Guarner Francisco
Digestive System Research Unit, University Hospital Vall d'Hebron, Barcelona, Spain.
Curr Opin Gastroenterol. 2005 Jul;21(4):414-8.
The human gut is the natural habitat for a large and dynamic bacterial community. There is a substantial body of evidence implicating the resident flora in the pathogenesis of chronic intestinal inflammation. This review discusses the possible role of a microbial imbalance in the pathophysiology of inflammatory bowel disease.
Recently developed molecular biologic tools suggest that a sizeable part of the microbial populations of the human gut remains to be defined. Conversely, the relevance of gut bacteria in the host's physiology is well documented. The specialised lymphoid follicles of the gut mucosa are the major sites for induction of effector and regulatory mechanisms of the intestinal immune system, and it is now becoming clear that resident and in-transit microorganisms play an essential role in the homeostasis of local and systemic immunity. An infectious origin of inflammatory bowel disease is not supported by our current knowledge. Several studies, however, have disclosed substantial differences in the intestinal flora between patients with inflammatory bowel disease and healthy subjects, in regard to both composition and mucosal colonisation. Aggressive species are abundant on the inflammatory bowel disease mucosal surface whereas protective genera are underrepresented, but the biologic relevance of these changes needs further investigation.
A balanced microbial environment would likely help in both prevention and control of inflammatory bowel disease. Research is needed to identify microorganisms able to mediate immunoregulation in the gut mucosa.
人类肠道是庞大且动态变化的细菌群落的自然栖息地。有大量证据表明肠道固有菌群与慢性肠道炎症的发病机制有关。本综述探讨了微生物失衡在炎症性肠病病理生理学中的可能作用。
最近开发的分子生物学工具表明，人类肠道中相当一部分微生物种群仍有待确定。相反，肠道细菌在宿主生理学中的相关性已有充分记录。肠道黏膜的特殊淋巴滤泡是诱导肠道免疫系统效应和调节机制的主要部位，现在越来越清楚的是，固有和过路微生物在局部和全身免疫的稳态中起着至关重要的作用。目前的知识并不支持炎症性肠病起源于感染。然而，几项研究已经揭示，炎症性肠病患者与健康受试者在肠道菌群的组成和黏膜定植方面存在显著差异。炎症性肠病黏膜表面侵袭性菌种丰富，而保护性菌属数量不足，但这些变化的生物学相关性需要进一步研究。
平衡的微生物环境可能有助于预防和控制炎症性肠病。需要开展研究以识别能够介导肠道黏膜免疫调节的微生物。
