Early-life House Dust and Infant Nasal Microbiota Similarity is Diminished in Infants who Develop Atopy

RATIONALE: Early-life house dust microbiota exposures co-vary with atopy and recurrent wheeze development at three years of age. The upper airway microbiota is related to acute respiratory infection and childhood asthma. We thus hypothesize that the house dust microbiota in early life is related to the upper airway microbiota of infants, and that atopy development at 3 years of age is related to specific nasal taxa also found in the residential environment.

METHODS: Dust samples from the living rooms of children enrolled in the Urban Environment and Childhood Asthma (URECA) birth cohort were collected at 3 months of age, nasal wash samples were collected at 12 months, and atopy determined at 3 years of age. A total of 72 paired nasal and house dust samples underwent 16S rRNA bacterial biomarker sequencing and were analyzed.

RESULTS: The three-month house dust and 12-month nasal microbiota composition were related (Procrustes; M²=0.94; p=0.049). Compared with healthy (non-atopic non-recurrent wheeze) infants, atopic subjects possessed nasal microbiota that were less similar to paired house dust microbiota (linear model β=0.057; p=0.039), following adjustment for site. The abundance of a specific Moraxella taxon in nasal washes was positively associated with atopy development (β=3.53; q<0.001), while abundance of a specific Haemophilus taxon was negatively associated (b=-3.72; q=0.013). These specific taxa were also detected in house dust microbiota.

CONCLUSIONS: Increased similarity between the microbiota of house dust at 3 months of age and nasal wash samples at 12 months of age is associated with protection from atopy at age 3 years.