Project Details
Projekt
Microbial burden and the role of environmental exposure for food allergy and tolerance
Subject Area
Clinical Immunology and Allergology
Pediatric and Adolescent Medicine
Pediatric and Adolescent Medicine
Term
since 2019
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 409525714
B1 investigates involvement of microbiota in food allergy health trajectories. Recruitment of participants in A1 and A2 was delayed due to the pandemia, however pilot runs of samples through the workflow for metagenomic analysis of stool microbiota was initiated. Samples from 64 allergic and 24 sensitized but tolerant individuals were sequenced to date, roughly meeting initial goals at least for baseline samples, with remainder expected finished during 2022. Preliminary analysis of these subjects show a relatively modest distinction between tolerant and allergic subjects (a distinction affecting 116 bacterial genera). These gut signatures and biomarkers likely distinguish individuals at high risk of food allergy. Accordingly, we started together with the clinical partners recruitment of non-allergic controls, with a pilot set of N=6 such sequenced to date, to test this.We compared these non-allergic controls with a representative set of N=6 food allergic subjects from A2, and additionally with a dataset of metabolic syndrome patients (N=71 baseline samples from Maifeld et al., 2021), selected as we there can ensure the same experimental protocol was used, to verify fidelity of our workflow. Overall, the study samples show similar gut microbial compositions to those other human gut samples. Relative abundance of gut microbiota on phylum level was overall similar between subjects in allergic, non-allergic and metabolic syndrome groups, although the phylum Chloroflexi is significantly more abundant in allergic subjects (Kruskal-Wallis FDR: 0.03). No significant differences in alpha diversity operationalized as Shannon index were found between groups. Beta diversity operationalized as Bray-Curtis dissimilarity was also not significantly different between groups, nor was enterotype distribution between the groups.As skin samples were collected and stored in the first funding period, but without funding of the specific metagenomics analysis, these materials are now available in the second funding period. Reflecting the relatively weak signal of dog ownership in the gut microbiome, we will carry out metagenomic analysis on the collected skin samples within the second period, anticipating stronger signatures within this space. In addition, we will perform dedicated sample nucleotide extraction on the collected biobanked material to assess whether higher-resolution measurements of mycobiome or virome reveal a stronger link between these spaces and food allergy outcomes. Food allergens will be measured in dust samples as an influencing variable in the development of food allergy and tolerance. Immunoglobulin binding to bacteria in stool samples and quantification of IgA, IgM and IgG content in stool samples of allergic, sensitized but tolerant and healthy individuals will be performed as a proxy for a healthy or non-healthy immune maturation and intact mucosal barrier function.
DFG Programme
Clinical Research Units
Subproject of
KFO 339:
Food Allergy and Tolerance (Food@)
