Natural Phenolic-Metal Framework Strengthened Mesona Chinensis Polysaccharides Microgels for Improved Viability of Probiotics to Alleviate the Liver Injury and Gut Microbiota Dysbiosis

Oral probiotics meet challenges during processing, storage, and gastrointestinal harsh conditions. Polysaccharide-based hydrogels delivery system is promising in probiotic protection, but its semi-solid and weak strength, and often requires additional cross-links to solidify its structure. Herein a ferric ion co-crosslinked microgel of Mesona chinensis polysaccharides and mechanically strengthened by phenolic-metal frameworks of naturally bound brown bioactives is designed. These microgels has an intact structure in acidic condition and ruptured only at pH neutral conditions which can responsively release highly viable probiotics with high mucoadhesion and colonization. Brown bioactives are naturally bound to polysaccharides (MCPC) by hydrophobic interactions and hydrogen bonding, and they exhibited outstanding anti-inflammatory and antioxidant properties. Moreover, these brown bioactives are the precise prebiotics which can specifically improve the abundance of Akkermansia genus in gut in vivo. Then, the probiotics Akkermansia muciniphila (AKK) are loaded into brown bioactives frameworks strengthened microgels. There is a more synergistic healthy benefit between MCPC components and loaded AKK compared with free and pasteurized AKK. MCPC microgels can deliver high viable AKK specifically to gut consequently modulating the microbiota balance, and protecting the intestinal barriers. MCPC microgels also delivered the antioxidant brown bioactives specifically into liver to alleviate the hepatic oxidative stress and inflammation.