Ileal digestibility of dietary protein in the growing pig and adult human

Amélie Deglaire, Cécile Bos, Daniel Tomé, Paul J. Moughan
2009 British Journal of Nutrition  
The suitability of the pig as an animal model for predicting protein digestibility in man was evaluated. Healthy adult human subjects (mean body weight 67 kg; n 11) and growing pigs (mean body weight 40 kg; n 15) were fed semi-synthetic mixed meals containing, as a sole source of N, casein (C), hydrolysed casein (HC) or rapeseed isolate (R). There was no prior adaptation to the test meal. Ileal digesta were sampled through a naso-ileal tube (human subjects) or a post-valve T-caecum cannula
more » ... caecum cannula (pigs) after ingestion of a bolus meal. The protein sources were 15 N-labelled. Amino acid (AA) digestibilities were not determined for R. Ileal apparent N digestibility was markedly lower (14-16 %; P, 0·001) in human subjects than in pigs (C, HC, R). Similarly, most apparent ileal AA digestibilities were lower (8 % on average; P,0·05) in human subjects (C, HC). Ileal true N digestibility was slightly lower (3 -5 %; P,0·001) in human subjects than in pigs (C, HC, R) and most true ileal AA digestibilities were similar (P. 0·05) between the species (C, HC). Exceptions were for phenylalanine, tyrosine, lysine, histidine and aspartic acid for which digestibilities were lower (3 % on average; P, 0·001) in human subjects. A similar ranking of the diets was observed for true ileal N digestibility between species. The inter-species correlation for true ileal digestibility was high for N (r 0·98 over 3 £ 2 data; P¼ 0·11) and AA (r 0·87 over 26 £ 2 data; P,0·0001). Overall, this supports the use of the pig as a model for predicting differences among dietary protein digestibility, especially regarding true ileal N digestibility, in man. Human adults: Pigs: Digestibility: Ileal digestibility: Protein * Corresponding author: Professor Paul J. Moughan, fax þ 64 6 350 5655, email p.j.moughan@massey.ac.nz Abbreviations: AA, amino acid; BW, body weight; C, intact casein-based; DNFL, dietary nitrogen flow; HC, hydrolysed casein-based; PEG, polyethylene glycol; PVTC, post-valve T-caecum; R, rapeseed isolate protein-based; TNFL, total nitrogen flow.
doi:10.1017/s0007114509991267 pmid:19706206 fatcat:diqni5oijza6fdg2duzuk2qwnu