Effects of 7S and 11S on the intestine of weaned piglets after injection and oral administration of soybean antigen protein

Soybeans are used increasingly in food products because of their health benefits. In this study, we investigated the effect of soybean antigen protein on weaned piglet intestine. Seventy piglets were randomly divided into seven groups with 10 piglets each. At 7 and 14 days of age, groups A–C were injected with saline, and D–G were intramuscularly injected with or orally administered 7S or 11S. Groups B–G were artificially sensitized by dietary 7S or 11S. At 27 days, the small intestinal tissues were collected to determine levels of histamine, sIgA protein, and IgA mRNA. Histamine in B–G was significantly decreased in the duodenum and ileum. Moreover, sIgA expression was higher in all groups than in A, with B/C>D–G and F/G>D/E; the trend in IgA expression was similar. Collectively, these results indicated that soybean antigen protein‐immunizing agents decrease sIgA and IgA levels. Additionally, the effect of injection immunization occurred prior to that of oral immunization.