In this study, the macroscopic IGF-1 effects in the colon were not accompanied by changes in tissue cytokine levels or mucosal barrier function in the small intestine, as indicated by the urinary lactulose/mannitol ratio, bacterial load in the bone marrow or goblet cell density, despite that the overall NEC severity was similar to that reported in earlier similar studies in preterm pigs (39, 44, 45). This evidence concerns the gene IGF1 and necrotizing enterocolitis.