Methods and compositions are provided for treating (e.g., therapeutically or prophylactically) gastrointestinal diseases, disorders, and conditions. In particular, one aspect provides compositions comprising Lactobacillus (e.g., Lactobacillus rhamnosus GG or other Lactobacillus species) p40 protein (e.g., isolated, recombinant, or overexpressed p40 protein) and methods of using same for treating a gastrointestinal disease, disorder, or condition.
