Send to

Choose Destination
Best Pract Res Clin Gastroenterol. 2003 Dec;17(6):943-56.

Intestinal absorption in health and disease--sugars.

Author information

Departments of Physiology and Pediatrics, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095-1751, USA.


Carbohydrates are mostly digested to glucose, fructose and galactose before absorption by the small intestine. Absorption across the brush border and basolateral membranes of enterocytes is mediated by sodium-dependent and -independent membrane proteins. Glucose and galactose transport across the brush border occurs by a Na(+)/glucose (galactose) co-transporter (SGLT1), whereas passive fructose transport is mediated by a uniporter (GLUT5). The passive exit of all three sugars out of the cell across the basolateral membrane occurs through two uniporters (GLUT2 and GLUT5). Mutations in SGLT1 cause a major defect in glucose and galactose absorption (glucose-galactose Malabsorption), but mutations in GLUT2 do not appear to disrupt glucose and galactose absorption. Studies on GLUT1 null mice and Fanconi-Bickel patients suggest that there is another exit pathway for glucose and galactose that may involve exocytosis. There are no known defects of fructose absorption.

[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center