Morphological Study : Application to Breastfeeding Nursing, Influence of Supplemental Feeding at the Early Neonatal Stage

Purpose: We investigated the effects of breast-feeding and supplementary-feeding on jejunal villi morphology and jejunal absorptive capacity at the early neonatal stage. Methods: Newborn Wistar rats were separated from their mothers immediately after birth and allocated to a breast-fed, mixed-fed (breast-feeding and formula-feeding), or formula-fed group. Rats were fed accordingly for 3 days. We then investigated the morphology of jejunal villi and the mechanism of macromolecular uptake by absorptive cells in each group. Horseradish peroxidase (HRP) was used as a representative macromolecule. Results: After three days of feeding, jejunal villi of breast-fed rats were longest, followed by the mixed-fed, and then formula-fed groups. Additionally, HRP underwent transcytosis from the apical membrane to the basolateral membrane of absorptive cells in the breast-fed group. HRP did not undergo transcytosis in either the formula-fed or mixed-fed rat jejuna. Conclusion: Our findings suggest that supplementary feeding affects normal villus development and impairs endocytosis and transcytosis in early neonatal stage jejunal absorptive cells.