Probiotic Supplementation in Chronic Kidney Disease: Outcomes on Uremic Toxins, Inflammation, and Vascular Calcification from Experimental and Clinical Models

Chronic kidney disease (CKD) is associated with gut microbiota alterations that contribute to increased inflammation and the generation of uremic toxins and may worsen the disease progression. While probiotics may improve the pro-inflammatory cytokine profile, their effects on mineral metabolism, vascular calcification (VC), and CKD progression remain unclear. We aimed to evaluate the impact of a commercial probiotic (Probimel) supplementation on kidney function, mineral metabolism, inflammation and VC in both an experimental rat model and patients with advanced CKD and VC. The experimental model of VC was performed through 5/6 nephrectomy (Nx), a high-phosphate diet, and calcitriol. Animals were divided into three groups: Sham, Nephrectomy, and Nephrectomy + Probiotic. In the exploratory clinical study, 23 patients with advanced stage 5 CKD and VC were randomized and either received or did not receive daily probiotics for 6 months. Kidney function, mineral metabolism, uremic toxins, inflammation, VC, and fecal microbiota were evaluated. Probiotic supplementation decreased interleukin-6 (IL-6) and interpheron-γ (IFN-γ) and levels of the uremic toxin, indoxyl sulfate (IS), in the experimental model. However, no clear evidence of improvement in kidney function or vascular calcification was observed in either rats or patients with this probiotic. Under our experimental and clinical conditions, the selected probiotic did not modify key parameters related to CKD progression or VC.