Seasonal shifts in the microbial community of natural Drosophila melanogaster populations

Many insects benefit from gut microbial communities that contribute digestive or detoxifying enzymes, provision limiting nutrients, or defend the host against pathogens. Although it is well established that abiotic and biotic factors can shape insect-associated microbial communities, the seasonal dynamics and their potential impact on host fitness remain poorly studied. Here we investigated the seasonal patterns in bacterial and fungal communities associated with the model organism Drosophila melanogaster, for which it was previously reported that diet and temperature drive variations in microbial communities, affecting larval growth, development, and reproduction. Our results reveal high inter-individual variation, but also consistent changes in bacterial and fungal communities of three wild D. melanogaster populations from early spring to late summer. Elucidating the potential adaptive value of seasonally changing microbial communities will enhance our understanding of how symbiotic microbes may contribute to ecological niche shifts and geographic range expansions in insects and other animals.