The research interests of our laboratory are broadly in the areas of nutrition and animal health. We are very interested in nutritional factors that promote healthy development and growth, and how manipulation of these nutrients can lead to obesity and related morbidities and behaviors related to nutritional stress. We use primarily aquatic animal and rodent models in nutrition studies related to human disease. Our typical outcomes include understanding the physiology and biochemistry of healthy weight gain, including genomics and transcriptomics, immunological responses, and the microbiome in response to nutritional and environmental stressors. We are particularly interested in those outcomes related to changes in body composition and the mechanisms therein. To this end, we formulate and produce animal diets that vary in ingredient and nutrient content.

At this time we are promoting strategies and educational platforms that will lead to the development of standard reference diets for important models of human disease. We believe the lack of understanding of nutrition and the continued use of unsuitable research diets in many animal models will limit our ability to translate timely knowledge concerning the onset, progression, and management of human disease.

We are directly involved in the enhancement of zebrafish and sea urchin models for their value in biomedical research. These species are important in many research communities, and we are defining nutrition to improve husbandry and to further promote these models in translational research.

We are also interested in nutrition research as it relates to improving aquaculture of commercially relevant species. Global food security will require enhanced protein production and distribution, and production will depend on developing nutritional strategies that promote efficient protein production. Our recent research efforts incorporate the use of novel protein sources that are derived from agricultural waste products, leading to sustainable food production. We utilize the nutrition framework to better understand the ecology and evolution of nutrient requirements and apply this information towards understanding the role of nutrition in regulating human health disease.

The primary research topics in our laboratory include:

• Understanding the effects of nutrition and the environment on growth demographics, body composition, and physiological function of aquatic organisms. Primary emphases include:
  • Understanding mechanisms related to nutrition and diet, which will lead to a healthy growth span in aquatic models of human disease, including zebrafish and sea urchins
  • Using related approaches to foster the development of diets and farming practices that promote growth and health in common aquaculture species, including shrimp and finfish. Knowledge of these economically important organisms will enhance aquaculture practices
• Evaluating the link between the gastrointestinal tract and the brain as associated with common digestive disorders and related mental distress
• Developing tools to advance functional genomic studies in sea urchins
• Optimizing lab culture of sea urchins leading to the production of specific pathogen free models
• Optimizing cryopreservation technologies to increase the utility of sea urchins as a model organism
• Evaluating the nature and role of the microbiome in aquatic models, with emphasis in the response of the gut microbiome to nutrients and bioactive food components
• Evaluating emerging ingredients as nutrient sources in animal diets, including single cell proteins
• Using nanotechnologies to develop nutrient and drug delivery systems in aquatic animals.
• Linking resource sustainability and global food security.

Developing a National Lab Animal Nutrition Program (NLANP) for Lab Animal Models

Animal models have been an essential resource in medical research for decades. For animal models to be effective, variables that may affect research outcomes must be controlled. Animal nutrition is a known critical variable that affects experimental outcomes and reproducibility. Recognizing the need for nutritional standards in experiments using rodent models, the American Institute of Nutrition (AIN) encouraged rigorous and reproducible research by sponsoring the development of the AIN-76 rodent diet as the first open formulation standard reference diet. Refinements and modifications over the next decade led to the release of an improved formulation, AIN-93. This singular formulation can be modified for specific research investigations. Contemporary formulations of the AINs diets have supported >30 years of research and greatly increased the utility and value of rodent models for in vivo biomedical research.

Numerous invertebrate and non-rodent animal models, from zebrafish to non-human primates, are increasingly used in medical research. Many of these models lack nutritional control in experimental design. In fact, nutritionally adequate diets have not been defined for most of these models due to a lack of knowledge of specific dietary requirements. Consequently, experimental outcomes related to health can be significantly compromised and may lack reproducibility.

Despite the wide-spread appeal of aquatic and other non-rodent models, open formulation standard reference diets have not been adequately developed. To address these critical shortcomings, several national meetings were held to discuss dietary standards in zebrafish and other animal models of human disease. There was decisive agreement that unifying guidelines to develop dietary standards have not been identified and guidance in establishing dietary requirements and diet formulations is required.

The Problem: The lack of understanding of nutrition and the continued use of unsuitable research diets in many animal models will limit our ability to translate timely knowledge concerning the onset, progression, and management of human disease.

The Solution:  An overarching approach must evolve, leading to 1) the determination of dietary requirements, 2) the development of open formulation standard reference diets, and 3) the advancement of feed management criteria in all animal models, and 4) the re-education of the science community in the value and use of diets in study design

We are coordinating an approach to define nutritional standardization in lab animals. A NLANP will assist in the development of a network of stakeholders including scientists, national or international centers or societies, commercial vendors of ingredients and diets, and appropriate regulatory and government agencies to promote high value research in lab animals.

The importance of a national organization to develop standards in nutrition cannot be overstated. A NLANP will:

• Promote lab animal performance and welfare
• Boost the rate of scientific progress in understanding human disease
• Stimulate positive and timely translation to human health
• Reduce the long-term cost of research
• Reduce the human cost of disease

• Gulley, K.M. (in press). Nourishing Horizons: Unmasking the Link Between Food Environment Index, Undergraduate Gut Health and Dietary choices ID 2024-
• Green, G.B.H., Williams, M.B., Brandom, J.L., Chehade, S.B., Fay, C.X., Morrow, C.D., Lawrence, A.L., Bej, A.K., Watts, S.A. 2024. A bacterial-sourced protein diet induces beneficial shifts in the gut microbiome of the zebrafish, Danio rerio. Current Devel. Nutrition. DOI:https://doi.org/10.1016/j.cdnut.2024.102077
• Yeramilli, V, C.S. Rizek, J. Graham, Md. Moughnyeh, C. Taylor, R. Cheddadi, S.B. Chehade, S. A. Watts and C. Martin. (in press). Parental pre-conception stress in zebrafish induces long lasting anxiety in offspring. Physiology and Behavior.
• Jensen, K.E., R.J. Barry, M.L. Powell, L.R. D’Abramo, D. Allen Davis and S. A. Watts . 2023 Integrated aquaculture of sea urchins (Lytechinus variegatus) and shrimp (Litopenaeus vannamei). Vol 42(3), 471-477.
• Williams, M.B.,G.B.H. Green, J.W. Palmer, C.X. Fay, S.B. Chehade, A.L. Lawrence, R.J. Barry, M.L. Powell, M.L. Harris, S. A. Watts . 2023) Replacement Of Dietary Fish Protein With Bacterial Protein Results In Decreased Adiposity Coupled With Liver Gene Expression Changes In Female Danio Rerio, Current Developments in Nutrition, https://doi.org/10.1016/j.cdnut.2023.102057.
• Green, G.B.H., M.B. Willimas, S.B. Chehade, J.T. Flowers, C.D. Morrow, A.L. Lawrence, A.K. Bej, S. A. Watts. 2023. Body metrics and the gut microbiome in response to macronutrient limitation in zebrafish Danio rerio. Current Devel. In Nut. Vol 7(4): 100065
• Sharpton, T.J. Y. Lu, M.L. Kent, S. A. Watts and Z.M. Varga. 2023. 10^th Aquatic Animal Models of Human Disease Conference 2022 Workshop Report: Aquatics Nutrition and Reference Diet Development. Zebrafish DOI: 10.1089/zeb.2023.0079
• Cunningham, A.C., V.K. Gibbs and S. A. Watts . 2023. A histological assessment of the reproductive cycle of the sea urchin, Lytechinus variegatus. Gulf and Caribbean Research 34: 97-106 https://doi.org/10.18785/gcr.3401.15
• Williams, M.B., A.L. Lawrence, S.B. Chehade, Y. Yuan, A.L. Fowler, R.J. Barry, M.L. Powell and S. A. Watts . 2023. Zebrafish Danio rerio exhibit positive growth profiles when fed dietary yeast and bacterial-based single-cell protein as a replacement for fish protein hydrolysate. North Amer. J. Aquaculture https://doi.org/10.1002/naaq.10299
• Chehade, S.B., C. D. Graham, A. Chakraborti, G. B. Green, B. Vashai, A. Moon, M.B. Williams, B. Vickers, T. Berryhill, W. Van Der Pol, L. Wilson, M. L. Powell, D. L. Smith, Jr., S. Barnes, C. Morrow, S. M. Mukhtar, G. D. Kennedy, J. A. Bibb, S. A. Watts. 2022. A Modified Standard American Diet (mSAD) Induces Physiological Parameters Associated With Metabolic Syndrome In C57BL/6J Mice. Frontiers in Nutrition doi: 10.3389/fnut.2022.929446
• Williams, M.B., K. M. Almansoob, S. A. Watts. In review: Daily Ration Size Affects Weight Gain and Adiposity in the Zebrafish (Danio rerio). Zebrafish Journal
• Williams, M.B., L.N. Dennis-Cornelius, N.D. Miyasaki, R.J. Barry, M.L. Powell, R.A. Makowsky, L.A. Fowler, S. A. Watts and D.S. Smith. 2022. Macronutrient ratio modification in a semi-purified diet composition: Effects on growth and body composition of juvenile zebrafish, Danio rerio. North American Journal of Aquaculture. ISSN: 1522-2055 print / 1548-8454 online  DOI: 10.1002/naaq.10265
• Dennis-Cornelius, L.N., M. B. Williams, J. A. Dawson, M. L. Powell, S. A. Watts. 2022.  The effect of diet and body size on fecal pellet morphology in the sea urchin Lytechinus variegatus. Journal of Shellfish Research, 41(1):135-144. https://doi.org/10.2983/035.041.0111 (nominated for paper of the year)
• Fowler, A.L., A. Powers, M. B. Williams, R. J Barry, L.R. D'Abramo, S. A. Watts. 2021. The Effects of Dietary Saturated Fat Source on Weight Gain and Adiposity are Influenced by Both Sex and Total Dietary Lipid Intake in Zebrafish. PLOS One, https://doi.org/10.1371/journal.pone.0257914
• Williams, M.B., J. Palmer, S. Chehade, A. Hall, R. J. Barry, M. L. Powell, M. Harris, L.Y. Sun, S. A. Watts. 2021. Effect of Long-Term Consumption of Poultry Egg Products on Growth, Body Composition and Liver Gene Expression in Zebra Fish Danio rerio. Current Developments in Nutrition 5 (12) 134, https://doi.org/10.1093/cdn/nzab134
• Watts, S.A. and L.R. D’Abramo. 2021. Standardized reference diets for zebrafish: addressing nutritional control in experimental methodology. Annual Review Nutrition. Vol. 41, https://doi.org/10.1146/annurev-nutr-120420-034809
• Blum, J., R. Epstein, S. A. Watts and Thalacker-Mercer A.E. 2021. Importance of nutrient availability and metabolism for skeletal muscle regeneration: A review. Frontiers in Physiology, https://doi.org/10.3389/fphys.2021.696018
• Yuan Yuan, A.L. Lawrence, S.B. Chehade, K.E. Jensen, R.J. Barry, L.A. Fowler, R. Makowsky, M.L. Powell and S. A. Watts . 2021. Feed intake as an estimation of attractability in Pacific white shrimp Litopenaeus vannamei. Aquaculture 532, https://doi.org/10.1016/j.aquaculture.2020.736041
• Ayanabha Chakraborti, Christopher Graham, Sophie Chehade, Bijal Vashi, Alan Umfress, Pradeep Kurup, Benjamin Vickers, H Alexander Chen, Rahul Telange, Taylor Berryhill, William Van Der Pol, Mickie Powell, Stephen Barnes, Casey Morrow, Daniel L Smith Jr, M Shahid Mukhtar, Stephen Watts, Gregory Kennedy, James Bibb. 2021. High Fructose Corn Syrup-Moderate Fat Diet Potentiates Anxio-Depressive Behavior and Alters Ventral Striatal Neuronal Signaling. Frontiers in Neuroscience, https://doi.org/10.3389/fnins.2021.669410
• Green, GBH, J.A. Hakim, J.W. Chen, H. Koo, C.D. Morrow, S. A. Watts , A.K. Bej. 2021. The gut microbiota of naturally occurring and laboratory aquaculture Lytechinus variegatus revealed differences in the community composition, taxonomic co-occurrence and predicted functional attributes. Appl. Microbiol. 2021, 1, 201–224. https://doi.org/10.3390/applmicrobiol1020016
• Fowler, L.A., L.N. Dennis-Cornelius, J.A. Dawson, R..J. Barry, J.L. Davis, M.L. Powell, Y. Yuan, M.B. Williams, R. Makowsky, L.R. D’abramo and S. A. Watts . 2020. Dietary Intake of Both n-6:n-3 Fatty Acid Ratio and Total Lipid Positively Influences Outcomes in Adiposity and Reproductive Health in a Zebrafish Model. Current Developments in Nutrition 4(4), https://doi.org/10.1093/cdn/nzaa034
• Williams, M.B and S. A. Watts . 2019. Current basis and future directions of zebrafish nutrigenomics. BMC Genes and Nutrition 14:34 https://doi.org/10.1186/s12263-019-0658-2
• Park, Jieun, Daniel S. Levic, Skaelyn D. Sumigray, Jennifer Bagwell, Oznur Eroglu, Carina Block, Cagla Eroglu, Robert Barry, Colin R. Lickwar, John F. Rawls, Stephen A. Watts, Terry Lechler and Michel Bagnat. 2019. Lysosome- rich enterocytes mediate protein absorption in the vertebrate gut. Development Cell, 51, 7-20. https://doi.org/10.1016/j.devcel.2019.08.001
• Hakim, J.A., C.D. Morrow, S. A. Watts , and A.K. Bej. 2019. High throughput amplicaon sequencing datasets of the metacommunit DNA of the gut microbiota of naturally occurring and laboratory aquaculture green sea urchins Lytechinus variegatus. Data in Brief 26, 104405.
• Fowler, L.A., M.B. Williams, L.N. Dennis-Cornelius, S. Farmer, R.J.Barry, M.L. Powell and S. A. Watts . 2019. Influence of commercial and laboratory diets on growth, body composition, and reproduction in the zebrafish Danio rerio. Zebrafish 16(6), 508-521.
• Taylor, J.C., M.B. Williams, S.K. Katiyar and S. A. Watts . 2019. Parental dietary B-carotene intake in Lytechinus variegatus affects early development of offspring exposed to UV radiation. J. Ala. Acad. Sci. 89, 83-99. (Carmichael Award for Best Paper of the Year)
• Jensen, K., J.C. Taylor, J.A. Barry, M. Powell, L. D’Abramo, A. Davis, S. A. Watts. 2019. The value of the sea urchin, Lytechinus variegatus, egesta consumed by the shrimp vannamei.  J. World Aqua. Soc. 50, 614-621.  DOI: 10.1111/jwas.12578
• Hakim, J.A., J.B. Schram, A.W.E. Galloway, CD. Morrow, M.R. Crowley, S. A. Watts and A.K. Bej. 2019. The pacific north-west purple sea urchin Strongylocentrotus purpuratus demonstrates a compartmentalization of gut bacterial microbiology, predictive, functional attributes, and taxonomic co-occurrence. MDPI Microorganisms 2019, 7(2), 35; https://doi.org/10.3390/microorganisms7020035
• Hakim, J.A., Koo, H., and S. A. Watts . 2018. Small is big, unlocking the hidden potential of microbes for aquaculture. Global Aquaculture Advocate (Animal Health and Welfare). https://www.aquaculturealliance.org/advocate/small-is-big-unlocking-the-hidden-potential-of-microbes-for-aquaculture/
• Taylor, J.C., L.S. Dewberry, S.K. Totsch, L.R. Yessick, J.J. DeBerry, S. A. Watts and R.E. Sorge. 2017. A novel zebrafish-based model of nociception. Physiology and Behavior 174, 83-88.

• Senior Faculty, Nutrition and Obesity Research Center
• Adjunct Faculty, Department of Surgery
• Senior Faculty, Comprehensive Diabetes Center
• Director, Lab Animal Nutrition Core (Animal Models Core, NORC)
• Co-Director, Animal Models Core (NORC)
• Co-Director, Zebrafish Research Facility, RSB
• Co-Director, Sustainable Smart Cities

• Faculty Advisor to Alpha Epsilon Delta, the Pre-Health Society
• Faculty Advisor to the Accelerated Bachelors/Masters program
• Faculty Advisors to the Early Acceptance Program