1. Introduction
intestinal cellular injury, gastrointestinal disorders, gastrointestinal tract
CELL DAMAGE, GASTROINTESTINAL DISORDERS
These authors contributed equally to this work.These authors contributed equally to this work.Gut barrier disruption can lead to enhanced intestinal permeability, which allows endotoxins, pathogens, and other proinflammatory substances to move through the intestinal barrier into circulation. Intense exercise over a prolonged period increases intestinal permeability, which can be further worsened by the increased production of reactive oxygen species (ROS) and pro-inflammatory cytokines. The aim of this study was to assess the degree of intestinal permeability in elite football players and to exploit the effect of cocoa polyphenols on intestinal permeability induced by intensive physical exercise. Biomarkers of intestinal permeability, such as circulating levels of zonulin, a modulator of tight junctions, occludin, a tight junction protein, and LPS translocation, were evaluated in 24 elite football players and 23 amateur athletes. Moreover, 24 elite football players were randomly assigned to either a dark chocolate (>85% cocoa) intake (The gut barrier is a semipermeable structure that allows the absorption of essential nutrients, functions in immune sensing, and protects against toxins, food antigens, and bacteria. Indeed, the intestinal barrier is a restrictive and selective physical barrier that prevents the translocation of bacterial components such as lipopolysaccharide (LPS) into the lamina propria and then into the systemic circulation [Physical exercise acts as a modulator of the intestinal environment and microbiota, affecting its overall structure and functionality. However, not every type of physical exercise negatively affects the gut microbiota. Indeed, there is convincing evidence that low-to-moderate intensity exercise has positive effects on the gastrointestinal tract, including mucosa preservation, increasing microbiota diversity, and increasing butyrate-producing bacteria as well as butyrate concentrations [Athletes who experienced gastrointestinal disorders showed an overall impact on health status and a reduction in performance. Recently, it has been demonstrated that in resistance-trained men, the lactulose–rhamnose (L/R) ratio and level of intestinal fatty acid-binding protein (I-FABP), both measures of intestinal cellular injury [Despite this evidence, more studies are needed to highlight the role of exercise in intestinal permeability and to identify other variables that may influence this phenomenon.Among the several strategies that could mitigate the impact of exercise on gut permeability, nutrition and dietary supplements may play role in preventing the cell damage and gut permeability associated with exercise [The impact of acute or chronic effects of a wide range of supplements, such as bovine colostrum, glutamine, probiotics, supplemental carbohydrate, and antioxidants was tested in a variety of endurance exercise protocols [Dietary polyphenols constitute the biggest group of naturally occurring phytochemicals that exert a powerful antioxidant action and a wide range of pharmacological properties [Therefore, the purpose of this study was to verify the level of gut barrier permeability in elite football (soccer) players and to test if supplementation with polyphenols in the form of dark chocolate before exercise is effective at reducing the intestinal permeability.