#1-98E. Engineering Probiotics: A Novel Strategy for Peanut Allergy Tolerance (The Journal of Allergy and Clinical Immunology, 2025)

Oral immunotherapies for food allergies are often limited by safety concerns and inconsistent efficacy. This study explores a novel probiotic-based strategy using E. coli Nissle 1917 (EcN) engineered to co-display the major peanut allergen Ara h 2 and an inhibitory Siglec ligand to dampen allergen-specific B cell responses. In a peanut-sensitized mouse model, oral administration of this engineered EcN suppressed B cell activation, leading to decreased serum IgE and IgG levels and significantly attenuated anaphylactic reactions. The core finding is the proof-of-concept that orally delivered, engineered probiotics can induce antigen-specific immune tolerance, offering a scalable and non-invasive therapeutic alternative. However, a critical point to consider is that the study focused solely on a single allergen, Ara h 2, which may limit its efficacy against the multiple allergens involved in real-world peanut allergy45. For clinicians, this research is significant as it presents a potential future therapeutic avenue for food allergies, and possibly other autoimmune conditions, moving beyond the challenges of current desensitization methods.

Citation: Zilic, J. M., Keys, T. G., & Hennet, T. Decreased anaphylaxis by probiotic E. coli overexpressing Siglec ligand and peanut allergen. The Journal of Allergy and Clinical Immunology. 2025.

DOI: https://doi.org/10.1016/j.jaci.2025.09.022

Disclaimer: This audio summary is based on personal interpretation and does not guarantee the exact content of the original paper. Please refer to the original article for details.