Guarner Francisco
Digestive System Research Unit, Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD), University Hospital Vall d'Hebron, ES-08035 Barcelona, Spain.
Dig Dis. 2009;27(3):412-7. doi: 10.1159/000228582. Epub 2009 Sep 24.
The pathophysiological mechanisms that generate chronic inflammatory lesions in inflammatory bowel disease (IBD) have, at least in part, been unveiled. Abnormal communication between gut microbial communities and the mucosal immune system is being incriminated as the core defect leading to intestinal injury in genetically susceptible individuals. The therapeutic manipulation of gut microecology has attracted high expectation as a strategic area for the control and prevention of IBD.
Literature review.
The gut is the major site for induction of regulatory T cells, which secrete immunoregulatory cytokines such as IL-10 and TGF-beta and can regulate both Th1 and Th2 responses. Recent findings suggest that some gut commensals, including lactobacilli, bifidobacteria and helminths, play a major role in the induction of regulatory T cells in gut lymphoid follicles. Such T cell-mediated regulatory pathways are essential homeostatic mechanisms by which the host can tolerate the massive burden of innocuous antigens within the gut without responding through inflammation. In clinical practice, the evidence for the use of probiotics or prebiotics is strongest in the case of pouchitis. In addition, one probiotic strain appears to be equivalent to mesalazine in maintaining remission of ulcerative colitis. However, studies of probiotics in Crohn's disease have been disappointing.
Further research is needed to optimize the use of probiotics, prebiotics or helminths for these indications.
炎症性肠病（IBD）中产生慢性炎症病变的病理生理机制至少部分已被揭示。肠道微生物群落与黏膜免疫系统之间的异常通讯被认为是导致遗传易感个体肠道损伤的核心缺陷。肠道微生态的治疗性调控作为IBD控制和预防的一个战略领域已备受期待。
文献综述。
肠道是诱导调节性T细胞的主要部位，调节性T细胞分泌免疫调节细胞因子如IL-10和转化生长因子-β，并可调节Th1和Th2反应。最近的研究结果表明，包括乳酸杆菌、双歧杆菌和蠕虫在内的一些肠道共生菌在肠道淋巴滤泡中调节性T细胞的诱导中起主要作用。这种T细胞介导的调节途径是重要的稳态机制，宿主可通过该机制耐受肠道内无害抗原的巨大负荷而不通过炎症反应。在临床实践中，益生菌或益生元使用证据最充分的情况是在袋炎中。此外，一种益生菌菌株在维持溃疡性结肠炎缓解方面似乎等同于美沙拉嗪。然而，益生菌在克罗恩病中的研究结果令人失望。
需要进一步研究以优化益生菌、益生元或蠕虫在这些适应症中的应用。
