Intestinal fructose absorption: regulation and relation to human diseases

Abstract

Fructose is a hexose sugar found naturally in our diet and not only represents a source of body energy but also promotes lactate production, glycogenesis, gluconeogenesis and lipogenesis. GLUT2 and GLUT5 are the facilitative glucose transporters responsible for the intestinal absorption of fructose. After intestinal absorption, this monosaccharide is mainly metabolized in the liver before passing into the systemic circulation. Fructose transport in the small intestine is a highly regulated process and GLUT5, a specific fructose carrier, plays an essential role in this process. Excessive fructose consumption has been documented over the last decades and associated with the growing incidence of certain diseases, including type 2 diabetes, non-alcoholic fatty liver disease, cardiac disease, gastrointestinal disorders, and cancer development. In this review, we will describe the multiple mechanisms involved in the regulation of intestinal fructose absorption and the effects of consumption of this sugar on human health.