Interestingly, antibiotics did not directly affect viral replication or prevent tissue infection but acted specifically to trigger the expression of receptors for antiviral cytokine IFN-λ and to stimulate the expression of Stat1 and Irf3. In another murine model of norovirus infection, while IL-10−/− SPF mice showed dramatically aggravated intestinal inflammation and mucosa damage, IL-10−/− GF mice were free of epithelial barrier disruption, and transplantation of defined flora to these mice was sufficient to restore inflammatory lesions in the intestine (53). Here, IL10 is linked to infection.