Dietary sphingomyelin alleviates experimental inflammatory bowel disease in mice

The effect of dietary sphingomyelin (SM) on inflammatory bowel disease (IBD) induced with dextran sodium sulfate (DSS) was examined in mice. Although the severity of IBD as expressed by the disease activity index (DAI) markedly increased with DSS administration, feeding a diet containing SM lowered the DAI value significantly. Myeloperoxidase (MPO) activity in colonic tissue also increased with DSS administration, suggesting the development of inflammation. Because simultaneous administration of SM with DSS prevented the MPO activity increase, we concluded that SM could suppress the development of inflammation. These results provide novel evidence that dietary supplementation with SM can alleviate the symptoms of IBD in mice. Dietary SM also increased the amount of IgA in the large intestine, suggesting that SM promotes IgA secretion into the large intestine. These results suggest that the mechanism of IBD mitigation by SM is complex and involves the immune system.