Reactive oxygen species (ROS) play vital roles in intestinal
inflammation. Therefore, eliminating ROS in the inflammatory site by
antioxidant enzymes such as
catalase and
superoxide dismutase may effectively curb
inflammatory bowel disease (IBD). Here, Escherichia coli Nissle 1917 (
ECN), a kind of oral probiotic, was genetically engineered to overexpress
catalase and
superoxide dismutase (
ECN-pE) for the treatment of intestinal
inflammation. To improve the bioavailability of
ECN-pE in the gastrointestinal tract,
chitosan and
sodium alginate, effective biofilms, were used to coat
ECN-pE via a layer-by-layer electrostatic self-assembly strategy. In a mouse IBD model induced by different chemical drugs,
chitosan/
sodium alginate coating
ECN-pE (
ECN-pE(C/A)2) effectively relieved
inflammation and repaired epithelial barriers in the colon. Unexpectedly, such engineered
EcN-pE(C/A)2 could also regulate the intestinal microbial communities and improve the abundance of Lachnospiraceae_NK4A136 and Odoribacter in the intestinal flora, which are important microbes to maintain intestinal homeostasis. Thus, this study lays a foundation for the development of living therapeutic
proteins using probiotics to treat intestinal-related diseases.