House dust exposure: GI microbiome Lactobacillus enrichment and increased airway immune defense

Hypoallergenic pets no more! In a recent article (2013) from PNAS, researchers have found that mice exposed to dust collected from households that had dogs compared to dust collected from households with no pets had significantly lower lung Th2 cytokine mRNA expression levels (IL-4 and IL-13) compared with those treated with dust from no pet houses. Further, the mucous associated gene, gob5, mRNA expression, IgE serum and inflammation levels were also significantly reduced.

Using a phylogenetic microarray, they found dog and no-pet-dust exposed animals exhibited different compositions of microbiota in the lower GI tract compared to control animals, showing that exposure of environmental microbes is sufficient for modifying the GI microbiome. Of the many enriched microbes found in the GI tract, Lactobacillus johnsonii was the most enriched. When L. johnsonii, was supplemented to the GI micro biome composition compared to the control, they found the composition of taxa was significantly altered, showing it elicits changes in the community phylogeny. This research may allow us to manipulate microbiome composition and provide relief to individuals with pulmonary and airway infections and diseases.

Jennifer Flanagan is an undergraduate in Jonathan Eisen’s lab, working on aquariums as part of the microbiology of the built environment


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Jennifer Flanagan

Jennifer Flanagan is a research specialist at UCSF.