title: p-Cresyl sulfate serum concentrations in haemodialysis patients are reduced by the prebiotic oligofructose-enriched inulin.
abstract: BACKGROUND
  Protein-bound uraemic retention solutes, including p-cresyl sulfate and indoxyl sulfate, contribute substantially to the uraemic syndrome. These and several other uraemic retention solutes originate from intestinal bacterial protein fermentation. We investigated whether the prebiotic oligofructose-enriched inulin reduced serum concentration of p-cresyl sulfate and indoxyl sulfate, through interference with intestinal generation.
  
  
  METHODS
  We performed a single centre, non-randomized, open-label phase I/II study in maintenance HD patients with a 4-week, escalating dose regimen of oligofructose-enriched inulin (ORAFTI Synergy 1, Tienen, Belgium) (www.clinicaltrials.gov NCT00695513). Changes in p-cresyl sulfate and indoxyl sulfate serum concentrations as well as changes in p-cresyl sulfate and indoxyl sulfate generation rates were analysed.
  
  
  RESULTS
  Compliance with therapy was excellent. p-Cresyl sulfate serum concentrations at 4 weeks were significantly reduced by 20% (intention to treat, P = 0.01; per protocol, P = 0.03). Also p-cresyl sulfate generation rates were reduced (P = 0.007). In contrast, neither indoxyl sulfate generation rates (P = 0.9) nor serum concentrations (P = 0.4) were significantly changed.
  
  
  CONCLUSIONS
  The prebiotic oligofructose-inulin significantly reduced p-cresyl sulfate generation rates and serum concentrations in haemodialysis patients. Whether reduction of p-cresyl sulfate serum concentrations, an independent predictor of cardiovascular disease in HD patients, will result in improved cardiovascular outcomes remains to be proven.
authors.affiliation: Division of Nephrology, Department of Medicine, University Hospital Leuven, 3000 Leuven, Belgium.
authors.forename: Björn K I
authors.initials: BK
authors.lastname: Meijers
authors.forename: Vicky
authors.initials: V
authors.lastname: De Preter
authors.forename: Kristin
authors.initials: K
authors.lastname: Verbeke
authors.forename: Yves
authors.initials: Y
authors.lastname: Vanrenterghem
authors.forename: Pieter
authors.initials: P
authors.lastname: Evenepoel
mesh_terms: D000284:Administration, Oral; D000368:Aged; D003408:Cresols / Q000097:blood*; D005260:Female; D006801:Humans; D007200:Indican / Q000097:blood; D007444:Inulin / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D007676:Kidney Failure, Chronic / Q000097:blood / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D009844:Oligosaccharides / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D056692:Prebiotics; D006435:Renal Dialysis / Q000379:methods*; D013463:Sulfuric Acid Esters / Q000097:blood*
chemical_list: D003408:Cresols; D009844:Oligosaccharides; D056692:Prebiotics; D013463:Sulfuric Acid Esters; C120489:oligofructose; C408690:4-cresol sulfate; D007444:Inulin; D007200:Indican