The invention includes a formulation comprising: (i) a therapeutically effective amount of at least one antibiotic; and (ii) a therapeutically effective amount of at least one probiotic material. The formulation is prepared in a dosage form for delivery to the gastrointestinal tract. The invention further includes a method of preventing or minimizing the proliferation of Clostridium difficile in the gastrointestinal tract of a mammal undergoing an antibiotic therapy comprising by administration of the formulation of the invention for the duration of the antibiotic therapy; methods of preventing or minimizing the occurrence of antibiotic-associated diarrhea in a mammal undergoing an antibiotic therapy that includes administering the formulation; and methods of preventing or minimizing the occurrence of antibiotic-associated colitis or pseudomembranous colitis in a patient undergoing an antibiotic therapy that includes administering the formulation. Also included are methods of reducing or preventing a failure of treatment for an antibiotic-treatable infection in a patient comprising orally administering the formulation. Described by the invention are formulations for the treatment of a C. difficile infection comprising: (i) a therapeutically effective amount of at least one antibiotic; and (ii) a therapeutically effective amount of at least one probiotic material. The antibiotic includes a non-systemic gram negative antibiotic (such as, for example, fodaximicin) and formulation is prepared in a dosage form for delivery to the gastrointestinal tract. Also included are methods of treatment of a C. difficile infection in mammal that include administering to the digestive tract of the mammal the above described formulation. Such methods provide that the likelihood that the mammal shall experience a reoccurrence of the C. difficile infection is 70% or less.L'invention concerne une formulation comprenant : (i) une quantité thérapeutiquement efficace d'au moins un