Microbiota and microRNAs in lung diseases: mutual influence and role insights

Trillions of microbial cells colonize human body both internally and externally. The prevalent amount of these reside in the gastrointestinal tract (gut microbiome). Gut microflora support the transformation of food nutrients. The products of this modification processes both modulate gastro-intestinal immunity, and influence other organs such as lung and brain. Recently, it was reported the role of micro-RNAs (miRNAs) as regulators in different pathways of the innate and/or adaptive immune responses. Latest studies discussed the aptitude of probiotics strains to balance the host immune response at a post-transcriptional level by controlling miRNAs expression. We speculated a model of lung immune regulation driven by the axis microbiota-microRNAs, involving asthma, acute injury, cancer and COPD. Based on this axis, we propose a novel approach based on the modification of microRNAs expression centered not exclusively on antagomiRs but also on microbiota modification in order to further potentiate their therapeutic effects.