Meet Our Postdoctoral Fellows

Learn more about our current Post-Doctoral Training in Genomic Medicine Research trainees.

Sarah Heston

Funding supported by T32 Grant

Sarah Heston headshot

Hometown
Memphis, TN

Current research
I am studying the ability of the gut metagenome of pediatric hematopoietic stem cell transplant (HSCT) recipients to predict infectious outcomes, such as mucosal barrier injury bloodstream infections, in an effort to determine modifiable factors that will lead to infection prevention in these high-risk children.

How did you become interested in your field of study?
I am interested in learning how to work with big data to improve research in immunocompromised children. I found a mentor in my Division with similar interests and have been working with a growing dataset of shotgun metagenomic sequencing of fecal samples from pediatric HSCT recipients.

What excites you about your work?
The gut is such a large source of infection for these patients. Additionally, advances in genomic medicine are making production and analysis of "-omic" data more affordable and accessible, to the point it will likely soon be used in routine clinical care. If we can find a clinically-relevant, non-invasive way to predict the onset of infection from stool samples, it could have a huge impact on the clinical care of these children.

Where do you see yourself in 10 years?
I would like to be an independent clinical researcher specializing in statistical methods for analyzing "big data." I aim to use my work to make metagenomics more clinically-relevant and accessible for the clinicians. Hopefully, my research will inform infection prevention strategies that will impact the rate of infection in immunocompromised children


Nathan Bihlmeyer

Funding supported by T32 Grant

Nathan Bihlmeyer headshot

Hometown
Raleigh, NC

Current research
I am currently a computational genetics post-doc fellow in Svati Shah's lab at Duke studying molecular mechanisms of pediatric and adult obesity, with a focus on microbiome-mediated metabolic pathways. The design of the primary study involves using multi-omics (metabolomics, proteomics, microbiome metagenomics and lipidomics) before and after a multi-factorial diet and exercise intervention in children with obesity from two cohorts. We are also performing deeper mechanistic studies around the role of the microbiome, conducting fecal transplant studies in gnotobiotic mice through a collaboration with John Rawls. I am also studying molecular pathways in adult obesity, analyzing metabolomics and proteomics data in several different large weight loss intervention cohorts (behavioral, exercise, surgical and pharmacologic). Identified molecular markers will be assessed for independent and incremental association with cardiovascular endpoints to filter for the most clinically important markers. The primary goal of my current work is to develop a personalized approach to weight loss interventions in pediatric and adult obesity, with the goal of identifying a biomarker that will target children and adults with obesity to the most beneficial weight loss intervention for that individual.

How did you become interested in your field of study?
Omics technologies have long been of interest to me. The overall theme of my past scientific research has been built upon a strong foundation of computational expertise and a passion for genetics and application of genetics to tackle issues of human health. Much of this work has focused on cardiovascular and related diseases. Another theme in my work is collaborating and leading large human consortiums to better identify potential genetic and metabolic pathways to generate hypotheses for disease mechanisms that I then validate in model organisms. My career path underlying these themes has provided me expertise in hands-on analysis and integration of diverse omics technologies, bioinformatic interrogation, and leadership in large collaborative groups studying human disease.

What excites you about your work?
Working under the mentorship of Dr. Shah, and utilizing the incredible resources at Duke and within the Duke Molecular Physiology Institute (DMPI), has allowed me to gain additional expertise in order to expand and continue my work to lead to an independent career. These resources include access to data and biospecimens from cardiovascular and obesity cohorts of children and adults, access to highly capable collaborators, involvement in large consortia studies of genetics and metabolomics, and a physical infrastructure within the DMPI with cutting0edge molecular technologies and easy access to basic science collaborators.

Where do you see yourself in 10 years?
My long-term career goal is to obtain a research-based tenure-track assistant professorship in the field of computational genomics, studying the molecular epidemiology of cardiometabolic diseases. My method to obtain this goal is to continue forward with the themes from my previous work, such as my passion for genetics and application of genetics to tackle issues of human health, focusing on cardiometabolic disease. Another theme I plan to continue is collaborating in large human consortium to use omics technologies in order to generate hypotheses that I would functionally validate in model organisms through collaborations.


Olivia Dong

Funding supported by T32 Grant

Hometown
San Jose, CA

Current research
My current research involves conducting health economic analyses of pharmacogenetic testing for patients within the Veterans Affairs (VA) health system. One project I will be conducting these health economic analyses for is the PHarmacogenomics Action for cancer SuRvivorship (PHASeR), a new precision health initiative that is providing preemptive pharmacogenetic testing to veterans at various sites across the US. In addition, I will be developing predictive models that identifies patients who would likely benefit from pharmacogenetic testing. By doing these analyses, the VA health system will be better positioned to understand the potential impact pharmacogenetic testing can have on improving patient care and the associated costs to the VA system.   

How did you become interested in your field of study?
One of my mentors, Dr. Martin Kohlmeier, was influential in sparking my initial interest in the precision medicine field. I was working as an intern for his Nutrition in Medicine Medical School Curriculum Program while I was completing my MPH at UNC, and we had many discussions about the impact that genetic variations can have on the effectiveness of clinical interventions. I started to get involved with some of his precision medicine research projects and enjoyed it so much that I decided to go on and pursue a PhD in the pharmacogenetics field.

What excites you about your work?
It is exciting to me to be able to find efficient ways of delivering health care services that are individualized to account for important genetic variations that are present in the population. I enjoy being able to utilize my scientific training to uncover areas of clinical care that can be improved for patients. I also find it inspiring to work with talented researchers from diverse backgrounds because they each bring a unique perspective to patient care.

Where do you see yourself in 10 years? 
In the future I would like to be an independent researcher with expertise in the application of precision medicine interventions within health systems. Within the precision medicine field, I want to specialize in the application of genetics to optimize nutritional and pharmacological interventions for patients with preventable chronic conditions. I would like to provide health systems with evidence-based decisions that allows for efficient and optimal delivery of genetic interventions to patients.


Melody Shi

Funding supported by T32 Grant

Hometown
Bethesda, MD

Current research
Vitamin D is a key player in calcium homeostasis and its synthesis and breakdown is tightly regulated by cytochrome P450 enzymes. One gene in particular, CYP24A1, encodes the enzyme 24-hydroxylase, which degrades active vitamin D into inactive metabolites thereby attenuating its effects on calcium absorption. This gene has been shown to be both upregulated and downregulated in a variety of human disease states and has been a target for pharmacologic intervention in the treatment of disorders like metabolic bone disease, certain types of cancer and rheumatologic conditions. However, our understanding of 24-hydroxylase in calcium and vitamin D metabolism, specifically its primary tissue site of action, is limited by lack of a suitable mouse model of CYP24A1 deficiency. To address this gap in knowledge, our lab has created transgenic inducible mouse models of CYP24A1 deficiency which will allow us to delineate the role of CYP24A1 in mineral homeostasis. As a clinical correlate, I will also identify infants with history of vitamin D toxicity and sequence them for CYP24A1 mutations. Recent studies have shown that mutations in CYP24A1 are more common than we think and might change the way we approach universal vitamin D supplementation in infants.

How did you become interested in your field of study?
Through my clinical training as a pediatric resident and now endocrinology fellow, I have witnessed first-hand the multitude of bone disorders for which management remains a challenge despite advances in the pathogenesis of skeletal disorders. I became aware of the consequences of disordered bone growth and metabolism, with skeletal deformities, pathologic fractures, and deterioration of motor development often leading to profound disability. The desire to understand and treat these bone diseases pushes me to pursue research in this particular field.

What excites you about your work?
I feel so fortunate to have the opportunity to work alongside such esteemed scientists who are truly experts in their field. Duke fosters a collaborative training environment and with my current fellowship in pediatric endocrinology, research lab in adult nephrology and additional training program in genomic medicine, I feel robustly supported in my clinical and research endeavors. 

Where do you see yourself in 10 years?
My career goal is to become an established academic physician-scientist in pediatric endocrinology, performing translational research in vitamin D metabolism for the development of targeted therapies to improve patient outcomes. I hope to specialize in pediatric bone disorders and bring what I discover in the lab directly to my patients and families.


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