The effect of feeding route (IV or oral) on the protein metabolism of the neonate

Abstract

We have examined the effect of the route of feeding (intravenous versus enteral) on the protein metabolism of postsurgical human neonates. Twelve infants, birth weight 2.5 +/- 0.2 kg, gestational age 38 +/- 1 wk, were studied. The IV study was carried out 1-4 days after surgery at a postnatal age of 14 days and a weight of 2.6 +/- 0.2 kg. The repeat (oral) study was carried out 16 days later. Protein intakes were similar during both studies (2.7 g/kg/d). Energy intakes were within the requirement range for age and feeding route and were: IV, 85 +/- 4 kcal/kg/d; oral, 111 +/- 7 kcal/kg/d. Whole body protein metabolism was studied using a continuous infusion of 15N-glycine. Amino nitrogen flux, protein synthesis, and breakdown were 40% higher during the enteral than the IV studies (p less than 0.001). Skeletal muscle degradation was investigated by measuring urinary excretion of creatinine and N-T-methylhistidine. No differences were detected due to feeding route. We suggest that the differences seen in whole body protein turnover rates reflect the rapid growth and development of the gut in the enterally (rather than the IV) fed infant.

Lysine kinetics in preterm infants: the importance of enteral feeding

“…33 Their study compared the effect of feeding route (intravenous or enteral) on protein metabolism of the neonate and concluded that orally fed neonates utilise amino acids for synthesis more efficiently than total parenterally fed infants. 33 Early parenteral supply of amino acids is given to prevent protein loss but the present study clearly shows that enteral feeding is a far more efficient way of feeding preterm infants. Unfortunately, intestinal immaturity often impairs early full enteral feeding but our data suggest that maximal effort should be paid to initiate enteral feeding as soon as possible in preterm infants.…”

Plasma Amino Acid Pattern during the First Month of Life in Calves Fed the First Colostrum at 0–2 h or at 24–25 h after Birth

“…As a consequence, nutrient requirements for nitrogen and for amino acids, as well as for protein, are relatively high. Rates of body protein synthesis and nitrogen turnover are higher during enteral as compared to parenteral feeding, suggesting a more intensive synthesis and turnover of gastrointestinal (GI) proteins during enteral feeding ( Duffy & Pencharz 1986). Protein synthesis and turnover in new‐borns are reduced following food withdrawal and are enhanced by colostrum feeding, as shown in lambs ( Patureau‐Mirand et al .…”

The Low Birth Weight Infant and Parenteral Nutrition

“…Protein requirements suggested by various sources are given in Table 1. The effect of type of feeding route on protein metabolism in the neonate has been extensively reported elsewhere (Duffy & Pencharz, 1986;Pencharz et al 1989).…”