ABSTRACT
Objective:To investigate the correlation between gut microbiota and serum diamine oxidase (DAO) level and to analyze the differences in gut microbiota between high DAO (DAO-H) and normal DAO populations.Methods:This study recruited 62 adult volunteers (31 in DAO-H group and 31 in normal control group) taking health examination in the Strategic Support Forces Special Medical Center in 2021. Their stool samples were collected to analyze the composition of gut microbiota in the two populations by full-length 16S rRNA gene sequencing.Results:No significant difference in the alpha diversity of gut microbiota was found between the DAO-H group and the normal control group, but the structure and function of gut microbiota varied. In the DAO-H group, commensal bacteria decreased, such as Phocaeicola and Bacteroidetes, while potential pathogenic bacteria increased, such as Klebsiella pneumoniae. There were changes in the metabolism of gut microbiota in the DAO-H group, including inhibited sphingolipid metabolism and enhanced biosynthesis of vancomycin group antibiotics, one carbon pool by folate pathway, terpenoid backbone biosynthesis, cell cycle-Caulobacter, protein export, base excision repair and nitrogen metabolism.Conclusions:Compared with the people with normal DAO, the population with high DAO had unique characteristics in gut microbiota composition and metabolism.