For her PhD, Dr. Garcia-Santamarina joined Professor Elena Hidalgo laboratory [University Pompeu Fabra (Barcelona)] where she worked on mechanisms of oxidative stress signaling and toxicity in fission yeast. There, she focused on understanding how oxidative stress triggers signaling cascades, how cells cope with the excess of oxidants, and which are their toxic effects in proteins, using the fission yeast as a model organism. After her PhD, she joined the laboratory of Professor Dennis J. Thiele at Duke University (USA) for her first postdoc. In the Thiele lab, she worked with a human fungal pathogen, Cryptococcus neoformans, in a fungal pathogen-host interface context. Her postdoc focused on understanding how C. neoformans keeps metal homeostasis during infection. The host immune system uses transition metals, essential for all living organisms but toxic when excess, as a first line of defense against pathogens [both metal deprivation (“nutritional immunity”) and metal bombardment (toxicity)]. As part of her postdoctoral work, she identified the regulatory mechanisms important for C. neoformans to thrive in environments that rapidly fluctuate in copper concentrations, such as within the host, and characterized two novel proteins with roles in copper detoxification and copper import, respectively, which are fungal virulence determinants. She moved to EMBL (Heidelberg) in 2018, for a second postdoc, with a prestigious Interdisciplinary Marie Curie fellowship (EIPOD). At EMBL, she had shared appointment in the laboratories of Dr. Athanasios Typas, Dr. Kiran R. Patil and Prof. Dr. Peer Bork, where she became an expert in the microbiome field. There, she optimized an in vitro microbiomics platform to answer whether bacterial members of the gut microbiota behave the same against external perturbations (drugs) when they are alone or as part of a community. By comparing the species' behavior in isolation and in the community, she discovered that frequently emergent phenotypic traits are only visible in the community context. She followed up these with metabolomics and in-depth molecular biology and biochemistry experiments to dissect how a particular drug becomes inactive in microbial consortia. In toto, she uncovered that a combination of drug metabolism, drug bioaccumulation and interspecies interactions are the primary drivers of microbial community traits. As a new group leader at ITQB Nova, Dr. Garcia-Santamarina research goal is to deepen into the mechanisms of gut microbial metabolism at the gene and strain level in a competitive environment, namely other gut microbes and host cells. Gut microbial metabolism has developed to take advantage of any metabolite as a potential energy source, and therefore is highly hydrolytic and reductive, mostly relying on metalloenzymes especially suited for electron transfer reactions in anaerobiosis. Thus, in the case of the gut microbiota, metalloenzymes are involved in carbohydrate degradation, pathogen colonization resistance, vitamins and cofactors biosynthesis, reductive amino acid metabolism, or xenobiotics metabolism. She plans to combine her expertise in the metal’s biology field with her knowledge in the microbiome field to set-up experimental pipelines that lead to an understanding of the role of metals in driving gut microbial metabolism and its implications in human health and disease, e.g. inflammatory diseases, cancer, aging, or genetic diseases that course with host metal overloading or defects.