It was found that the protein level of NOS2 in the DSS + LBP 200 mg/kg group was markedly decreased in contrast with the DSS group (Figures 1H, I), while the protein level of Arg-1 was obviously increased in contrast with the DSS group (Figures 1H, J), suggesting that LBP may protect against IBD by regulating macrophage polarization. Here, ARG1 is linked to inflammatory bowel disease.