2022 Fiscal Year Final Research Report
Effect of tea catechins on gut bacterially produced uremic toxins derived from tyrosine.
Project/Area Number |
20K11565
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Research Category |
Grant-in-Aid for Scientific Research (C)
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Allocation Type | Multi-year Fund |
Section | 一般 |
Review Section |
Basic Section 59040:Nutrition science and health science-related
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Research Institution | Tokyo Kasei Gakuin University |
Principal Investigator |
Unno Tomonori 東京家政学院大学, 人間栄養学部, 教授 (90439753)
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Project Period (FY) |
2020-04-01 – 2023-03-31
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Keywords | カテキン / クレゾール / 尿毒素 / 腸内細菌 |
Outline of Final Research Achievements |
p-Cresol (PC) is recognized as an uremic toxin that is bacterially produced from tyrosine. This study aimed to reveal whether epigallocatechin-3-gallate (EGCG), a major catechin in green tea, could reduce the plasma and urinary levels of PC by limiting its bacterial production in mice. Mice were fed respective diets: a control diet, a 0.05% EGCG diet, a 0.1% EGCG diet or a 0.2% EGCG diet for 2 weeks. The results demonstrated that the addition of EGCG decreased the plasma and urinary concentrations of PC in a dose-dependent manner. However, once EGCG was hydrolyzed to epigallocatechin and gallic acid, such effects were lost almost completely. Dietary EGCG (0.2%) was accompanies by a decreased abundance of Clostridiales at the order level, which constitute a part of PC production from tyrosine, but EGCG hydrolyte did not show significant differences on the fecal bacterial composition.
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Free Research Field |
食品科学
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Academic Significance and Societal Importance of the Research Achievements |
本研究は,尿毒素の一種であるp-クレゾール(PC)が緑茶に含まれるエピガロカテキンガレート(EGCG)によって抑制されることを明らかにした。その作用機序として,EGCGがチロシンからPCを産生する腸内細菌の種類を抑制したためであると推察された。腸内細菌が産生したPCは体内に取り込まれると抱合体に変換されるが,クレシル硫酸は糖尿病性腎症の憎悪因子として理解されていることから,食品成分の摂取によってそのリスク低減に影響する可能性を示唆するとして学術的な意義を有する。
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