Human microbiome and cardiovascular diseases.

A number of microorganisms are co-evolved with the host, among which bacteria are the predominant organisms in the colonic site. The human microbiota contributes to various physiological functions, including the digestion and degradation of food components, harvesting of inaccessible nutrients, immune system regulation, maintenance of gut barrier function, and regulation of brain function and behavior. Microbes in the gut produce a wealth of metabolites from the exogenous dietary substances or endogenous metabolic compounds produced by the host and the resident microorganisms. These microbial-derived metabolites are the major factors in the host-microbiota cross-talk and influence the host's cardiometabolic health directly or indirectly depending on the structure and function of the microbial community. Evidence suggests that the perturbation in the composition and function of gut microbiota (referred to as gut dysbiosis) is associated with the development of several diseased conditions such as that of the gastrointestinal tract or colorectal cancer, metabolic diseases such as obesity, diabetes, immune disorders e.g. asthma, allergies, depression, anxiety and cardiometabolic disease. Several pathological conditions in the gastrointestinal tract may impair the intestinal barrier that allows translocation of bacteria and their metabolites to a remote organ such as the heart, which may ultimately be associated with systemic inflammation and the development of CVDs. In this chapter, we will discuss various gut microbiota-dependent metabolites, which have a significant role in cardiovascular diseases' pathologic processes and their risk factors. Finally, we will discuss the therapeutic potential of the gut-metabolite-heart axis as a novel target for the treatment of CVD and highlight the current updates and exciting directions for future research.