title: Dietary fructooligosaccharide, xylooligosaccharide and gum arabic have variable effects on cecal and colonic microbiota and epithelial cell proliferation in mice and rats.
abstract: Two experiments were conducted to determine if supplementing soluble fiber (fructooligosaccharide, xylooligosaccharide or gum arabic) to a semi-elemental diet would beneficially change cecal and colonic microbiota populations and enhance epithelial cell proliferation. Experiments 1 and 2 used identical dietary regimens; mice and rats were given free access to a powdered semi-elemental diet. Animals were assigned to one of the four following treatment groups: control, no supplemental dietary fiber, fructooligosaccharide, xylooligosaccharide and gum arabic. Dietary fiber was supplied via drinking water at 30 g/L. In Experiment 1 populations of Bifidobacteria and total anaerobic flora were enumerated from the contents of the cecum and colon of weanling mice. Consumption of fructooligosaccharide increased (P < 0.05) the concentrations of Bifidobacteria and the ratio of Bifidobacteria to total anaerobic flora. In Experiment 2 tissue from the cecum and distal colon of weanling rats was examined for morphological changes of the mucosa. Consumption of xylooligosaccharide increased (P < 0.05) cecal crypt depth and labeling index relative to the other three treatments. Consumption of gum arabic and the control diet increased (P < 0.01) cecal proliferation zone. Consumption of xylooligosaccharide and the control diet increased (P < 0.01) cecal cell density (number of cells in a vertical-half of the crypt). Distal colonic crypt depth was greatest (P < 0.05) in controls and rats fed fructooligosaccharide, intermediate in those fed gum arabic, and smallest in those fed xylooligosaccharide. These results suggest that fructooligosaccharide effectively stimulates growth of Bifidobacteria and xylooligosaccharide supports a modest enhancement of cecal epithelial cell proliferation.
authors.affiliation: Department of Animal Science, University of Missouri, Columbia 65211, USA.
authors.forename: M D
authors.initials: MD
authors.lastname: Howard
authors.forename: D T
authors.initials: DT
authors.lastname: Gordon
authors.forename: K A
authors.initials: KA
authors.lastname: Garleb
authors.forename: M S
authors.initials: MS
authors.lastname: Kerley
mesh_terms: D000818:Animals; D001644:Bifidobacterium / Q000187:drug effects / Q000254:growth & development* / Q000302:isolation & purification; D002432:Cecum / Q000166:cytology / Q000187:drug effects / Q000382:microbiology*; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D003106:Colon / Q000166:cytology / Q000187:drug effects / Q000382:microbiology*; D004043:Dietary Fiber / Q000494:pharmacology*; D004847:Epithelial Cells; D004848:Epithelium / Q000187:drug effects / Q000382:microbiology; D005260:Female; D006170:Gum Arabic / Q000494:pharmacology*; D007413:Intestinal Mucosa / Q000166:cytology / Q000382:microbiology / Q000502:physiology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009844:Oligosaccharides / Q000494:pharmacology*; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D004043:Dietary Fiber; D009844:Oligosaccharides; D006170:Gum Arabic