Excretion of amino acid residues from diets based on low-fibre wheat or high-fibre rye bread in human subjects with ileostomies.

OBJECTIVE

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.

METHODS

The study was performed as a cross-over design.

METHODS

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.

METHODS

Six men and two women, all proctocolectomised for ulcerative colitis, volunteered to participate in the study.

METHODS

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 proline were significantly (P < 0.05) lower during the high-fibre diet period.

CONCLUSIONS

It was indicated that the effect of the high-fibre rye-based diet was a generally impaired ileal amino acid absorption.