Effect of early nutritional derivation and diet on translocation of bacteria from the gastrointestinal tract in the newborn rat

The gastrointestinal (GI) barrier function is immature in the preterm neonate and might thus facilitate translocation of enteric bacteria and gut-derived septicemia. Circumstantial evidence suggests that bacterial uptake from the intestine may be further enhanced by an alteration of the host nutritional status. To test this hypothesis, neonatal rats were fed normal or restricted amounts of either breast milk or of a rat milk-simulated formula for 3-5 d. At the end of the study, various sections of the GI tract, mesenteric lymph nodes, liver, spleen, and blood were analyzed for bacteria using standard microbiologic procedures. Normal breast feeding was associated with bacterial translocation to mesenteric lymph nodes and in some cases to liver or spleen in 27% of rats, whereas all bacterial cultures were negative in a control group killed immediately after birth. Restricted breast feeding did not increase translocation compared with normal breast feeding. By contrast, feeding normal or restricted amounts of formula increased the numbers of gut bacteria by 2-3 logs, altered the morphology of the small intestinal mucosa, and resulted in ample bacterial translocation to the mesenteric lymph nodes and to systemic organs including the blood. Bacterial translocation may normally occur in suckling neonatal rats and is not increased by food restriction. Artificial feeding dramatically enhances translocation of gut bacteria.