The Lee Lab investigates how microbial metabolites regulate energy balance and promote mucosal healing in the gastrointestinal tract, with particular focus on inflammatory bowel disease (IBD). Our work centers on microbiota-sourced purines and their dual role in fueling host epithelial metabolism and supporting microbial cross-feeding networks that drive butyrate production. We use a multidisciplinary approach combining targeted metabolomics and multi-omics to explore host–microbe metabolic interactions at the mucosal interface. Current efforts aim to define the purine–butyrate axis as a central regulator of gut repair and to develop engineered live biotherapeutics that restore metabolic function in the inflamed intestine.