Peripheral arterial disease (PAD) is a common manifestation of atherosclerosis, affecting arteries in the leg, and it’s symptomatic stages are associated with significant impact in daily life in terms of walking impairment, loss of independence, rest pain or ulcers or gangrene which may lead to amputation. All stages, including the asymptomatic stage is additionally associated with increased cardiovascular disease mortality and morbidity. This disease affects mainly elderly people and is more prevalent in women than men and leads to an overall decline in quality of life (QoL). Data from several studies support a role of gut microbiota and dietary consumption of phosphatidylcholine (which is often found in western diet such as meat) in the pathogenesis of atherosclerosis. Production of trymethyamine N-oxide (TMAO) by gut microbiota metabolism of dietary phosphatidylcholine has been associated with the development and progression of atherosclerosis in humans. Despite its high prevalence PAD remains under diagnosed and receives less attention in scientific literature compared to coronary artery disease. The overall aim of this project is to investigate whether changes in TMAO levels and gut microbiota composition are associated with inflammation and quality of life in men and women with different stages of peripheral arterial disease. We will explore gut microbiota composition and evaluate TMAO levels together with inflammatory markers in PAD patients. Quality of life and diet will be assessed in PAD patients using questioners. Correlation studies will be performed to evaluate associations between QoL, diet and different biomedical parameters analysed. Defining the process in pathophysiology linking of gut microbes, TMAO and PAD development could lead to new intervention strategies involving specific dietary and pharmacological approaches to improve health and quality of life in PAD patients.