Rioux Kevin P, Fedorak Richard N
Division of Gastroenterology, Department of Medicine, University of Alberta, Edmonton, Al, Canada.
J Clin Gastroenterol. 2006 Mar;40(3):260-3. doi: 10.1097/00004836-200603000-00019.
The demonstration that immune and epithelial cells can discriminate between different microbial species has extended our understanding of the actions of probiotics beyond simple antimicrobial concepts. Several probiotic mechanisms of action, relative to inflammatory bowel disease, have been elucidated: (1) competitive exclusion, whereby probiotics compete with microbial pathogens; (2) immunomodulation and/or stimulation of an immune response; (3) antimicrobial activity and suppression of pathogen growth; (4) enhancement of barrier activity; and (5) induction of T cell apoptosis. The unraveling of these mechanisms of action has led to new support for the use of probiotics in the management of clinical inflammatory bowel disease. While level 1 evidence now supports the therapeutic use of some probiotics in the maintenance treatment of pouchitis, only level 2 and 3 evidence are currently available in support of the use of probiotics in the treatment of ulcerative colitis and Crohn's disease. Nevertheless, one significant and consistent finding has emerged over the course of research in the past year: not all probiotic bacteria have similar therapeutic effects. Rigorously designed, controlled clinical trials, to investigate the unresolved issues related to efficacy, dose, duration of use, single or multistrain formulation, and the concomitant use of prebiotics, synbiotics or antibiotics, are vital.
免疫细胞和上皮细胞能够区分不同微生物种类，这一发现拓展了我们对益生菌作用的理解，使其超越了简单的抗菌概念。关于炎症性肠病，已阐明了几种益生菌的作用机制：（1）竞争排斥，即益生菌与微生物病原体竞争；（2）免疫调节和/或刺激免疫反应；（3）抗菌活性及抑制病原体生长；（4）增强屏障活性；（5）诱导T细胞凋亡。这些作用机制的阐明为益生菌用于临床炎症性肠病的治疗提供了新的支持。虽然一级证据现在支持某些益生菌在袋炎维持治疗中的治疗用途，但目前仅有二级和三级证据支持益生菌用于溃疡性结肠炎和克罗恩病的治疗。然而，在过去一年的研究过程中出现了一个重要且一致的发现：并非所有益生菌都有相似的治疗效果。严格设计、对照的临床试验对于研究与疗效、剂量、使用持续时间、单菌株或多菌株配方以及益生元、合生元或抗生素的联合使用相关的未解决问题至关重要。
