Effects of Synbiotic Supplementation on Bone Turnover Markers in Kidney Transplant Recipients: A Randomized Controlled Trial.

Bone disorders are common in kidney transplant (KT) recipients. This research explores the impact of synbiotic supplementation on markers related to bone turnover in these patients. In a randomized controlled trial, 46 KT recipients were allocated at random to either a synbiotic group or a placebo group. Those in the synbiotic group received two capsules daily for a duration of 12 weeks, while the placebo group was given an equivalent placebo. The study measured several bone resorption markers, including C-telopeptide and receptor activator of nuclear factor kappa B ligand (RANKL), as well as serum levels of the bone formation marker osteocalcin and the bone resorption inhibitor osteoprotegerin. The findings revealed that serum levels of C-telopeptide were significantly lower in the synbiotic group compared to the placebo group (p = 0.014). There was a significant increase in osteocalcin levels within the synbiotic group compared to the placebo group (p = 0.041). Serum concentrations of RANKL and osteoprotegerin decreased significantly in both the synbiotic and placebo groups compared to baseline. However, the change in serum concentrations of RANKL and osteoprotegerin did not show a significant difference between the two groups. Throughout the study period, no significant changes were observed in serum iPTH, calcium, phosphorus, or 25-hydroxycholecalciferol levels within each group. In conclusion, synbiotic supplementation decreases serum C-telopeptide, a marker of bone resorption, and increases serum osteocalcin, a marker of bone formation, in KT recipients.