The human gastrointestinal tract harbors approximately 100 trillion microorganisms with different microbial compositions across geographic locations. In this work, we used RNASeq data from stomach samples of non-disease (164 individuals from European ancestry) and gastric cancer patients (137 from Europe and Asia) from public databases. Although these data were intended to characterize the human expression profiles, they allowed for a reliable inference of the microbiome composition, as confirmed from measures such as the genus coverage, richness and evenness. The microbiome diversity (weighted UniFrac distances) in gastric cancer mimics host diversity across the world, with European gastric microbiome profiles clustering together, distinct from Asian ones. Despite the confirmed loss of microbiome diversity from a healthy status to a cancer status, the structured profile was still recognized in the disease condition. In concordance with the parallel host-bacteria population structure, we found 16 human loci (non-synonymous variants) in the European-descendent cohorts that were significantly associated with specific genera abundance. These microbiome quantitative trait loci display heterogeneity between population groups, being mainly linked to the immune system or cellular features that may play a role in enabling microbe colonization and inflammation.

中文翻译：

---

来自欧洲和亚洲的胃癌患者中的胃微生物组多样性模仿人类的人口结构，部分受微生物组定量性状位点的驱动。

人的胃肠道在地理位置上具有大约100万亿个微生物组成不同的微生物。在这项工作中，我们使用了来自公共数据库的非疾病胃样本（来自欧洲的164个人）和胃癌患者（来自欧洲和亚洲的137）的RNASeq数据。尽管这些数据旨在表征人的表达谱，但它们可以可靠地推断出微生物组的组成，这一点已通过诸如属覆盖率，丰富度和均匀度等方法得到了证实。胃癌中的微生物组多样性（加权UniFrac距离）模拟了世界各地的宿主多样性，欧洲的胃微生物组概况聚集在一起，与亚洲的不同。尽管已确认微生物组多样性从健康状态到癌症状态的丧失，在疾病条件下仍然可以识别结构化轮廓。与平行的宿主细菌种群结构一致，我们在欧洲后裔队列中发现了16个人类基因座（非同义变体），这些基因座与特定属的丰度显着相关。这些微生物组定量特征基因座在人群之间表现出异质性，主要与免疫系统或细胞特征有关，这些免疫系统或细胞特征可能在使微生物定植和炎症中起作用。