CYP7A1 and fatty liver disease: Finally, TMAO may enhance the risk of fatty liver disease by lowering the total bile acid pool size through the reduction of bile acid production via the following: (1) the suppression of the important enzymes CYP7A1 and CYP27A116 and (2) the restriction of bile acid enterohepatic circulation by repression of the organic anion transporter and the expression of the multidrug resistance protein family [45].