It has been hypothesised (the "hygiene hypothesis") over the last few decades that the taking of antibiotics has a role in the increase in asthma and allergy observed over the same time. This paper describes the creation of a mouse model for antibiotic-induced disturbance of the microbial flora in the gut. Once the mice have been given antibiotics they become susceptible to an allergic airway response to stimulus by Aspergillus fumigatus spores. If the mice are not given antibiotics they do not develop the allergic response.
This is the first experimental demonstration that antibiotics and gut flora can influence allergic airway disease, and highlights the concept that events in a distant mucosal site such as the gut can play an important role in regulating immune responses in the lungs.