Endocrine Abstracts

Previous observational studies found associations between Helicobacter pylori infection and autoimmune thyroid diseases (AITDs), but the causal nature of this association is still uncertain. We investigated the causal effect of 6 crucial antibodies against H. pylori on AITDs using a bidirectional Mendelian randomization (MR). We found anti-H. pylori OMP significantly increased the risk of hyperthyroidism and Graves’ disease (GD). In addition, our reverse MR analysis indicated hyperthyroidism could increase the levels of CagA and OMP antibodies. We also observed causal roles of GD on anti-H. pylori OMP. Our analyses indicate the mutual effects of H. pylori infection and AITDs, suggesting the existence of a gut-thyroid axis. These results also provide evidence of the bidirectional causal association between anti-H. pylori OMP with hyperthyroidism and GD, resulting in a vicious circle.