The Journal of allergy and clinical immunology
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J. Allergy Clin. Immunol. · Mar 2016
ReviewThe microbial environment and its influence on asthma prevention in early life.
There is accumulating evidence to suggest that the environmental microbiome plays a significant role in asthma development. The very low prevalence of asthma in populations highly exposed to microbial environments (farm children and Amish populations) highlights its preventive potential. This microbial diversity might be necessary to instruct a well-adapted immune response and regulated inflammatory responses to other inhaled and ingested environmental elements, such as allergens, particles, and viruses. ⋯ The diversity of the external microbial world will ensure that of the many maladapted pathways leading to asthma development, most, if not all, will be counterbalanced. Likewise, important contributors to asthma, such as allergen sensitization and allergic manifestations early in life, are being suppressed. Thus the facets of innate immunity targeted by microbes and their compounds and metabolites might be the master switch to asthma and allergy protection, which has been found in environments rich in microbial exposures.
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J. Allergy Clin. Immunol. · Mar 2016
ReviewThe contributions of allergic sensitization and respiratory pathogens to asthma inception.
Of the chronic diseases affecting grade-school children, asthma is the most common and accounts for the greatest number of school days missed. Moreover, it can influence family dynamics and function in other ways, and unfortunately, it can also be associated with mortality, particularly in the inner-city environments of the United States. ⋯ Both of these factors appear to exert their influences within the first few years of life, such that asthma becomes established before the child enters grade school at age 5 to 6 years. Therefore, because both allergic sensitization and viral and bacterial illnesses can occur in children who do not have asthma, it is paramount to identify genetic and environmental factors that activate, interact with, and/or direct the immune system and components of the respiratory tract along pathways that allow asthma to become established and expressed clinically.