Laboratoire de Bactériologie, Virologie et Microbiologie Industrielle, Faculté des Sciences Pharmaceutiques, Université Paul Sabatier, 35 chemin des Maraîchers, 31062 Toulouse Cedex 09, France.
Int J Food Microbiol. 2010 Nov 15;144(1):42-50. doi: 10.1016/j.ijfoodmicro.2010.09.007. Epub 2010 Sep 17.
There is emerging evidence of the efficiency of probiotic, prebiotic and synbiotic treatments in inflammatory bowel diseases (IBDs) and one of their long-term complications, colorectal cancer (CRC). In this study, various strains of probiotic lactic acid bacteria, prebiotic glucooligosaccharides (GOS) or a synbiotic combination of the two were screened for anti-inflammatory and anti-proliferative effects in different in vitro models in the context of such diseases. To mimic IBD response to Gram negative bacteria, HT-29 cells were sensitised to inflammatory response to lipopolysaccharide (LPS) by IFNγ which increased expression of TLR4, the LPS biosensor, and were then treated by probiotics, prebiotics and synbiotics. Secreted IL-8 and activated NF-κB were monitored as inflammation biomarkers. A selection of active strains were then subjected to a second inflammatory cell culture model consisting of inflammatory activated transgenic Caco-2 cells transfected by a reporter gene under the control of NF-κB inducible promoter. Quantification of reporter gene expression allowed us to demonstrate some probiotic inhibitory properties or to confirm such characteristics in two different models. Proliferation of cancerous HT-29 cells was monitored by XTT assay. Only three probiotic strains induced a proliferation decrease, but with a lack of reproducibility. Binary or ternary probiotic associations, complemented or not by prebiotic GOS, significantly decreased proliferation, especially with a synbiotic association of Bifidobacterium breve, Lactococcus lactis and oligoalternan, a GOS. This combination was selected for the following experiments. We showed the involvement of both bacterial and carbohydrate compounds of this synbiotic in the observed effect by dose range tests. We demonstrated that this decrease in proliferation may be due to an induction of a differentiated phenotype, as shown by the up-regulation of intestinal alkaline phosphatase, a biomarker of differentiation, monitored by real-time RT-PCR in HT-29 cells treated by the selected synbiotics. Thus, this study demonstrates the ability of probiotics to exert anti-inflammatory effects and shows some anti-proliferative characteristics for a specific synbiotics. These products should be further evaluated in animal models to confirm the in vitro results.
越来越多的证据表明，益生菌、益生元和合生菌疗法在炎症性肠病（IBD）及其一种长期并发症——结直肠癌（CRC）方面具有疗效。在这项研究中，筛选了各种益生菌乳酸杆菌菌株、益生元低聚半乳糖（GOS）或两者的合生菌组合，以在这些疾病的不同体外模型中检测其抗炎和抗增殖作用。为了模拟 IBD 对革兰氏阴性菌的反应，用 IFNγ 使 HT-29 细胞对脂多糖（LPS）的炎症反应敏感，增加了 LPS 生物传感器 TLR4 的表达，然后用益生菌、益生元和合生菌进行处理。监测分泌的 IL-8 和激活的 NF-κB 作为炎症生物标志物。然后选择一些活性菌株，用于第二个炎症细胞培养模型，该模型由转染 NF-κB 诱导启动子控制的报告基因的炎症激活转基因 Caco-2 细胞组成。报告基因表达的定量使我们能够证明一些益生菌的抑制特性，或者在两种不同的模型中确认这些特性。通过 XTT 测定法监测癌细胞 HT-29 的增殖。只有三种益生菌菌株诱导增殖减少，但缺乏可重复性。二元或三元益生菌联合，辅以或不辅以益生元 GOS，显著降低了增殖，特别是与短双歧杆菌、乳球菌乳亚种和 oligoalternan 的合生菌联合，GOS。选择这种组合进行后续实验。我们通过剂量范围测试表明，这种合生菌的细菌和碳水化合物化合物都参与了观察到的效果。我们证明，这种增殖减少可能是由于诱导分化表型，如用实时 RT-PCR 监测 HT-29 细胞中肠碱性磷酸酶的上调所显示的分化生物标志物。因此，这项研究表明益生菌具有抗炎作用，并显示出特定合生菌的一些抗增殖特性。这些产品应在动物模型中进一步评估，以确认体外结果。
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