Acidified Feedings in Preterm Infants: A Historical and Physiological Perspective.

The use of acidified milk for feeding infants has a long, interesting history that appears to have developed from the use of buttermilk in Holland as early as the late 19th century for feeding infants with diarrhea. Physicians in the early 20th century assumed that the observed benefits were from buttermilk's acidity leading to the practice of acidifying infant formula. The historical and physiological perspective on the use of acidified infant formula is now especially relevant with the emergence of an acidified liquid human milk fortifier for preterm infants. Here, we review that history, with a deeper dive into the contemporary research on the use of acidified human milk fortifiers, the consequences for preterm infants, and the underlying physiological mechanisms. KEY POINTS: · In the late 19th and early 20th century acidified feedings were in common use for sick infants.. · By the mid-20th century, acidified feedings tested in preterm infants resulted in acidic physiology and poor growth.. · The current practice of acidifying feedings in preterm infants has been associated with metabolic acidosis, poor tolerance, and delayed growth..

High-protein formulas: evidence for use in preterm infants.

Relatively high amounts of protein are required to achieve normal fractional protein synthetic rates during the late second through early third trimester of fetal growth. Once preterm infants achieve higher protein intakes for sustained periods, growth begins to approximate that of the normally growing fetus and long-term neurodevelopmental outcomes are improved. Preterm formulas have been developed that are enriched in protein. This review discusses several factors when using standard preterm formulas and high-protein preterm formulas in the neonatal intensive care unit, with an emphasis on quantity and quality of enteral protein delivery and risks to insufficient and/or excess protein administration.

Determination of total potentially available nucleosides in human milk from Asian women.

OBJECTIVE: The objective was to measure the total potentially available nucleosides (TPAN) in breast milk from Asian women. METHODS: One hundred sixty milk samples were collected from 135 healthy, lactating women in Hong Kong, the Philippines, and Singapore at four stages of lactation: colostrum (1 to 3 days postpartum), transitional (7 to 10 days postpartum), early mature (28 to 35 days postpartum), and late mature (90 to 100 days postpartum). Samples were pooled by site and stage of lactation before analysis. RESULTS: The mean TPAN concentration was 203 microM/L (69.4 mg/L corrected for recovery). Average TPAN concentrations were 171.9 microM/L in colostrum, 208.1 microM/L in transitional milk, 221.6 microM/L in early mature milk, and 210.6 microM/L in late mature milk, with no notable differences between countries. The major sources of nucleosides were RNA (43.3% of TPAN) and free nucleotides (39.9% of TPAN). The average percentages of cytidine, uridine, guanosine, and adenosine monophosphates were 44.5%, 23.1%, 16.5%, and 16.1% of TPAN, respectively. The sources of nucleosides and percentages of nucleotide bases were similar for all stages of lactation. Over 91% of the TPAN was present in the non-cellular component except in colostrum. CONCLUSIONS: The average TPAN level in Asian women is similar to that in European and American women, and free nucleotides in human milk represent less than half of the TPAN.

Effect of nucleotides on diarrhea and immune responses in healthy term infants in Taiwan.

OBJECTIVES: The aim of this study was to compare the effects of an infant formula fortified with nucleotides (NF) with those of a control formula (CF) on the incidence of diarrhea, respiratory tract infections (RTIs), and immune responses in healthy term infants. METHODS: This 12-month, double-blind study was conducted on 1- to 7-day-old infants randomized to receive NF or CF exclusively until 12 weeks of age, and fed the assigned formula with solid food until 12 months. NF was supplemented with 72 mg/L of nucleotides, based on the total potentially available nucleotide content of human milk. Subjects were evaluated within 1 week of birth, at 4 weeks, and every 4 weeks thereafter until 48 weeks of age. The primary outcome variable was the incidence of diarrhea. Secondary variables included RTIs, serum immunoglobulin concentrations, and response to hepatitis B vaccine. RESULTS: Compared with subjects fed CF (n = 170), those fed NF (n = 166) had a trend toward reduced risk of diarrhea from 8 to 48 weeks of age and a significantly lower risk of 25.4% (P = 0.05) between 8 and 28 weeks. NF subjects had significantly higher serum immunoglobulin A concentrations ( P < 0.05) throughout the 48-week study. The NF group had an increased risk of upper RTIs, the same incidence of lower RTIs, and the same antibody response to hepatitis B vaccination as the CF group, based on one-sided tests. Growth was normal in both groups, and no adverse events were considered to be formula-related. CONCLUSIONS: Healthy term infants from 8 to 28 weeks of life are less likely to experience diarrhea and have higher serum immunoglobulin A concentrations with NF compared with formula without added nucleotides.