Advances in the engineering of living probiotics for cancer immunotherapy

The role of bacteria in tumor development has been increasingly recognized through advances in sequencing technologies, revealing their influence on the tumor microenvironment and immune system. Live bacterial therapy, known for its unique ability to target tumors, colonize cancerous tissues, and activate immune responses, is emerging as a novel approach to cancer treatment. To enhance the therapeutic efficacy and safety of this strategy, various engineering techniques have been developed to modify bacteria, enabling the creation of advanced bacteria-based drug delivery systems. Living probiotics can selectively colonize the tumor microenvironment, where they interact with immune cells to enhance antitumor responses. This review provides an overview of the complex relationship between bacteria and tumors and discusses engineering methods for bacterial modification, including physicochemical approaches and synthetic biology. It further highlights the applications of these strategies in enhancing cancer therapies. Finally, it examines the future opportunities for engineered bacteria in cancer therapy, focusing on the potential of combination therapies, personalized medicine, and the role of the microbiome in enhancing therapeutic outcomes. With ongoing advancements, engineered bacteria hold great promise for improving the efficacy and safety of cancer treatments, offering a new frontier in oncology.