Nutritional Factors Affecting Uremic Toxin Production

Chronic kidney disease (CKD) is characterized by persistent exposure to uremic toxins (UTs), many of which originate from gut microbial metabolism and contribute to renal, cardiovascular, and metabolic complications. Current evidence indicates that CKD is associated with dysbiosis and the enrichment of microbial taxa carrying genes involved in UT precursor production. Diet is a major modulator of the gut microbiota and therefore represents a promising lever to reduce UT generation in synergy with current nephroprotective therapies. Beyond simple protein restriction, more specific dietary approaches, particularly plant-based low-protein diets, appear especially relevant. Additional factors, including amino acid composition, lipid quality, food processing, constipation, transit time, meal timing, and circadian rhythms, may also influence microbial metabolism and UT production. This review examines the role of nutrition in shaping the gut microbiota–UT–kidney axis and discusses how dietary modulation may support precision nutrition in the context of CKD. It also highlights future directions based on multidimensional phenotyping and robust biomarkers to capture interindividual variability, guide personalized interventions, and ultimately improve renal and cardiovascular outcomes in CKD.