To understand the characteristics of T cells in the neonatal intestine and how probiotic LR17938 modulates the Foxp3+ Tregs in the intestines after oral administration to newborn rats, we first examined the phenotypic composition of T cell subsets in the distal 4-cm of terminal ileum from day of life (DOL) 0 to DOL 4 during the course of NEC in a neonatal rat model. This evidence concerns the gene FOXP3 and necrotizing enterocolitis.