Major advances have been made in stroke treatment and prevention in the past decades. However, the burden of stroke remains high. Identification of novel targets and establishment of effective interventions to improve stroke outcomes are, therefore, needed. Recent research highlights the contribution of the gut microbiota to stroke pathogenesis.
Compositional and functional alterations of the gut microbiota, termed dysbiosis, are linked to stroke risk factors, such as obesity, metabolic diseases, and atherosclerosis. In acute cerebral ischemia, the gut microbiota plays a key role in bidirectional interactions between the gut and brain, referred to as the microbiota-gut-brain axis. Gut dysbiosis prior to ischemic stroke affects outcomes. Additionally, the brain affects the gut microbiota during acute ischemic brain injury, which in turn impacts outcomes. Interactions between the gut microbiota and stroke pathogenesis are mediated by several factors including bacterial components (e.g., lipopolysaccharide), gut microbiota-related metabolites (e.g., short-chain fatty acids and trimethylamine N-oxide), and the immune and nervous systems. Clinical studies have reported that patients with acute ischemic stroke exhibit gut dysbiosis, which is associated with host metabolism and inflammation, as well as functional outcomes. Modulation of the gut microbiota or its metabolites improves conditions related to stroke pathogenesis, including inflammation, cardiometabolic disease, atherosclerosis, and thrombosis. Key Messages: Accumulating evidence indicates that the gut microbiota plays a possible role in stroke pathogenesis. Modulation of the gut microbiota may provide a novel therapeutic strategy for the treatment and prevention of stroke.

© 2021 The Author(s) Published by S. Karger AG, Basel.