Background and Objectives: Type 1 diabetes mellitus (T1DM) is a chronic and serious condition that is characterized by inadequate pancreatic-β-cells’ insulin production. The connection between T1DM and Helicobacter pylori infection remains uncertain. This study aimed to conduct a systematic meta-analysis to examine the association between H. pylori infection, hemoglobin A1c levels, and the development of T1DM. Materials and Methods: The initial search identified 451 articles on the association between H. pylori infection and T1DM. Among them, 12 articles had 2797 participants who met the inclusion criteria for an advanced meta-analysis. Results: A significant association was observed between H. pylori infection and T1DM (OR 1.77, 95% CI 1.47–2.12, p < 0.0001), with heterogeneity: Tau² = 0.47; Chi² = 57.07, df = 11 (p < 0.0001); I² = 81%. Subgroup analysis showed that H. pylori infection was significantly associated with a longer duration of T1DM and higher hemoglobin A1c levels (p < 0.001 for both) but not with age at T1DM diagnosis (p = 0.306). Conclusions: These findings contribute to the understanding of the association between H. pylori infection and T1DM and highlight the potential role of H. pylori in influencing the duration and glycemic control of diabetes. Therefore, pediatric patients who have longstanding T1DM and poor glycemic control should be screened for H. pylori infection.

This study aimed to present a systematic meta-analysis examining the association between Helicobacter pylori (H. pylori) infection, hemoglobin A1c levels, and the development of type 1 diabetes mellitus. The initial search identified 451 articles related to the association between H. pylori infection and T1DM. Among them, 14 articles had 2,971 participants meeting the inclusion criteria for advanced meta-analysis. A significant association was observed between H. pylori infection and T1DM, with an odds ratio (OR) of 1.87 (95% confidence interval [CI]: 1.27–2.78, p = 0.002). A subgroup analysis on H. pylori status showed that a longer duration of diabetes diagnosis and higher hemoglobin A1c levels were significantly associated with H. pylori infection (p < 0.001 for both). However, there was no significant association between H. pylori infection and the diagnostic age of diabetes (p = 0.306). These findings contribute to the understanding of the association between H. pylori infection and T1DM, thereby highlighting the potential role of H. pylori in influencing the duration and glycemic control of diabetes.