ABC Heart Fail Cardiomyop 2022; 2(2): 222-225

The Heart-Gut Microbiome Intersection in Heart Failure

Jefferson L. Vieira , Alessandra F.R.R. Sidrim, Mandeep R. Mehra

DOI: 10.36660/abchf.20220039

The human body is co-inhabited by over a trillion microorganisms, including > 2000 species of bacteria, archaea, viruses, and single-celled eukaryotes that live symbiotically with their hosts. The gut microbiota is a dynamic and complex ecological community in the gastrointestinal tract, an essentially anaerobic environment with abundant nutrients and ideal conditions for colonization; it acts as a virtual endocrine system that communicates with organs through metabolism-dependent pathways, releasing de novo products and transforming external nutrients and host metabolites into hormone-like signals.

In addition to metabolic benefits, the gut microbiota provides essential capacities for regulating the intestinal epithelial barrier, immune homeostasis, optimal immune responses, and protection against pathogen colonization.^– One of the most important roles of gut microbiota is to act in digestion and nutrient absorption, producing short-chain fatty acids that serve as energy substrate for intestinal epithelial cells. After short-chain fatty acids bind to their receptor, the enteroendocrine hormone peptide YY is released, which regulates host appetite and contributes to dietary energy availability. Intestinal flora act to convert various dietary nutrients into trimethylamine, which is rapidly absorbed and oxidized in the liver to produce trimethylamine N-oxide (TMAO). Some foods, like red meat, eggs, and fish, are rich in nutritional precursors that can be converted into trimethylamine through specific microbial enzymes; therefore, a change in microbiota composition can alter circulating TMAO levels.

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