Effect of synbiotic supplementation on microbiota derived protein-bound uremic toxins, systemic inflammation, and biochemical parameters in hemodialysis patients: A double-blind placebo-controlled randomized clinical trial: Synbiotic, protein-bound uremic toxins, and inflammation

Abstract Objective The generation of key nephrovascular protein-bound uremic toxins, indoxyl sulfate and phenol, in hemodialysis (HD) patients is attributed to the dysbiotic gut microbiota. This study aimed to investigate the effects of synbiotic (SYN) supplementation on serum levels of indoxyl sulfate, phenol, inflammation, and biochemical parameters in HD patients. Research Methods & Procedures A total of 42 HD patients (synbiotic group: n = 21; placebo group: n = 21) were analyzed in this randomized, double-blind, placebo-controlled trial study. During a 2-month intervention, the synbiotic group received two synbiotic capsules daily, between the main meals, while the placebo group received maltodextrin as the placebo. Blood pressure, uremic factors, and biochemical parameters were assessed before the start and after the end of the study. Results After adjustment for potential confounders, there was no significant effect of SYN on serum levels of urea, creatinine, liver enzymes, hs-CRP, sodium, potassium, phosphorus, blood pressure, and albumin in the treatment group compared with the placebo group. A significant increase in indoxyl sulfate and parathyroid hormone (PTH) levels were observed only in the treatment group. However, between-group analyses were not significant. Compared with the baseline values, phenol levels were decreased in both intervention and placebo groups (P≤001), with no significant between-group difference. Conclusions Synbiotic supplementation might increase indoxyl sulfate and PTH levels in HD patients.