Development of a novel treatment for radiation induced gastrointestinal disorders using intestinal flora

• Project/Area Number: 18K15578
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 52040:Radiological sciences-related
• Research Institution: Hirosaki University
• Principal Investigator: Tsujiguchi Takakiyo 弘前大学, 保健学研究科, 助教 (90737454)
• Project Period (FY): 2018-04-01 – 2022-03-31
• Project Status: Completed (Fiscal Year 2021)
• Budget Amount: ¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000); Fiscal Year 2021: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000); Fiscal Year 2020: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000); Fiscal Year 2019: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000); Fiscal Year 2018: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
• Keywords: 被ばく医療 / 放射線事故 / 腸内フローラ / 原子力災害医療 / 放射線誘発消化管障害 / 消化管障害

Outline of Final Research Achievements

Severe gastrointestinal disorders induce sepsis and lead to death in individuals exposed to high doses radiation. Gastrointestinal bacteria that cause septicemia are called "intestinal flora" and are known to be strongly associated with lifestyle-related diseases and cardiovascular diseases. There are many unclear points about the relationship between. In order to clarify this problem, in this study, we have investigated the usefulness of gut microbiota in the treatment of intestinal disorders as well as the analysis of changes in gut microbiota after exposure to radiation. As a result, it was clarified that a large amount of lactic acid bacteria outflow occurred in the individuals exposed to the lethal dose. In addition, since life-prolonging and life-saving effects have not been confirmed in rectal stool transplantation experiments at this stage, transplantation using cultured bacteria will be carried out in the future.

Academic Significance and Societal Importance of the Research Achievements

被ばく傷病者における被ばく線量を過小評価してしまうと，潜伏期を経て臨床症状が発症する造血・消化管障害への対応が遅れてしまうため，治療戦略を決定する上で正確な線量評価は必須である．現在，染色体評価と核断片化評価が国際的に採用されているが，これらを実行するには高価な機材が必要および人材不足という問題が並行している．しかし，本研究の腸内フローラ解析結果は線量評価における新規バイオマーカーとしての有用性を提供する．特定の腸内フローラが線量および時間依存的に変化することを見出せば，簡便な遺伝子増幅法を利用することで新たな線量評価法への発展が期待され，社会的意義の高い研究である．

Research Products

• [Journal Article] 腸内フローラを利用した放射線曝露個体の消化管障害新規治療法の開発 (2021)
  • Author(s): 辻口貴清、山内可南子、伊藤勝博
  • Journal Title: Medical Science Digest Volume: 47 Pages: 599-601
  • Peer Reviewed
• [Journal Article] Short-Term Changes in Gut Microflora and Intestinal Epithelium in X-Ray Exposed Mice (2020)
  • Author(s): Tsujiguchi Takakiyo、Yamaguchi Masaru、Yamanouchi Kanako
  • Journal Title: Journal of Radiation Protection and Research Volume: 45 Issue: 4 Pages: 163-170
  • DOI: 10.14407/jrpr.2020.45.4.163
  • Peer Reviewed / Open Access
• [Journal Article] Determination of gut bacterial metabolites in radiation exposed mice (2019)
  • Author(s): Sakamoto Yamato, Tsujiguchi Takakiyo, Ito Koichi, Yamanouchi Kanako
  • Journal Title: Radiation Protection Dosimetry Volume: 184 Issue: 3-4 Pages: 493-495
  • DOI: 10.1093/rpd/ncz094
  • Peer Reviewed / Open Access
• [Journal Article] Short-term follow-up of intestinal flora in radiation-exposed mice (2019)
  • Author(s): Yamanouchi Kanako、Tsujiguchi Takakiyo、Sakamoto Yamato、Ito Koichi
  • Journal Title: Journal of Radiation Research Volume: 印刷中 Issue: 3 Pages: 328-332
  • DOI: 10.1093/jrr/rrz002
  • Peer Reviewed / Open Access
• [Presentation] Determining gut bacterial metabolites in radiation exposed mice (2018)
  • Author(s): Yamato Sakamoto, Takakiyo Tsujiguchi, Koichi Ito, Kanako Yamanouchi
  • Organizer: 9th International Conference on High Level Environmental Radiation Areas
  • Int'l Joint Research
• [Presentation] 原子力災害時に応用可能な早期治療・検査法構築へ向けて-腸内フローラ変化の追跡- (2018)
  • Author(s): 辻口貴清、山内可南子
  • Organizer: 第77回日本公衆衛生学会総会