As shown in Fig. 1, the MDA content in colons of the SOD group of T2D rats (0.69) was not significantly higher than in the L-SOD group (0.62) (P > 0.05), while the GSSG/GSH ratio (Fig. 2) of the SOD group (1.63) was significantly higher than that of the L-SOD group (0.95) (P < 0.01). This evidence concerns the gene SOD1 and type 2 diabetes mellitus.