How are Helicobacter and Allergie related?

The relationship between Helicobacter pylori (H. pylori) and allergies is an active research area with conflicting evidence. Some studies support the 'hygiene hypothesis': early H. pylori infection may modulate the immune system, reducing allergic diseases like asthma and hay fever. Mechanistically, H. pylori is thought to induce regulatory T cells (Tregs) and dampen excessive Th2 responses. However, other studies find no significant association or even an increased allergy risk in infected individuals. Confounders such as socioeconomic status, antibiotic use, and geographic variation complicate interpretation. Importantly, a home DNA or stool test for H. pylori cannot predict allergy predisposition. Detecting H. pylori alone does not justify treatment for allergy prevention. Clinical decisions should follow established guidelines (e.g., eradication for peptic ulcer). For allergies, validated tests (specific IgE, skin prick) and medical consultation are required. The evidence for a causal link remains unclear.