Renal Nutrition

There is increasing clinical evidence that patients with chronic kidney disease (CKD) have a distinctly dysbiotic intestinal bacterial community, termed the gut microbiota, which in turn drives a cascade of metabolic abnormalities, including uremic toxin production, inflammation, and immunosuppression, that ultimately promotes progressive kidney failure and cardiovascular disease. As the gut microbiota is intimately influenced by diet, the discovery of the kidney-gut axis has created new therapeutic opportunities for nutritional intervention. This review discusses the metabolic pathways linking dysbiotic gut microbiota with adverse health outcomes in patients with CKD, as well as novel therapeutic strategies for targeting these pathways involving dietary protein, fiber, prebiotics, probiotics, and synbiotics. These emerging nutritional interventions may ultimately lead to a paradigm shift in the conventional focus of dietary management in CKD.

Poor nutritional status and protein-energy wasting are common among maintenance dialysis patients and associated with unfavorable outcomes. Providing foods, meal trays, snack boxes, and/or oral nutritional supplements during hemodialysis can improve nutritional status and might also reduce inflammation, enhance health-related quality of life, boost patient satisfaction, and improve survival. Potential challenges include postprandial hypotension and other hemodynamic instabilities, aspiration risk, gastrointestinal symptoms, hygiene issues, staff burden, reduced solute removal, and increased costs. Differing in-center nutrition policies exist within organizations and countries around the world. Recent studies have demonstrated clinical benefits and highlight the need to work toward clear guidelines. Meals or supplements during hemodialysis may be an effective strategy to improve nutritional status with limited reports of complications in real-world scenarios. Whereas larger multicent...

Thanks to advancements in immunosuppression, patients are living longer with kidney transplants, and nonimmunologic factors (particularly nutritional) have become a major source of morbidity and mortality after successful kidney transplantation (KTx). In this current study, we have prospectively assessed, in a cohort of kidney transplant recipients (KTR), the course of some nonimmunologic factors liable to hinder the long-term outcome of KTR. Forty-four consecutive KTR with stable functioning grafts received dietary recommendations and were on the lowest effective dose of steroids. Biochemical nutritional markers, C-reactive protein, lipid profile, and body composition determined by dual-energy X-ray absorptiometry were studied over the first year, 2 years, and 5 years after KTx. No patients died during the follow-up. All patients but 2 were considered normotensive. Clinical diabetes developed in 3 patients. Visceral proteins stabilized at a normal range after the first year. Most of the patients normalized their inflammatory status. A significant improvement in lipid profile was observed. Female patients had a significant increase of weight (13.5%), mainly because of an increase in fat mass: 3.4 kg (19.4%) at 1 year and 5.6 kg (29.7%) at 2 years. In male patients, body composition remained stable and close to baseline values. The evolution of bone mass varied according to gender, total corticoid doses, and calcineurin inhibitors. Patients on low doses of steroids normalized their Z-score over the 5-year period. The increase in bone mass (paired t-test, P = .006) was only significant in patients treated with tacrolimus (analysis of variance for repeated measures, P < .001). Simple measures and dietary intervention to prevent or correct nonimmunologic disorders should permit improvement of long-term morbidity and mortality of KTR without compromising the functional outcome of their transplant.