Digestion of certain fractions of dietary fiber in humans.
The digestion of cellulose, hemicellulose, and lignin has been investigated in humans. Two groups of subjects were studied--healthy subjects with an ileostomy and normal subjects. Both were put on a fixed diet of known cellulose, hemicellulose, and lignin content. From the feces excreted the fiber components were measured by the acid and neutral detergent method. From the small bowel 84.5% of the ingested cellulose was excreted from the ileostomy subjects. From the normal subjects 22.4% of the ingested cellulose was excreted, indicating approximately 80% of the cellulose was digested in the normal subjects. From the water insoluble ingested hemicelluloses 27.5% were excreted from the small bowel, 4.0% from normal subjects. That is approximately 96% digestion of the hemicelluloses in normal subjects. Lignin was found to be undigested in both the small and large bowel. This has important implications in future fiber research.
D002482:Cellulose / Q000378:metabolism*; D004032:Diet; D004043:Dietary Fiber / Q000378:metabolism*; D004063:Digestion; D007887:Fabaceae; D005243:Feces; D005260:Female; D006801:Humans; D007081:Ileostomy; D007082:Ileum / Q000502:physiology; D007420:Intestine, Large / Q000502:physiology; D007421:Intestine, Small / Q000502:physiology; D008031:Lignin / Q000378:metabolism*; D008297:Male; D010946:Plants, Medicinal; D013329:Structure-Activity Relationship
D004043:Dietary Fiber; D002482:Cellulose; D008031:Lignin