A pharmaceutical composition comprising: a) an effective amount of one or more lytic bacteriophages specific against Fusobacterium nucleatum selected from FnpΦ02-14, FnpΦ11 and FnnΦ107 or mixtures of them; and b) one or more pharmaceutically acceptable carrier and/or excipients. Method for preventing and/or treating diseases associated with Fusobacterium nucleatum and the use of the pharmaceutical composition for treating a disease associated with Fusobacterium nucleatum of the oral cavity such as periodontal disease, among others.