Colon microenvironment restorative nano-armored probiotics–rosmarinic acid bioconjugation for synergistic alleviation of inflammatory bowel disease

) that accumulated on the probiotic surface facilitated the formation of a pH-responsive enteric coating. This coating, composed of hydroxypropyl methylcellulose acetate succinate (HPMCAS) mixed with sodium alginate (SA), acted as a protective nano-armor on the surface, yielding EcN-RA@AS/SA. This nano-armor protected the probiotics during gastric transit, ensuring their safe delivery to the intestine. In a mouse model of IBD, EcN-RA@AS/SA demonstrated efficacy in restoring the colon microenvironment by alleviating symptoms through downregulating the expression of proinflammatory cytokines, repairing the intestinal barrier, and regulating the gut flora.