SOD1 and inflammatory bowel disease: For instance, it has repeatedly been demonstrated that IBD patients show a lower total blood antioxidant status, as reflected by decreased total antioxidant capacity (TAC) and low levels of antioxidants such as β-carotene, glutathione peroxidase (GPx), superoxide dismutase (SOD) and catalase (CAT) [38,39,40,41].