COMPARISON OF THE ILEAL AND FECAL DIGESTIBILITY OF DIETARY AMINO-ACIDS IN ADULT HUMANS AND EVALUATION OF THE PIG AS A MODEL ANIMAL FOR DIGESTION STUDIES IN MAN
Am. Rowan et al., COMPARISON OF THE ILEAL AND FECAL DIGESTIBILITY OF DIETARY AMINO-ACIDS IN ADULT HUMANS AND EVALUATION OF THE PIG AS A MODEL ANIMAL FOR DIGESTION STUDIES IN MAN, British Journal of Nutrition, 71(1), 1994, pp. 29-42
The aim of the study was to determine if there is a difference between
ileal and faecal assays for determining amino acid and N digestibilit
ies in adult human subjects. Comparison of true ileal amino acid and N
digestibilities was also made between adult human subjects and growin
g pigs to establish the usefulness of the pig as a model animal. Five
subjects with established ileostomies and six subjects with intact lar
ge bowels consumed a constant diet consisting of meat, vegetables, fru
it, bread and dairy products for 7 d with collection of ileostomy cont
ents or faeces respectively over the last 4 d. The study was repeated
using 25 kg body weight ileostomized and intact pigs. Apparent amino a
cid and N digestibility coefficients were determined. For human subjec
ts the faecal digestibility values were significantly higher (P < 0.05
) than the ileal values for Arg, Asp, Gly, Phe, Pro, Ser, Thr and Trp.
The faecal digestibility of Met was significantly lower than the ilea
l value. Determination of DNA, diaminopimelic acid (DAPA) and the dige
stibilities of pectin, hemicellulose and cellulose in human subjects i
ndicated that some microbial colonization had occurred at the terminal
ileum after formation of an ileostomy; however, this was not as exten
sive as in the large intestine. True deal amino acid and N digestibili
ties were calculated after correcting for the endogenous contribution
of amino acids at the terminal ileum determined using a protein-free d
iet. There were no significant differences between adult human subject
s and pigs for true ileal dietary amino acid digestibility except for
Thr, Phe, Cys and Met. There were no significant differences between a
dult humans and pigs for the heal digestibility of dry matter and the
faecal digestibility of gross energy.