Fig. 4: Phenotypes in the progeny of parental germ-free mice conventionalized with antibiotic-perturbed microbiota.

Progeny of germ-free mice that had been conventionalized with the fecal microbiota of antibiotic-exposed or control SPF mice (see Fig. 3a) were evaluated at sacrifice for immune responses to HDM antigen. a Serum IgE levels were determined by IgE-specific ELISA. b BAL was evaluated for total cell counts by trypan blue staining, or after BAL samples were cytocentrifuged and differentially stained, for proportion of eosinophils, or neutrophils. Lung single cell suspensions were isolated and evaluated by flow cytometry for differences in the c myeloid compartment or d stimulated ex vivo using PMA and ionomycin. Data were collected from three independent experiments; each individual experiment yielded the same trend. Subsets of the offspring mice were evaluated for differences in lung function by methacholine challenge assay, using a Scireq FlexiVent apparatus. Offspring mice sensitized and challenged with HDM or PBS were evaluated for e airway resistance and airway elastance in response to increasing methacholine doses (PBS, n = 5–8 per group and HDM, n = 10–12 per group, data are from three independent experiments). *p < 0.05; **p < 0.01; ***p < 0.001, ****p < 0.0001; nonparametric one-way ANOVA.