Synthetic biology strategies for engineering probiotics and commensal bacteria for diagnostics and therapeutics

Microorganisms inhabit diverse environments, including nearly every organ in the human body. The human microbiome-a complex community of microorganisms residing in the human body-has gained increasing attention as a key contributor to human health and disease, making it an important target for the development of diagnostic and therapeutic strategies. However, the inherent complexity of microbial communities and the challenges of engineering diverse non-model microorganisms present significant barriers. To address these challenges, synthetic biology has provided powerful tools and strategies to engineer microorganisms capable of sensing disease-specific environments and performing targeted therapeutic functions. In particular, the development of synthetic genetic circuits has significantly improved the precision and reliability of disease diagnosis and treatment, enabling real-time disease monitoring, therapeutic, and even preventive interventions. This review highlights state-of-the-art synthetic biology tools and strategies for engineering the probiotics and commensal bacteria aimed at the diagnosis and treatment of human diseases, with accompanying examples. Future challenges and prospects are also discussed.