Influence of oral periodontal disease bacteria on intestinal immunity and intestinal bacteria, and its relation to inflammatory bowel disease

• Project/Area Number: 18K09565
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 57020:Oral pathobiological science-related
• Research Institution: Kurume University (2020); Fukuoka University (2018-2019)
• Principal Investigator: Takedatsu Hidetoshi 久留米大学, 医学部, 准教授 (80352144)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Project Status: Completed (Fiscal Year 2020)
• Budget Amount: ¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000); Fiscal Year 2020: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000); Fiscal Year 2019: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000); Fiscal Year 2018: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
• Keywords: 炎症性腸疾患 / 歯周病菌 / 歯周病

Outline of Final Research Achievements

Inflammatory bowel disease (IBD) is an autoimmune disease that causes chronic intestinal inflammation. Intestinal microbiota is involved in the pathogenesis of IBD. In this study, we investigated the effects of periodontal bacterial species on IBD patients. We found that the amount of bacteria was higher in CD than in healthy controls. Fusobacterium nucleatum associated with periodontal disease was found to be more abundant in UC.
Furthermore, Fusobacterium nucleatum was orally administered to mice. However, no direct effect on the mesenteric lymph nodes or intestine was observed. Fusobacterium nucleatum was also orally administered to a mouse model of dextran sulfate-induced colitis, however no direct effects on enteritis or inflammatory responses were observed.

Academic Significance and Societal Importance of the Research Achievements

歯周病は口腔内の慢性炎症であり、全身疾患や自己免疫疾患、特に慢性関節リウマチと強い関連性が示されている。歯周病菌とIBDの関連性を検討する必要性が考えられた。今回の検討では対象患者に歯周病はなかったが、口腔内菌量がクローン病に多いこと、Fusobacterium nucleatumが潰瘍性大腸炎に多く認められることが分かった。
Fusobacterium nucleatumのマウスへの投与に対する反応は有意な差を認めなかったが、引き続きFusobacterium nucleatumが腸管炎症にどのように関わっているか明らかとすることでIBDの炎症増悪の原因解明につながると考えられる。