Schultsz C, Van Den Berg F M, Ten Kate F W, Tytgat G N, Dankert J
Department of Medical Microbiology, Academic Medical Centre, Amsterdam, The Netherlands.
Gastroenterology. 1999 Nov;117(5):1089-97. doi: 10.1016/s0016-5085(99)70393-8.
BACKGROUND & AIMS: Whether the bacterial flora contributes to the pathogenesis of inflammatory bowel disease (IBD) by increased penetration in mucus, increased adherence to epithelial cells, or invasion of the epithelium is unknown. We therefore studied the spatial distribution of bacteria in the mucosa of rectal biopsy specimens from patients with IBD and from controls.
Rectal biopsy specimens from 19 patients with IBD and from 14 controls were studied by using nonradioactive ribosomal RNA in situ hybridization. Total mucosal surface length examined for each patient was measured, and the number of bacteria visualized was estimated semiquantitatively.
No bacteria were observed in biopsy specimens from 10 controls (71%) and 6 IBD patients (32%) (P = 0.04; odds ratio, 5.42; 95% confidence interval, 1.23-23.9). IBD rectal specimens contained significantly more bacteria than control samples (P = 0.004). Bacteria were localized within the mucus layer but did not adhere to the epithelial cells and were not present within the lamina propria. There was no correlation between the numbers of bacteria present and either the degree of inflammation or the use of anti-inflammatory agents or sulfasalazine compounds.
The intestinal mucus in IBD patients is less protective against the endogenous microflora than in controls, resulting in increased association of luminal bacteria with the mucus layer.
尚不清楚肠道菌群是否通过增加在黏液中的穿透、增加对上皮细胞的黏附或侵入上皮而导致炎症性肠病（IBD）的发病机制。因此，我们研究了IBD患者和对照者直肠活检标本黏膜中细菌的空间分布。
采用非放射性核糖体RNA原位杂交技术，对19例IBD患者和14例对照者的直肠活检标本进行研究。测量每位患者检查的黏膜总表面长度，并对观察到的细菌数量进行半定量估计。
10例对照者（71%）和6例IBD患者（32%）的活检标本中未观察到细菌（P = 0.04；比值比，5.42；95%置信区间，1.23 - 23.9）。IBD直肠标本中的细菌明显多于对照样本（P = 0.004）。细菌定位于黏液层内，但未黏附于上皮细胞，且在固有层中不存在。存在的细菌数量与炎症程度、抗炎药物或柳氮磺胺吡啶化合物的使用之间均无相关性。
与对照者相比，IBD患者的肠道黏液对内源微生物群的保护作用较弱，导致管腔细菌与黏液层的关联增加。
