Here, we constructed a mouse model of enteritis caused by pulmonary infection with a strong-virulence strain of Lp; based on this model we demonstrated that the systemic inflammatory cytokines, such as IL-6, could activate caspase 3, through upregulating the expression of p53 and inhibiting the expression of Bcl-2, leading to the enteritis phenotype. Here, CASP3 is linked to enteritis.