Gastrointestinal carbohydrate and fat absorption processes

Gastrointestinal carbohydrate and fat absorption processes represent the physiological pathways for the breakdown and uptake of dietary nutrients in the small intestine. Carbohydrate digestion is primarily facilitated by alpha-glucosidase enzymes in the brush border, which convert complex sugars into monosaccharides for transport via proteins such as Sodium/glucose cotransporter 1 (SGLT1) and GLUT2 (StatPearls, 2023; PubMed, 2004). Fat absorption requires emulsification by bile salts and hydrolysis by pancreatic lipase, followed by the uptake of lipids and cholesterol through transporters such as Niemann-Pick C1-Like 1 (NPC1L1) and CD36 (PubMed, 2021; NIH, 2022). These processes are major therapeutic targets for metabolic conditions; alpha-glucosidase inhibitors like acarbose are used to control postprandial hyperglycemia in type 2 diabetes, while lipase inhibitors like orlistat and cholesterol absorption inhibitors like ezetimibe are used to manage obesity and hyperlipidemia (StatPearls, 2023; PubMed, 2017). Because these interventions result in undigested nutrients reaching the large intestine, they are commonly associated with gastrointestinal side effects, including flatulence, diarrhea, and malabsorption of fat-soluble vitamins (StatPearls, 2023).

Other names

Intestinal nutrient absorptionMacronutrient absorptionDietary carbohydrate and lipid absorption

Inhibition of intestinal enzymes (e.g., alpha-glucosidase, pancreatic lipase) and transport proteins (e.g., NPC1L1) to reduce the systemic uptake of glucose and lipids.