Department of Food Technology, Faculty of Food Science and Technology, Universiti Putra Malaysia, Selangor, Malaysia.
Benef Microbes. 2010 Jun;1(2):149-54. doi: 10.3920/BM2009.0035.
Consumption of probiotics has been associated with decreased risk of colon cancer and reported to have antimutagenic/ anti-carcinogenic properties. One possible mechanism for this effect involves physical binding of the mutagenic compounds, such as heterocyclic amines (HCAs), to the bacteria. Therefore, the objective of this study was to examine the binding capacity of bifidobacterial strains of human origin on mutagenic heterocyclic amines which are suspected to play a role in human cancers. In vitro binding of the mutagens Trp-p-2, IQ, MeIQx, 7,8DiMeIQx and PhIP by three bacterial strains in two media of different pH was analysed using high performance liquid chromatography. Bifidobacterium pseudocatenulatum G4 showed the highest decrease in the total HCAs content, followed by Bifidobacterium longum, and Escherichia coli. pH affects binding capacity; the highest binding was obtained at pH 6.8. Gram-positive tested strains were found to be consistently more effective than the gram-negative strain. There were significant decreases in the amount of HCAs in the presence of different cell concentrations of B. pseudocatenulatum G4; the highest decrease was detected at the concentration of 10(10) cfu/ml. The results showed that HCAs were able to bind with all bacterial strains tested in vitro, thus it may be possible to decrease their absorption by human intestine and increase their elimination via faeces.
益生菌的消费与结肠癌风险的降低有关，并被报道具有抗突变/抗癌特性。这种效应的一个可能机制涉及到将诱变化合物（如杂环胺（HCAs））与细菌物理结合。因此，本研究的目的是研究来源于人类的双歧杆菌菌株对可能在人类癌症中起作用的诱变杂环胺的结合能力。使用高效液相色谱法分析了三种细菌在两种不同 pH 值的培养基中对诱变剂 Trp-p-2、IQ、MeIQx、7,8DiMeIQx 和 PhIP 的体外结合情况。双歧杆菌假链状亚种 G4 显示出最高的总 HCAs 含量降低，其次是长双歧杆菌和大肠杆菌。pH 值影响结合能力；在 pH 值为 6.8 时获得最高的结合。革兰氏阳性测试菌株被发现比革兰氏阴性菌株更有效。双歧杆菌假链状亚种 G4 的不同细胞浓度存在时，HCAs 的含量显著降低；在浓度为 10(10)cfu/ml 时检测到最高的降低。结果表明，HCAs 能够与所有测试的细菌菌株在体外结合，因此可能减少它们在人类肠道中的吸收，并通过粪便增加它们的排泄。
