The Microbiome Regulates Pulmonary Responses to Ozone in Mice

Previous reports demonstrate that the microbiomeimpacts allergic airwayresponses, including airwayhyperresponsiveness, a characteristic feature of asthma. Here we examined the role of the microbiomein pulmonary responses to a nonallergic asthma trigger, ozone. We depleted the microbiota of conventional mice with either a single antibiotic (ampicillin, metronidazole, neomycin, or vancomycin) or a cocktail of all four antibiotics given via the drinking water. Mice were then exposed to room air or ozone. In air-exposed mice, airwayresponsiveness did not differ between antibiotic- and control water–treated mice. Ozone caused airwayhyperresponsiveness, the magnitude of which was decreased in antibiotic cocktail–treated mice versus water-treated mice. Except for neomycin, single antibiotics had effects similar to those observed with the cocktail. Compared with conventional mice, germ-free mice also had attenuated airwayresponsiveness after ozone. 16S ribosomal RNAgene sequencing of fecal DNA to characte...