Synbiotics Easing Renal Failure by Improving Gut Microbiology (SYNERGY): A Randomized Trial

Area of Science:

• Nephrology
• Microbiome research
• Gastroenterology

Background:

• Gut dysbiosis in chronic kidney disease (CKD) elevates uremic toxins like indoxyl sulfate (IS) and p-cresyl sulfate (PCS).
• Synbiotics, combining prebiotics and probiotics, may modulate the gut microbiota and reduce toxin production.

Purpose of the Study:

• To investigate the effect of synbiotic therapy on gut microbiota composition.
• To assess the impact of synbiotics on serum concentrations of IS and PCS in CKD patients.

Main Methods:

• A randomized, double-blind, placebo-controlled, crossover trial was conducted over 6 weeks with a 4-week washout period.
• Participants with predialysis CKD (eGFR 10-30 ml/min/1.73 m²) received either synbiotics or placebo.
• Primary outcome was serum IS; secondary outcomes included serum PCS, stool microbiota, and various biomarkers.

Main Results:

• Synbiotic therapy significantly reduced serum PCS but not serum IS.
• Microbiome alterations included enrichment of Bifidobacterium and depletion of Ruminococcaceae.
• Reductions in PCS and IS were more pronounced in patients not receiving antibiotics.

Conclusions:

• Synbiotics effectively decreased serum PCS and favorably modified the gut microbiome in CKD patients.
• The therapy did not significantly impact serum IS levels.
• Larger clinical trials are recommended to confirm these findings.