INS and infection: PICRUSt analysis indicated that compared with the non-infected group, SE infection increased abundances of cecal microbial functions involved in microbial infection and anti-infection such as Salmonella infection, Shigellosis, NOD-like receptor signaling pathway, flagella assembly, streptomycin biosynthesis, prodigiosin biosynthesis, acarbose and validamycin biosynthesis, biotin metabolism, ascorbate and aldarate metabolism, biosynthesis of vancomycin group antibiotics and insulin signaling pathway.