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.

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牙周炎与胃肠道疾病的关联：双向孟德尔随机研究

背景牙周炎（PD）和胃肠道（GIT）疾病之间的双向联系已在之前的流行病学研究中进行过研究。然而，结论仍然存在争议。本研究的目的是全面探讨帕金森病与各种胃肠道疾病之间的双向因果关系。方法基于全基因组关联研究（GWAS）的汇总水平数据，进行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] 和憩室病）相关的单核苷酸多态性 (SNP) GWAS 中的肠道 [DI]）被用作暴露。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 疾病之间的因果关系的调查，IVW 方法显示存在因果影响GU 上的 PD 值（比值比 [OR] 1.088；95% 置信区间 [CI]，1.036–1.141；调整后p= 0.004）和 DI（OR 0.938；95% CI，0.911–0.965；调整后p= 0.000）。然而，没有观察到 PD 对 CG、DU、GERD 和 IBS 的因果影响具有显着的遗传倾向。此外，初步分析并未证明胃肠道疾病对帕金森病有因果影响。结论这项 MR 研究表明，帕金森病可能与 GU 风险增加和 DI 风险降低相关，但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。