Superoxide dismutase recombinant Lactobacillus fermentum ameliorates intestinal oxidative stress through inhibiting NF- jB activation in a trinitrobenzene sulphonic acid- induced colitis mouse model

Aims: Superoxide dismutase (SOD) can prevent and cure inflammatory bowel diseases by decreasing the amount of reactive oxygen species. Unfortunately, short half-life of SOD in the gastrointestinal tract limited its application in the intestinal tract. This study aimed to investigate the treatment effects of recombinant SOD Lactobacillus fermentum in a colitis mouse model. Methods and Results: In this study, we expressed the sodA gene in Lact. fermentum I5007 to obtain the SOD recombinant strain. Then, we determined the therapeutic effects of this SOD recombinant strain in a trinitrobenzene sulphonic acid (TNBS)-induced colitis mouse model. We found that SOD activity in the recombinant Lact. fermentum was increased by almost eightfold compared with that in the wild type. Additionally, both the wild type and the recombinant Lact. fermentum increased the numbers of lactobacilli in the colon of mice (P < 0.05). Colitis mice treated with recombinant Lact. fermentum showed a higher survival rate and lower disease activity index (P < 0.05). Recombinant Lact. fermentum significantly decreased colonic mucosa histological scoring for infiltration of inflammatory cells, lipid peroxidation, the expression of pro-inflammatory cytokines and myeloperoxidase (P < 0.05) and inhibited NF-kappa B activity in colitis mice (P < 0.05). Conclusions: SOD recombinant Lact. fermentum significantly reduced oxidative stress and inflammation through inhibiting NF-kappa B activation in the TNBS-induced colitis model. Significance and Impact of the Study: This study provides insights into the anti-inflammatory effects of SOD recombinant Lact. fermentum, indicating the potential therapeutic effects in preventing and curing intestinal bowel diseases.