Effect of gut microbiota on the development of atopic dermatitis in NC/Nga mice

Abstract

Recent researches on gut microbiome provided better understanding of relationship between gut microbiota and host pathology, including atopic dermatitis, of which occurrence and development are known to be associated with gut microbiota but not characterized so far. To identify intestinal microorganisms related with atopic dermatitis, specific antibiotic cocktails were developed to change the two major phylotypes of gut microbiota, of which composition was examined by pyrosequencing using 16S rRNA gene tags. NC/Nga mice, model animal for atopic dermatitis, were administered two different antibiotic cocktails targeting either Gram negative (GNA) or Gram positive (GPA) bacteria by either ad libitum drinking water or oral gavage for 6 weeks. The GPA group showed an increased serum IgE level accompanied with more severe skin damage compared to the control and GNA groups. Bacterial community analysis data also revealed dramatic changes in the gut microbiota composition of the GPA group with a significant increase in abundance of the species Enterobacter cowanii and Enterobacter hormaechei belonging to the Proteobacteria. The involvement of the two bacteria in the pathology of atopic dermatitis was tested by oral administration to NC/Nga mice. Only the mouse group colonized with Enterobacter hormaechei showed an aggravation of skin damage and an increased serum IgE level. Our data suggest that enterobacteria, Enterobacter hormaechei, may play an important role in development and severity of atopic dermatitis in NC/Nga mice