Decreased 1,25-dihydroxycholecalciferol [1,25(OH)2D] and upregulated IL-33/IL-31 axis can alter the balance between inflammatory Th1/Th17 cells and T regulatory (Treg) cells and promote the bacterial translocation, associated with the pathophysiological processes of autoimmune diseases like IBD (38, 39). This evidence concerns the gene IL31 and autoimmune disease.