Uremic toxins, particularly the so-called gut-derived uremic toxins (GDUTs), play a central role in the progression of chronic kidney disease (CKD) and its complications. These substances are produced by the metabolism of gut bacteria and accumulate in the body as kidney function declines. They promote systemic inflammation, arterial stiffness, vascular damage, and increase cardiovascular risk – even when kidney function (measured by creatinine or eGFR) remains stable. The new probiotic Lactobacillus rhamnosus L34 from Chulalongkorn University targets precisely these toxins and has been shown in studies to lower their levels. Uremic toxins are a heterogeneous group of substances that are not adequately excreted in impaired kidney function. Particularly problematic are the protein-bound uremic toxins (PBUTs), which are bound to proteins in the blood and therefore difficult to remove by conventional dialysis. The most important gut-derived representatives are: In CKD, there is a dysbiosis of the…