Department of Medicine, University of North Carolina, Division of Digestive Diseases, Chapel Hill, North Carolina, U.S.A.
Inflamm Bowel Dis. 1997 Fall;3(3):230-5.
: Both pathogenic and normal enteric microflora can induce and perpetuate chronic intestinal inflammation with systemic manifestations in genetically susceptible hosts. At the present time, there is no convincing indication that the majority of cases of ulcerative colitis or Crohn's disease is caused by persistent infection by Mycobacterium paratuberculosis, measles, Listeria monocytogenes, or Helicobacter species, but this possibility remains a valid hypothesis. Transient infection with any of a number of pathogens including upper respiratory tract infections and common enteric pathogens could provide one of the environmental triggers that initiate or reactivate IBD, which is then perpetuated in susceptible hosts by resident (not pathogenic) commensal luminal bacteria. Recent results in animal models demonstrate the absence of colitis, gastritis, and arthritis in a sterile (germ-free) environment, showing the importance of resident bacteria as persistent antigenic stimuli in the genetically susceptible hosts. Furthermore, there is an indication that not all normal luminal bacteria have equal capacities to induce mucosal injury, since some species can induce inflammation (Bacteroides), some are neutral (E. coli) and others may be protective (Lactobacilli). These observations have important therapeutic implications, such that altering luminal bacterial components and thereby decreasing the persistent antigenic drive offer alternative or adjuvant approaches to ongoing efforts to block mucosal immune responses to these stimuli.
无论是病原性还是正常的肠道微生物群都可以在遗传易感宿主中引发和持续慢性肠道炎症并伴有全身表现。目前，尚无令人信服的证据表明大多数溃疡性结肠炎或克罗恩病是由结核分枝杆菌、麻疹、单核细胞增生李斯特菌或幽门螺杆菌持续感染引起的，但这种可能性仍然是一个有效的假设。包括上呼吸道感染和常见肠道病原体在内的许多病原体的短暂感染可能会提供引发或重新激活 IBD 的环境触发因素之一，然后由常驻（非病原性）共生腔内细菌在易感宿主中持续存在。动物模型的最新结果表明，在无菌（无菌）环境中不存在结肠炎、胃炎和关节炎，这表明常驻细菌作为遗传易感宿主中持续的抗原刺激物的重要性。此外，有迹象表明并非所有正常腔内细菌都具有同等的诱导粘膜损伤的能力，因为某些物种可以诱导炎症（拟杆菌），有些是中性的（大肠杆菌），而另一些则可能具有保护作用（乳杆菌）。这些观察结果具有重要的治疗意义，即改变腔内细菌成分，从而减少持续的抗原驱动，为阻断这些刺激物对粘膜免疫反应的现有努力提供替代或辅助方法。
