New research from the Centro Nacional de Investigaciones Cardiovasculares (CNIC) identifies imidazole propionate (ImP), a gut microbiota-derived metabolite, as associated with early active atherosclerosis in both mouse models and human cohorts. The metabolite’s blood levels correlated with atherosclerotic plaque extent, suggesting potential as a diagnostic biomarker and therapeutic target. Findings published in Nature highlight the microbiome’s role in cardiovascular disease progression and the opportunity for microbiota-focused interventions.