Changes in the mucosal immunity induced by diets enriched with cocoa and hesperidin in intensively trained and exhausted rats

Mucosal immunity can be altered by exhausting exercise, while it may be enhanced by flavonoid-enriched diets. This study aimed both to ascertain the influence of exhausting exercise in rats on mucosal immunity, and to establish the effect of 10% cocoa-enriched diets, alone (C10) or together with 0.5% hesperidin (CH), on the alterations in the mucosal immune system caused by exhausting exercise. For 6 weeks, Lewis rats were fed either standard, C10, or CH diets while following an intensive exercise training program. The animal groups included sedentary, trained, or exhausted rats for each diet. Results showed no effect of exercise on intestinal permeability or the main lymphocyte subsets of mesenteric lymph nodes (MLNs), although a higher proportion of NK cells were observed after training. Exhaustion increased the proportion of CD62L + Th and Tc cells but did not modify the lymphocyte functions of MLNs. Diets enriched with cocoa prevented the increase in the proportion of NK cells in MLNs whereas increased the proportion of B, Tc, and Tγδ cells. Although exercise did not modify the immunoglobulin synthesis, cocoa diets resulted in a rise in the synthesis of IgG and a lower salivary IgA content. In conclusion, few mucosal changes were induced in the model of exercise performed in Lewis rats, thus cocoa diets could not demonstrate a preventive effect on these alterations. Nevertheless, cocoa-enriched diets enhanced some aspects of intestinal immunity.