Microorganisms infection was thought to be associated with atherosclerosis (AS), but the results of trials investigating antibiotic therapy in patients with coronary artery disease were controversial. Recently, a series of studies explored the relationship between gut flora and obesity, which showed that western-style diet (high fat) could induce imbalanced ratio of the Firmicutes versus the Bacteroidetes in the gut of germ-free mice and human beings, and gut flora could promote obesity through several novel pathways, such as inhibition of fasting-induced adipocyte factor. Meanwhile, data from some studies confirm that some link exists between the abdominal obesity and satiety centers (hindbrain and hypothalamus) with neurotransmitters and hormones. All of the above showed some connection between western-style diet, gut flora, visceral fat, and satiety centers, but until now, no study has shown us the exact mechanism about it. It is proposed that the vicious cycle composed of gut flora and visceral fat may initiate and promote AS. Attempts to confirm this hypothesis may lead to new directions in the study of the pathogenesis of AS and the development of novel strategies for the treatment of AS.