Dietary fiber, especially soluble dietary fiber, has been reported to modulate various human physiological functions, and has been attracting attention in recent years. In addition to their physicochemical properties, including water retention and viscosity, their physiological activities are reported to be due to prebiotic effects mediated by intestinal bacteria. Pectin and inulin, which are discussed in this review, have been increasingly used in recent years to promote health. This review thus focuses on pectin and inulin, and their potential functions as prebiotics and as substances with structures related bioactivities, with particular emphasis on recent studies of their ability to induce morphological changes in the small intestine. Key Words: soluble dietary fiber, pectin, inulin, intestinal epithelial cell, fibronectin |