Narrative review of the association between gut microbiota and peripheral artery disease (PAD)

It has been posited that the inflammatory process seen in atherosclerosis is underpinned by gut dysbiosis. Dysbiosis refers to alterations in the function, composition, and diversity of the human gut microbiota, all of which are influenced by endogenous and exogenous stimuli. Currently there is limited literature describing the association between gut microbiota and peripheral artery disease (PAD). This review summarizes the evidence surrounding the role of gut microbiota in the initiation of atherosclerosis (through direct infection of atherosclerotic plaque or systemic immune response to bacterial products and metabolites) and how dysbiosis may influence the various treatment modalities for PAD, including medical therapy (pharmacotherapy, lifestyle changes, and supervised exercise training) and surgery (endovascular and open revascularization). In particular, the role of short chain fatty acids (SCFAs), the effects of exercise on SCFA-producing and lactic acid bacteria (LAB) and, consequently, the lack of targeted research into dietary interventions and supplementation are highlighted in this review. This review highlights the potential for gut microbiota as not only a therapeutic target in patients with PAD, but also as a diagnostic and screening tool. It is imperative that the focus of future research is on the potential for personalized treatment which targets the gut microbiota (such as synbiotics, postbiotics, nicotinamide adenine dinucleotide (NAD) supplementation, selective antibiotics, resistance exercise, senolytics, and fecal microbial transplantation [FMT]) to be utilized as adjuncts to already existing treatment options for PAD. This review also highlights the potential role of biobanks and analysis of atherosclerotic plaques in further advancing knowledge and research in this area.