Decreased renal function, elevated circulating levels of urea, intestinal levels of urea-degrading bacteria, and gut-derived uremic metabolites are present in end-stage renal disease (ESRD), a cohort that has reduced muscle mass and physical function, and poor muscle composition. This phenotype, defined as the kidney-gut-muscle axis, is similarly represented in older adults that do not have ESRD. The purpose of this short communication is to illuminate these findings, and to propose a strategy that can positively impact the kidney-gut-muscle axis. For example, dietary fiber is fermented by intestinal bacteria, thereby producing the short-chain fatty acids (SCFAs) acetate, propionate, and butyrate, which affect each component of the kidney-gut-muscle axis. Accordingly, a high-fiber diet may be an important approach for improving the kidney-gut-muscle axis in ESRD and in older adults that do not have ESRD.
Keywords: ESRD; aging; gut microbiome-derived uremic metabolites; muscle composition; renal function; sarcopenia.