Programmable microbial therapeutics: advances in engineered bacteria for targeted in vivo delivery and precision medicine

This review centers on four main areas. First, programmable gene circuits and biosensors enable conditional drug release only when desired. Second, targeting strategies-such as adhesion molecules and microenvironmental cues-guide bacteria to disease sites. Third, delivery system designs (e.g., encapsulation and surface coating) improve bacterial survival and payload stability. Fourth, expression-optimization methods fine-tune therapeutic output levels. We also discuss biosafety measures like kill-switches and auxotrophy, and outline future directions including intelligent feedback loops, multifunctional circuits, and streamlined regulatory pathways.