A recently developed approach in tumor therapy using Salmonella

There are three main approaches in cancer treatment: surgery, chemotherapy, and radiotherapy. Recently, the use of bioengineered bacteria as therapeutic agents has been shown to have some valuable properties in the treatment of cancer, which do not exist in conventional approaches. Bacteria in particular can target tumors, and they can preferentially proliferate and accumulate within tumors and inhibit the growth of cancer cells by inducing cytotoxicity. Thus, bacteria can be easily detected in tumor sites. Moreover, bacteria-derived factors exert an immunostimulatory effect. Over the past decade, Salmonella, Clostridium, and other bacterial genera have been shown to inhibit tumor growth and promote the survival rate in animal models. Clinical trials for cancer treatment with bacteria have shown improved results by combination with other therapeutic methods such as chemotherapy or radioactive agents. This review is an effort to introduce the use of healthy bacteria in tumor therapy. We specifically focus on Salmonella, which has been extensively used in tumor therapy. Therefore, in this review study, we discuss the merits, mechanisms, and attenuated strains of a combination therapy compared to other therapeutic approaches in Salmonella-mediated cancer therapy.