Presenter: Ashlyn Venoo

Faculty Sponsor: Michael Esmail

School: UMass Amherst

Research Area: Animal Science

Session: Poster Session 4, 2:15 PM - 3:00 PM, Auditorium, A85

ABSTRACT

Mouse models are staples of biological research, particularly in immunology and gut microbiota studies, where experimental outcomes may be influenced by stress. However, growing evidence suggests that husbandry choices and protocol design can factor into stress levels in laboratory mouse models. Factors such as housing conditions, enrichment, handling methods, mouse strain and substrain, diet, and bedding can alter experimental markers such as stress hormone levels and gut microbial diversity. These changes may influence experimental findings and contribute to variability between studies and research facilities. Animal husbandry choices and their impact on study results and reproducibility may not be sufficiently considered when designing studies, potentially leaving room for them to contribute unexpected or unwanted influence.

This review examines original research investigating the effects of husbandry and procedural variables on physiological stress markers and microbiome composition in mice. We evaluate commonly used husbandry practices and assess their reported effects on stress-sensitive outcomes, including endocrine, immune, and microbial measures. We also compare methodological differences across studies to identify potential sources of variability that may influence reproducibility.

We hypothesize that variation in husbandry and protocol design represents a significant but underrecognized source of experimental variability in stress-sensitive mouse studies. Greater awareness and improved standardization of these factors may strengthen reproducibility, improve translational relevance, and support the principles of the 3Rs by reducing unnecessary animal use. We recommend the use of reporting and planning frameworks such as ARRIVE and PREPARE to improve consistency and transparency in animal research.