Are mouth and gut microbes linked to how much peanut triggers an allergic reaction?

Details

The amount of peanut needed to trigger a reaction varies widely among people with peanut allergy and is not predictable or well understood. The researchers sought to characterize relationships between the oral and gut microbiomes and systemic processes associated with the reaction threshold in peanut allergy.

The cohort included 120 children with suspected peanut allergy who underwent double-blind, placebo-controlled food challenges. To identify threshold-associated markers and their interrelationships, the researchers generated and analyzed parallel profiles of the oral and gut microbiomes, peripheral blood transcriptome, peripheral blood cytometry, and serum antibody levels.

Of the 120 children, 23 had no peanut allergy, 74 had high-threshold peanut allergy, reacting to at least 443 mg of cumulative peanut protein, and 23 had low-threshold peanut allergy, reacting to less than 443 mg of cumulative peanut protein.

The researchers constructed saliva and stool microbiome networks and identified ten hub microbes in each. Among them, saliva Rothia aeria and stool Bacteroides sp. were associated with reaction threshold. These hub microbes were also associated with peripheral blood transcript levels for threshold-associated key drivers of FcγR-mediated phagocytosis and TLR signaling.

The researchers also constructed correlation networks using additional data on threshold-associated peripheral blood neutrophil abundance and peanut-specific serum IgE and Ara h 2 antibody levels. These networks showed central roles for saliva Rothia aeria and stool Bacteroides sp. in local-systemic networks for IgE- and IgG-mediated peanut allergy.

The integrated study of oral and stool microbiomes, blood transcriptome, cellular profiles, and peanut-specific serum antibodies revealed new relationships between local microbiota and systemic measures associated with peanut allergy reaction threshold.