Burns Anthony J, Rowland Ian R
Northern Ireland Centre for Food and Health, School of Biomedical Sciences, University of Ulster, Coleraine BT52 1SA, UK.
Mutat Res. 2004 Jul 13;551(1-2):233-43. doi: 10.1016/j.mrfmmm.2004.03.010.
Six strains of lactic acid producing bacteria (LAB) were incubated (1 x 10(8)cfu/ml) with genotoxic faecal water from a human subject. HT29 human adenocarcinoma cells were then challenged with the resultant samples and DNA damage measured using the single cell gel electrophoresis (comet) assay. The LAB strains investigated were Bifidobacterium sp. 420, Bifidobacterium Bb12, Lactobacillus plantarum, Streptococcus thermophilus, Lactobacillus bulgaricus and Enterococcus faecium. DNA damage was significantly decreased by all bacteria used with the exception of Strep. thermophilus. Bif. Bb12 and Lact. plantarum showed the greatest protective effect against DNA damage. Incubation of faecal water with different concentrations of Bif. Bb12 and Lact. plantarum revealed that the decrease in genotoxicity was related to cell density. Non-viable (heat treated) probiotic cells had no effect on faecal water genotoxicity. In a second study, HT29 cells were cultured in the presence of supernatants of incubations of probiotics with various carbohydrates including known prebiotics; the HT29 cells were then exposed to faecal water. Overall, incubations involving Lact. plantarum with the fructooligosaccharide (FOS)-based prebiotics Inulin, Raftiline, Raftilose and Actilight were the most effective in increasing the cellular resistance to faecal water genotoxicity, whereas fermentations with Elixor (a galactooligosaccharide) and Fibersol (a maltodextrin) were less effective. Substantial reductions in faecal water-induced DNA damage were also seen with supernatants from incubation of prebiotics with Bif. Bb12. The supernatant of fermentations involving Ent. faecium and Bif. sp. 420 generally had less potent effects on genotoxicity although some reductions with Raftiline and Elixor fermentations were apparent.
将6株产乳酸细菌（LAB）（1×10⁸cfu/ml）与人受试者具有遗传毒性的粪便水一起培养。然后用所得样品处理HT29人腺癌细胞，并使用单细胞凝胶电泳（彗星）试验测量DNA损伤。所研究的LAB菌株为双歧杆菌属420、双歧杆菌Bb12、植物乳杆菌、嗜热链球菌、保加利亚乳杆菌和粪肠球菌。除嗜热链球菌外，所有使用的细菌均使DNA损伤显著降低。双歧杆菌Bb12和植物乳杆菌对DNA损伤显示出最大的保护作用。用不同浓度的双歧杆菌Bb12和植物乳杆菌培养粪便水表明，遗传毒性的降低与细胞密度有关。无活性（热处理）益生菌细胞对粪便水遗传毒性没有影响。在第二项研究中，HT29细胞在益生菌与包括已知益生元在内的各种碳水化合物培养的上清液存在下培养；然后将HT29细胞暴露于粪便水中。总体而言，植物乳杆菌与基于低聚果糖（FOS）的益生元菊粉、益生素、低聚半乳糖和Actilight一起培养，在提高细胞对粪便水遗传毒性的抗性方面最有效，而与低聚半乳糖（一种低聚半乳糖）和Fibersol（一种麦芽糊精）的发酵效果较差。用双歧杆菌Bb12与益生元培养的上清液也可显著降低粪便水诱导的DNA损伤。粪肠球菌和双歧杆菌属420培养的上清液对遗传毒性的影响通常较小，尽管在益生素和低聚半乳糖发酵中有一些降低是明显的。
