No potential causal link between HP infection and IBD: A 2way Mendelian randomization study

Area of Science:

• Gastroenterology and Epidemiology
• Infectious Diseases
• Genetics

Background:

• Epidemiological studies suggest a potential negative correlation between Helicobacter pylori infection and inflammatory bowel disease (IBD).
• Conflicting evidence exists regarding the causal relationship, making it difficult to establish prevention or treatment strategies for H. pylori and IBD.
• This ambiguity necessitates robust investigation into the potential link between H. pylori infection and IBD.

Purpose of the Study:

• To investigate the potential causal relationship between Helicobacter pylori infection and inflammatory bowel disease (IBD) using Bidirectional Mendelian Randomization (MR).
• To analyze genetic variants associated with H. pylori infection and IBD to determine causality.
• To provide evidence-based insights for clinical recommendations regarding H. pylori and IBD management.

Main Methods:

• Utilized antibodies (anti-H. pylori IgG, VacA, GroEl) as indicators for H. pylori infection.
• Acquired genetic variants from Genome-wide Association Studies (GWAS) datasets for IBD and H. pylori.
• Conducted Bidirectional Mendelian Randomization (MR) analysis, including IVW, MR-Egger, and weighted median methods, with sensitivity analyses to assess causality and robustness.

Main Results:

• The comprehensive MR analysis revealed no significant causal relationship between H. pylori infection and IBD across multiple methodologies (P > 0.05 for IVW).
• Sensitivity analyses did not indicate significant horizontal pleiotropism, and while heterogeneity was detected, results remained reliable.
• A single exception in reverse MR analysis (MR-Egger, P < 0.05) was noted but deemed less significant than the IVW findings.

Conclusions:

• Based on MR research, there is no direct causal link observed between H. pylori infection and IBD risk.
• Eradicating H. pylori is unlikely to offer substantial benefits in preventing or treating IBD, and vice versa.
• Limitations of serological markers exist, and further research with histological diagnosis and additional MR studies is recommended for a comprehensive understanding.