Fetal Food - Preemie's Prerequisite? Studies on human fetal and neonatal protein metabolism

In 1960, the terms ‘neonatology’ and ‘neonatologist’ were first coined in a textbook on newborns. In hindsight, that decade turned out to be the start of modern care for prematurely born babies. Since then, survival chances for premature infants improved dramatically: for 1-kg-weighing infants from hardly any to approximately 90% nowadays. In addition, due to ongoing research, many infants born too early now have good health outcome, although there is also a large group facing mild handicaps and a smaller group facing more severe handicaps. In the Netherlands, the incidence of all live births delivered preterm – that is before 37 weeks of gestation – was 7.3% in 2004. Infants born alive very preterm (<32 weeks) make up 1.1% of the 194.007 births in the Netherlands that same year. These very preterm infants spent on average 28 days on a neonatal intensive care unit (NICU). In the United States, the current incidence of births delivered preterm amounts 12.8% and is thus higher than in the Netherlands. Moreover, the percentage is on the rise: between 1981 and 2005 it increased with 35% (Figure 1). Although we are aware of several factors responsible for this increase (see below), prematurity is becoming a problem affecting society more and more

The Effect of Pasteurization on the Antioxidant Properties of Human Milk:A Literature Review

High rates of oxidative stress are common in preterm born infants and have short- and long-term consequences. The antioxidant properties of human milk limits the consequences of excessive oxidative damage. However, as the mother’s own milk it is not always available, donor milk may be provided as the best alternative. Donor milk needs to be pasteurized before use to ensure safety. Although pasteurization is necessary for safety reasons, it may affect the activity and concentration of several biological factors, including antioxidants. This literature review describes the effect of different pasteurization methods on antioxidant properties of human milk and aims to provide evidence to guide donor milk banks in choosing the best pasteurization method from an antioxidant perspective. The current literature suggests that Holder pasteurization reduces the antioxidant properties of human milk. Alternative pasteurization methods seem promising as less reduction is observed in several studies

The influence of a maternal vegan diet on carnitine and vitamin B2 concentrations in human milk

Background: The maternal diet greatly influences the nutritional composition of human milk. With the rise of vegan diets by lactating mothers, there are concerns about the nutritional adequacy of their milk. Two important nutrients, vitamin B2 and carnitine, are mostly ingested via animal products. Objective: We investigated the influence of a vegan diet on the vitamin B2 and carnitine concentrations in milk and serum of lactating women. Methods: In this case–control study, 25 lactating mothers following an exclusive vegan diet were comparted to 25 healthy lactating mothers with an omnivorous diet without use of supplements. High-performance liquid chromatography and liquid chromatography–tandem mass spectrometry were used to measure vitamin B2 and carnitine concentrations, respectively. A linear regression model was used to determine differences in human milk and serum concentrations between study groups. Results: Vitamin B2 concentrations in human milk and serum did not differ between study groups. While the human milk free carnitine (C0) and acetyl carnitine (C2) concentrations did not differ between study groups, serum carnitine concentrations were lower in participants following a vegan diet than in omnivorous women (p &lt; 0.0001). Conclusion: A maternal vegan diet did not affect human milk concentration of vitamin B2 and carnitine. Breastfed infants of mothers following an exclusive vegan diet therefore are likely not at increased risk of developing a vitamin B2 or carnitine deficiency

Analysis of [U-13C6]glucose in human plasma using liquid chromatography/isotope ratio mass spectrometry compared with two other mass spectrometry techniques

The use of stable isotope labelled glucose provides insight into glucose metabolism. The 13C-isotopic enrichment of glucose is usually measured by gas chromatography/mass spectrometry (GC/MS) or gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS). However, in both techniques the samples must be derivatized prior to analysis, which makes sample preparation more labour-intensive and increases the uncertainty of the measured isotopic composition. A novel method for the determination of isotopic enrichment of glucose in human plasma using liquid chromatography/isotope ratio mass spectrometry (LC/IRMS) has been developed. Using this technique, for which hardly any sample preparation is needed, we showed that both the enrichment and the concentration could be measured with very high precision using only 20 µL of plasma. In addition, a comparison with GC/MS and GC/IRMS showed that the best performance was achieved with the LC/IRMS method making it the method of choice for the measurement of 13C-isotopic enrichment in plasma samples

Amino Acid Metabolism in the Human Fetus at Term: Leucine, Valine, and Methionine Kinetics

Human fetal metabolism is largely unexplored. Understanding how a healthy fetus achieves its fast growth rates could eventually play a pivotal role in improving future nutritional strategies for premature infants. To quantify specific fetal amino acid kinetics, eight healthy pregnant women received before elective cesarean section at term, continuous stable isotope infusions of the essential amino acids [1

Amino acids for the neonate: Search for the ideal dietary composition

Amino acids play crucial roles as precursors for proteins and neurotransmitters, as transport molecules, and in cell signaling. In this review, we describe the unique functions of the individual amino acids and conclude that the amino acid requirements of parenterally fed neonates are inadequately defined. Parenterally fed neonates are at risk of amino acid deficiency or toxicity because the intestines serve as an important site of metabolism, regulating systemic availability of individual amino acids