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.