Preventative Health National Research Flagship, CSIRO Animal, Food and Health Sciences, PO Box 10041, Adelaide BC SA 5000, Australia.
Nutrients. 2013 Sep 23;5(9):3740-56. doi: 10.3390/nu5093740.
High dietary intakes of some protein sources, including soy protein, can increase colonic DNA damage in animals, whereas some carbohydrates attenuate this. We investigated whether inulin and xylo-oligosaccharides (XOS) could be protective against DNA strand breaks by adding them to a human colonic simulator consisting of a proximal vessel (PV) (pH 5.5) and a distal vessel (DV) (pH 6.8) inoculated with human faeces and media containing soy protein. Genotoxicity of the liquid phase and microbial population changes in the vessels were measured. Soy protein (3%) was fermented with 1% low amylose cornstarch for 10 day followed by soy protein with 1% XOS or 1% inulin for 10 day. Inulin did not alter genotoxicity but XOS significantly reduced PV genotoxicity and increased DV genotoxicity. Inulin and XOS significantly increased butyrate concentration in the DV but not PV. Numbers of the key butyrate-producing bacterium Faecalibacterium prausnitzii were significantly increased in the PV and DV by inulin but significantly decreased by XOS in both vessels. Other bacteria examined were also significantly impacted by the carbohydrate treatments or by the vessel (i.e., pH). There was a significant overall inverse correlation between levels of damage induced by the ferments and levels of sulphate-reducing bacteria, Bacteroides fragilis, and acetate. In conclusion, dietary XOS can potentially modulate the genotoxicity of the colonic environment and specific bacterial groups and short chain fatty acids may mediate this.
高膳食纤维的一些蛋白质来源，包括大豆蛋白，可增加动物结肠 DNA 损伤，而一些碳水化合物则可减弱这种损伤。我们研究了菊粉和木二糖（XOS）是否可以通过添加到由近端容器（PV）（pH5.5）和远端容器（DV）（pH6.8）组成的人类结肠模拟器中来预防 DNA 链断裂，该模拟器用人类粪便接种，并含有大豆蛋白的培养基。测量了液相间的遗传毒性和容器中微生物群的变化。将 3%的大豆蛋白与 1%的低直链淀粉玉米淀粉发酵 10 天，然后分别用 1%的 XOS 或 1%的菊粉与 1%的大豆蛋白发酵 10 天。菊粉不会改变遗传毒性，但 XOS 显著降低了 PV 的遗传毒性，并增加了 DV 的遗传毒性。菊粉和 XOS 显著增加了但在 PV 中没有增加，DV 中的丁酸浓度。在 PV 和 DV 中，菊粉显著增加了关键丁酸产生菌普拉梭菌的数量，但在两个容器中，XOS 都显著降低了数量。检查的其他细菌也受到碳水化合物处理或容器（即 pH）的显著影响。发酵物引起的损伤水平与硫酸盐还原菌、脆弱拟杆菌和乙酸盐的水平之间存在显著的整体负相关。总之，饮食中的 XOS 可能会调节结肠环境的遗传毒性和特定细菌群，而短链脂肪酸可能介导这种作用。
