We’ve been told since childhood to brush our teeth after every meal to maintain a healthy mouth. Now, research out of Japan indicates poor oral hygiene can affect the entire body.
Researchers at Tokyo Medical and Dental University have identified a way by which periodontal disease might cause metabolic syndrome.
Periodontal disease is an infection of the tissues, or gums, that hold your teeth in place.
Metabolic syndrome, according to the Mayo Clinic, is a cluster of conditions that increase the risk of heart disease, stroke, and diabetes. Metabolic syndrome includes high blood pressure, high blood sugar, excess body fat around the waist and abnormal cholesterol levels.
By studying patients with metabolic syndrome, the researchers demonstrated high antibody concentrations against Porphyromonas gingivalis, the bacterium that causes periodontal disease.
Infection with Porphyromonas gingivalis causes skeletal muscle metabolic dysfunction, the precursor to metabolic syndrome, by altering the composition of the gut microbiome.
“Metabolic syndrome has become a widespread health problem in the developed world,” the study’s first author, Kazuki Watanabe, said. “The goal of our study was to investigate how periodontal bacterial infection might lead to metabolic alterations in skeletal muscle and thus to the development of metabolic syndrome.”
For their study, the researchers investigated antibody concentrations to Porphyromonas gingivalis in the blood of patients with metabolic syndrome and found a positive correlation between the antibodies and increased insulin resistance.
“These results showed that patients with metabolic syndrome were likely to have undergone infection with Porphyromonas gingivalis and thus have mounted an immune response yielding antibodies against the germ,” the university wrote in a press release.
When the researchers fed mice a high-fat diet (a prerequisite to developing metabolic syndrome) with Porphyromonas gingivalis, the mice developed increased insulin resistance, and fat infiltration and lower glucose uptake in the skeletal muscle compared with mice that did not receive the bacteria.
The researchers found that in mice fed with Porphyromonas gingivalis, the gut microbiome was significantly altered, which might decrease insulin sensitivity.
“These are striking results that provide a mechanism underlying the relationship between infection with the periodontal bacterium Porphyromonas gingivalis and the development of metabolic syndrome and metabolic dysfunction in skeletal muscle,” said corresponding author Sayaka Katagiri, who is a professor at the university.
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