Phage therapy or viral phage therapy is the therapeutic use of bacteriophages to treat pathogenic bacterial infections. Phage therapy has many potential applications in human medicine as well as dentistry, veterinary science, and agriculture. If the target host of a phage therapy treatment is not an animal, the term "biocontrol" (as in phage-mediated biocontrol of bacteria) is usually employed, rather than "phage therapy".
Bacteriophages are much more specific than antibiotics. They are typically harmless not only to the host organism, but also to other beneficial bacteria, such as the gut flora, reducing the chances of opportunistic infections.They have a high therapeutic index, that is, phage therapy would be expected to give rise to few side effects. Because phages replicate in vivo (in cells of living organism), a smaller effective dose can be used.
