Abstract
Abdominal aortic aneurysm (AAA) is a large-vessel disease with high mortality, characterized by complex pathogenic mechanisms. Current therapeutic approaches remain insufficient to halt its progression. Fungi are important members of the gut microbiota. However, their characteristic alterations and roles in AAA remain unclear. This study investigated the role of gut fungal communities in the development of AAA through metagenomic sequencing of fecal samples from 31 healthy individuals and 33 AAA patients. We observed significant dysbiosis in the gut mycobiomes of AAA patients compared to healthy individuals, characterized by an increase in pathogenic fungi like Candida species and a decrease in beneficial yeasts such as Saccharomyces cerevisiae. The changes in fungal populations correlated strongly with clinical indicators of AAA, highlighting their potential for diagnosing and predicting AAA progression. Furthermore, our animal experiments demonstrated that Saccharomyces cerevisiae significantly ameliorated pathological alterations in AAA mice, suggesting a protective role for specific yeast strains against AAA development. These findings underscore the significant impact of gut mycobiomes on AAA and suggest that modulating these fungal communities could offer a novel therapeutic approach. Our research advances the understanding of the influence of gut microbiome on vascular diseases and suggests potential non-surgical approaches for managing AAA. By elucidating the diagnostic and therapeutic potential of gut fungi in AAA, this study provided important clues for future clinical strategies and therapeutic developments in the field of vascular medicine. Importance: Our research highlights the crucial role of gut fungi in abdominal aortic aneurysm (AAA) development. By analyzing fecal samples from AAA patients and healthy controls, we discovered significant dysbiosis in gut fungal communities, characterized by an increase in harmful Candida species and a decrease in beneficial yeasts like Saccharomyces cerevisiae. This dysbiosis was correlated with the severity of AAA. Importantly, in animal experiments, supplementing with Saccharomyces cerevisiae significantly slowed AAA progression. These findings suggest that modulating gut fungi may offer a novel, non-surgical approach to the diagnosis and treatment of AAA, potentially reducing the need for invasive procedures.