Two linked Nature/Nature Biotechnology reports describe engineered nonpathogenic E. coli programmed with a blood‑inducible circuit to secrete a barnacle‑derived adhesive (CP43K) and a therapeutic mucosal factor (TFF3) in response to gastrointestinal bleeding. In mouse models of inflammatory bowel disease, a single rectal or oral dose enabled bacteria to adhere to inflamed mucosa for days, reduce bleeding, promote mucosal repair and improve clinical endpoints versus controls. The work demonstrates an autonomous sensing‑to‑action synthetic biology approach that couples an adhesion module with payload secretion to sustain local therapy. Authors highlight translational hurdles including safety, containment, regulatory classification of living therapeutics, and manufacturability. Clarification: 'living glue' here refers to engineered microbes that both sense pathological bleeding and produce adhesive plus therapeutic proteins to localize and extend treatment at damaged mucosa.