EXCRETION OF AMINO-ACID-RESIDUES FROM DIETS BASED ON LOW-FIBER WHEAT OR HIGH-FIBER RYE BREAD IN HUMAN-SUBJECTS WITH ILEOSTOMIES

Objectives: The effect of consumption of a wheat-flour bread-based low-fibre diet (13.6 g/day fibre per portion) or a rye bran bread and whole-grain rye crispbread-based high-fibre diet (43.5 g/day fibre per portion) on the ileal excretion of amino acid residues and crude protein was studied. Design: The study was performed as a cross-over design. Setting: The subjects were studied as outpatients except on the sampling days when all subjects were admitted to the research ward and stayed in a nearby patient hotel overnight. Subjects: Six men and two women, all proctocolectomised for ulcerative colitis, volunteered to participate in the study. Interventions: During each dietary period of 3 weeks, food and excreta were collected and analysed on days 3, 17 and 18. Results: The excretion of crude protein and amino acids (free and bound) was generally higher during the high-fibre diet period, although the relative proportion of amino acids was similar in the ileal effluents from the two diets. The apparent digestibilities of crude protein and all amino acids except histidine, tyrosine and iii proline were significantly (P < 0.05) lower during the high-fibre diet period. Conclusion: It was indicated that the effect of the high-fibre rye-based diet was a generally impaired ileal amino acid absorption. Sponsorship: This project was supported by the Swedish Council of Forestry and Agricultural Research (SJFR) and Wasabrijd AB. Descriptors: amino acids, digestibility, human, ileostomy, rye.