Macromolecular Absorption in Preterm and Term Infants

Abstract

Human alpha-lactalbumin (alpha-LA) has been used as a marker for measuring macromolecular absorption. The serum concentration of human alpha-LA after a human milk feed has been studied in 32 healthy very low birthweight infants (VLBW), fed human milk (gestational age 26-32 weeks) and in 56 term, breast-fed infants, age 3-140 days. At 31 weeks of gestation the serum concentration of human alpha-LA was more than 10 times higher (mean value 3,000 and median value 2,101 micrograms/l serum/l human milk/kg body weight, n = 11) than in the term infants aged 3-30 days (mean value 257 and median value 152, n = 29). The serum concentration of alpha-LA decreased with increasing maturity in the VLBW-infants. At a postconceptional age of 37 weeks the values were similar (mean value 200 and median value 99, n = 8) to those found for term infants during the first month. In the term infants a decreasing absorption of alpha-LA was found with increasing postnatal age.

Prototypic Long Pentraxin PTX3 Is Present in Breast Milk, Spreads in Tissues, and Protects Neonate Mice from Pseudomonas aeruginosa Lung Infection

“…Consequently, ingested molecules and cells are rapidly found in plasma and organs after feeding (22,44,46,47). In accordance with this property, orally administered recombinant PTX3 was rapidly accumulated in neonatal tissues.…”

“…The neonatal gastrointestinal system is permeable for biomolecules present in milk, which may rapidly accumulate in the neonate tissues (22,46,47). To evaluate whether PTX3 contained in milk diffuses in neonatal tissues, we analyzed whether orally administered PTX3 in neonate mice can be detected in the tissues.…”

A rapid gas-liquid chromatography method for the determination of lactulose and mannitol in urine: Clinical application in studies of intestinal permeability

“…It is known that there is an enhanced intestinal permeability in the preterm newborn (4,8) which represents an immaturity of the gut mucosa, but there is also a rapid decline in permeability which follows the onset of oral feeding (9).…”

“…The disaccharide is absorbed by a paracellular route across tight junctions between adjacent enterocytes, whereas the monosaccharide is absorbed via the water-filled trough in the enterocyte membrane. In cases where the mucosal barrier is damaged, such as celiac disease (3,6), cystic fibrosis (5) and cow's milk protein intolerance (7) or those where gut closure is incomplete like in the newborn infant, especially preterm neonates (8,9), the gut is permeable to intact sugars and proteins (9). For this reason, an increase in the disaccharide/monosaccharide urine excretion ratio would indicate an abnormal passive uptake of sugars and maybe antigens, due to the use of the same paracellular route across the mucosal barrier.…”

Mucosal immune response development: breastfeeding and environmental influence

“…Embora o papel biológico de alguns desses componentes ainda não esteja definido, a integridade da barreira epitelial no período neonatal é um importante mecanismo de resposta inespecífica 43 . Esta barreira pode ser implementada por fatores presentes no LM, tais como o Fator de Crescimento Epitelial, fatores de maturação (cortisol), enzimas que degradam mediadores (PAF acetil-hidrolase) e moduladores de leucócitos (lisozima, IgAs).…”