Household environmental microbiota influences early‐life eczema development

Abstract

SummaryExposure to a diverse microbial environment during pregnancy and early postnatal period is important in determining predisposition towards allergy. However, the effect of environmental microbiota exposure during preconception, pregnancy and postnatal life on development of allergy in the child has not been investigated so far. In the S‐PRESTO (Singapore PREconception Study of long Term maternal and child Outcomes) cohort, we collected house dust during all three critical window periods and analysed microbial composition using 16S rRNA gene sequencing. At 6 and 18 months, the child was assessed for eczema by clinicians. In the eczema group, household environmental microbiota was characterized by presence of human‐associated bacteria Actinomyces, Anaerococcus, Finegoldia, Micrococcus, Prevotella and Propionibacterium at all time points, suggesting their possible contributions to regulating host immunity and increasing the susceptibility to eczema. In the home environment of the control group, putative protective effect of an environmental microbe Planomicrobium (Planococcaceae family) was observed to be significantly higher than that in the eczema group. Network correlation analysis demonstrated inverse relationships between beneficial Planomicrobium and human‐associated bacteria (Actinomyces, Anaerococcus, Finegoldia, Micrococcus, Prevotella and Propionibacterium). Exposure to natural environmental microbiota may be beneficial to modulate shed human‐associated microbiota in an indoor environment.

Home Environment in Early-Life and Lifestyle Factors Associated with Asthma and Allergic Diseases among Inner-City Children from the REPRO_PL Birth Cohort

“…The second unexpected finding of our research was that neither urine cotinine concentration nor parental smoking were predictors of asthma or any of the other studied diseases. In other studies [27,29], parental smoking and cotinine levels were strong predictors of asthma development. Nevertheless, just 31% of investigated families reported exposure to tobacco smoke.…”

“…Research by O'Connor et al [27] based on children up to 7 years of age showed that higher concentrations of cockroach, mouse, and cat allergens in house dust in the first three years of life were associated with a lower risk of asthma (for cockroach allergen, the odds ratio for an increase in the interquartile range 0.55; 95% CI, 0.36 to 0.86; p < 0.01). At the same time, the abundance of a number of bacterial taxa in house dust was associated with increased or decreased asthma risk [29]. On the other hand, it is known that diesel pollution and exhaust fumes intensify the action of allergens, which may affect the development of allergic inflammation [30,31].…”

Smoke exposure and childhood atopic eczema and food allergy: A systematic review and meta‐analysis

“…For instance, early-life environmental microbial exposure is critical to immune development and may modulate allergy risk. 61,62 Of note, this meta-analysis highlighted the importance of in utero programming in allergy development.…”

Effects of Residential Environment and Lifestyle on Atopic Eczema Among Preschool Children in Shenzhen, China

“…The environmental pathogenic mechanisms of eczema in children may be multifaceted and have not been fully understood, which may be related to the dysregulation of cytokines and inflammatory mediators directly or indirectly induced by chronic exposure to xenobiotics ( 50 – 52 ). Besides, evidence have proved that indoor exposure to exogenous microbiota may alter intestinal microbiota in children, and thus regulate the immunological functions ( 53 – 55 ). In addition, indoor wood materials and coating on the walls may release organic pollutants such as organophosphates or brominated flame retardants, which may also exert hazardous effects on gut microbiota and potentially impair immune systems ( 56 , 57 ).…”