JAM2 and infection: Before experimental infection (60 d of age), the expression levels of MUC-2 (Figure 3a) and JAM-2 (Figure 3b) were prominently upregulated (p < 0.05) in groups fed MSP at a level of 1 × 108 CFU/kg when compared with the control group (1.73- and 1.44-fold, respectively).