Intestinal-level anti-inflammatory bioactivities of catechin-rich green tea: Rationale, design, and methods of a double-blind, randomized, placebo-controlled crossover trial in metabolic syndrome and healthy adults

Joanna K Hodges; Jiangjiang Zhu; Zhongtang Yu; Yael Vodovotz; Guy Brock; Geoffrey Y Sasaki; Priyankar Dey; Richard S Bruno

doi:10.1016/j.conctc.2019.100495

Intestinal-level anti-inflammatory bioactivities of catechin-rich green tea: Rationale, design, and methods of a double-blind, randomized, placebo-controlled crossover trial in metabolic syndrome and healthy adults

Contemp Clin Trials Commun. 2019 Nov 20:17:100495. doi: 10.1016/j.conctc.2019.100495. eCollection 2020 Mar.

Authors

Joanna K Hodges¹, Jiangjiang Zhu^{1

2}, Zhongtang Yu³, Yael Vodovotz⁴, Guy Brock⁵, Geoffrey Y Sasaki¹, Priyankar Dey¹, Richard S Bruno¹

Affiliations

¹ Human Nutrition Program, The Ohio State University, Columbus, OH, USA.
² James Comprehensive Cancer Center, The Ohio State University, Columbus, OH, USA.
³ Department of Animal Sciences, The Ohio State University, Columbus, OH, USA.
⁴ Department of Food Science and Technology, The Ohio State University, Columbus, OH, USA.
⁵ Department of Biomedical Informatics, The Ohio State University, Columbus, OH, USA.

Abstract

Metabolic endotoxemia initiates low-grade chronic inflammation in metabolic syndrome (MetS) and provokes the progression towards more advanced cardiometabolic disorders. Our recent works in obese rodent models demonstrate that catechin-rich green tea extract (GTE) improves gut barrier integrity to alleviate the translocation of gut-derived endotoxin and its consequent pro-inflammatory responses mediated through Toll-like receptor-4/nuclear factor κB (TLR4/NFκB) signaling. The objective of this clinical trial is to establish the efficacy of GTE to alleviate metabolic endotoxemia-associated inflammation in persons with MetS by improving gut barrier function. We plan a double-blind, placebo-controlled cross-over trial in persons with MetS and age- and gender-matched healthy persons (18-65 y; n = 20/group) who will receive a low-energy GTE-rich (1 g/day; 890 mg total catechins) confection snack food while following a low-polyphenol diet for 28 days. Assessments will include measures of circulating endotoxin (primary outcome) and secondary outcomes including biomarkers of endotoxin exposure, region-specific measures of intestinal permeability, gut microbiota composition, diversity, and functions, intestinal and systemic inflammatory responses, and catechins and microbiota-derived catechin metabolites. Study outcomes will provide the first report of the GTE-mediated benefits that alleviate gut barrier dysfunction in relation to endotoxemia-associated inflammation in MetS persons. This is expected to help establish an effective dietary strategy to mitigate the growing burden of MetS that currently affects ~35% of Americans.

Keywords: BMI, body mass index; Catechin; Endotoxemia; GTE, green tea extract; Gut barrier function; Gut dysbiosis; Gut microbiota; Inflammation; LBP, LPS binding protein; LPS, lipopolysaccharides; MetS, metabolic syndrome; Metabolic syndrome; NFκB, nuclear factor κB; PCoA, principal coordinates analysis; SCFA, short chain fatty acid; TLR4, Toll-like receptor-4; TNF- α, tumor necrosis factor-α; Tea.

Abstract

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