Drosophila as a model for intestinal dysbiosis and chronic inflammatory diseases.

The association between deregulated intestinal microbial consortia and host diseases has been recognized since the birth of microbiology over a century ago. Intestinal dysbiosis refers to a state where living metazoans harbor harmful intestinal microflora. However, there is still an issue of whether causality arises from the host or the microbe because it is unclear whether deregulation of the gut microbiota community is the consequence or cause of the host disease. Recent studies using Drosophila and its simple microbiota have provided a valuable model system for dissecting the molecular mechanisms of intestinal dysbiosis. In this review, we examine recent exciting observations in Drosophila gut-microbiota interactions, particularly the links among the host immune genotype, the microbial community structure, and the host inflammatory phenotype. Future genetic analyses using Drosophila model system will provide a valuable outcome for understanding the evolutionarily conserved mechanisms that underlie intestinal dysbiosis and chronic inflammatory diseases.