Home dust microbiota is disordered in homes of low-income asthmatic children.

OBJECTIVE

Exposure to microorganisms has repeatedly been found to influence development of atopic diseases, such as asthma. Innovative techniques have been developed that can comprehensively characterize microbial communities. The objective of this study was to characterize the home microbiota of asthmatic children utilizing 16S rRNA-based phylogenetic analysis by microarray.

METHODS

In this cross-sectional study, DNA was extracted from home dust and bacterial 16S rRNA genes amplified. Bacterial products were hybridized to the PhyloChip Array and scanned using a GeneArray scanner (Affymetrix, Santa Clara, CA). The Adonis test was used to determine significant differences in the whole microbiome. Welch's t-test was used to determine significant abundance differences and genus-level richness differences.

RESULTS

Nineteen homes were included in the analysis (14 asthma and five no asthma). About 1741 operational taxonomic units (OTUs) were found in at least one sample. Bacterial genus richness did not differ in the homes of asthmatics and non-asthmatics (p = 0.09). The microbial profile was significantly different between the two groups (p = 0.025). All the top 12 OTUs with significant abundance differences were increased in homes of asthmatics and belonged to one of the five phyla (p = 0.001 to p = 7.2 × 10(-6)). Nearly half of significant abundance differences belonged to the phylum Cyanobacteria or Proteobacteria.

CONCLUSIONS

These results suggest that home dust has a characteristic microbiota which is disturbed in the homes of asthmatics, resulting in a particular abundance of Cyanobacteria and Proteobacteria. Further investigations are needed which utilize high-throughput technology to further clarify how home microbial exposures influence human health and disease.