Living biotherapeutic products based on engineered bacteria: current status and future prospects

Live biotherapeutic products (LBPs) represent a distinct category of biological products containing viable organisms, such as bacteria, utilized for the prevention and treatment of human diseases (excluding vaccines). Presently, research and development efforts in LBPs are predominantly centered on live bacteria. Compared to traditional drugs, the LBPs demonstrate unique characteristics, including replicability, target specificity, and responsiveness. Owing to these properties, LBPs have emerged as hotspots in the development of specialized treatments for various major diseases, with applications spanning malignant tumors, metabolic disorders, inflammatory bowel diseases, genetic defects, and more. Nevertheless, natural bacteria face inherent limitations—such as low activity, instability, and safety concerns—that hinder their pharmacological potential. As a result, engineering strategies have become essential for enhancing the properties of bacteria and facilitating their clinical applications. This article delves into recent advancements in LBPs derived from engineered bacteria, offering a systematic review of reported engineering strategies, which are broadly categorized into chemical, physical, and genetic modifications. The findings indicate that no single engineering approach can comprehensively address all the challenges associated with converting viable bacteria into effective LBPs. To overcome this limitation, a concept of "multi-engineered bacteria" is introduced. This framework advocates for the integration of physical, chemical, and biological engineering strategies to develop next-generation LBPs with enhanced functionality and clinical potential. This article provides a concise review of current research on LBPs based on engineered bacteria and outlines forward-looking perspectives for advancing their development through innovative engineering approaches.