Digestion and Absorption of Sphingolipids as Functional Food Components

Abstract

Sphingolipids are ubiquitous components of the cell membrane in all eukaryotic organisms, and are involved with differentiation and apoptosis. Recently, various physiological functions of dietary sphingolipids, especially the improvement of skin barrier function, have been noted. In order to understand the function of dietary sphingolipids, details of their digestion and absorption need to be clarified. Dietary sphingolipids such as glucosylceramide and sphingomyelin can be hydrolyzed to sphingoid bases, which are then taken up by intestinal mucosal cells. However, the capacity of the intestine for digestion and absorption of sphingolipids is relatively low. Sphingoid bases, except for sphingosine, appear to be transported out of cells across the apical membranes of enterocytes by P-glycoprotein after absorption, and consequently their intestinal uptake is poor. To utilize sphingolipids effectively as food functional components, further study of the mechanism of their selective absorption will be necessary.