Abstract
Some children are more susceptible to viral and bacterial respiratory infections in the first few years of life than others. However, the factors contributing to this susceptibility are incompletely understood. In a retrospective analysis of clinical samples collected from a prospectively-enrolled cohort of 358 children we sought associations between physician-attended illness visits and bacterial colonization in the first five years of life. A subset of children was identified by unsupervised clustering analysis as infection and allergy prone (IAP). Several respiratory infection- and allergy-mediated illnesses co-occurred at higher rates in IAP children, while the rates of other illnesses were not significantly different between the groups. Analyses of nasopharyngeal (NP) pathobionts and microbiota commensals showed that early age of first colonization with pathobionts Streptococcus pneumonia, non-typeable Haemophilus influenzae, and Moraxella catarrhalis was associated with IAP children, and particularly Moraxella abundance was negatively associated with NP microbiome diversity. We conclude that mucosal pathobiont exposures in early life can influence susceptibility to respiratory illnesses in children.
Highlights
Infections are common in young children as immune and microbiome development occur
Our findings suggest that early-life colonization with S. pneumoniae, H. influenzae, and M. catarrhalis is associated with increased occurrence of clinically significant respiratory conditions in early life
infection and allergy prone (IAP) children had significantly more physician-attended illness visits from 6–30 months of age compared to non-infection and allergy prone (NIAP) children, corroborating the clustering analysis (Fig 1B)
Summary
Infections are common in young children as immune and microbiome development occur. Early-life respiratory infections may impact immune development in early life. This has been highlighted by studies linking respiratory infections caused by rhinovirus or RSV and/or colonization with pathogenic bacteria to asthma susceptibility later in childhood [3, 4]. These findings suggest that microbiota commensal composition and pathogenic infections in early life can have a long-lasting influence on health and disease
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