AMINO-ACID LOSSES IN ILEOSTOMY FLUID ON A PROTEIN-FREE DIET

The contribution of losses via the gastrointestinal tract to maintenan ce amino acid requirements was assessed by collecting the ileostomy fl uid of volunteers given a protein-free diet for 5 d. The subjects were eight adult men and women with terminal ileum ileostomies after ulcer ative colitis. Four consecutive 24-h collections of both digesta and u rine were made. On the last 2 d an antibiotic was given that suppresse d microbial activity in the digesta and slightly reduced ileostomy out flow. Mean daily amino acid excretion in ileostomy fluid ranged from 3 2 mg/d for methionine to approximate to 330 mg/d for aspartate and glu tamate. These losses were compared with current international estimate s of amino acid requirements. For most essential amino acids gastroint estinal losses accounted for 14-33% of daily maintenance requirements but for threonine the contribution was 61%.