Role of gut microbiota in atherosclerosis

Key Points Microorganisms that reside in the human body, the majority of which colonize the gut, might affect host physiology in various ways Bacteria from the gut or the oral cavity might translocate to atherosclerotic plaques and could affect the development of atherosclerosis and cardiovascular disease Microbial transplantations in mice influence diet-enhanced susceptibility to atherosclerosis and thrombosis Dietary components can either alter the composition of gut microbiota or be processed into metabolites that can delay or accelerate the development of atherosclerosis Trimethylamine N -oxide is a potentially harmful bacterial metabolite that influences cholesterol metabolism and thrombosis activity To determine the role of the (gut) microbiota in cardiovascular disease and atherosclerosis, the underlying mechanisms need to be further elucidated Microorganisms that populate the human body have been shown to be involved in metabolic and cardiovascular disorders, but the precise mechanisms are not completely understood. In this Review, Lindskog Jonsson and Bäckhed describe the different pathways by which the gut microbiota might affect the development of atherosclerosis. Infections have been linked to the development of cardiovascular disease and atherosclerosis. Findings from the past decade have identified microbial ecosystems residing in different habitats of the human body that contribute to metabolic and cardiovascular-related disorders. In this Review, we describe three pathways by which microbiota might affect atherogenesis. First, local or distant infections might cause a harmful inflammatory response that aggravates plaque development or triggers plaque rupture. Second, metabolism of cholesterol and lipids by gut microbiota can affect the development of atherosclerotic plaques. Third, diet and specific components that are metabolized by gut microbiota can have various effects on atherosclerosis; for example, dietary fibre is beneficial, whereas the bacterial metabolite trimethylamine- N -oxide is considered harmful. Although specific bacterial taxa have been associated with atherosclerosis, which is supported by increasing mechanistic evidence, several questions remain to be answered to understand fully how the microbiota contributes to atherosclerosis and cardiovascular disease. Such knowledge might pave the way for novel diagnostics and therapeutics based on microbiota.