host-Microbioal Interactions and the Penn Center for Musculoskeletal Disorders.

Source: Université de la Pennsylvanie
Journal: Cell Host & Microbe
Bailleur de fonds: NIH/National Institute of Dental and Craniofacial Research

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