Current Trainee Research


Mark Heggen

Nutrition and Metabolism Graduate Program
Major Advisor: Dr. JP van Pijkeren, PhD (Dept of Food Sciences)

The roles of (p)ppGpp in the survival of gut symbionts throughout gastrointestinal transit

Maintaining microbial diversity in the gastrointestinal tract is key to human health. While many factors influence microbial diversity, microbe-microbe interactions play a key role. Guanosine Pentaphosphate/ Tetraphosphate ((p)ppGpp/ppGpp) is an alarmone that bacteria use to respond to stressors, and it remains unknown the role that (p)ppGpp plays in microbe-microbe interactions. I hypothesize that (p)ppGpp promotes survival by mediating resistance to bacterial-derived antimicrobials in the intestinal tract. This project aims to determine the physiological effects of ppGpp on antimicrobial resistance in the gut, as well as determine the mechanism behind said resistance.

Eric McGregor

Nutrition and Metabolism Graduate Program
Major Advisor: Dr. Rozalyn Anderson, PhD (Dept of Medicine)

Metabolic control of brain metabolism by adiponectin receptor signaling aging

My project aims to understand the role of adiponectin in regulating neural metabolism at a cellular and tissue level. Adiponectin is the most abundant adipose-derived hormone in circulation. It is known to impact a variety of processes, including activating oxidative metabolism. Importantly, adiponectin receptors are present in high concentrations in multiple cell types and across brain regions. Despite this, little is understood about adiponectin’s role in the metabolic control of the brain. I hypothesize that by coordinating metabolic changes in neurons and astrocytes, adiponectin signaling creates a more metabolically efficient brain. Using both in vivo and in vitro approaches, I am examining how an adiponectin receptor agonist changes metabolic and neuroinflammatory states and in terms of functional output, the electrical properties of brains.

Hubert Peng

Nutrition and Metabolism Graduate Program
Major Advisor: Dr. Eric Yen, PhD (Dept of Nutritional Sciences)

The role of intracellular fatty acid metabolism in intestinal stem cell functions

Fatty acid oxidation in ISCs is thought to be critical for their functions, as chemical or genetical inhibition of carnitine palmitoyltransferase 1 (Cpt1), needed for importing long-chain fatty acids into mitochondrial, reduces ISC proliferation.  However, we found that mice lacking carnitine palmitoyltransferase 2 (Cpt2), catalyzing the conversion of acyl-carnitine produced from Cpt1 back to acyl-CoA, exhibited increased ISC proliferation. We hypothesize that elevated long-chain acylcarnitine, rather than ATP or acetyl CoA produced from FAO, promotes ISC proliferation. My project aims to test this hypothesis and assess to what extent increasing ISC proliferation protects intestine during aging and after radiation injury. 


Elizabeth Poad

Nutrition and Metabolism Graduate Program
Major Advisor: Dr. Brian Parks, PhD (Dept of Nutritional Sciences)

Vitamin B12 metabolism in adipocyte biology

Adipogenesis is a complex and coordinated process driven by peroxisome proliferator-activated receptor gamma (PPARγ). In a genetically diverse mouse population, our lab identified an epistatic interaction associated with fat mass gain between PPARγ and MMADHC (CblD). CblD is a vitamin B12 trafficking protein that is essential for the delivery of vitamin B12 to methylmalonyl CoA mutase and methionine synthase. However, the role of CblD during the process of adipogenesis has not been investigated. The aim of my research is to determine the role and mechanisms of CblD and its interaction with PPARγ in adipocyte biology.

Samuel Saghafi

Comparative Biomedical Sciences Graduate Program
Major Advisor: Dr. Dawn Davis, MD, PhD (Dept of Medicine)

Understanding the weight loss and glycemic effects of Vertical Sleeve Gastrectomy using mice and different dietary interventions

Vertical Sleeve Gastrectomy (VSG) is a surgical procedure performed in humans that induces weight loss and improved glycemic control, though the exact mechanisms behind these changes are unknown. We feed mice high fat and high sucrose diet to induce obesity and hyperglycemia, then perform VSG and Sham operations. Glucose and insulin tolerance tests are performed to assess glycemic control and insulin sensitivity. Tissues are harvested for gene expression and protein analysis. We want to assess how VSG impacts accumulation of senescent cells over time, as well as if different amounts of dietary protein can exasperate the effects of VSG.


Dr. Dawda Jawara, MD

Department of Surgery
Major Advisor: Dr. Luke Funk, MD, PhD (Dept of Surgery)

Using machine learning to develop a weight gain prediction model for adults with overweight and obesity using the All of Us dataset

Obesity is a prevalent issue affecting almost one-third of U.S. adults. There is a dearth of weight gain prediction models for adults derived from longitudinal datasets. Our goal is to utilize the comprehensive All of Us (AoU) dataset, which represents a diverse national sample. We aim to construct robust weight gain prediction models, specifically targeting a ≥10% increase in total body weight over a two-year period. The robustness of the AoU dataset allows us to integrate essential behavioral factors, such as alcohol use and physical activity, along with genomic variables, enhancing the predictive accuracy of our models.


Dr. Lauren Lucas, PhD

Department of Bacteriology
Major Advisor: Dr. Federico Rey, PhD (Dept of Bacteriology)

Understanding how various environmental factors and microbial interactions impact the regulation of bacterial bile acid metabolism

To systematically investigate the roles of pH, nutrient availability, and bile acid concentration/composition on bacterial bile acid metabolism, I will grow gut bacteria in monoculture, coculture, and small synthetic communities under various physiological conditions and measure gene expression and fitness using metatranscriptomics and metagenomics, respectively. I will use this in vitro data to design in vivo studies in gnotobiotic mouse models to dissect causal relationships between the gut microbiota, bile acid metabolism, and host health (e.g., gut inflammation). In addition, I will be able to describe the foundational concepts that govern microbial bile acid metabolism in any environmental context.

Dr. Nate Willis, PhD

Department of Nutritional Sciences
Major Advisor: Dr. Joe Pierre, PhD (Dept of Nutritional Sciences)

Investigating the timing and effects of key TPN components on the development and severity of TPN associated liver dysfunction

Total parenteral nutrition (TPN) is known to induce hepatic complications leading to organ failure. Two key components of the TPN formulation (i.e., lipid source) and administration (i.e., infusion schedule) contribute to hepatic complications. My projects seek to investigate the potentially therapeutic effects of novel lipid sources (i.e., bovine milk-derived lipid) and infusion schedules to reduce hepatic dysfunction.