Kien Lab Research
- Effects of long and short chain fatty acids on metabolism. This work includes current NIH-funded studies of the effects of dietary saturated fat (palmitic acid) and monounsaturated fat (oleic acid) on both liver and muscle glucose utilization and muscle lipid metabolism.
- Fermentation of carbohydrate and its effects on butyrate production and cell function.
- To determine how ingestion of dietary fatty acids may alter the risks of obesity, cardiovascular disease, type 2 diabetes, and cognitive decline. One working hypothesis is that the complications of obesity are determined in part by the type of distinct fatty acids habitually ingested and stored in tissues such as adipose tissue and muscle. Our research is identifying biomarkers that may be gender-dependent, and our findings may be relevant not only to dietary guidelines (dietary fat) but also to therapeutic approaches involving pharmaceutical agents.
- To determine if the ingestion of starches and sugars, which are not fully digested in the human intestine, provide medical benefit through the production of butyric acid, a bacterial metabolite. Our work has shown that the mammalian colon produces small quantities of butyrate that appear to alter intestinal growth and pancreatic ß-cell function. Our studies have potential relevance to the health effects of dairy products (including infant feeding) and resistant starches.
Types of Research Performed
Human Translational Research: Work performed in the Kien Lab is focused mainly on human studies at the UVM Clinical Research Center where we are studying the effects of dietary palmitic and oleic acid and, in collaboration with Dr. Jana Kraft of the Department of Animal Science at UVM, cow milk-derived fatty acids. Current projects involving the effects of dietary fatty acids include:
- Studies of body composition, energy expenditure, and insulin sensitivity (intravenous glucose tolerance test and euglycemic/hyperinsulinemic clamp);
- Lipidomic studies of blood and muscle (includes work both at UVM on muscle lipid composition and with Drs. Muoio and Koves at Duke University). These studies include a heavy emphasis on principal components analysis and path analysis (with Dr. Janice Bunn, Department of Mathematics/Statistics, UVM);
- Stable isotope tracer studies of glucose and palmitic acid metabolism (with Dr. Dwight Matthews, Department of Chemistry, UVM);
- Studies of the effects of palmitate and oleate on inflammatory pathways in peripheral blood mononuclear cells and skeletal muscle (protein and gene expression studies; activation of toll-like receptor 4 and the NLRP3 inflammasome) (with Drs. Matthew Poynter and Naomi Fukagawa, Department of Medicine, UVM);
- Studies of ER stress markers in skeletal muscle (protein expression and gene expression) (with Dr. Vikas Anathy, Department of Pathology, UVM); and
- Studies of physical activity, mood, executive function, cognition, and activation of relevant brain regions (fMRI studies), currently in collaboration with Dr. Julie Dumas (Department of Psychiatry, UVM) and Dr. Joshua Nickerson (Department of Radiology, UVM and the MRI Center for Biomedical Imaging).
Studies in Animal Models: Dr. Kien's lab is collaborating with Dr. Tom Jetton (Department of Endocrinology, Diabetes and Metabolism, UVM) in studies of the interaction of dietary starch, butyrate, intestinal growth, and pancreatic function using animal models. Valuable collaboration has been provided by Drs. Ruth Blauwiekel (University of Vermont Veterinarian), Sally Huber (Department of Pathology, UVM), and Matthew Poynter (Pulmonary Medicine, UVM).