Department of Gastroenterology, Hepatology and Endocrinology, Charite Hospital, Berlin, Germany.
J Physiol Pharmacol. 2009 Dec;60 Suppl 6:61-71.
The intestinal flora harbors varies pathogens. Clostridium perfringens (gas gangrene), Enterococci (endocarditis), Enterobacteriaceae (sepsis), Bacteroides (abscesses) are present in the large intestine of every healthy person in high concentrations. These bacteria are, however, separated from the colonic wall by an impenetrable mucus layer and are tolerated by the host. This separation is disturbed in patients with inflammatory bowel disease (IBD), where bacteria adhere to the mucosa and invade epithelial cells with concomitant inflammatory response. This chronic bowel inflammation can not subside as long as the mucus barrier remains defective. The inflammatory response interferes with the state of tolerance to the intestinal bacteria and leads to characteristic changes in the biostructure of the faecal microbiota. These changes in the biostructure of faecal microbiota are specific for active Crohn's disease and ulcerative colitis (UC) and can be longitudinally monitored. The reason for the defect of the mucus barrier in IBD patients is unclear. Epidemiologic studies indicate a negative role of western lifestyle and foods and document the rise in the incidence of IBD in the industrialized countries during the 20(th) century. In parallel to this, detergents were introduced in households and emulsifiers were increasingly added to food. The cleaning effect of these on the colonic mucus has to be investigated. The present contribution summarizes new data on the biostructure of the intestinal microbiota.
肠道菌群中存在各种病原体。产气荚膜梭菌（气性坏疽）、肠球菌（心内膜炎）、肠杆菌科（败血症）和拟杆菌（脓肿）在每个健康人的大肠中都以高浓度存在。然而，这些细菌被一层无法穿透的黏液层与结肠壁隔开，并被宿主耐受。在炎症性肠病（IBD）患者中，这种分离被破坏，细菌黏附在黏膜上并侵入上皮细胞，同时伴有炎症反应。只要黏液屏障仍然存在缺陷，这种慢性肠道炎症就不会消退。炎症反应干扰了对肠道细菌的耐受状态，并导致粪便微生物组的生物结构发生特征性变化。粪便微生物组的这种生物结构变化是活动性克罗恩病和溃疡性结肠炎（UC）的特异性变化，可以进行纵向监测。IBD 患者黏液屏障缺陷的原因尚不清楚。流行病学研究表明，西方生活方式和食物起着负面作用，并记录了 20 世纪工业化国家 IBD 发病率的上升。与此平行的是，家用清洁剂被引入家庭，食品中越来越多地添加乳化剂。必须研究这些物质对结肠黏液的清洁效果。本综述总结了肠道微生物群生物结构的新数据。
