Haley Hallowell, PhD
Postdoctoral Scholar in the Suez Lab at Johns Hopkins University
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How is the gut resistome impacted by environmental and host stimuli?
Bacterial members of the gut microbiome harbor a collection of antibiotic resistance genes, termed the resistome, that can be transferred to invading pathogens. I am working to understand how stimuli other than antibiotics themselves drive changes in the gut resistome and rate of horizontal gene transfer. Read more in recent publications here and here
There are trillions of microorganisms naturally residing on and within us that form connected communities termed microbiomes. Within these communities, such as the gut microbiome, every domain of life is represented. The gut microbiome has an intricate and intimate relationship with host physiology and disease, though many of the mechanisms of this relationship remain unknown. The goal of my current and future research program aims to tease apart this mechanistic relationship by utilizing computational, in vivo, and in vitro experimentation.
How does the gut virome directly impact host disease?
It is becoming increasingly clear that the collection of viruses within the gut, termed the gut virome, plays a role in the protection from, or promotion of, disease in hosts. I seek to understand the mechanistic underpinnings of this relationship. I am also working to develop computational tools to increase the resolution of viral taxonomy specifically for gut virome datasets. Read more about this work here and here
How are phage:host relationships impacted by environmental stimuli and host physiology?
In addition to the impact on their mammalian host, the gut bacteriophages also have profound impacts on their host bacterial populations. Using in vivo and in vitro methods, I seek to understand how both environmental stimuli and host physiology influence the interplay between these two constituents of the gut microbiome.
RESEARCH INTERESTS
ABOUT
Through hard work and dedication, I reached a milestone in my career when I graduated and became a professional Researcher in 2000. Since then, my research has progressed and evolved into new projects driven by the results of my experimentation. I invite you to take a look at my published work to get a better idea of the fruits of my research labor. Feel free to get in touch with me to say hi or for more information about my work.
Publications
Hallowell, H. A., Gao, A. L., Kelly, K. E., & Suez, J. (2023). Interactions Between Microbial Therapeutics and the Endogenous Microbiome. Probiotics, Prebiotics, Synbiotics, and Postbiotics: Human Microbiome and Human Health, 421.
Tassia, M. G., Hallowell, H. A., Waits, D. S., Range, R. C., Lowe, C. J., Graze, R. M., ... & Halanych, K. M. (2023). Induced immune reaction in the acorn worm, Saccoglossus kowalevskii, informs the evolution of antiviral immunity. Molecular Biology and Evolution, 40(5), msad097.
Hallowell, H. A., Gao, A. L., & Suez, J. (2022). Double-edged sword: impact of fecal microbiome transplants on the gut resistome. Current Opinion in Gastroenterology, 39(1), 16-22.
Crits-Christoph, A., Hallowell, H. A., Koutouvalis, K., & Suez, J. (2022). Good microbes, bad genes? The dissemination of antimicrobial resistance in the human microbiome. Gut Microbes, 14(1), 2055944.
Stockler, R. M., Hallowell, H.A., Higgins, K. V., Groover, E. S., Hiltbold, E. M., Newcomer, B., & Walz, P. H. (2022). Characterization and comparison of the rumen luminal and epithelial microbiome profiles using metagenomic sequencing technique. Frontiers in Veterinary Science, 9, 799063.
Hallowell, H. A., Higgins, K. V., Roberts, M., Johnson, R. M., Bayne, J., Maxwell, H. S., ... & Hiltbold Schwartz, E. (2021). Longitudinal analysis of the intestinal microbiota in the obese mangalica pig reveals alterations in bacteria and bacteriophage populations associated with changes in body composition and diet. Frontiers in Cellular and Infection Microbiology, 11, 698657.
Higgins, K. V., Woodie, L. N., Hallowell, H.A., Greene, M. W., & Schwartz, E. H. (2021). Integrative longitudinal analysis of metabolic phenotype and microbiota changes during the development of obesity. Frontiers in Cellular and Infection Microbiology, 11, 671926.
Stockler, R. M., Higgins, K. V., Hallowell, H.A., Groover, E. S., Hiltbold, E. M., Newcomer, B. W., & Walz, P. H. (2020). In vivo microbiome profiling of the luminal and mucosal surface of the duodenum using a cannulated yearling bovine model. Frontiers in Veterinary Science, 7, 601874.
Warren, M. F., Hallowell, H. A., Higgins, K. V., Liles, M. R., & Hood, W. R. (2019). Maternal dietary protein intake influences milk and offspring gut microbial diversity in a rat (Rattus norvegicus) model. Nutrients, 11(9), 2257.
Ganger, M. T., Hiles, R., Hallowell, H.A., Cooper, L., McAllister, N., Youngdahl, D., ... & Ewing, S. J. (2019). A soil bacterium alters sex determination and rhizoid development in gametophytes of the fern Ceratopteris richardii. AoB Plants, 11(2), plz012.