PI: dr.ssa Maria Elena Martino

Title: Experimental Microbiome Evolution: Deciphering the role of microbiota in promoting animal growth

Abstract: All animals establish continuous interactions with commensal microorganisms, named microbiota. Regardless of the microbial ability to colonize their host, the constant interplay between microbes and their animal partners leads to a considerable number of mutual benefits. Specifically, microbiota is able to significantly increase animal growth. Nevertheless, animal/microbiota interactions are extremely complex, as they are strictly dependent on multiple external factors. In particular, the continuous microbial evolutionary processes, together with environmental factors, such as nutrition, constantly affect the biological outcomes for the two partners. Scientific research has provided invaluable contributions to our understanding of animal/microbe mutualism. However, the molecular basis of microbiota benefits to its host and the role of external factors in shaping this relationship remain elusive. The goal of this research proposal is to decipher the molecular and ecological dialogue governing the microbiota benefits towards its animal partner. To this end, I will use an animal model, Drosophila melanogaster, and one of its natural commensals, Lactobacillus plantarum. I aim to develop a multiscale integrative approach combining the use of meta’omics techniques, animal models and experimental microbial evolution to pinpoint the microbial and the host traits required to shape animal/microbes relationship. I will reveal the bacterial genetic and metabolic networks involved in the microbial benefit to host growth and will uncover the dependency of these benefits from host factors. Using a model lactic acid bacterial species and an animal model, this approach is relevant to most lactobacilli/host interactions, including those occurring in humans. This project will provide fresh and unbiased insights into the fundamental biological question of animal/microbe mutualism.