Abstract: Protective role of prebiotics such as inulin type fructans (Synergy 1®) in colon cancer prevention was demonstrated using animal models. In vitro and in vivo studies have shown the inhibitory effects of dietary fiber and isoflavones such as genistein against the development of cancer. However, the underlying mechanisms of these phytonutrients remain elusive. The aim of this study was to examine the anticancer effects of Synergy1® and soybean extracts in combinations on colon cancer cell line (Caco-2). Cells were incubated (12 and 24 h) with specific concentrations of Syn1®, SM, Syn1®+SM (25-200 μg mL-1), isoflavones (0.125-0.8 μg mL-1) and butyric acid (0.1-0.8 μg mL-1). Lactate dehydrogenase (LDH) release (%) was higher in cells at all concentrations following 24 h incubation with a mixture of Syn1® + SM compared to the cells treated with the extracts alone. LDH release (%) was increased by two fold in cells after incubation with genistein for 24 h compared to the LDH release after 12 h. Caspase-3 activity; a measure of apoptosis seems to be proportional to incubation time in cells treated with Syn1® and SM extracts. Histone associated DNA fragmentation and release of oligonucleotides was higher in cells incubated with a mixture of Syn1®+SM and butyric acid extracts. These results suggests anti-neoplastic properties of Synergy1® and Soybean in combinations by inducing cell toxicity and apoptosis (Caspase-3 and histone associated DNA fragmentation) as a result of synergism between bioactive components present in these functional ingredients. Phytochemical combinations tested at lowest and safer levels in this study may be effective in colon cancer prevention.