Disclosed are methods and compositions using glycoside hydrolases, such as an alpha-L-fucosidases, to prevent and/or treat a pathogenic infection and/or diarrhea in an animal wherein the pathogenic infection is caused by a pathogen capable of binding to an animal intestinal cell wherein said binding of the pathogen is dependent on the presence of a pathogen binding site having at least one glycan structure substituted with at least one alpha-1,2-L-fucose moiety comprising administering to the animal an effective amount of a glycoside hydrolase capable of removing the at least one alpha-1,2-L-fucose moiety from the pathogen binding site.