title: Fermentability of various fiber sources by human fecal bacteria in vitro.
abstract: Certain beneficial effects of fiber in the human diet may be mediated by short-chain fatty acids (SCFAs) produced during anaerobic fermentation in the colon. Two studies, both involving in vitro incubations with human fecal bacteria as inoculum, were conducted to assess fermentation of various fiber sources and to quantitate the SCFAs produced. In experiment 1, substrate fermentability based on total SCFA production ranked as follows: citrus pectin greater than soy fiber greater than sugarbeet fiber greater than pea fiber greater than oat fiber. Fermentation of soy fiber led to higher proportions of propionate and butyrate than did fermentation of other substrates. In experiment 2, fermentation of gum arabic, a mixture of arabic and guar, and apple pectin resulted in greater SCFA production than did fermentation of either oat fiber or corn bran. Fermentation of gums led to more propionate and butyrate production than did that of apple pectin. It may be possible to select fiber sources capable of supporting stipulated amounts of both total and individual SCFA production in the human colon.
authors.affiliation: Division of Nutritional Sciences, University of Illinois, Urbana.
authors.forename: E C
authors.initials: EC
authors.lastname: Titgemeyer
authors.forename: L D
authors.initials: LD
authors.lastname: Bourquin
authors.forename: G C
authors.initials: GC
authors.lastname: Fahey
authors.forename: K A
authors.initials: KA
authors.lastname: Garleb
mesh_terms: D001419:Bacteria / Q000378:metabolism*; D004043:Dietary Fiber / Q000378:metabolism*; D002523:Edible Grain; D007887:Fabaceae; D005232:Fatty Acids, Volatile / Q000096:biosynthesis*; D005243:Feces / Q000382:microbiology*; D005285:Fermentation; D005685:Galactans / Q000378:metabolism; D006170:Gum Arabic / Q000378:metabolism; D006801:Humans; D008351:Mannans / Q000378:metabolism; D010368:Pectins / Q000378:metabolism; D053149:Plant Gums; D010946:Plants, Medicinal; D013025:Glycine max
chemical_list: D004043:Dietary Fiber; D005232:Fatty Acids, Volatile; D005685:Galactans; D008351:Mannans; D053149:Plant Gums; D010368:Pectins; D006170:Gum Arabic; C007894:guar gum