In contrast, CYP7A1 mRNA expression increased in Western diet rats, indicating that the synthesis of bile acids is generally increased in these rats, as also observed in obese subjects and in NAFLD/NASH patients [50], further suggesting that the reduction of CA is due to CYP8B1 downregulation, since CYP7A1 catalyzes the first and common step of primary BA synthesis. Here, CYP8B1 is linked to metabolic dysfunction-associated steatotic liver disease.