Tumor-homing bacteria are facultative or obligate anaerobic bacteria (capable of producing ATP when oxygen is absent or is destroyed in normal oxygen levels) that are able to target cancerous cells in the body, suppress tumor growth and survive in the body for a long time even after the infection. When this type of bacteria is administered into the body, it migrates to the cancerous tissues and starts to grow, and then deploys distinct mechanisms to destroy solid tumors. Each bacteria species uses a different process to eliminate the tumor. Some common tumor homing bacteria include Salmonella, Clostridium, Bifidobacterium, Listeria, and Streptococcus.[1] The earliest research of this type of bacteria was highlighted in 1813 when scientists began observing that patients that had gas gangrene, an infection caused by the bacteria Clostridium, were able to have tumor regressions.[2]