Enhancing Experimental Rigor and Reproducibility in Laboratory Animal Research on the Gut-Brain-Immune Axis

Warda M., Shaalan M.

Laboratuvar Hayvanları Bilimi ve Uygulamaları dergisi (Online), cilt.6, sa.1, ss.76-94, 2026 (TRDizin)

Özet

Laboratory animal models are essential for investigating neuroimmune and systemic biological processes; however, experimental outcomes are often influenced by unrecognized biological and methodological variability. Increasing evidence suggests that coordinated dysfunction across multiple epithelial interfaces including gastrointestinal, dermal, and respiratory barriers represents an underappreciated source of variability in laboratory animal research. In standardized rodent studies, such barrier interdependence may contribute to systemic inflammation, neuroimmune priming, and inconsistent experimental findings. This narrative review synthesizes evidence from laboratory animal science and comparative pathology to propose a unified multi-barrier framework for interpreting experimental validity in gut-brain-immune (GBI) axis research. We examine how epithelial barrier disruption, metabolic and mitochondrial stress, and innate immune activation particularly sterile inflammatory pathways involving NLRP3 signaling interact to influence central nervous system homeostasis and commonly measured neuroimmune and behavioral outcomes. Emerging concepts, including epigenetic programming and glymphatic clearance, are discussed as integrative mechanisms linking peripheral physiological stress to central nervous system responses. The review also highlights environmental stressors, housing conditions, species- and strain-specific susceptibility, and perimortem tissue handling as important yet frequently overlooked variables in laboratory animal studies. Comparative observations from wild and captive species are considered as sentinel indicators of barrier vulnerability within a One Health framework. In addition, methodological refinements such as nano-enabled delivery platforms are discussed as tools that may improve dosing consistency and mechanistic interpretability. As a narrative review, the proposed framework is hypothesis-generating and remains conceptually oriented rather than causally established.