Analysis of Gut Microbiota in Coronary Artery Disease Patients: a Possible Link between Gut Microbiota and Coronary Artery Disease

Aim: Recent studies have suggested that metabolic disorders such as obesity and type 2 diabetes are associated with gut microbiota. The association between atherosclerosis and gut microbiota has also been attracting increased attention. Our aim was to specify a characteristic trend of gut microbiota in coronary artery disease (CAD). Methods: This study included 39 CAD patients, 30 age-and sex-matched no-CAD controls (Ctrls) with coronary risk factors and 50 healthy volunteers (HVs) without coronary risk factors. Bacterial DNA was extracted from their fecal samples and analyzed by terminal restriction fragment length polymorphism. Results: A characteristic change of gut microbiota was observed in CAD patients, where the order Lactobacillales was increased (CAD, Ctrl vs. HV; 13.6%+/- 12.0%, 6.2%+/- 7.7% vs. 4.1%+/- 5.9%; p< 0.001) and the phylum Bacteroidetes (Bacteroides+ Prevotella) was decreased (CAD, Ctrl vs. HV; 35.5%+/- 11.6%, 43.9%+/- 11.2% vs. 47.4%+/- 11.5%; p< 0.001). The CAD group was over-represented in enterotype "others" (III), compared with the Ctrl or HV group (p< 0.001, chi-squared test), although we could not deny the possibility that some drugs affect the gut flora types. Conclusions: Although this study had some limitations, we demonstrated that the incidence of CAD was linked with an alteration of gut microbiota. A prospective study is desired to clarify a causal relationship between CAD and gut microbiota.