Flavanol-Enriched Cocoa Powder Alters the Intestinal Microbiota, Tissue and Fluid Metabolite Profiles, and Intestinal Gene Expression in Pigs

Background: Consumption of cocoa-derived polyphenols has been associated with several health benefits; however, their effects on the intestinal microbiome and related features of host intestinal health are not adequately understood. Objective: The objective of this study was to determine the effects of eating flavanol-enriched cocoa powder on the composition of the gut microbiota, tissue metabolite profiles, and intestinal immune status. Methods: Male pigs (5 mo old, 28 kg mean body weight) were supplemented with 0, 2.5, 10, or 20 g flavanol-enriched cocoa powder/d for 27 d. Metabolites in serum, urine, the proximal colon contents, liver, and adipose tissue; bacterial abundance in the intestinal contents and feces; and intestinal tissue gene expression of inflammatory markers and Toll-like receptors (TLRs) were then determined. Results: O-methyl-epicatechin-glucuronide conjugates dose-dependently increased (P < 0.01) in the urine (35- to 204-fold), serum (6- to 186-fold), and adipose tissue (34- to 1144-fold) of pigs fed cocoa powder. The concentration of 3-hydroxyphenylpropionic acid isomers in urine decreased as the dose of cocoa powder fed to pigs increased (75-85%, P < 0.05). Compared with the unsupplemented pigs, the abundance of Lactobacillus species was greater in the feces (7-fold, P = 0.005) and that of Bifidobacterium species was greater in the proximal colon contents (9-fold, P = 0.01) in pigs fed only 20 or 10 g cocoa powder/d, respectively. Moreover, consumption of cocoa powder reduced TLR9 gene expression in ileal Peyer's patches (67-80%, P < 0.05) and mesenteric lymph nodes (43-71%, P < 0.05) of pigs fed 2.5-20 g cocoa powder/d compared with pigs not supplemented with cocoa powder. Conclusion: This study demonstrates that consumption of cocoa powder by pigs can contribute to gut health by enhancing the abundance of Lactobacillus and Bifidobacterium species and modulating markers of localized intestinal immunity.