Amniotic fluid and necrotizing enterocolitis in preterm pigs

Preterm neonates are susceptible to gastrointestinal (GI) disorders such as necrotizing enterocolitis (NEC). Maternal milk, and especially colostrum, protects against NEC via growth promoting, immunomodulatory and antimicrobial factors. The fetal enteral diet, amniotic fluid (AF), contains similar bioactive components and we hypothesized that postnatal AF administration would reduce inflammatory responses and NEC in preterm neonates. Thirty preterm pigs (92% gestation) were delivered by caesarean section and fed total parental nutrition (TPN) for 48 h followed by enteral porcine colostrum (COLOS, n=7), infant formula (FORM, n=13) or formula + porcine AF (AF, n=10). Using a previously validated model of NEC in preterm pigs, we determined the structural, functional, microbiological and immunological responses to AF when administered prior to and after introduction of a suboptimal enteral formula diet. Keywords: Healthy versus inflammed tissues in relation to necrotizing enterocolitis Pigs from each treatment group (COLOS, n=4; FORM, n=6; and AF, n=7) were randomly selected for microarray analysis of frozen distal small intestine samples. The FORM group was further divided into formula-fed healthy pigs (F-HEA, n=3) and formula-fed NEC pigs (F-NEC, n=3) in order to compare sick versus healthy formula fed pigs. Equal amounts of total distal small intestinal RNA from all pigs were pooled to make the reference sample. Samples and reference pool were labelled with Oyster 550 and 650, respectively. The in-house spotted porcine oligonucleotide microarray version 4 (POM4) is a low density microarray consisting of 384 different oligonucleotide probes representing more than 200 different immune related genes.