For example, the highly abundant bile acid and FXR ligand glycochenodeoxycholate sulfate and the intestinal FXR-dependent hormone FGF-19 were upregulated at later time points even with BMI adjustment in participants randomized to RYGB, consistent with prior reports in patients post-RYGB11,12,14,15 and in those with hypoglycemia after gastric bypass50. This evidence concerns the gene FGF19 and Hypoglycemia.