Gut microbiota dysbiosis drives stroke-associated pneumonia: mechanisms and targeted therapeutic strategies.

The gut microbiota has been increasingly recognized as a central regulator of immune function, with growing research highlighting its association with the development of stroke-associated pneumonia (SAP). This review provides an overview of current research on the correlation between SAP and alterations in gut microbial composition and metabolism, with a focus on microbial imbalance, changes in key metabolites, and relevant biological mechanisms. Clinical and preclinical studies consistently report a decline in short-chain fatty acids (SCFAs)-producing bacteria, an increase in potentially harmful microbial species, reduced SCFAs levels, and elevated lipopolysaccharide (LPS) concentrations. These disturbances appear to be associated with SAP progression through the microbiota-gut-brain and microbiota-gut-lung axes by affecting immune regulation and inflammatory responses. The review also examines microbiota-targeted treatment approaches, including dietary modification, antibiotic therapy, probiotics, microbiota-regulating compounds, fecal microbiota transplantation (FMT), and respiratory microbiota transfer. A deeper understanding of how microbial disturbances are correlated with SAP may help explain the increased vulnerability to pulmonary infections following stroke and support the design of more effective, microbiota-based therapeutic strategies.