Diverse microbial communities live in the gut regions of animals. The precise ecological and evolutionary circumstances that govern relationships between hosts and their gut communities is unclear. In this study, we hypothesize that host feeding strategy shapes the microbial communities within the gut systems of insects. We collected five insect species from the Sevilleta National Wildlife Refuge that exhibited herbivorous, detritovorous and carnivorous diets. Using gut samples from the insects we measured if and how microbial communities are shaped based on any effect host feeding strategy might have. Analysis of bacterial 16S rDNA sequences indicate that insect gut bacterial communities correlate with host feeding type. Analysis has also shown that sequences from the phyla Firmicutes and Proteobacteria appear to contribute most significantly to the differences between communities of different feeding types. Our study further defines the ecological circumstances that shape the microbial populations within living systems.