lncRNAs as a Biomarker to Assess the Therapeutic Impact of Oral Absorbent ± Probiotics in CKD Patients With PAD

Participants with chronic kidney disease (CKD) are at a higher risk of developing atherosclerotic peripheral artery disease (PAD). Retention of uremic toxins such as indoxyl sulfate (IS), p-cresyl sulfate (PCS) and trimethylamine N-oxide (TMAO) during CKD is detrimental to endothelial and vascular function and can predispose to the development and progression of PAD. Many of the uremic toxins originate from gut microbial metabolism. Removal of these uremic toxins by carbonaceous oral adsorbent is beneficial, slowing down the deterioration of renal function and delaying the need for dialysis in CKD patients. However, if carbonaceous oral adsorbent could also improve vascular function and clinical outcomes in CKD patients with established PAD, remains unknown. In this proposal, the investigators aim to determine the therapeutic impact of a carbonaceous oral adsorbent made of activated bamboo charcoal (ABC) with/without probiotics on the endothelial/vascular function, CV outcome and mortality in CKD patients with PAD. In addition, the investigators hypothesize that circulating long noncoding RNA (lncRNA) expression profiles and metabolome may serve as a sensitive and reliable biomarker to predict the adverse CV outcomes and death in CKD patients with established PAD. In addition, it is hypothesized that circulating lncRNAs and linked to adverse CV outcomes in CKD patients with PAD are associated with dysbiosis of gut microbiota. The investigators also hypothesize that the administration of ABC could normalize the dysbiosis of gut microbiota, dysregulated circulating lncRNAs and metabolome that are linked to adverse CV/limb outcomes in CKD patients with PAD. This will be a prospective, randomized, open-labeled, blinded end-point trial for 6 months, followed by integrated assessment of endothelial/vascular function, changes in conventional athero- and inflammation-relevant biomarkers, circulating long noncoding RNAs, metabolome, and gut microbiota at baseline, ends of the 3rd and 6th month, as well as clinical CV, renal and limb outcomes up to 3 years.