The significantly increased genes in the CKD patients were related to TMA production in the intestinal tract, including K07811 (functional annotation: trimethylamine oxidoreductase (cytochrome c) 1), K07821 (functional annotation: trimethylamine oxidoreductase (cytochrome c) 2, c-type cytochrome subtribe activity regulation transducer), and K03532 (functional annotation: trimethylamine oxidoreductase (cytochrome c) 1, c-type cytochrome subtribe activity regulation transducer). Here, CYC1 is linked to chronic kidney disease.