Effect of sucroferric oxyhydroxide on gastrointestinal microbiome and uremic toxins in patients with chronic kidney disease undergoing hemodialysis

Background In patients with chronic kidney disease (CKD), dysbiosis in the gastrointestinal microbiome is thought to be associated with increased production of uremic toxins, such as indoxyl sulfate (IS) and p- cresyl sulfate (PCS). Sucroferric oxyhydroxide (SFO), an iron-based phosphate binder, may affect the gastrointestinal microbiome and the production of uremic toxins. We aimed to examine whether SFO administration affected distribution of gastrointestinal microbiome and serum uremic toxin levels in CKD patients undergoing hemodialysis. Methods In this single-center, open-label, interventional study, 18 maintenance hemodialysis patients with hyperphosphatemia were prescribed with SFO. We collected serum samples before and after 3 months of administration, and serum levels of IS and PCS were measured. A control group of 20 hemodialysis patients without SFO was evaluated. We evaluated gastrointestinal microbiome of patients pre- and post-SFO administration by 16S rDNA sequencing and bioinformatics analysis. Results Serum IS and PCS levels were significantly elevated after administration of SFO (IS before 2.52 ± 1.60 mg/dl vs. after 3.13 ± 1.51 mg/dl, P = 0.008; PCS before 2.32 ± 2.44 mg/dl vs. after 3.45 ± 2.11 mg/dl, P = 0.002), while serum IS and PCS levels did not change in the control group. Microbiome analysis in the SFO group showed no significant change in diversity and major components in phylum, class, order, family, gene, and species. Conclusion Administration of SFO increased the serum levels of IS and PCS with no change of major components of gastrointestinal microbiome.