DataSheet2_Investigating causal relationships between the gut microbiota and allergic diseases: A mendelian randomization study.PDF

Observational studies revealed altered gut microbial composition in patients with allergic diseases, which illustrated a strong association between the gut microbiome and the risk of allergies. However, whether such associations reflect causality remains to be well-documented. Two-sample mendelian randomization (2SMR) was performed to estimate the potential causal effect between the gut microbiota and the risk of allergic diseases. 3, 12, and 16 SNPs at the species, genus, and family levels respectively of 15 microbiome features were obtained as the genetic instruments of the exposure dataset from a previous study. GWAS summary data of a total of 17 independent studies related to allergic diseases were collected from the IEU GWAS database for the outcome dataset. Significant causal relationships were obtained between gut microbiome features including Ruminococcaceae, Eggerthella, Bifidobacterium, Faecalibacterium, and Bacteroides and the risk of allergic diseases. Furthermore, our results also pointed out a number of putative associations between the gut microbiome and allergic diseases. Taken together, this study was the first study using the approach of 2SMR to elucidate the association between gut microbiome and allergic diseases.

观察性研究显示，过敏性疾病患者的肠道微生物组成发生改变，表明肠道微生物组与过敏风险之间存在密切关联。然而，此类关联是否反映因果关系，仍有待充分证实。本研究采用两样本孟德尔随机化（two-sample mendelian randomization, 2SMR）方法，评估肠道菌群与过敏性疾病风险之间的潜在因果效应。从既往研究中获取了15个微生物组特征在物种、属、科水平上的3、12和16个单核苷酸多态性（Single Nucleotide Polymorphism, SNP），作为暴露数据集的遗传工具变量。从IEU全基因组关联研究（Genome-Wide Association Study, GWAS）数据库中，收集了共计17项与过敏性疾病相关的独立研究的GWAS汇总数据，作为结局数据集。研究发现，瘤胃球菌科（Ruminococcaceae）、埃格特菌属（Eggerthella）、双歧杆菌属（Bifidobacterium）、粪杆菌属（Faecalibacterium）及拟杆菌属（Bacteroides）等肠道微生物组特征与过敏性疾病风险存在显著因果关联。此外，本研究结果还揭示了若干肠道微生物组与过敏性疾病之间的潜在关联。综上，本研究是首个采用两样本孟德尔随机化方法阐明肠道微生物组与过敏性疾病关联的研究。