 Methods: Study participants will include patients arriving to Rabin Medical Center with suspected CAD. Patients will provide medical, lifestyle, and nutritional questionnaires. Vital signs measurements will be taken as well as fecal samples andor rectal swabs. Blood samples will be drawn to measure blood chemistry including lipid profile and trimethylamine-N-oxide TMAO levels. Patients will undergo cardiac CT andor cardiac catheterization in accordance with the decision of the cardiologist to evaluate andor treat CAD. Genomic DNA will be extracted from stool samples for Microbiome analysis. 