TY - JOUR
T1 - Tryptophan Requirement of the Enterally Fed Term Infant in the First Month of Life
AU - Huang, L.S.
AU - Hogewind-Schoonenboom, J.E.
AU - Zhu, L.
AU - Kraaijenga, J.V.S.
AU - van Haren, N.P.C.
AU - Voortman, G.J.
AU - Twisk, J.W.R.
AU - Huang, Y.
AU - Chen, C.
AU - van Goudoever, J.B.
AU - Schierbeek, Henk
PY - 2014
Y1 - 2014
N2 - OBJECTIVES: Tryptophan not only is an amino acid essential to protein synthesis but also serves as a precursor in 2 important metabolic pathways: the serotonin and the kynurenine pathways. Tryptophan is related to sleeping patterns. The objective of the present study was to determine the tryptophan requirement of term infants using the indicator amino acid oxidation (IAAO) method with L-[1-C]phenylalanine as the indicator. METHODS: Enterally fed infants were randomly assigned to tryptophan intakes ranging from 0.5 to 73 mg · kg · day as part of an elemental diet. After 1-day adaptation to the test diet, [C]bicarbonate and L-[1-C]phenylalanine tracers were given enterally. Breath samples were collected at baseline and during isotopic plateaus. The mean tryptophan requirement was determined by using the biphasic linear regression crossover analysis on the fraction of CO2 recovery from L-[1-C]phenylalanine oxidation (FCO2). Data are presented as mean ± standard deviation. RESULTS: A total of 30 term neonates (gestational age 39 ± 1 weeks) were studied at 9 ± 4 days. FCO2 decreased until a tryptophan intake of 15 mg · kg · day; additional increases in tryptophan intake did not affect FCO2. Mean requirement was determined to be 15 mg · kg · day. CONCLUSIONS: The mean tryptophan requirement for elemental formula-fed term infants is 15 mg · kg · day. This requirement is lower than the present recommended intake of 29 mg · kg · day, which is based on the average intake of a breastfed infant. © 2014 by European Society for Pediatric Gastroenterology, Hepatology, and Nutrition and North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition.
AB - OBJECTIVES: Tryptophan not only is an amino acid essential to protein synthesis but also serves as a precursor in 2 important metabolic pathways: the serotonin and the kynurenine pathways. Tryptophan is related to sleeping patterns. The objective of the present study was to determine the tryptophan requirement of term infants using the indicator amino acid oxidation (IAAO) method with L-[1-C]phenylalanine as the indicator. METHODS: Enterally fed infants were randomly assigned to tryptophan intakes ranging from 0.5 to 73 mg · kg · day as part of an elemental diet. After 1-day adaptation to the test diet, [C]bicarbonate and L-[1-C]phenylalanine tracers were given enterally. Breath samples were collected at baseline and during isotopic plateaus. The mean tryptophan requirement was determined by using the biphasic linear regression crossover analysis on the fraction of CO2 recovery from L-[1-C]phenylalanine oxidation (FCO2). Data are presented as mean ± standard deviation. RESULTS: A total of 30 term neonates (gestational age 39 ± 1 weeks) were studied at 9 ± 4 days. FCO2 decreased until a tryptophan intake of 15 mg · kg · day; additional increases in tryptophan intake did not affect FCO2. Mean requirement was determined to be 15 mg · kg · day. CONCLUSIONS: The mean tryptophan requirement for elemental formula-fed term infants is 15 mg · kg · day. This requirement is lower than the present recommended intake of 29 mg · kg · day, which is based on the average intake of a breastfed infant. © 2014 by European Society for Pediatric Gastroenterology, Hepatology, and Nutrition and North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition.
U2 - https://doi.org/10.1097/MPG.0000000000000434
DO - https://doi.org/10.1097/MPG.0000000000000434
M3 - Article
C2 - 24824360
SN - 0277-2116
VL - 59
SP - 374
EP - 379
JO - Journal of pediatric gastroenterology and nutrition
JF - Journal of pediatric gastroenterology and nutrition
IS - 3
ER -
