Gut microbiota metabolic characteristics in coronary artery disease patients with hyperhomocysteine

Hyperhomocysteine (HHcy) is known as a risk factor for coronary artery disease (CAD). Despite the knowledge that gut microbiota related metabolism pathway shares metabolites with that of Hcy, little has been shown concerning the association between HHcy and gut microbiota. To explore their relationship in the context of CAD, 105 patients and 14 healthy controls were recruited from one single medical center located in Beijing, China. Their serum and fecal samples were collected, with multi-omics analyses performed via LC/MS/MS and 16S rRNA gene V3-V4 region sequencing, respectively. Participants from the prospective cohort were divided into CAD, CAD & HHcy and healthy controls (HC) groups based on the diagnosis and serum Hcy concentration. The results revealed significant different metabolic signatures between CAD and CAD & HHcy groups. CAD patients with HHcy suffered a heavier atherosclerotic burden compared to CAD patients, and the difference was closely associated to betaine-homocysteine S-methyltransferase (BHMT)-related metabolites and trimethylamine N-oxide (TMAO)-related metabolites. Dimethylglycine (DMG) exhibited a strong positive correlation with serum total Hcy (tHcy), and TMAO and trimethylysine (TML) were associated with heavier atherosclerotic burden. Multiple other metabolites were also identified to be related to distinct cardiovascular risk factors. Additionally, Clostridium cluster IV and Butyricimonas were enriched in CAD patients with elevated tHcy. Our study suggested that CAD patients with elevated tHcy were correlated with higher atherosclerotic burden, and the impaired Hcy metabolism and cardiovascular risk were closely associated with BHMT-related metabolites, TMAO-related metabolites and impaired gut microbiota homeostasis.