Kaelin Loftus
Pronouns: She/her
Research Mentor(s): Dave Bridges
Research Mentor School/College/Department: Nutritional Sciences / Public Health
Program: UROP
Session: Session 2 (10:00am – 10:50am)
Authors:
Abstract
Ketogenic diets are characterized by elevated fat and reduced carbohydrate intake. A ketogenic diet increases lipid concentration in the body, while bile acids enable fat and sterol transportation. Bile acid biosynthesis is the major mechanism by which cholesterol is excreted, and by which fat is absorbed. Primary bile acids emulsify sterols, facilitating cholesterol absorption in the intestine, then move intestinal cholesterol to the blood and liver. Bile acids also maintain cholesterol homeostasis by excreting bile salts. A better understanding of bile acid metabolism is critical in studying ketogenic diets and their potential to be used in CVD patients. There are two pathways for primary bile acid synthesis, and each is dependent on 7a-hydroxylase enzymes. The first and rate-limiting step in the primary pathway of converting cholesterol to bile acids is catalyzed by the Cyp7a1 gene. Expressed exclusively in the liver, Cyp7a1 can be downregulated via primary bile acids binding to FXR receptors in the liver or intestines. Currently, the interaction between ketogenic diets and bile acid metabolism is not understood. We are going to determine how ketogenic diets affect Cyp7a1 protein and mRNA levels, respectively. The role of mTOR on Cyp7a1 regulation can also be studied through the methods described. With the knowledge acquired from our experiment, the ketogenic diet and its effects on cholesterol metabolism through bile acid synthesis can serve as evidence for possible diet-based interventions for hypercholesteremic patients.
