Effects of Spermidine on Gut Microbiota Modulation in Experimental Abdominal Aortic Aneurysm Mice

Accumulating evidence in recent years has demonstrated the important role of gut microbiota in maintaining cardiovascular function. However, their functions in abdominal aortic aneurysm (AAA) are largely unexplored. In this study, we established a porcine pancreatic elastase-infused experimental AAA mouse model and explored gut microbiota modulation using 16S rDNA sequencing. Here, we found that a significant alteration to gut microbiota composition and function occurred in AAA. The functional change in the gut microbiome revealed dysregulated biosynthesis metabolism and transport of spermidine in AAA. Furthermore, exogenous spermidine was administrated via drinking water and attenuated the progression of experimental AAA disease, which supports our recent study that spermidine alleviates systemic inflammation and AAA. These effects were associated with remitted gut microbiota dysbiosis and metabolism in AAA progression as demonstrated by 16S rDNA gene analysis. In addition, several bacterial florae, such as Bacteroides, Parabacteroides and Prevotella, were identified to be associated with the progression of AAA. Our results uncovered altered gut microbial profiles in AAA and highlighted the potential therapeutic use of spermidine in the treatment of gut microbiota dysbiosis and AAA.