Gut microbiota and fecal 2-methylbutyric acid in coronary heart disease: a cross-sectional study

The influence of gut microbiota diversity and/or metabolite levels on the development of coronary heart disease (CHD) is unclear. This cross-sectional study investigated whether specific gut microbiota and/or their metabolites are associated with CHD development. The study cohort comprised 55 Thai male volunteers, including 24 normal controls (N), 17 patients with hyperlipidemia (H), and 14 with CHD. We used gas chromatography-mass spectrometry to measure the short-chain fatty acid (SCFA) and branched short-chain fatty acid (BSCFA) contents of fecal water extracts. We also determined the gut microbiota composition for each group using 16S rRNA gene sequencing. Although comprising only a minor proportion, an unidentified Eubacterium spp. with 100% sequence similarity to E. liposum was more dominant in CHD than the N (false discovery rate (FDR) = 0.0002) or H groups (FDR = 0.0018). Furthermore, the CHD group exhibited significantly higher levels of 2-methylbutyric acid, a BSCFA, than the N (FDR = 0.0006). In addition, Spearman's correlation analysis showed a moderately significant association between 2-methylbutyric acid and CHD development (r = 0.5037, p = 0.0001). In conclusion, our observations revealed that patients with CHD had a prominent abundance of Eubacterium and 2-methylbutyric acid. Further in-depth studies are needed to draw definitive conclusions.