Certain nondigestible oligosaccharides can be selectively utilized by probiotics and reduce the risk
of colon cancer. However, the inhibitory effects of xylooligosaccharides (XOS) on colon cancer are not well
documented. This study evaluated the effects of xylooligosaccharides and fructooligosaccharides (FOS) on the
alteration of cecal microbiota, cecal pH, cecal weight, and serum lipid levels, and also their inhibitory effect on
precancerous colon lesions in male Sprague-Dawley rats. The rats were randomly assigned to 4 groups: control,
treatment with 1,2-dimethylhydrazine (DMH) [15 mg/(kg body wt wk) for 2 wk], treatment with DMH 60 g
XOS/kg diet, and treatment with DMH 60 g FOS/kg diet. Rats were fed the experimental diets for 35 d, beginning
1wk after the second dose of DMH. Both XOS and FOS markedly decreased the cecal pH and serum triglyceride
concentration, and increased the total cecal weight and bifidobacteria population. XOS had a greater effect on the
bacterial population than did FOS. Moreover, both XOS and FOS markedly reduced the number of aberrant crypt
foci in the colon of DMH-treated rats. These results suggest that XOS and FOS dietary supplementation may be
beneficial to gastrointestinal health, and indicate that XOS is more effective than FOS.
