Protective effect of a multi-strain probiotics mixture on azoxymethane/dextran sulfate sodium-induced colon carcinogenesis

Abstract

Supplementation with probiotics is considered to be a promising intervention strategy for attenuating colorectal cancer (CRC) by regulating gut microenvironment. This study aimed to investigate the potential CRC ameliorating effect of a multi-strain probiotics mixture on azoxymethane/dextran sulfate sodium-induced CRC mice. After establishing the CRC mouse model, the mice were gavaged with probiotics mixture once daily (∼1 × 109 CFU/mouse) for 8 consecutive weeks. The anti-tumorigenesis effect of probiotics mixture was investigated from the aspects of intestinal microbiota, inflammation, barrier function and oxidative stress. The fecal microbiota was analyzed by 16S rRNA gene sequencing. Results showed that probiotics mixture could significantly inhibit tumorigenesis and inflammatory response. The intestinal barrier function was ameliorated after treatment with this probiotics mixture by recovering the expression of tight junction-related proteins and preventing goblet cell loss. The oxidative stress was alleviated under the increase of antioxidant mediators (total mercapto, reduced glutathione and superoxide dismutase) and the decrease of oxidative mediators (malondialdehyde and myeloperoxidase). In addition, supplementation of probiotics mixture led to an increase of some beneficial bacteria (Lachnospiraceae and Roseburia) and a decrease of some harmful bacteria (Bacteroides and Desulfovibrio), which in turn increased short-chain fatty acids and decreased lipopolysaccharide. These results suggested that the anti-CRC effect of probiotics mixture is mediated by regulating intestinal microbiota, maintaining intestinal barrier function, alleviating inflammation and oxidative stress, which further suggested that this probiotics mixture can be considered as a potential functional food ingredient to attenuate CRC.