Role of probiotic bacteria in cancer prevention

Various studies have proved that different kinds of food compounds can contribute to the decrease or increase of cancer incidence rate. Fermented food products and probiotic drugs are among products which have beneficial effects on preventing cancer incidence. The study aims at reviewing the important role of probiotics on preventing cancer incidence. In so doing, a synthesis of the results of several studies, regarding this subject, which are provided in different prestigious textbooks and articles, is presented in here. Having the GRAS property including 1.nonpathogenesis and 2.beneficial effects, Lactobacillus and bifidobacterium strains are the most important probiotic microorganisms which play a fundamental role in prevention of cancer incidence. Their various mechanisms include attaching to carcinogenic materials - such as nitrous amines - and decomposing them, strengthening the immune system and increasing resistance against chemical materials, decreasing the production of harmful bacteria and food enzymes which involve in changing pre-carcinogenic materials to carcinogenic one, and producing anti-carcinogenic and anti-mutative compounds in human body. Several studies have demonstrated that probiotic bacterium, or their products, decrease carcinogenic cells' proliferation by effecting on epithelial cells. Although the role of probiotic bacteria and their fermented products in controlling cancer incidence has been proved, the immunity standard of these products must be verified by licensed authorities. Further studies should be done to prove exactly the most effective strains, consumption dosage, the rate of influence and control of cancer by probiotic bacteria and products containing those bacteria on human body. These studies should be followed by their characterization by laboratory tests and animal models. Then, they can be used routinely after validation procedures.