Investigation of saliva effect on intestinal immune response based on intestinal flora analysis

2021 Fiscal Year Final Research Report

• Project/Area Number: 18K09543
• 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: Tsurumi University
• Principal Investigator: Kawaguchi Kouji 鶴見大学, 歯学部, 准教授 (50277951)
• Co-Investigator(Kenkyū-buntansha): 藤原 久子 鶴見大学短期大学部, 歯科衛生科, 教授 (80396746) ; 熊谷 賢一 東京大学, 医学部附属病院, 助教 (10518129) ; 濱田 良樹 鶴見大学, 歯学部, 教授 (70247336)
• Project Period (FY): 2018-04-01 – 2022-03-31
• Keywords: 唾液腺摘出 / 菌叢解析 / 組織学的変化 / 絨毛

Outline of Final Research Achievements

This study examined histological changes in the intestinal mucosa, expression level of factors related to intestinal immune response, and intestinal microbiome using mice with sialoadenectomy (submandibular, sublingual, and parotid glands). There was no significant difference in body weight changes during the experimental. However, the volume of saliva secretion in sialoadenectomy group was significantly decreased and depending time increase was also significantly suppressed. In addition, histopathological changes were observed in the villi of jejunum and ileum with significantly shortness in sialoadenectomy group one month after surgical treatment. They did not recover in the sixth postoperative month.
The results of gut microbiome analysis showed that alpha diversity was significantly higher in the sham-operated group at six months postoperatively. Beta diversity was higher in the explanted group at three months and in the sham-operated group at six months.

Free Research Field

口腔外科

Academic Significance and Societal Importance of the Research Achievements

本研究の結果、唾液腺摘出によって唾液分泌量が低下するだけでなく、空腸・回腸の絨毛長が短縮し、摘出術後６か月経過しても回復しないこと、更に腸内細菌叢にも変化があることが分かった。従って、唾液の作用は従来考えられていた、咀嚼や嚥下・会話を円滑にすることや、自浄作用によるカリエスや歯周病の予防、口腔粘膜の保護だけではなく、遠隔臓器である消化管にも影響があることが示唆され、唾液分泌量低下を来たす疾患や病態の解明が進むと期待できる。