Multiplexed Engineering of Salmonella Typhimurium for Targeted Cancer Therapies

Synthetic biology has driven growing interest in engineered bacteria for cancer therapy. Salmonella Typhimurium stands out as one of the most promising live biotherapeutic products (LBPs) because of its innate tumor-targeting and colonizing abilities. However, the pathogenicity and inconsistent performance of wild-type S. Typhimurium have hindered further clinical translation. Recent advances in programmable and modular genetic redesign now enable precise reprogramming of bacterial functions, facilitating the creation of customized LBPs with enhanced safety and efficacy. In this review, we propose a systematic engineering framework with adaptive optimization and therapeutic enhancement for transforming S. Typhimurium into an effective anticancer LBP. This integrated strategy encompasses multiple facets, including strain attenuation, targeted enhancement, colonization optimization, therapeutic production, lysis-controlled release, and auxiliary modules. This review summarizes the key methodologies for engineering S. Typhimurium, highlighting its evolution from a pathogen to an antitumor vehicle. Furthermore, we summarize the multimodule collaborative engineering design and applications and call for more combinatorial strategies to enhance therapeutic efficacy. We also discuss the challenges and bottlenecks of engineered S. Typhimurium from the perspectives of genetic stability and clinical translation. Finally, we highlight how these synthetic biology advances are refining the mechanistic understanding of bacteria-mediated tumor therapy and paving the way toward safer, more effective, and clinically controllable anticancer strategies.