摘要Background Appropriate iron supplementation is essential for neonatal growth and development.However,there are few reports on the effects of iron overload on neonatal growth and immune homeostasis.Thus,the aim of this study was to investigate the effects of iron nutrition on neonatal growth and intestinal immunity by administering different levels of iron to neonatal pigs.Results We found that iron deficiency and iron overload resulted in slow growth in neonatal pigs.Iron deficiency and iron overload led to down-regulation of jejunum intestinal barrier and antioxidant marker genes,and promoted CD8+T cell differentiation in jejunum and mesenteric lymph nodes(MLN)of pigs,disrupting intestinal health.Moreo-ver,iron levels altered serum iron and tissue iron status leading to disturbances in redox state,affecting host innate and adaptive immunity.Conclusions These findings emphasized the effect of iron nutrition on host health and elucidated the importance of iron in regulating redox state and immunity development.This study provided valuable insights into the regulation of redox state and immune function by iron metabolism in early life,thus contributing to the development of tar-geted interventions and nutritional strategies to optimize iron nutrition in neonates.