Background

Bioaccessibility of food allergens may be a key determinant of allergic reactions.
Objective

To develop a protocol allowing the detection of the major peanut allergen, Ara h 6, in the bloodstream following ingestion of low amounts of peanut, and to compare Ara h 6 bioaccessibility by food matrix. We further assessed for differences in absorption in healthy versus peanut‐allergic volunteers.
Methods

A blood pretreatment combining acidic shock and thermal treatment was developed. This protocol was then applied to blood samples collected from human volunteers (n=6, healthy controls; n=14, peanut‐allergic patients) at various timepoints following ingestion of increasing levels of peanut incurred in different food matrices (cookies, peanut butter, chocolate dessert). Immuno‐detection was performed using an in‐house immunoassay.
Results

An original pretreatment protocol was optimised, resulting in irreversibly dissociation of human antibodies‐Ara h 6 immune complex, thus rendering Ara h 6 accessible for its immunodetection. Ara h 6 was detected in samples from all volunteers following ingestion of 300‐1000mg peanut protein, although variations in the kinetics of passage were observed between individuals and matrices. Interestingly, in peanut‐allergic subjects, Ara h 6 could be detected following ingestion of lower doses, and at higher concentrations than in non‐allergic volunteers.
Conclusions and Clinical Relevance

The kinetics and intensity of Ara h 6 passage in bloodstream depend on both individual and food matrix. Peanut‐allergic patients appear to demonstrate higher absorption rate, the clinical significance of which warrants further evaluation.