 Background: The human gastrointestinal system is populated with a variety of symbiotic microorganisms, namely microbiota. The microbiome is the total genetic data of the microbiota. The human gut microbiota interacts extensively with the host through metabolic exchange; thereby contribute to a variety of metabolic and immunologic mechanisms in the human body. Coronary artery disease CAD is major cause of morbidity and mortality worldwide and is a major field of interest in microbiota research. There have been several findings that connect the gut microbiota to CAD pathophysiology, but these data relates solely to the interaction between human gut microbiome and cardiovascular risk factors. As far as known , data regarding patients who already developed CAD is lacking. 