Gastrointestinal uremic toxins (UTs)

Gastrointestinal uremic toxins are metabolic byproducts, primarily derived from the gut microbiota's breakdown of dietary proteins, that accumulate in patients with chronic kidney disease (CKD) due to decreased renal clearance (Niwa, 2011, PMID: 21558704). Key examples include indoxyl sulfate and p-cresyl sulfate, which are known to exert pro-inflammatory and pro-fibrotic effects on the kidneys and cardiovascular system (Vanholder et al., 2014, PMID: 24623102). These toxins are targeted by spherical carbon adsorbents like AST-120 (Kremezin), which are orally administered to bind the toxins and their precursors within the intestinal lumen (Asai et al., 2019, PMID: 30841454). By preventing the absorption of these solutes into the systemic circulation, these adsorbents help mitigate the uremic burden and potentially slow the progression of CKD. This therapeutic approach is particularly focused on protein-bound uremic toxins that are difficult to remove via conventional hemodialysis. Clinical use of these adsorbents is often monitored through levels of serum indoxyl sulfate and markers of renal function. Common side effects include gastrointestinal disturbances such as constipation, and there is a potential for the adsorbent to interfere with the absorption of other oral medications. Overall, targeting these toxins represents a strategy to manage the systemic complications of uremia and preserve residual renal function.

Other names

Uremic retention solutesGut-derived uremic toxinsProtein-bound uremic toxinsPBUTsIndoxyl sulfate precursors

Physical adsorption of toxins and their precursors within the gastrointestinal tract to prevent systemic absorption.