Microbes, allergic sensitization, and the natural history of asthma

Abstract

Purpose of review Understanding factors that lead to asthma development in early life is essential to developing strategies aimed at primary or secondary prevention. Recent findings This article will review current evidence addressing the development of early life allergic sensitization in relation to microbes and the gut and airway microbiome. Wheezing illnesses, particularly viral, remain a significant risk factor for asthma inception; however, bacterial pathogens have recently emerged as an additional important contributor to asthma risk, either alone or as cofactors with viral infections. The combined influence and interaction of early life viral wheezing and aeroallergen sensitization is important, with allergic sensitization preceeding the onset of viral wheeze. Lastly, we review recent data from longitudinal studies regarding the development of irreversible airway obstruction and its impact on the natural history of asthma. Summary The development of asthma remains complex and incompletely understood. There is interplay between genetic predisposition and environmental exposures, including allergens and microbes. Interventions aimed at these risk factors during the preschool years may prevent the longitudinal course of asthma progression to irreversible airway obstruction.

Longitudinal Asthma Patterns in Italian Adult General Population Samples: Host and Environmental Risk Factors

“…In a US general adult population sample (≥65 years) with active asthma, patients with COPD had a four-fold higher risk of having asthma-related hospitalizations in the last 12 months [ 26 ]. A similar result was found in a Canadian study, using health administrative databases: higher rates of asthma claims were found in patients with than in those without COPD [ 27 ]. Moreover, active asthma was significantly associated with an increased risk for chronic bronchitis, emphysema, and COPD over a 20-year follow-up [ 28 ].…”

Metagenomic Characterization of Indoor Dust Bacterial and Fungal Microbiota in Homes of Asthma and Non-asthma Patients Using Next Generation Sequencing

“…Feng et al (2016) reported that parental allergic diseases, atopy, diet and early life exposures might explain the higher prevalence of asthma in the urban environment. Also, there is a complex interplay between genetic predisposition and environmental exposures, including microbes and allergens (Anderson and Jackson, 2017). Regarding exposure to molds, it is estimated that in France about 125,000 individuals suffer from severe asthma with fungal sensitization (SAFS) episodes (189 cases/100,000 adults per year) (Gangneux et al, 2016).…”

Dietary and Plasma Polyunsaturated Fatty Acids Are Inversely Associated with Asthma and Atopy in Early Childhood

“…Wheezing illnesses in the preschool age population are common and associated with significant morbidity and cost. 1,2 Risk of asthma and wheeze in this age group is multifactorial with genetic and environmental contributions, 3,4 and the presence of allergic sensitization has been linked to asthma that persists later in life. 5 Environmental and behavioral changes, including dietary factors, may be major contributors to childhood asthma risk.…”