The Efficacy of Prebiotic, Probiotic, and Synbiotic Supplementation in Modulating Gut-Derived Circulatory Particles Associated With Cardiovascular Disease in Individuals Receiving Dialysis: A Systematic Review and Meta-analysis of Randomized Controlled Trials

Abstract

Objective: This systematic review and meta-analyses provide an up-to-date synthesis on the effects of supplementation on circulating levels of toxic metabolites, markers of uremia and inflammation, blood lipids, and other clinical outcomes.

Methods: Seventeen databases were searched, supplemented with internet and hand searching. Randomized controlled trials of adult end-stage renal-disease individuals receiving either hemodialysis or peritoneal dialysis were eligible. Trials were restricted to those which had administered a prebiotic, probiotic, or synbiotic as an oral supplement. Primary outcomes were measures of circulating endotoxin, indoxyl-sulphate, and p-cresyl sulfate.

Results: Twenty-one trials were eligible (1152 randomized participants), of which 16 trials were considered to have a high risk of bias. The number of trials available for meta-analysis varied for each primary outcome. Synthesized data indicated that supplementation significantly reduced circulating levels of endotoxin (standardized mean difference, -0.61; 95% confidence interval, -1.03 to -0.20; P = .004; I² = 0%), indoxyl-sulphate (-0.34; -0.64 to -0.04; P = .02; I² = 0%), and p-cresyl sulfate (-0.34; -0.61 to -0.07; P = .01; I² = 0%). For secondary outcomes, supplementation significantly reduced gastrointestinal symptoms (-0.54; -1.02 to -0.07; P = .02; I² = 0%).

Conclusions: Supplementation reduces toxic metabolites associated with cardiovascular disease and mortality in individuals receiving dialysis. However, the majority of trials included were low in quality.