Intestinal microbiota imbalance may worsen the progression of ulcerative colitis (UC). Lacticaseibacillus rhamnosus LS8 (LR) has the potential ability to regulate microbiota through producing a novel antibacterial substance, cyclic opine: cycloalanopine. This study aimed to investigate whether LR could ameliorate dextran sulfate sodium-induced UC in mice via modulating intestinal microbiota using fecal microbiota transplantation (FMT) experiment. The results showed that both LR and FMT attenuated UC as evidenced by 1) alleviating disease activity index and colonic pathology; 2) up-regulating MUCs and tight junction proteins; 3) increasing oxidative mediators and decreasing antioxidant mediators; 4) down-regulating proinflammatory cytokines and chemokines. These results were mainly attributable to the microbiota-regulating effect of LR, including increasing benefi cial bacteria (like Akkermansia) and its related SCFAs, while decreasing harmful bacteria (like Proteobacteria) and its related LPS, thereby suppressing the hyperactivation of TLR4/NF-κB pathway. Consequently, LR can alleviate UC and is a potential dietary supplement to attenuate UC.

Colorectal cancer (CRC) is one of the most common cancers and supplementation of probiotics may be a promising intervention method. The present study aimed to investigate the anti-CRC effects of Lactiplantibacillus plantarum KX041 on a CRC mouse model. The CRC mice were induced by 10 mg/kg azoxymethane and 2% dextran sulfate sodium. L. plantarum KX041 was orally administrated once daily (1 × 10⁹ CFU/mouse). Results showed that L. plantarum KX041 could significantly inhibit inflammation, tumor formation, and induce tumor cells apoptosis. Moreover, this probiotic could ameliorate the damage of intestinal barrier by recovering tight junction protein expression (like Occludin, Claudin-1, and ZO-1) and preventing goblet cell loss. Furthermore, the oxidative stress was alleviated by increasing the level of antioxidant mediators (like GSH and SOD) and reducing the level of oxidative mediators (like MDA and MPO). In addition, treatment with L. plantarum KX041 could directly regulate gut microbiota, thereby increasing the abundance of beneficial bacteria (like SCFAs-producing bacteria, Akkermansia) and decreasing the abundance of harmful bacteria (like pro-inflammatory bacteria, Parasutterella), which in turn raised SCFAs levels and lowered LPS levels. In conclusion, L. plantarum KX041 could effectively ameliorate CRC via reshaping intestinal microenvironment, alleviating inflammation, maintaining intestinal permeability, and attenuating oxidative stress.