Total parenteral nutrition alters molecular and cellular indices of intestinal inflammation in neonatal piglets

Background: The adverse effects of TPN on systemic immunity are well-documented; however, the impact of IV feeding on neonatal intestinal immunity is unknown. Methods: A piglet TPN model was used to compare immune cell composition within the intestinal epithelium and lamina propria of parenterally and orally fed piglets. Results: Small intestinal weight of piglets maintained intravenously was reduced 50% after 7 days. Intestinal atrophy in piglets fed parenterally was evidenced by decreased width of intestinal villi and colon cuffs and reduced intestinal crypt depth. The numbers of CD4(+) and CD8(+) T lymphocytes were threefold greater within the lamina propria of jejunal and ileal villi of piglets supported intravenously. Inverse correlations were observed between villus height or width and T-lymphocyte numbers (r = -.80; p < .05). Major histocompatibility complex class II mRNA expression, an indicator of localized inflammation, was increased in the ileum and colon of piglets receiving parenteral nutrition. Goblet cell numbers were two-fold greater in jejunal and ileal villi, and mast cells were more abundant in the colon of piglets fed parenterally. Furthermore, jejunal T-lymphocyte numbers were correlated with goblet cell numbers (r = .80; p = .01). Conclusions: These data identify molecular and cellular indices of intestinal inflammation that are responsive to IV feeding in neonates and provide a. novel framework to investigate mechanisms underlying gut atrophy during TPN.