Does periodontopathic bacterial infection affect increased intestinal permeability?

• Project/Area Number: 16K20667
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Periodontology
• Research Institution: Niigata University
• Principal Investigator: Haruna Miyazawa 新潟大学, 医歯学総合病院, 特任助教 (50733721)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Project Status: Completed (Fiscal Year 2018)
• Budget Amount: ¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000); Fiscal Year 2018: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000); Fiscal Year 2017: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000); Fiscal Year 2016: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000)
• Keywords: 歯周病原細菌 / 腸管透過性 / dysbiosis / 歯学

Outline of Final Research Achievements

We proposed a mechanism linking periodontitis and systemic diseases, in which orally administered Porphyromonas gingivalis affects gut microbiota composition and leads to systemic inflammation. However, the mechanism by which P. gingivalis generates systemic effects from the gut is unknown. The aim of this study is to investigate P. gingivalis infection affect the intestinal permeability.
Intestinal epithelial cell line were treated with P. gingivalis LPS, live bacteria or supernatant culture liquid. Gene expressions of adhesion molecules and the permeability tended to change concentration-dependent manner. However, there are no significant differences in lower concentration. P. gingivalis administration to germ-free mice didn’t induce alveolar bone resorption, inflammatory response in intestinal tissue. Endotoxin and IL-6 levels in the serum were not different from those of sham-administered mice. There may be indirect mechanisms for gut-mediated systemic effects by P. gingivalis.

Academic Significance and Societal Importance of the Research Achievements

腸上皮細胞に対するP. gingivalis の特異的作用が検討できただけではなく、唾液とともに嚥下している他の歯周病原細菌や、それらにより変動した腸内細菌における腸管・生体への作用を比較検討する際にも応用できる。本研究は歯周炎と全身疾患との因果関係を検証していくうえで、常在細菌叢のバランス破綻が生体機能に及ぼす影響を解明する足がかりとなると考える。