The human microbiome is evolving rapidly (i.e. over our lifetimes) following changes in modern lifestyles, especially in industrialized countries. Our lab seeks to understand how horizontal gene transfer shapes interactions within the human intestinal microbiota and what the implications of this widespread phenomenon are for community properties relevant to human health (for example, the ability of the gut community to recover after antibiotic treatment). There is currently only a superficial understanding of the different cellular roles of most exchanged genes, the mechanisms governing their spread and their effect on community dynamics. The García-Bayona lab works on bridging the existing gap between the current systems-level observational studies and a mechanistic understanding through bacterial genetics and physiology. We take a bottom-up approach (from genes to communities), incorporating genetics, metagenomics, population analyses and experimental evolution in tractable bacterial consortia.