Inulin Promotes Intestinal Epithelial Growth Factor Secretion by Acting Directly on Differentiated Caco-2 Cells
Hayata IRITANI1，Tomio YABE1，2，3 *
1Department of Life Science and Chemistry，Graduate School of Natural Science and Technology，Gifu University
2Department of Applied Life Science，Faculty of Applied Biological Sciences，Gifu University
3Center for Highly Advanced Integration of Nano and Life Sciences (G-CHAIN)，Gifu University
Inulin is known to have a beneficial physiological effect on health and has been used in various foods in recent years. It has been reported that the mechanism of action of inulin is not only due to its physicochemical features，such as water retention and viscosity，but also due to the prebiotic effects mediated by promotion of enterobacteria. In addition，we hypothesized that inulin directly interacts with intestinal epithelial cells and exerts its function independently，regardless of the presence of enterobacteria. To prove this，we investigated the effect of inulin addition on Caco-2 cells which are model cells of the small intestinal epithelium. We found that some growth factors were secreted onto the basolateral side of the cells when inulin was applied to the apical side of differentiated Caco-2 cells，suggesting that there is a receptor that recognizes inulin molecules on the apical surface of intestinal epithelial cells. We also found that this physiologic effect on cells depends on the average molecular weight of inulin added. These results strongly suggest that inulin not only exerts a prebiotic effect via enterobacteria，but also interacts directly with intestinal epithelial cells to regulate intestinal functions.
Key Words: Caco-2 cell，cell proliferation，growth factor，inulin |
