Bacteriophages as Therapeutic Agents for Pulmonary Infections: From Biological Principles to Clinical Applications

Respiratory infections remain a significant global health concern, especially as multidrug-resistant (MDR) respiratory pathogens reduce the effectiveness of conventional antibiotics. Patients with chronic lung diseases face persistent biofilm-related infections that are difficult to treat, underscoring the urgency for new solutions. This challenge has renewed focus on bacteriophage therapy as a promising alternative in respiratory antimicrobial management. Bacteriophages are viruses that selectively infect and lyse bacteria, showing strong potential as a precise and effective therapy for resistant pulmonary infections. This review focuses on the mechanisms of phage biology and therapy in lung infections, highlighting their unique interactions with mucus, surfactants, and immune defenses-all of which are central to their clinical promise. The review examines advances in phage engineering, delivery strategies, and inhaled formulations aimed at maximizing phage stability and targeting within the airways. It summarizes recent preclinical and clinical progress targeting MDR respiratory pathogens and discusses regulatory, manufacturing, and safety considerations key to integrating phage therapy into mainstream respiratory care.