Glucosylceramide (G1cCer) has various effects such as skin moisturizing, improvement of atopic dermatitis, and enhancement of skin barrier function. However, the mechanism of GlcCer on skin barrier function remains unclear. In this study, the effect of G1cCer from pineapples (P-GlcCer) on dry skin protection and intestinal immunity was investigated using HR-1 hairless mice fed on a special diet and an in vitro co-culture model consisting of intestinal epithelial Caco-2 and macrophage RAW264.7. The oral administration of P-GlcCer showed an improvement in skin barrier function and enhancement of interleukin-23p19 mRNA (I123a) expression in the small intestine. 1123a expression in LPS-stimulated RAW264.7 cells was enhanced by the purified GlcCer in P-GlcCer. Furthermore, pretreatment of Caco-2 with a beta-glucocere brosid ase or a ceramidase inhibitor suppressed the enhancement of112.3a expression, but a sphingosine kinase inhibitor did not. It was demonstrated that not P-GIcCer itself but the intestinal metabolite 4,8-sphingadienine ameliorated dry skin symptoms. (C) 2017 Elsevier Ltd. All rights reserved.