Casey Theriot

Bio

My past research experiences have spanned the fields of molecular microbiology, protein biochemistry, microbial ecology, and bacterial pathogenesis. This multi-disciplinary training has fostered an ability to think outside the box in developing new approaches to understand mechanisms of bacterial pathogenesis. As an undergraduate researcher at the University of Georgia I studied the presence and absence of Desulfovibrio in the intestinal tracts of primates exposed to elemental mercury. After graduating from UGA, I went to work at the Centers for Disease Control and Prevention in Atlanta, Georgia. At CDC I was able to work with NARMS, the National Antimicrobial Resistance Monitoring System, and work on a collection of clinical enteric pathogen isolates from around the United States. My graduate work was a departure from working with intestinal pathogens and was focused on characterizing metalloproteases in Archaeal organisms. During my graduate career at North Carolina State University, I worked closely with the Army Research Office to engineer proteins from Pyrococcus species for stable and long term detoxification of nerve agents. The training in biochemistry and protein structure has been valuable in my current research, analyzing the structure and function of the gastrointestinal tract and its role in Clostridium difficile pathogenesis.

To build upon my prior research training and to contribute to public health research, I went to the University of Michigan to complete my postdoctoral training with Dr. Vincent Young, a leader in the field of microbial ecology and bacterial pathogenesis. My research is multidisciplinary and collaborative, bridging basic research with translational research. My postdoctoral research training has focused on exploring the interplay between the gastrointestinal tract microbiota and the pathogen C. difficile, a significant and re-emerging public health problem. C. difficile infection (CDI) is the leading cause of antibiotic-associated colitis, and is responsible for significant morbidity, mortality, and increased healthcare costs. My research has shown that antibiotics disrupt the indigenous gut microbiota reducing resistance to C. difficile colonization. My broad research career goal is to understand the complex interactions among the gastrointestinal microbiota, pathogens, and the host. I am currently focused on characterizing these mechanisms with respect to antibiotic usage. To accomplish my research goals I integrate data obtained from high-throughput methods that analyze the gastrointestinal microbiome, metabolome and host immune responses in animal models and human biological specimens to model these interactions.

AFFILIATIONS

The American Society for Microbiology
North Carolina Branch, The American Society for Microbiology
Anaerobe Society of the Americas

Area(s) of Expertise

Computational Biology and Bioinformatics, Gastroenterology, Global Health, Infectious Diseases
• Identifying the role of the gastrointestinal tract microbiome and metabolome in shaping colonization resistance against Clostridium difficile
• Clostridium difficile physiology and pathogenesis
• Metabolism of bile acids by the indigenous gastrointestinal microbiota

Publications

• Dietary protein source alters gut microbiota composition and function , ISME JOURNAL (2025)
• Large Quantities of Bacterial DNA and Protein in Common Dietary Protein Source Used in Microbiome Studies , PROTEOMICS (2025)
• Bile acids impact the microbiota, host, and C. difficile dynamics providing insight into mechanisms of efficacy of FMTs and microbiota-focused therapeutics , GUT MICROBES (2024)
• Metagenomic, metabolomic, and lipidomic shifts associated with fecal microbiota transplantation for recurrent Clostridioides difficile infection , MSPHERE (2024)
• Offline Two-Dimensional Liquid Chromatography-Mass Spectrometry for Deep Annotation of the Fecal Metabolome Following Fecal Microbiota Transplantation , JOURNAL OF PROTEOME RESEARCH (2024)
• Bile salt hydrolases shape the bile acid landscape and restrict Clostridioides difficile growth in the murine gut , NATURE MICROBIOLOGY (2023)
• Intestinal bile acids provide a surmountable barrier against C. difficile TcdB-induced disease pathogenesis , PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA (2023)
• The microbial-derived bile acid lithocholate and its epimers inhibit Clostridioides difficile growth and pathogenicity while sparing members of the gut microbiota , JOURNAL OF BACTERIOLOGY (2023)
• Using Multidimensional Separations to Distinguish Isomeric Amino Acid-Bile Acid Conjugates and Assess Their Presence and Perturbations in Model Systems , ANALYTICAL CHEMISTRY (2023)
• Bile acid distributions, sex-specificity, and prognosis in colorectal cancer , BIOLOGY OF SEX DIFFERENCES (2022)

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