克罗恩病人肠黏膜炎性区域真菌菌群组成变化研究

Changes of the fungal microbiota in inflamed intestinal mucosa of the patients with Crohn's disease

目的 :比较克罗恩病人肠黏膜炎性与非炎性区域真菌菌群组成的差异,探讨黏膜真菌菌群变化与克罗恩病的潜在联系。方法 :手术收集7例活动性克罗恩病人肠黏膜炎性与非炎性区域组织,提取DNA,采用巢式PCR扩增18S r RNA基因片段,行变性梯度凝胶电泳,确定肠黏膜真菌菌群多样性和组成。结果 :与非炎性黏膜相比,炎性区域真菌菌群丰富度和多样性显著升高(P<0.05)。肠黏膜炎性区域真菌菌群组成发生显著改变,主要表现为条件致病白色念珠菌,热带假丝酵母菌,串珠状赤霉菌,甘蓝链格孢菌和新型隐球菌的相对丰度显著增加(P<0.05);而共生菌酿酒酵母菌,芽殖酵母菌,产黄青霉菌和双色蜡蘑菌显著降低(P<0.05)。结论 :克罗恩病人肠黏膜炎性区域真菌菌群严重失衡,条件致病真菌定植增加可能参与了肠黏膜炎性损伤的形成。

Objective： The study aimed to characterize the difference of the fungal microbiota between the inflamed and non-inflamed intestinal mucosa in patients with Crohn＇s disease （CD） and explore the potential relation between their changes and the pathogenesis of CD. Methods： Seven patients with active CD were enrolled and the specimens was obtained from the inflamed and non-inflamed mucos a during operation. Tissue DNA was extracted and then amplified by nested polymerase chain reaction （PCR） with the premier sets NS1/FR1 and EF390/GC-FR1. Denaturing gradient gel electrophoresis was subsequently conducted to profile the structure and composition of the fungal microbiota. Results： Compared to those of noninflamed region, the species richness and diversity of the fungal microbiota in inflamed region were significantly increased （P 〈 0.05）. The predominant fungal composition in inflamed region was significantly altered, mainly characterized by the increase of opportunistic pathogens including Candida albicans, Candida tropicalis, Gibberella moniliformis, Alternaria brassicicola and Cryptococcus neoformans relative to that of noninflamed region （P 〈 0.05）, compared with those of noninflamed region. Conversely, the proportion of the commensals, for example Saccharomyces cerevisiae, Saccharomyces castellii, Penicillum chrysogenum and Laccaria bicolor, were significantly decreased in inflamed region （P 〈 0.05）. Conclusion： The fungal microbiota of the inflamed intestinal mucosa is severely dysbiotic in CD patients result in inflammatory damage. The colonization of some pathogenic fungi could participate and