Transient hypersensitivity to soybean proteins resulting in diarrhea and poor health status is well known in the nutrition of weaned pigs (Li et al., 1990; Dewey, 1993; reviewed by Jezierny et al., 2010). Literature is very limited in using ESBM in weaned pigs. Dierick et al. (2004) reported that there was less residual antigenicity against the soy protein in the stomach and foregut content of piglets on the protease diets and the IgG titers to soy proteins in the sera of protease fed piglets was lowed. Song et al. (2010) found that weaned pigs with 6.58 kg body weights fed diets with fermented soybean meal for 2 weeks were more healthy (less diarrhea) than those fed the diet without fermented soybean meal.