The gut and the heart: a concise narrative review

Abstract

Foods have a wider role besides simply satisfying hunger, and the gut may be the source of several diseases. The human gut is populated by 100 trillion microorganisms and the most abundant phyla are the Firmicutes ( 60 a 80%), such as the lactobacilli, and the Bacteroidetes ( 20 a 40%), such as the gender Bacteroides.The obesity epidemics may be related to the constant availability of food, less physical exercise, and influences on the gut microbiota such as type of food ingested (low fiber, high calorie, and high fat). The beneficial effects of the gut microbiota result partly from products derived from the fermentation of nondigestible carbohydrates (fibers), which generate short chain fatty acids, which in turn influence hormones that stimulate insulin secretion, improve insulin receptor sensitivity, promote satiety and inhibit glucagon secretion. Obese individuals have increased intestinal permeability and LPS release may promote, through metabolic endotoxaemia, an inflammatory state, such as seen in type II diabetes mellitus and obesity. Chronic heart failure results in a decreased perfusion of the gastrointestinal tract, with edema, dysmotility and malabsorption, which facilitates LPS release, which may induce negative inotropic effects, myocardial hypertrophy, fibrosis and apoptosis via tumor necrosis factor (TNF)-α, interleukin (IL)-1 and IL-6. Trimethylamine-N-oxide (TMAO) is a microbiota derived metabolite and is pro-atherogenic. Eating healthy and making judicious use of antibiotics may promote cardiovascular health via effects on the gut microbiota.