Co-delivery of microbial consortia and astaxanthin via liposomes for colitis relief and synergistic treatment of colorectal cancer

Both microbes and the hydrophobic antioxidant astaxanthin (AST) are promising tools for the treatment of inflammatory bowel disease (IBD) and colorectal cancer (CRC), but clinical use is still limited. Synergistic application and co-delivery of the 2 are valuable for broadening both microbial and antioxidant therapies. It is necessary to find a solution for co-delivery that kills two birds with one stone for effective intestinal delivery. In this study, a simple to prepare and stable liposomal system (Lipo@AST@PRO) has been constructed for co-delivery of a microbial consortium and AST. For microbes, it provided microbial gastrointestinal protection and prolonged microbial intestinal retention. For AST, it exhibited good colonic release and bad odors masking effect. Lipo@AST@PRO demonstrated dextran sulfate sodium (DSS)-induced colitis relief by restoring the intestinal barrier and the recovery of intestinal stem cells (ISCs). It also demonstrated synergistic antitumor efficacy with 5-fluorouracil (5-FU) in CT26 tumor-bearing mice by modulating the immune microenvironment and promoting vascular normalization. In conclusion, a platform was established for the co-delivery of multiple microorganisms and xenobiotics, which was beneficial for the intestinal illness. It broadened the therapeutic forms of intestinal diseases and provided a new reference for the application of microbial and hydrophobic antioxidants in food and drug forms.