Colon cancer is the third most common newly diagnosed cancer in the United States and the third most common cause of cancer-related deaths. Diet is the single greatest contributor to human cancer, including colon cancer, and may be associated with 35–70% of the incidence of the disease. It has been suggested that nondigestible oligosaccharides enhance the growth of bifidobacteria and could inhibit colon carcinogenesis. Based on current knowledge of the pathogenesis of colon cancer, it is reasonable to predict that consumption of a fiber-rich diet and probiotics is associated with reduced risk of colon cancer. In this study, we investigated the effect of diet on inhibition of colon cancer by comparing AOM-induced ACF formation in rats. The ACF was scored under a Stereoscopic microscope. AOM injected rats had significantly lower body weight. However, prebiotic and probiotic culture fed rats had recovered their body weight. Cecal pH was dramatically lowered in rats fed probiotic cultures compared with the control group. There was a significant overall effect of diet on the formation of ACF in the total colon of rats injected with AOM. Rats fed prebiotic and probiotic had about 60% reduction of ACF. As expected, ACF in the distal colon of all groups were more numerous than in the proximal colon. In conclusion, feeding prebiotic and probiotic culture reduced the development of ACF in rats. This study provides evidence that dietary antioxidants, prebiotic and probiotic suppressed AOM-induced colon tumorigenesis in rats.