Chronic kidney disease and cognitive impairment: The role of diet and gut microbiota.

Several important milestones have been achieved in recent years in the area of slowing the progression of chronic kidney disease (CKD). Consequently, additional facets of reducing quality of life (QoL) in CKD patients have emerged, including progressive cognitive impairment (CI) in up to 50% of patients. Accumulating evidence suggests that gut microbiome dysregulation may promote CI in a paradigm of kidney-brain-gut axis. Systemic inflammation, oxidative stress, uremic toxins and increased intestinal permeability ("leaky gut") are key components of the kidney-brain-gut axis dysfunction. Correcting this cross-stalk through dietary changes may improve brain function and prevent further kidney damage. Beneficial nutritional guidelines include plant-based (Mediterranean style) low-protein diet, substitution of animal protein with soy isolate, ketoanalogues of essential amino acids supplementation, modification of the gut microbiota through prebiotics, probiotics, synbiotics and metabiotics. Although being a subject of debate, there are many worthwhile areas for research in kidney-brain-gut axis dysfunction. In this review, we aimed to address knowledge gaps in studies of CI in CKD patients in the context of the kidney-brain-gut axis.