Figure 1.

The pathophysiology of gut microbial associations with coronary artery disease. Diet critically shapes the gut microbiota, providing substrates for fermentation. Undigested fiber consumed by bacteria leads to the production of SCFA. Low levels of SCFA have been linked to host inflammation, which may influence atherosclerosis. Many bacterial species also produce TMA using choline as a source. TMA is metabolized to TMAO in the liver by flavin monooxygenases, and is associated with atherosclerosis. Bacterial LPS leaking into the circulation from the gut initiates TLR-mediated systemic inflammation, also linked to atherosclerosis. LPS: Lipopolysaccharide, SCFA: short-chain fatty acids, TLR: toll-like receptor, TMAO: trimethylamine N-oxide.