Evaluation of antioxidant activity of novel potential probiotic cocktail in mice model of gut inflammation via oxidative stress-related pathways

Oxidative stress plays a key role in colitis, a type of Inflammatory Bowel Disease, particularly when associated with a high-fat diet (HFD). Probiotics are known to alleviate inflammation through multiple mechanisms. This study aimed to evaluate the efficacy of a potential probiotic mixture with high antioxidant activity in attenuating colitis in mice fed either a normal diet (ND) or an HFD, with a focus on oxidative stress-related pathways. Eighty-eight Lactobacillus and Bifidobacterium strains isolated from healthy human faeces and milk were screened for antioxidant capacity. The six most active strains were selected to formulate a probiotic cocktail. Male C57BL/6 mice were divided into ND and HFD groups, each receiving dextran sulphate sodium (DSS) alone or combined with the probiotic cocktail. Disease indices, histopathology, and the expression of genes related to NF-kB and Nrf2 signalling, as well as oxidative and inflammatory markers, were assessed. Mice treated with the probiotic cocktail showed significant attenuation of DSS-induced colitis, evidenced by lower Disease Activity Index and pathological scores, and improved intestinal morphology ( P < 0.05). Both dietary groups exhibited elevated antioxidant enzyme activity and anti-inflammatory cytokine levels ( P < 0.05). The modulation of Nrf2 and NF-kB-related gene expression was more pronounced in ND-fed mice. The findings suggest that this novel probiotic cocktail can effectively alleviate colitis symptoms, likely by regulating oxidative stress and inflammatory pathways. Its incorporation as an adjunct therapy, particularly alongside a balanced diet, may offer a promising strategy for colitis management.