Institute of Nutrition, Department of Nutritional Physiology, Friedrich Schiller University, Dornburger Str. 24, 07743 Jena, Germany.
Clin Nutr. 2012 Feb;31(1):22-9. doi: 10.1016/j.clnu.2011.08.012. Epub 2011 Oct 2.
Colonic microbiota is involved in the etiology of colon cancer according to several reports. Studies also indicate that the microbiota differs between atopic patients and healthy subjects.
To evaluate whether a probiotic mix containing Lactobacillus paracasei Lpc-37, Lactobacillus acidophilus 74-2, and Bifidobacterium animalis subsp. lactis DGCC 420 can affect the microbiota and its genotoxic activity in healthy subjects and patients with atopic dermatitis (AD).
A placebo-controlled cross-over study was conducted. Fifteen healthy adults and 15 adult AD patients consumed 2×100 ml/d of either a probiotic or a placebo drink for 8 weeks followed by a wash out period of 2 weeks before crossing the intervention. Faecal water was isolated from stool samples collected at the end of each period. HT29c19a cells incubated with faecal water were measured for DNA damage using single-cell gel electrophoresis ("comet assay"). Bacterial species were determined by qPCR and concentrations of short-chain fatty acids were measured by means of gas chromatography.
Probiotic supplementation resulted in a significant increase in lactobacilli, whereas numbers of Bifidobacteria and Bacteroidetes remained unchanged. Clostridium perfringens cluster I-II was significantly reduced in healthy subjects. Genotoxic potential (expressed as tail intensity) of faecal water, was not affected. However, tail intensity decreased significantly in the probiotic period compared to placebo (23.5 vs. 16.7%) in AD patients. Although faecal concentrations of short-chain fatty acids were not affected, faecal pH was significantly reduced (7.0 vs. 6.6) in AD patients after probiotics.
The results indicate that probiotics lower the genotoxic potential of faecal water in AD patients. The faecal C. perfringens cluster I-II levels remained unaffected suggesting either a change in their activity, or the fact that other bacterial species are responsible for the reduced genotoxic activity of faecal water.
根据多项研究报道，结肠微生物群与结肠癌的病因有关。研究还表明，过敏性患者和健康受试者的微生物群不同。
评估含有副干酪乳杆菌 Lpc-37、嗜酸乳杆菌 74-2 和动物双歧杆菌亚种 lactis DGCC 420 的益生菌混合物是否可以影响健康受试者和特应性皮炎（AD）患者的微生物群及其遗传毒性活性。
进行了一项安慰剂对照交叉研究。15 名健康成年人和 15 名成年 AD 患者分别饮用 2×100 ml/d 的益生菌或安慰剂饮料 8 周，然后在干预前进行 2 周的洗脱期。从每个时期结束时收集的粪便样本中分离粪便水。用单细胞凝胶电泳（“彗星试验”）测量用粪便水孵育的 HT29c19a 细胞中的 DNA 损伤。通过 qPCR 确定细菌种类，通过气相色谱法测量短链脂肪酸的浓度。
益生菌补充剂导致乳杆菌数量显著增加，而双歧杆菌和拟杆菌的数量保持不变。健康受试者中梭状芽胞杆菌簇 I-II 显著减少。粪便水的遗传毒性潜力（表示为尾部强度）没有受到影响。然而，与安慰剂相比，AD 患者在益生菌期的尾部强度显著降低（23.5%比 16.7%）。尽管粪便中短链脂肪酸的浓度没有受到影响，但 AD 患者在使用益生菌后粪便 pH 值显著降低（7.0 比 6.6）。
结果表明，益生菌可降低 AD 患者粪便水的遗传毒性潜力。粪便中梭状芽胞杆菌簇 I-II 水平保持不变，这表明其活性发生变化，或者其他细菌种类负责降低粪便水的遗传毒性活性。
