title: Fermentable carbohydrate supplementation alters nitrogen excretion in chronic renal failure.
abstract: BACKGROUND
  Considerable attention has been given to the impact of nutrition on kidney disease. Most dietary attempts to treat chronic renal failure (CRF) and to decrease uremia use a protein restriction. An alternative dietetic approach based on fermentable carbohydrate (FC) supplementation of the diet could lead to the same urea-lowering effect by increasing urea nitrogen (N) excretion in stool, with a concomitant decrease of the total N quantity excreted in urine.
  
  
  METHODS
  In the present prospective study, the impact of FC (40 g/d) on uremia and on N excretion routes was investigated during 5 weeks in nine CRF patients in the presence of a moderated restrictive protein diet (0.8 g/kg/d). Patients were their own controls and were treated by the cross-over method after randomization (5 weeks with FC versus 5 weeks without FC).
  
  
  RESULTS
  Feeding FC significantly increased the quantity of N excreted in stool from 2.1 +/- 0.8 to 3.2 +/- 1.1 g/d (+51%) (P < .01) and decreased, in parallel, the urinary N excretion from 9.4 +/- 1.7 to 8.3 +/- 1.4 g/d (-12%) (P < .01). The total N quantities excreted by the two routes were unchanged by the FC, which shows that the FC was efficient to shift N excretion from the urinary route toward the digestive route. As a result of the increase of urea transfer into the colon, the plasma urea concentration was significantly decreased from 26.1 +/- 8.7 to 20.2 +/- 8.2 mmol/L (-23%) (P < .05).
  
  
  CONCLUSIONS
  These results show the same beneficial effects in CRF as those obtained with a restrictive protein diet without its nutritional drawbacks. This should be confirmed by other prospective works over a longer duration and a larger number of patients to study the effects of FC on CRF progression and on CRF terminal stage tolerance.
authors.affiliation: Department of Nephrology, Hotel Dieu, CHU Clermont-Ferrand, France. hyounes@chu-clermontferrand.fr
authors.forename: Hassan
authors.initials: H
authors.lastname: Younes
authors.forename: Nadine
authors.initials: N
authors.lastname: Egret
authors.forename: Mohamed
authors.initials: M
authors.lastname: Hadj-Abdelkader
authors.forename: Christian
authors.initials: C
authors.lastname: Rémésy
authors.forename: Christian
authors.initials: C
authors.lastname: Demigné
authors.forename: Claudine
authors.initials: C
authors.lastname: Gueret
authors.forename: Patrice
authors.initials: P
authors.lastname: Deteix
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Alphonse
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000886:Anthropometry; D018592:Cross-Over Studies; D004040:Dietary Carbohydrates / Q000008:administration & dosage*; D004043:Dietary Fiber / Q000032:analysis; D004044:Dietary Proteins / Q000008:administration & dosage; D019587:Dietary Supplements; D002149:Energy Intake; D005243:Feces / Q000737:chemistry; D005260:Female; D005285:Fermentation; D006801:Humans; D007676:Kidney Failure, Chronic / Q000378:metabolism / Q000628:therapy* / Q000652:urine; D008297:Male; D008875:Middle Aged; D009584:Nitrogen / Q000032:analysis* / Q000652:urine; D009752:Nutritional Status; D010349:Patient Compliance; D011446:Prospective Studies
chemical_list: D004040:Dietary Carbohydrates; D004043:Dietary Fiber; D004044:Dietary Proteins; D009584:Nitrogen