Use of Exposome to Explain the Allergy Epidemics

Abstract

Worldwide, up to 50% of individuals will suffer from at least one allergy by 2050 due to environmental changes. Although daunting, proof of concept studies are being conducted that show the promise of the exposomic investigation and integration of different kinds of data to explain the allergy epidemics; the exposome being the totality of external environmental exposures (external exposome) to which an individual is exposed in life and their consequences in the body (internal exposome).The specific external exposome acting on allergic diseases include indoor and outdoor aeroallergens and chemical air pollutants.To it has to be added non-specific external exposome, namely the action of climate change, urbanization and loss of biodiversity that affect sources, emissions and concentrations of main aeroallergens and chemical air pollutants. In this context, thunderstorm-related asthma is a dramatic example of the effects of combined environmental factors and an in vivo model for understanding the mechanisms at work in respiratory allergy. In terms of internal exposome, environment- or lifestyle-driven aberrancies in the gut and skin microbiome composition represent a key mediator of allergic diseases. In addition, the role of epigenetic mechanisms (particularly DNA methylation) in allergic disease is also considered in the implementation of the exposome because these mechanisms are known to be at the interface among gene regulation, environmental stimuli and developmental processes, all of which are essential for the pathogenesis for asthma and allergies.Tools and methods to implement the external and internal exposome (sensors, geographic information systems, and ad hoc survey instruments) will be presented.A better knowledge of the impact of the exposome on allergy development is crucial for urging individuals, health professionals and policy makers to take actions to mitigate the effect of environmental changes and to adapt to them.