Breast milk protects the neonate from bacterial translocation.

Clinical and experimental evidence suggests that breast milk enhances the neonatal gut barrier. Using bacterial translocation (BT) as a measure of gut barrier function, a series of experiments was designed to explore the relationship between the neonatal gut barrier and breast milk as well as the factors associated with the feeding of breast milk. Full-term newborn rabbits were assigned to one of four groups: formula-fed (group I), fed with colostrum plus formula (group II), breast-fed with breast milk (group III), and fed with colostrum plus stored breast milk (group IV). At 7 days of age, body weights were obtained, the rabbits were killed, and the mesenteric lymph nodes (MLN), liver, and spleen were quantitatively cultured for translocating bacteria. The cecum was cultured for aerobic and anaerobic enteric organisms. Distal ileal tissues were examined by light and transmission electron microscopy and compared among groups. The viability of cells in the stored, frozen breast milk was assessed by Trypan blue staining. Group I rabbits had significantly lower mean body weights compared with the other groups. The animals breast-fed breast milk had no BT to the MLN or liver and had a 9% incidence of BT to the spleen. There was no difference between BT in groups III and IV. The stored breast milk contained no viable cells. The incidence of BT to all three areas was significantly lower than in groups I and II. The animals fed with formula alone had the highest incidence of BT to the MLN (88%), liver (60%), and spleen (32%). BT in this group was significantly higher compared with groups III and IV.(ABSTRACT TRUNCATED AT 250 WORDS)