A durably colonising engineered native symbiont enables sustained intestinal delivery for metabolic dysfunction and colitis

The authors aimed to develop a safety-optimized native bacterial chassis, specifically engineered murine *Escherichia coli* strain MEc30, for long-term gut colonization and sustained therapeutic delivery to address metabolic dysfunction and colitis. Their findings demonstrate that MEc30 can achieve lifelong intestinal colonization without disturbing host physiology, while effectively delivering nicotinic acid and interleukin-10 to improve metabolic health and alleviate inflammation in mouse models. This study suggests that engineered native symbionts like MEc30 could serve as a viable long-acting biotherapeutic strategy for chronic intestinal and metabolic diseases.