The Roar project is an effort to improve scientific understanding of the role of commensal bacteria in the spread of antimicrobial resistance. This is approached by 1) compiling existing commensal isolate data and literature into a Web-based bioinformatics tool; 2) using statistical, risk analysis, and mathematical modeling techniques to analyze the data in order to determine if the frequency of antibiotic resistance genes in commensals can predict the subsequent emergence of antibiotic resistance in pathogenic bacterial populations and 3) encouraging, directing, and funding research efforts to evaluate antibiotic resistance in commensals.