Researchers engineered nonpathogenic E. coli with a blood‑inducible circuit that secretes a barnacle‑derived adhesive protein (CP43K) and the gut‑repair factor TFF3 in response to gastrointestinal bleeding, enabling bacteria to adhere to inflamed mucosa and deliver therapeutics locally. In mouse models of inflammatory bowel disease the approach improved weight recovery, reduced bleeding, reversed colonic shortening and promoted mucosal healing. The study, published in Nature Biotechnology, demonstrates a living material that autonomously senses pathology and sustains localized therapeutic action for days—an advance in engineered living therapeutics and targeted mucosal delivery.