The microorganisms within a host, commonly referred to as the microbiota, play an important role in the development of an organism and their life history traits, including fecundity and lifespan. For example, in the model organism Drosophila melanogaster, it has been shown that host genotype can significantly alter the microbiota composition (Dobson 2015, Chaston 2016), meaning that host genotype can play a substantial role in how the microbiota is determined and can influence the locally adapted traits of an organism. What is not fully understood are the mechanisms by which host genotype selects the microbiota composition. My intentions are to understand how the genetic feeding preferences of D. melanogaster help determine host microbiota composition. To do this, I will set up assays where I will measure the variation exhibited in the microbiota of genotypically different flies when given a choice of different microbes in their diet; or when no choice is provided. This work will contribute to uncovering how host genotype influences the microbiota variation observed between genetically distinct organisms.