DIETARY FRUCTOOLIGOSACCHARIDE, XYLOOLIGOSACCHARIDE AND GUM-ARABIC HAVE VARIABLE EFFECTS ON CECAL AND COLONIC MICROBIOTA AND EPITHELIAL-CELLPROLIFERATION IN MICE AND RATS
Md. Howard et al., DIETARY FRUCTOOLIGOSACCHARIDE, XYLOOLIGOSACCHARIDE AND GUM-ARABIC HAVE VARIABLE EFFECTS ON CECAL AND COLONIC MICROBIOTA AND EPITHELIAL-CELLPROLIFERATION IN MICE AND RATS, The Journal of nutrition, 125(10), 1995, pp. 2604-2609
Two experiments were conducted to determine if supplementing soluble f
iber (fructooligosaccharide, xylooligosaccharide or gum arabic) to a s
emielemental diet would beneficially change cecal and colonic microbio
ta 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 on
e of the four following treatment groups: control, no supplemental die
tary fiber, fructooligosaccharide, xylooligosaccharide and gum arabic.
Dietary fiber was supplied via drinking water at 30 g/L. In Experimen
t 1 populations of Bifidobacteria and total anaerobic flora were enume
rated from the contents of the cecum and colon of weanling mice. Consu
mption of fructooligosaccharide increased (P < 0.05) the concentration
s of Bifidobacteria and the, ratio of Bifidobacteria to total anaerobi
c flora. In Experiment 2 tissue from the cecum and distal colon of wea
nling rats was examined for morphological changes of the mucosa. Consu
mption of xylooligosaccharide increased (P < 0.05) cecal crypt depth a
nd labeling index relative to the other three treatments. Consumption
of gum arabic and the control diet increased (P < 0.01) cecal prolifer
ation zone. Consumption of xylooligosaccharide and the control diet in
creased (P < 0.01) cecal cell density (number of cells in a vertical-h
alf 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 r
esults suggest that fructooligosaccharide effectively stimulates growt
h of Bifidobacteria and xylooligosaccharide supports a modest enhancem
ent of cecal epithelial cell proliferation.