Department of Gastroenterology, Portuguese Oncology Institute - Porto, Porto, Portugal.
Department of Surgery and Physiology, Porto Faculty of Medicine, Porto, Portugal.
Scand J Gastroenterol. 2021 Jun;56(6):708-716. doi: 10.1080/00365521.2021.1902560. Epub 2021 Apr 29.
Gastric dysbiosis has been hinted as a potential cause of gastric cancer. However, changes in microbiome throughout the major stages of gastric carcinogenesis remain mostly unknown.
To describe gastric microbiome at different stages, analysing for the first time dysbiosis specifically in patients with early gastric cancer (EGC).
Cross-sectional study including patients ( = 77) with endoscopically and histologically confirmed normal stomachs (controls; = 25), advanced atrophic gastritis with intestinal metaplasia (IM; = 18) and EGC ( = 34). Endoscopic biopsies from antrum and corpus ( = 154) were analyzed. Next-generation sequencing was performed characterizing microbial communities down to the species level based on full-length 16SrRNA gene profiling.
Significant differences were found in the microbiome profile between the groups. Firmicutes were more frequent ( = .012) and Proteobacteria were less frequent ( = .04) both in the IM and EGC when comparing to controls. Relative frequency of , when present, was much higher in the controls (83%) when comparing to the other groups (IM 1%, EGC 27%; = .006), being the dominant bacteria only in the controls. Dysbiosis was present already and more significantly at the IM stage, with two bacteria progressively increasing from controls to IM then to cancer: from 1.48 to 3.9% ( = .014); and from 19.3 to 33.7% ( = .04), being the EGC dominant bacteria.
Our results confirm dominancy in non-atrophic stomachs and progressive dysbiosis throughout gastric carcinogenesis. but particularly is significantly increased in patients with EGC. Specific modulation of these bacteria may change gastric cancer risk.
胃微生态失调已被提示为胃癌的潜在病因。然而，在胃癌发生的主要阶段，微生物组的变化仍知之甚少。
描述不同阶段的胃微生物组，并首次分析早期胃癌（EGC）患者的微生态失调。
这是一项包括内镜和组织学证实的正常胃（对照组；n=25）、伴有肠化生的进展性萎缩性胃炎（IM；n=18）和 EGC（n=34）患者的横断面研究。分析了胃窦和胃体的内镜活检标本（n=154）。基于全长 16SrRNA 基因谱，进行下一代测序以对微生物群落进行特征分析，直至种水平。
各组之间的微生物组谱存在显著差异。与对照组相比，IM 和 EGC 中厚壁菌门更为常见（P=.012），变形菌门较少（P=.04）。在对照组中，当存在时，的相对频率（83%）明显高于其他组（IM 1%，EGC 27%；P=.006），仅在对照组中为优势菌。在 IM 阶段就已经存在且更为显著的微生态失调，两种细菌从对照组到 IM 再到癌症逐渐增加：从 1.48%增加到 3.9%（P=.014）；从 19.3%增加到 33.7%（P=.04），在 EGC 中为优势菌。
我们的结果证实了 在非萎缩性胃中的优势地位和在胃癌发生过程中的逐渐失调。但特别是 在 EGC 患者中显著增加。这些细菌的特异性调节可能会改变胃癌的风险。
