As the analysis of variance showed, the activity of SOD detected in blood cells lysate was lower in rats with TNBS-induced colitis (ANOVA, p < 0.01), whereas feeding intervention with added oat beta-glucans resulted in a change in the activity of this enzyme after 3 and 7 days of feeding, which was confirmed by ANOVA analysis. The gene discussed is SOD1; the disease is colitis.