Mycobiome of Stool, Blood, Thrombus and Vessel Wall in Abdominal Aortic Aneurysm Patients

Abdominal aortic aneurysm (AAA) is a life-threatening vascular condition characterized by inflammatory degeneration of the vessel wall. Emerging evidence suggests that microbial factors contribute to its progression. In this study, we analyzed the mycobiome composition of stool, blood, thrombus and damaged vessel wall samples collected during surgery from 24 AAA patients using Internal Transcribed Spacer (ITS) sequencing. Significant differences in alpha and beta diversity were observed across the sample types, confirming compartmentalization of the mycobiome. However, individual fungal profiles did not establish a clear gut-blood-vessel wall axis, indicating that fungi translocated to the vessel wall may originate from other anatomical regions. Comparison AAA mycobiome with healthy arterial walls' mycobiome from organ donors revealed a dominance of anti-inflammatory Tomentella in healthy samples, while pro-inflammatory Malassezia species were prevalent in damaged vessel walls. These findings highlight the role of fungi in AAA progression and suggest potential thera-peutic avenues, including antifungal adjuvant treatments to mitigate inflammation and aneurysm development.