Specifically, nitrate reductase/nitrate oxidoreductase alpha and beta subunits, Nitrate reductase molybdenum cofactor assembly chaperone NarJ/NarW, divalent anion-Na+ symportor, fumarate reductase flavoprotein subunit, cysteine-S-conjugate beta-lyase, membrane-associated protein, and phosphatidylethanolamine-binding protein were significantly increased in the WT-to-CF gut microbiota as compared to the CF-to-CF gut microbiota. Here, KYAT1 is linked to cystic fibrosis.