Parassol Nadège, Freitas Miguel, Thoreux Karine, Dalmasso Guillaume, Bourdet-Sicard Raphaelle, Rampal Patrick
Laboratoire de Gastroentérologie et Nutrition, IFR50, Faculté de Médecine de Nice, Université de Sophia-Antipolis, 28 avenue de Valombrose, 06107 Nice cedex 2, France.
Res Microbiol. 2005 Mar;156(2):256-62. doi: 10.1016/j.resmic.2004.09.013. Epub 2004 Dec 15.
Probiotics are living microorganisms which, when ingested in adequate amounts, exert health benefits toward the host. For instance, probiotics might act through reinforcement of the intestinal epithelial barrier function. The goal of the present study was to determine whether Lactobacillus casei DN-114 001 could abrogate the increase in paracellular permeability induced by enteropathogenic Escherichia coli. We used the human colon T84 cell line infected with a wild-type enteropathogenic E. coli (strain E2348/69). Paracellular permeability was followed by monitoring transepithelial electrical resistance variations and by observing zonula occludens-1 distribution. Two infection procedures were used: co-incubation (the pathogenic and probiotic strains were simultaneously incubated with T84 cells) and post-infection (the probiotic was added in the presence of pathogenic bacteria 3 h after the beginning of the infection). We also investigated the effect of L. casei on enteropathogenic E. coli adhesion. L. casei DN-114 001 inhibited, in a dose-dependent-manner, the decrease in enteropathogenic E. coli-induced transepithelial electrical resistance and zonula occludens-1 redistribution using two different infection procedures. However, L. casei did not inhibit pathogenic strain adhesion. L. casei DN-114 001 inhibited the increase in EPEC-induced paracellular permeability. This property could partially explain the previously observed health benefits of this probiotic for human natural defenses, such as those associated with prevention of diarrhea.
益生菌是一类活的微生物，当摄入足够量时，会对宿主产生健康益处。例如，益生菌可能通过增强肠道上皮屏障功能发挥作用。本研究的目的是确定干酪乳杆菌DN-114 001是否能够消除由肠致病性大肠杆菌引起的细胞旁通透性增加。我们使用感染了野生型肠致病性大肠杆菌（菌株E2348/69）的人结肠T84细胞系。通过监测跨上皮电阻变化和观察闭合蛋白-1的分布来跟踪细胞旁通透性。使用了两种感染程序：共孵育（致病菌株和益生菌菌株同时与T84细胞孵育）和感染后（在感染开始3小时后在病原菌存在的情况下添加益生菌）。我们还研究了干酪乳杆菌对肠致病性大肠杆菌黏附的影响。干酪乳杆菌DN-114 001使用两种不同的感染程序，以剂量依赖的方式抑制了肠致病性大肠杆菌诱导的跨上皮电阻降低和闭合蛋白-1的重新分布。然而，干酪乳杆菌并未抑制致病菌株的黏附。干酪乳杆菌DN-114 001抑制了肠致病性大肠杆菌诱导的细胞旁通透性增加。这一特性可以部分解释先前观察到的这种益生菌对人体天然防御的健康益处，比如与预防腹泻相关的益处。
