The present invention provides methods and compositions for preventing or inhibiting human food-borne pathogens in animals, and methods for increasing feed efficiency in animals by administering to the animal effective amounts of probiotic lactic acid producing bacteria. Further provided are feed compositions comprising probiotic lactic acid producing bacteria. A preferred probiotic lactic acid producing bacteria is Lactobacillus acidophilus strain ATCC accession number PTA-5249. This bacterial strain inhibits nalidixic acid-resistant Escherichia coli 0157:H7
