Natural bacteria have a long history of aiding human health, and recent advancements in genetic engineering have led to the creation of hybrid bacteria with enhanced capabilities to treat various diseases. This review covers the characteristics and applications of natural and hybrid bacteria in disease treatment, including obesity, gastrointestinal disorders, and cancer. It also discusses conjugation methods, in vivo fate, complex disease treatments, and addresses clinical challenges while proposing future solutions to promote bacterial biotherapy in clinical settings.
