Degradation of konjac glucomannan by enzymes in human feces and formation of short-chain fatty acids by intestinal anaerobic bacteria.
Konjac (konnyaku) glucomannan was examined for its degradation in human intestines and fermentation products. The konjac glucomannan was degraded almost 100% by soluble enzymes in human feces to give 4-O-beta-D-mannopyranosyl-D-mannopyranose (beta-1,4-D-mannobiose), 4-O-beta-D-glucopyranosyl-D-glucopyranose (cellobiose), 4-O-beta-D-glucopyranosyl-D-mannopyranose, and small amounts of glucose and mannose. These three disaccharides were further degraded by a cell-associated enzyme(s) to glucose or mannose, or to both. Konjac glucomannan underwent fermentation by intestinal anaerobic bacteria and produced formic acid, acetic acid, propionic acid, and 1-butyric acid. These fatty acids were different in their proportions among test subjects, their total amounts ranging from 17.1% to 48.8% of the initial konjac glucomannan.
Matsuura
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Department of Nutritionl Science, Faculty of Health and Welfare Science, Okayama Prefectural University, Soja, Japan.
D019342:Acetic Acid / Q000378:metabolism; D000328:Adult; D001421:Bacteria, Anaerobic / Q000378:metabolism*; D020148:Butyric Acid / Q000378:metabolism; D002475:Cellobiose / Q000378:metabolism; D004043:Dietary Fiber; D005227:Fatty Acids / Q000096:biosynthesis*; D005243:Feces / Q000201:enzymology*; D005260:Female; D005285:Fermentation; D005502:Food; D005561:Formates / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D006801:Humans; D007422:Intestines / Q000382:microbiology*; D008297:Male; D008351:Mannans / Q000378:metabolism*; D008358:Mannose / Q000378:metabolism; D008875:Middle Aged; D011422:Propionates / Q000378:metabolism
D004043:Dietary Fiber; D005227:Fatty Acids; D005561:Formates; D008351:Mannans; D011422:Propionates; C030544:formic acid; D020148:Butyric Acid; C014647:mannobiose; D002475:Cellobiose; C022901:(1-6)-alpha-glucomannan; D005947:Glucose; C029658:propionic acid; D008358:Mannose; D019342:Acetic Acid