Engineered living therapeutics are living organisms—engineered bacteria, cells, or fungi—modified to produce therapeutic molecules inside the body. Genetic code encoding the desired drug (e.g. insulin, enzymes, cytokines) is introduced into probiotic or commensal strains; optional genetic switches allow production to be controlled by external triggers or biomarkers. The organisms act as in situ bioreactors, potentially reducing manufacturing cost substantially compared to conventional biopharmaceutical production and providing sustained, local delivery. Early targets include metabolic disease, where continuous supply could replace frequent injections, and conditions requiring long-term or conditional dosing.
The approach addresses limitations of conventional drugs: cost and complexity of production, short half-life requiring repeated dosing, and difficulty reaching certain tissues. By colonising or circulating in the body, living therapeutics could deliver therapy where and when needed. Research is advancing in strain design, safety (containment, biocides), and regulatory pathways. Clinical and preclinical programmes are underway for diabetes, phenylketonuria, inflammatory disease, and cancer. Challenges include controlling population dynamics, avoiding immune clearance, and ensuring predictable dosing.
Regulatory frameworks for living modified organisms used as drugs are still evolving. Manufacturing and quality control for live products differ from traditional biologics. If safety and efficacy are demonstrated, engineered living therapeutics could become a distinct class of medicine, particularly for chronic conditions and personalised regimens. The technology sits at the intersection of synthetic biology, microbiome science, and drug development.