The invention provides a method and composition for ameliorating or reducing the symptoms, signs, and markers and for the treatment of irritable bowel syndrome, inflammatory bowel disease or gastritis in a mammal in need thereof, said method comprising administering effective amounts of a pharmaceutically acceptable composition containing at least one probiotic microorganism strain comprising Pediococcus acidilactici for a time sufficient to ameliorate, reduce or treat at least one symptom, sign, or marker of irritable bowel syndrome, inflammatory bowel disease or gastritis.
