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Modulation of the postprandial utilization of dietary protein by both qualitative and quantitative factors of the protein intake in humans
Author(s) -
Juillet Barbara,
Fouillet Helene,
Bos Cecile,
Gaudichon Claire,
Tomé Daniel
Publication year - 2006
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.20.4.a9-b
Subject(s) - postprandial , meal , anabolism , catabolism , chemistry , medicine , endocrinology , food science , biology , metabolism , insulin
The consequences of an increased habitual protein intake on the metabolic utilization of dietary proteins remain unclear, due to both the complexity of postprandial dynamic phenomena and the difficulty to access experimentally to the major N pools in humans. Clinical experiment was coupled with compartmental modeling for studying the combined effects of the prevailing protein level in the diet and the protein source in the meal on the postprandial metabolic fate of meal N (N m ). Healthy subjects were adapted for 7d to a normal (NP: 1 g.kg −1 .d −1 ), and for the next 7d to a high (HP: 2 g.kg −1 .d −1 ) protein diet. After each period, they ingested a mixed meal containing 15 N‐labeled milk (M), soy (S) or wheat (W) proteins and N m kinetics were measured for 8h in some accessible pools of the ileum, blood and urine. These data were then analyzed using a 12‐compartment model for assessing the postprandial kinetics of N m in the major splanchnic and peripheral N pools. Main results: metabolic fate of N m in % of dose at 8hIncreasing the habitual protein intake led to (i) higher postprandial N m losses by deamination and lower entero‐hepatic recycling of N m ‐derived urea, and (ii) a 10‐25% lower peripheral anabolic utilization of dietary N. The gap between the nutritional values of M, S and W proteins was also increased at high levels of protein intake.