Progressive intestinal mucosal damage occurs over years prior to colorectal cancer (CRC) development. The endoscopic screening of polyps and histopathological examination are used clinically to determine the risk and progression of mucosal lesions. We analyzed fecal microbiota compositions using 16S rRNA gene-based metataxonomic analyses and the levels of short-chain fatty acids (SCFAs) using gas chromatography in volunteers undergoing colonoscopy and histopathological analyses to determine the microbiota shifts occurring at the early stages of intestinal mucosa alterations. The results were compared between diagnosis groups (nonpathological controls and polyps), between samples from individuals with hyperplastic polyps or conventional adenomas, and between grades of dysplasia in conventional adenomas. Some microbial taxa from theBacillotaandEuryarchaeotaphyla were the most affected when comparing the diagnosis and histopathological groups. Deeper microbiota alterations were found in the conventional adenomas than in the hyperplastic polyps. TheRuminococcus torquesgroup was enriched in both the hyperplastic polyps and conventional adenomas, whereas the familyEggerthellaceaewas enriched only in the hyperplastic polyps. The abundance ofPrevotellaceae,Oscillospiraceae,Methanobacteriaceae,Streptococcaceae,Christensenellaceae,Erysipelotrichaceae, andClostridiaceaeshifted in conventional adenomas depending on the grade of dysplasia, without affecting the major SCFAs. Our results suggest a reorganization of microbial consortia involved in gut fermentative processes.
结直肠癌发生前，肠道黏膜损伤会持续数年进展。临床上通过内镜下息肉筛查及组织病理学检查评估黏膜病变的风险与进展。本研究对接受结肠镜及组织病理学检查的志愿者进行粪便微生物群分析：采用基于16S rRNA基因的宏分类学分析检测菌群组成，运用气相色谱法测定短链脂肪酸水平，旨在探究肠道黏膜病变早期阶段的微生物群变化。通过对比诊断分组（非病理对照组与息肉组）、增生性息肉与传统腺瘤患者的样本，以及传统腺瘤中不同异型增生分级，发现诊断组与组织病理学组间差异最显著的微生物类群主要来自厚壁菌门和广古菌门。传统腺瘤组的微生物群改变较增生性息肉组更为显著：扭链瘤胃球菌群在两类息肉中均呈现富集，而艾格特菌科仅富集于增生性息肉。普雷沃氏菌科、颤螺旋菌科、甲烷杆菌科、链球菌科、克里斯滕森菌科、丹毒丝菌科及梭菌科的丰度在传统腺瘤中随异型增生程度发生变化，但主要短链脂肪酸水平未受影响。研究结果表明，参与肠道发酵过程的微生物群落发生了结构性重组。
肿瘤(癌症)患者之家