Digestion of certain fractions of dietary fiber in humans

• Published in: The American journal of clinical nutrition Vol. 31; no. 6; pp. 927 - 930
• Main Authors: Holloway, W D, Tasman-Jones, C, Lee, S P
• Format: Journal Article
• Language: English
• Published: United States 01.06.1978
• Subjects: cellulose; Cellulose - metabolism; Diet; dietary fiber; Dietary Fiber - metabolism; Digestion; Fabaceae; Feces; Female; gastrointestinal system; Humans; Ileostomy; Ileum; Ileum - physiology; Intestine, Large; Intestine, Large - physiology; Intestine, Small; Intestine, Small - physiology; lignin; Lignin - metabolism; Male; metabolism; physiology; Plants, Medicinal; Structure-Activity Relationship
• ISSN: 0002-9165
• DOI: 10.1093/ajcn/31.6.927

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.