Impact of Processing on the Anti-inflammatory and Gastrointestinal Protective Effects of Cocoa in High Fat-Fed Obese Mice

Abstract

Abstract Objectives The objective of this study was to determine the impact of fermentation and roasting steps on the anti-inflammatory and gastrointestinal (GI) protective efficacy of dietary cocoa in high fat-fed obese mice. Fermentation and roasting are important for flavor development, but have been shown to reduce total phenolic content in cocoa and are hypothesized to be detrimental for the health beneficial effects of cocoa. To date, however, the available data demonstrating the effect of fermentation and roasting on the anti-inflammatory and GI protective effects of cocoa are limited. Methods Obese male and female C57BL/6J mice were fed a high fat diet (HF) supplemented with one of seven cocoa powders (80 mg/g) that had been processed using different fermentation and roasting parameters. After 9 weeks, GI permeability was determined by gavaging mice with fluorescein isothiocyanate-conjugated dextran and measuring fluorescence in the blood. Markers of colonic inflammation were measured by quantitative reverse-transcriptase PCR. Metabolic endotoxemia was determined by measuring plasma lipopolysaccharide (LPS) and LPS binding protein (LBP). Results Cocoa treatment reduced GI permeability by 48 – 80% in male and female mice compared to HF-fed controls. These differences were paralleled by decreased plasma levels of LPS (25 – 70% lower) and LBP (25 – 57% lower) compared to HF-fed controls. Cocoa-treated mice had reduced colonic mRNA expression of interleukin (IL)1β, IL4, IL6, tumor necrosis factor (TNF)α, and inducible nitric oxide synthase (NOS2) compared HF-fed controls. In contrast to the hypothesis that fermentation and roasting are detrimental to the anti-inflammatory efficacy of cocoa, we found that unfermented/unroasted cocoa and more aggressively fermented/roasted cocoa were equally efficacious at reducing metabolic endotoxemia and colonic expression of IL1β, TNFα, and NOS2. Conclusions In summary, we found that dietary supplementation with cocoa reduces GI permeability, inflammation, and metabolic endotoxemia in HF-fed obese mice, and that the efficacy of cocoa was resilient to fermentation and roasting. Our on-going studies are focused on determining the phytochemical drivers of cocoa bioactivity, and identifying the role of the colonic microbiota as a mediator of the effects of cocoa. Funding Sources The current studies were funded by USDA NIFA.