The Drosophila Microbiome

How the gut microbiome shapes the health and traits of animals

All animals are colonized by microorganisms that play an important but poorly-understood role in sustaining the health and fitness of their animal host. The fruit fly Drosophila melanogaster and related drosophilid flies offer uniquely tractable systems to study how animals interact with their resident microbiota.

The association between Drosophila and its gut microbiota - a tractable model to study interactions between animals and their resident microorganisms

We have demonstrated that the microbiota in drosophilid flies is of low diversity, dominated by readily-culturable bacteria. Experiments using axenic (germ-free) flies and flies bearing specific bacteria have revealed the pervasive effects of the microbiota on nutritional health. Certain bacterial species and bacterial communities promote host growth and development, protect the host against excessive lipid accumulation on high-sugar diets, and provide B vitamins important for host health on low-nutrient diets.

We are using the natural genetic variation in both Drosophila and its bacterial partners to identify the host and microbial genes that influence the composition of the microbiota and their effects on host nutritional health. Genome-wide association studies (GWAS) using flies from the Drosophila Genetic Reference Panel and metagenome-wide association studies (MGWAS) of Drosophila colonized by different bacteria are revealing candidate genes that we are validating.

Dissected gut of Drosophila melanogaster

In parallel, we are interrogating the microbiota in natural populations of Drosophila species and the relationship between the taxonomic diversity of the microorganisms and the functional traits of both the microbiota and the host. These analyses provide the mechanistic underpinning to understand how the microbiota influence ecologically-important traits of their insect hosts, including food choice, competitive interactions and susceptibility to pathogens and parasites.

Selected Recent Publications

Full publication list

Chaston JM*, Newell PD* and Douglas AE, in press. Metagenome-wide association of microbial determinants of host phenotype in Drosophila melanogaster. MBio 5:e01631-14. [*Joint first authors]
Wong ACN*, Dobson AJ* and Douglas AE, 2014. Gut microbiota dictates the metabolic response of Drosophila to diet. Journal of Experimental Biology 217, 1894-1901[*Joint first authors]
Newell PD and Douglas AE, 2014. Among-species interactions determine the impact of gut microbiota on nutrient allocation in Drosophila melanogaster. Applied and Environmental Microbiology 80: 788-796.
Wong ACN*, Chaston JM* and Douglas AE, 2013. The inconstant gut microbiota of Drosophila species revealed by 16S rRNA gene analysis. The ISME Journal 7, 1922-32. [*joint first authors]

For financial support of our research on Drosophila and its microbiome, we thank:

NIH (NIGMS) R01GM095372: The protein nutrition of the symbiotic system between Drosophila and its gut microbiota (with A.G. Clark and B. P. Lazzaro, current)
NSF BIO 1241099 Animal-microbial interactions as an engine of phylogenetic and functional diversity (with J. Jaenike and G. Loeb, current)