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

Engineered native Escherichia coli strain MEc30 achieves lifelong gut colonization and sustained therapeutic delivery without disrupting host health or microbiota.

• Why it matters: Effective bacterial therapeutics are limited by poor colonization, safety concerns, and the need for repeated dosing, hindering their clinical potential for metabolic and inflammatory diseases.
• What they did: Researchers screened native murine E. coli isolates, optimized MEc30 by deleting virulence loci, and engineered it to produce nicotinic acid or deliver interleukin-10, testing in disease models.
• The result: MEc30 maintained stable colonization, produced therapeutic molecules continuously, improved metabolic and inflammatory outcomes, and demonstrated safety, enabling long-term live biotherapeutic strategies.