Liévin-Le Moal V, Amsellem R, Servin A L, Coconnier M-H
Institut National de la Santé et de la Recherche Médicale, Unité 510, Pathogénes et Fonctions des Cellules Epithéliales Polarisées, Faculté de Pharmacie, Université Paris XI, F-92296, Chãtenay-Malabry, France.
Gut. 2002 Jun;50(6):803-11. doi: 10.1136/gut.50.6.803.
The normal gastrointestinal microflora exerts a barrier effect against enteropathogens. The aim of this study was to examine whether lactobacilli, a minor genus of the resident gut microflora, exerts a protective effect against the cellular injuries promoted by the diarrhoeagenic Afa/Dr diffusely adhering Escherichia coli (Afa/Dr DAEC) C1845 strain in human intestinal cells.
Cultured human intestinal fully differentiated enterocyte-like Caco-2/TC7 cells were used. Antibacterial activity was examined by measuring the viability of the adhering C1845 bacteria. The distribution of brush border associated cytoskeleton and functional proteins was examined by immunofluorescence labelling coupled to confocal laser scanning microscopy analysis.
The activity of Lactobacillus acidophilus strain LB isolated from the resident human gastrointestinal microflora was examined. A dose dependent decrease in viability of C1845 bacteria was observed after both direct contact in vitro between the spent culture supernatant (LB-SCS) and the bacteria, and when the bacteria were adherent on Caco-2/TC7 cells. Protection against the C1845 induced alterations in expression of F-actin, sucrase-isomaltase, dipeptidylpeptidase IV, alkaline phosphatase, and fructose transporter alterations was observed when the cells were exposed to LB-SCS.
L acidophilus strain isolated from the resident adult human gastrointestinal microflora, together with its antimicrobial activity, exerts a protective effect against the brush border lesions promoted by the diarrhoeagenic Afa/Dr DAEC strain C1845.
正常胃肠道微生物群对肠道病原体具有屏障作用。本研究旨在探讨作为肠道常驻微生物群中一个次要属的乳酸菌，是否对致腹泻性Afa/Dr弥漫性黏附大肠杆菌（Afa/Dr DAEC）C1845菌株在人肠道细胞中引发的细胞损伤具有保护作用。
使用培养的人肠道完全分化的肠上皮样Caco-2/TC7细胞。通过测量黏附的C1845细菌的活力来检测抗菌活性。通过免疫荧光标记结合共聚焦激光扫描显微镜分析来检测刷状缘相关细胞骨架和功能蛋白的分布。
检测了从人胃肠道常驻微生物群中分离出的嗜酸乳杆菌菌株LB的活性。在体外，用过的培养上清液（LB-SCS）与细菌直接接触后，以及当细菌黏附在Caco-2/TC7细胞上时，均观察到C1845细菌的活力呈剂量依赖性下降。当细胞暴露于LB-SCS时，观察到对C1845诱导的F-肌动蛋白、蔗糖酶-异麦芽糖酶、二肽基肽酶IV、碱性磷酸酶表达改变以及果糖转运体改变具有保护作用。
从成年人体内胃肠道常驻微生物群中分离出的嗜酸乳杆菌菌株，连同其抗菌活性，对致腹泻性Afa/Dr DAEC菌株C1845引发的刷状缘损伤具有保护作用。
