Isomalto-oligosaccharides from rice and their potential use as pharma-nutraceuticals in prevention of colon cancer

Abstract

Background: Isomalto-oligosaccharides (IMO) were enzymatically produced from rice (rIMO) alone or in combination with product (instant rice porridge mixed rIMO) demonstrated bifidogenic and butyrogenic effects in in vitro studies. The potential use of IMO from rice for pharma-nutraceuticals to prevent or risk reduction of colon cancer was further investigated in rats in this study.Objective: To investigate potential use of IMO from rice on prevention or risk reduction of colon cancer and gut microbiota modulation in rats, colonic polyp formation, histological changes, gut microbiota modulation, and butyrogenic properties were evaluated.Methods: An acute toxicity test was performed in ICR mice with a single dose of 2,000 mg/kg of tested IMO. The effects of rIMO were performed in AOM/DSS-induced Wistar rats. The animals were divided in 8 groups and treated three times a week with vehicle, three doses of rIMO, cIMO, and product (instant rice porridge mixed rIMO) before and after carcinogen administration. Animals were sacrificed at the end of 19th week.Results: Oral administration at up to 2,000 mg/kg of rIMO and product containing rIMO could be considered safe. Additionally, the animals chemically induced with AOM/DSS and treated with rIMO (1,500 mg/kg) and product containing rIMO significantly lower the occurrence of colonic polyps about 60%. There were no changes in other blood hematologic and biochemistry values but an improved gut barrier function when compared with animals in control and vehicle groups. AOM/DSS-induced rats supplemented with product containing rIMO could retard the reduction of beneficial bacteria and butyric acid production and thereby suppres the increase of harmful bacteria through the AOM/DSS post-induction phase.Conclusion: The results of this in vivo study suggest that consumption of rIMO alone or in combination with brown rice porridge could potentially help protect histological changes and risk reduction of developing for colon cancer. IMO from rice has potential use for pharma-nutraceuticals for risk reduction of colon cancer.Keywords: colon cancer, isomalto-oligosaccharides, prebiotic, rice, gut modulation