Alterations in gut microbiota and physiological factors associated with abdominal aortic aneurysm

Abdominal aortic aneurysm(AAA)is a progressive focal dilatation and weakening of the abdominal aorta,causing 1.3%of all deaths among men aged 65–85 years worldwide.The formation of AAA is a complex process with multiple risk factors.Therefore,this study aimed to determine the relationship of disease severity and physiological factors,and gut microbiota structures in AAA patients.Physiological indicators and fecal 16S rRNA gene sequences from healthy controls and patients with AAA were collected.The correlations between the diameter of the AAA and clinical parameters,and gut microbiota composition were then analyzed separately using multivariable analysis.The diameter of AAA was extremely positively correlated with smoking index,alkaline phosphatase,blood glucose,and blood triglycerides and negatively correlated with prealbumin and Cystatin C.As the diameter of AAA increased,the α-diversity,including Chao 1,Shannon,and Simpson indices,of the gut microbiota decreased and presented a negative linear relationship.Patients with AAA with more severe disease had significantly increased relative abundance of Enterobacteriaceae and decreased relative abundance of Veillonellaceae.A strong correlation was observed between the diameter and physiological data,as well as between diameter and gut microbiota composition.This study could improve the understanding of AAA,and gut microbiota may be a potential target to prevent and treat this deadly disease.