Analysis of gut microbiota in patients with acute myocardial infarction by 16S rRNA sequencing.

Background: An increasing number of studies have shown that gut microbiota are associated with human cardiovascular disease, but the characteristics of intestinal flora in patients with acute myocardial infarction (AMI) are still unclear. In this study, we aimed to investigate the difference of intestinal microflora between patients with AMI and healthy people, and to find the effect of percutaneous coronary intervention (PCI) on intestinal microflora.

Methods: A total of 60 stool samples and 60 peripheral blood samples were collected from 20 previously diagnosed AMI patients and 20 healthy people serving as controls. Gut microbiota communities were analyzed via 16 ribosomal RNA-sequencing (16S rRNA). Gut microbiota-derived metabolites, trimethylamine N-oxide (TMAO) and short-chain fatty acids (SCFA), in the blood were detected using stable isotope dilution high-performance liquid chromatography with on line electrospray ionization tandem mass spectrometry (LC/MS/MS).

Results: The results showed that a distinct pattern of gut microbiota was observed in AMI patients compared to healthy controls. AMI patients had lower microbiological richness but no significant change in diversity. and showed an upward trend, whereas showed a downward trend in AMI patients. During a longitudinal study to compare the changes in bacteria before and after treatment, we found routine cardiac admission therapy 1 week after PCI surgery had no effect on the microbial community structure in patients. There were significantly higher levels of plasma TMAO in AMI patients' microbiota than that in the control group. Contrarily, there was no obvious change in SCFA.

Conclusions: The gut microbiota of patients with AMI differs from that of normal people, and the metabolic products of microflora are more abundant in the plasma of AMI than control cases. Microflora may act on the cardiovascular system through metabolites, and regulation of the microfloral structure may be used in the future treatment of cardiovascular diseases.