Dietary carbohydrate absorption

Dietary carbohydrate absorption is not a single molecule or receptor but rather a physiological process involving the enzymatic breakdown of dietary polysaccharides and disaccharides into monosaccharides—primarily glucose, galactose, and fructose—which are then absorbed across the small intestinal epithelium. The digestion begins in the mouth with salivary amylase acting on starches but primarily occurs in the small intestine via pancreatic amylase. Final hydrolysis to monosaccharides is performed by brush border enzymes such as maltase, sucrase, lactase, and isomaltase[1][2][3][5].\n\nAbsorption mechanisms differ for each sugar:\n\n- Glucose and galactose are absorbed via active transport through SGLT1 (sodium-glucose co-transporter 1), coupled with sodium ions.\n \n- Fructose is absorbed by facilitated diffusion through GLUT5 transporter.\n\nAll three sugars exit enterocytes into portal circulation via GLUT2 transporter[2][4][5].\n\nThis process ensures efficient uptake of dietary carbohydrates for use as energy or storage. Disruption can lead to clinical conditions like malabsorption syndromes or contribute to metabolic diseases if excessive.\n\n**Note:** \"Dietary carbohydrate absorption\" refers to a biological function/process rather than a discrete molecular target such as an enzyme or receptor. Therefore it should not be considered a canonical therapeutic target itself but may be modulated indirectly by drugs targeting specific enzymes involved in this pathway[2].

Other names

Carbohydrate absorptionIntestinal carbohydrate absorptionAbsorption of dietary carbohydrates

Inhibition of brush border enzymes (e.g., alpha-glucosidase) to delay breakdown of complex carbohydrates into absorbable monosaccharides