Elucidation of novel acting mehcanisms of gammma-amminobutyric acid

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K21293
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 38:Agricultural chemistry and related fields
• Research Institution: Nihon University
• Principal Investigator: TAKAHASHI Kyoko 日本大学, 生物資源科学部, 教授 (70366574)
• Co-Investigator(Kenkyū-buntansha): 松藤 寛 日本大学, 生物資源科学部, 教授 (70287605)
• Project Period (FY): 2020-07-30 – 2023-03-31
• Keywords: 腸内細菌 / γ-アミノ酪酸 / 腸管上皮細胞

Outline of Final Research Achievements

The purpose of this study was to elucidate the relationship between intestinal γ-aminobutyric acid (GABA) concentration and gut microbiota, and the physiological function and its mechanism of intestinal GABA. Administration of Bifidobacterium strain to mice altered the composition of gut microbiota, increased the concentration of intestinal GABA, and changed behavioral characteristics, such as a decrease in anxiety-like behavior. No significant changes were observed in serum GABA and cortisol levels. Furthermore, a bacterial strain isolated from mouse intestine was identified as having high GABA-producing ability. Expression of GABA receptors was detected on intestinal epithelial cells, and intracellular signaling was induced by GABA stimulation. These results suggested that intestinal GABA may act through the receptors expressed on intestinal epithelial cells.

Free Research Field

食品免疫学

Academic Significance and Societal Importance of the Research Achievements

本研究は、腸管内GABAに着目することにより、GABAの新規な機能発現メカニズムの可能性を示したものである。したがって、GABAの生理作用についてこれまでと異なる概念を確立し、脳腸相関の新たな側面を解明することにつながることが期待される。また、腸内細菌叢と腸管内GABA濃度の相関が示されたこと、腸内細菌叢と精神・神経疾患との関係が注目されていることから、腸内細菌叢への介入により、腸管GABAのコントロールを介した疾患の予防や治療への応用の道が拓かれることが期待される。