BackgroundThe bidirectional link of periodontitis (PD) and gastrointestinal tract (GIT) disorders has been investigated in previous epidemiological studies; however, the conclusions still remain controversial. The aim of this study was to comprehensively explore the bidirectional causal effect between PD and various GIT diseases.MethodsBased on summary‐level data of genome‐wide association studies (GWASs), a two‐sample bidirectional Mendelian randomization (MR) study was undertaken. Single‐nucleotide polymorphisms (SNPs) associated with PD or GIT disorders (chronic gastritis [CG], gastric ulcer [GU], duodenal ulcer [DU], gastroesophageal reflux disease [GERD], irritable bowel syndrome [IBS], and diverticular disease of the intestine [DI]) in GWASs were applied as exposure. The primary method employed was the inverse‐variance weighted (IVW) method, and several sensitivity analyses were performed to investigate potential pleiotropy.ResultsWith regard to the investigation of the causality between PD and GIT disorders, the IVW method revealed that there is a causal impact of PD on GU (odds ratio [OR] 1.088; 95% confidence interval [CI], 1.036–1.141; adjusted p = 0.004) and DI (OR 0.938; 95% CI, 0.911–0.965; adjusted p = 0.000). However, no significant genetic liability was observed for the causal effect of PD on CG, DU, GERD, and IBS. Furthermore, the primary analysis did not demonstrate a causal effect of GIT disorders on PD.ConclusionThis MR study suggests that PD may be associated with an increased risk of GU and a reduced risk of DI, with possibly limited clinical relevance. Further studies are needed to support the conclusions of this MR study.

中文翻译：

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牙周炎与胃肠道疾病的相关性：一项双向孟德尔随机化研究


背景在以前的流行病学研究中已经研究了牙周炎 （PD） 和胃肠道 （GIT） 疾病的双向联系;然而，结论仍然存在争议。本研究的目的是全面探讨 PD 与各种 GIT 疾病之间的双向因果效应。方法基于全基因组关联研究 （GWASs） 的摘要数据，进行了一项双样本双向孟德尔随机化 （MR） 研究。与 PD 或 GIT 疾病 （慢性胃炎 [CG]、胃溃疡 [GU]、十二指肠溃疡 [DU]、胃食管反流病 [GERD]、肠易激综合征 [IBS] 和肠憩室病 [DI]）相关的单核苷酸多态性 （SNP） 作为暴露应用于 GWAS。采用的主要方法是逆方差加权 （IVW） 方法，并进行了多项敏感性分析以研究潜在的多效性。结果关于PD和GIT疾病之间因果关系的调查，IVW方法显示PD对GU（比值比[OR]1.088;95%置信区间[CI]，1.036-1.141;校正p=0.004）和DI（OR 0.938;95%CI，0.911-0.965;校正p=0.000）存在因果影响。然而，未观察到 PD 对 CG 、 DU 、 GERD 和 IBS 的因果效应的显著遗传倾向。此外，初步分析未证明 GIT 疾病对 PD 的因果关系。结论这项 MR 研究表明，PD 可能与 GU 风险增加和 DI 风险降低有关，临床相关性可能有限。需要进一步的研究来支持这项 MR 研究的结论。