The human gut microbiota shapes allergic airway inflammation by modulating gut permeability. The human gut microbiota shapes allergic airway inflammation by modulating gut permeability

The composition of the gut microbiota in early childhood is linked to an individual’s asthma risk but the role of the gut microbiota in older patients with established asthma is less clear. Here, we develop a Naive Bayes Classifier (NBC) to discover disease-associated taxa in school-aged children and adults and to design mechanistic experiments in gnotobiotic mice. These experiments show that enterotoxigenic B. fragilis, which is enriched in individuals with asthma compared to healthy controls, causes increased gut permeability and is associated with increased oxidative stress in the lungs during allergic airway inflammation (AAI). Our results provide evidence that gut microbes directly shape airway inflammation outside of early childhood and suggest that therapies targeting the gut microbiota may be helpful tools for asthma control.