Qualitative and quantitative comparison of gut bacterial colonization in enterally and parenterally fed neonatal pigs

Total parenteral nutrition (TPN) has been associated with mucosal atrophy, impaired gut barrier function, and translocation of luminal bacteria with resultant sepsis in preterm human infants. Currently, we examined the effects of enteral (ENT) or TPN treatments on translocation events in neonatal pigs and on colonization and composition of microbiota in the neonatal gut. Newborn, colostrum-deprived pigs (<24 hours old) were fitted with intravenous catheters and were fed either ENT (n = 13) or TPN (n = 13) for 7 days. After 7 days of treatment, pigs were euthanized and samples were collected for bacterial culture from the blood, intestinal tract and organs. ENT pigs had increased numbers of bacterial genera isolated, higher concentrations of bacteria (CFU/g), and increased colonization of all segments of the intestinal tract compared to the TPN pigs. Translocation of bacteria from the intestinal tract to tissues or blood was similar (8 of 13) for both groups. The ENT group had 1/13 positive for Clostridium difficile toxin A whereas the TPN group had 5/13. We concluded that ENT favored increased bacterial concentrations comprised of more speciation in the gastrointestinal tract compared to TPN, and that TPN-treated piglets were at higher risk of colonization by toxin-expressing strains of C. difficile.