W1966 Unlike Deoxycholic Acid, Ursodeoxycholic Acid Does Not Cause DNA Damage or Activate the NF-κB Pathway in Barrett's Metaplasia In Vitro and In Vivo

diet containing no added RS. Prebiotic; two high amylose maize sources of RS were used, namely Hi-maize 958 and Hi-maize 260.Probiotic; control diet plus lyophilized cultures (1x10^11 cfu/g) of Bifidobacterium lactis at 1% by weight.Synbiotic; to each of the RS diets was added Bifidobacterium lactis at 1%.After 4 weeks on these nutritionally balanced diets, colonic neoplasms were induced by 2 weekly injections of azoxymethane (15 mg/kg B.W). Colons were resected after 30 weeks of feeding for evaluation of neoplasm formation, short chain fatty acids (SCFA), and epithelial biology.Results: Rats fed the synbiotic combination of RS with Bifidobacterium lactis significantly lowered the incidence and multiplicity of colonic neoplasms (P<0.01, using two-way factorial Poisson model) by over 50% compared to the Control group.There was a trend for protection by either RS alone (P=0.07) while no protection against colorectal cancer was seen in the group supplemented with only Bifidobacterium lactis.Fermentation events (SCFA, pH) were altered by the inclusion of RS into the diet while the inclusion of Bifidobacterium lactis into the diet had no significant effect on the fermentation parameters.Conclusion(s): The synbiotic combination of resistant starch and Bifidobacterium lactis significantly protects against the development of colorectal cancer in the rat-azoxymethane model to a degree not seen by the components.This suggests matching of prebiotic to probiotic might be important to maximise health benefit.(1) Le Leu, RK. et al.. Synbiotic combination of resistant starch and bifidobacterium lactis can facilitate apoptotic deletion of carcinogen-damaged cells in the rat colon.