Additionally, we focused on the specific bacterial genes of enzymes responsible for TMA-synthesis, including CutC, CntA, GrdH, and TorA. Intriguingly, CutC, CntA, and GrdH were remarkably upregulated in the gut of patients with AF when compared with non-AF controls (q = 0.0098 for CutC, q = 0.0246 for CntA, q = 0.0246 for GrdH; Fig. 3). Here, CUTC is linked to atrial fibrillation.