Gastric adenocarcinoma is associated with H. pylori infection and inflammation that can result in the dysbiosis of gastric microbiota. The association of intestinal microbiota with gastric adenocarcinoma subtypes or with gastric gastrointestinal stromal tumors (GIST) is however not well known. Therefore, we performed 16S rRNA gene sequencing on DNA isolated from stool samples of Finnish patients and controls to study differences in microbiota among different histological subtypes of gastric adenocarcinoma, gastric GIST and healthy controls. We found that gut microbiota alpha diversity was lowest in diffuse adenocarcinoma patients, followed by intestinal type and GIST patients, although the differences were not significant compared to controls. Beta-diversity analysis however showed significant differences in microbiota composition for all subtypes compared to controls. Significantly higher abundance of Enterobacteriaceae was observed in both adenocarcinoma subtypes, whereas lower abundance of Bifidobacteriaceae was seen only in diffuse adenocarcinoma and of Oscillibacter in intestinal adenocarcinoma. Both GIST and adenocarcinoma patients had higher abundance of Enterobacteriaceae and lower abundance of Lactobacillaceae and Oscillibacter while lower abundance of Lachnoclostridium, Bifidobacterium, Parabacteroides and Barnesiella was seen only in the adenocarcinoma patients. Our analysis shows association of higher Enterobacteriaceae abundance with all types of gastric tumors. Therefore it could be potentially useful as a marker of gastric malignancies. Lower gut microbiota diversity might be indicative of poorly differentiated, invasive, advanced or aggressive tumors and could possibly be a prognostic marker for gastric tumors.

中文翻译：

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不同亚型胃癌及胃肠道间质瘤患者的肠道菌群


胃腺癌与幽门螺杆菌感染和炎症有关，可导致胃微生物群失调。然而，肠道微生物群与胃腺癌亚型或胃胃肠道间质瘤（GIST）的关系尚不清楚。因此，我们对芬兰患者和对照粪便样本中分离的 DNA 进行了 16S rRNA 基因测序，以研究胃腺癌、胃 GIST 和健康对照不同组织学亚型之间微生物群的差异。我们发现弥漫性腺癌患者的肠道微生物群α多样性最低，其次是肠型和胃肠道间质瘤患者，尽管与对照组相比差异并不显着。然而，β 多样性分析显示，与对照组相比，所有亚型的微生物群组成存在显着差异。在两种腺癌亚型中观察到肠杆菌科丰度显着较高，而双歧杆菌科丰度仅在弥漫性腺癌中观察到，而颤杆菌在肠腺癌中丰度较低。 GIST和腺癌患者的肠杆菌科细菌丰度较高，乳杆菌科和颤杆菌丰度较低，而毛梭菌属、双歧杆菌属、副杆菌属和巴尼氏杆菌丰度较低，仅在腺癌患者中出现。我们的分析显示较高的肠杆菌丰度与所有类型的胃肿瘤之间存在关联。因此，它可能作为胃恶性肿瘤的标志物有用。肠道微生物群多样性较低可能表明分化不良、侵袭性、晚期或侵袭性肿瘤，并且可能是胃肿瘤的预后标志物。