Nitrogen Utilization from Elemental Diets

Repletion experiments were performed in malnourished, chair-adapted primates to explore recently reported differences in nitrogen utilization from elemental diets. Two elemental diets were fed consecutively for 8 days through a gastrostomy. Diet C (maltodextrins, peptides, crystalline amino acids) resulted in: larger weight gain (F1,6 = 17.93, p < 0.01); smaller decrease of serum albumin (F1,5 = 11.2, p < 0.015), larger increase in total iron binding capacity (F1,6 = 30.6, p < 0.002), and a more positive nitrogen balance (F1,6 = 30.4, p < 0.002) than diet V (glucose oligosaccharides, crystalline amino acids). Diet C was considered to be more effective in the nutritional repletion of the study animals. Additional experiments were performed in normal human volunteers to investigate the metabolic fate of ingested glutamine and whether the rapid catabolism and excretion of the amido nitrogen of this amino acid, which constitutes 11.56% of total nitrogen in diet V, could explain the differences observed in pri...