We are interested in the vast chemical space generated at the interface between diet, the gut microbiome, and the host. Many small molecules produced along this axis remain chemically uncharacterized, yet may have profound effects on physiology and disease. Our lab combines state-of-the-art high-resolution liquid chromatography–mass spectrometry (LC–MS), advanced metabolite separation and isolation technologies, and computational analysis to discover and identify these unknown metabolites, with a particular focus on compounds derived from dietary phytochemicals. Phytochemicals are a highly diverse class of small molecules found in plant-based foods that are widely consumed and often associated with health benefits, yet the mechanisms by which they influence host physiology remain only partially understood. A major goal of this work is to comprehensively profile the microbial transformation of dietary phytochemicals and identify the resulting metabolites that have biological activity in the host. By linking chemical signals to functional outcomes, we seek to expand the known metabolome and reveal new molecular mechanisms connecting nutrition, microbial metabolism, and health. This research area forms the foundation of our broader research program, providing the molecules, pathways, and hypotheses that drive our studies of liver biology, pharmacology, and cancer.