title: In vitro bile-acid binding and fermentation of high, medium, and low molecular weight beta-glucan.
abstract: The impact of beta-glucan molecular weight (MW) on in vitro bile-acid binding and in vitro fermentation with human fecal flora was evaluated. beta-Glucan extracted from oat line 'N979-5-4' was treated with lichenase (1,3-1,4-beta-D-glucanase) to yield high (6.87x10(5) g/mol), medium (3.71x10(5) g/mol), and low (1.56x10(5) g/mol) MW fractions. The low MW beta-glucan bound more bile acid than did the high MW beta-glucan (p<0.05). If the positive control, cholestyramine, was considered to bind bile acid at 100%, the relative bile-acid binding of the original oat flour and the extracted beta-glucan with high, medium, and low MW was 15, 27, 24, and 21%, respectively. Significant effects of high, medium, and low MW beta-glucans on total SCFA were observed compared to the blank without substrate (p<0.05). There were no differences in pH changes and total gas production among high, medium, and low MW beta-glucans, and lactulose. The low MW beta-glucan produced greater amounts of SCFA than the high MW after 24 h of fermentation. Among the major SCFA, more propionate was produced from all MW fractions of extracted beta-glucans than from lactulose. In vitro fermentation of extracted beta-glucan fractions with different MW lowered pH and produced SCFA, providing potential biological function.
authors.affiliation: Department of Food Science and Human Nutrition, Iowa State University, Ames, Iowa, USA.
authors.forename: Hyun Jung
authors.initials: HJ
authors.lastname: Kim
authors.forename: Pamela J
authors.initials: PJ
authors.lastname: White
mesh_terms: D018554:Avena / Q000737:chemistry*; D001419:Bacteria / Q000378:metabolism; D001647:Bile Acids and Salts / Q000737:chemistry*; D005243:Feces / Q000382:microbiology; D005285:Fermentation; D006801:Humans; D008954:Models, Biological; D008970:Molecular Weight; D010936:Plant Extracts / Q000737:chemistry* / Q000378:metabolism; D047071:beta-Glucans / Q000737:chemistry* / Q000378:metabolism
chemical_list: D001647:Bile Acids and Salts; D010936:Plant Extracts; D047071:beta-Glucans