Prebiotics, in particular the chicory derived beta(2-1)
fructans, have been shown to exert
cancer protective effects in animal models. The present study was carried out to determine the effects of two chicory
fructans--
oligofructose (RaftiloseP95; average degree of polymerization DP = 4) and long chain
inulin (RaftilineHP; average DP = 25), on apoptosis and bacterial metabolism associated with
carcinogenesis. Eighteen rats were fed a stock diet for one week. Three groups of six animals were then fed one of three diets: basal, basal with
oligofructose (5%w/w) or basal with long chain
inulin (5%w/w), for a three week period. All animals were then dosed with
1,2-dimethylhydrazine and killed 24 h later. The mean number of apoptotic cells per crypt was significantly higher in the colon of rats fed
oligofructose (P = 0.049) and long chain
inulin (P = 0.017) as compared to those fed the basal diet alone. This suggests that
oligofructose as well as the long chain
inulin exert protective effects at an early stage in the onset of
cancer, as the supplements were effective soon after the
carcinogen insult. Comparison of the apoptotic indices between the two
oligosaccharide diets showed no significant difference even though the mean apoptotic index was higher in animals fed long chain
inulin. For all animals, apoptosis was significantly higher in the distal colon as compared to the proximal colon (P = 0.0002) however no significant site specific effect of diet occurred. There were no significant dietary effects on bacterial
enzyme activities or
ammonia concentration despite a trend towards increased colonic
beta-glucosidase and reduced
ammonia concentration during the
oligosaccharide diets. This is the first time that a significant effect of chicory
fructans on apoptosis has been shown and the results contribute to the growing evidence that chicory
fructans may have
cancer preventing properties.