The concept of a “common mucosal immune system” relies on cross-talk between mucosal compartments. A balance must be struck that maintains homeostasis between the microbiome and the host. This balance is constantly challenged by a number of factors leading to “dysbiosis”(imbalance) in the microbial community, which is found in asthma. The microbiome (airway or gut) may play a role in the development of specific phenotypes such as allergic or nonallergic asthma and treatment-resistant asthma. Studies of oral or aerosol administration of the microbiota for the treatment and prevention of asthma are in planning stages.
The microbiome in asthma. Yvonne J. Huang et al. JACI, January 2015, Volume 135, Issue 1, Pages 25–30 (free full text).