Identification and functional analysis of genes important for the activity of bifidobacteria in the intestine harboring intestinal microbiota

2018 Fiscal Year Final Research Report

• Project/Area Number: 16H04893
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Applied microbiology
• Research Institution: Hokkaido University
• Principal Investigator: Fukiya Satoru 北海道大学, 農学研究院, 講師 (10370157)
• Co-Investigator(Kenkyū-buntansha): 小椋 義俊 九州大学, 医学研究院, 准教授 (40363585) ; 園山 慶 北海道大学, 農学研究院, 教授 (90241364)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: ビフィズス菌 / 腸内活動 / INSeq法 / R-IVET / 腸内細菌叢 / 腸管定着

Outline of Final Research Achievements

Bifidobacteria are well-known for their beneficial effects on human health, but the molecular mechanisms how bifidobacteria are colonizing and surviving in the intestine are not fully understood especially in the presence of the intestinal microbiota. To clarify the molecular mechanisms, the breeding system of the conventional mice that allows long-term colonization of the human-derived bifidobacteria was established. Using this system, bifidobacterial genes specifically expressed in the intestine were identified by R-IVET analysis. Furthermore, a transposon mutant library comprising 48,000 mutants was constructed and administered to the germ-free mice. Increase and decrease of each mutant in the intestine were comprehensively evaluated by the INSeq analysis. Finally, 442 genes were identified that were important to the colonization and survival in the intestine.

Free Research Field

応用微生物学

Academic Significance and Societal Importance of the Research Achievements

本研究では，R-IVET法とINSeq法という分子生物学的な手法を駆使して，腸内で特異的に発現する遺伝子および腸内での生存・定着に重要なビフィズス菌遺伝子を多数同定することができた．この成果は，ビフィズス菌が腸内でどのようなメカニズムで活動し，健康に有用な効果を発揮しているのかというビフィズス菌研究の根源的な問いに答える端緒となるものである．また，高齢化によって腸内での菌数が減少することが知られているビフィズス菌をどのようにして維持し，健康維持につなげるのか，その方策の基盤となる情報を得られたという点で，社会的にも重要な研究であると評価することができる．