Abstract
Enteropathogenic bacteria are a major cause of morbidity and mortality globally. While mouse models have been indispensable in advancing our understanding of infectious enteric diseases, key differences in intestinal microbiota and immunobiology between mice and humans underscore the need for alternative mammalian models that better recapitulate human disease states. The naked mole rat (NMR), the longest-lived rodent and a model of healthy ageing, presents a unique opportunity. It possesses an exceptionally robust intestinal barrier, an abundance of goblet cells, a thicker mucin layer, and reduced gut permeability compared to mice. Additionally, the NMR gut microbiome exhibits compositional and functional features shared with human centenarians and traditional-lifestyle populations (e.g. Hadza hunter-gatherers), including an enrichment of health-associated taxa and metabolic pathways. Here, we leverage this model to show that systemic Citrobacter braakii infection is associated with colonic inflammation and epithelial injury that closely mimics human haemorrhagic colitis. Infected NMRs develop mucosal erosions, ulcerations, depletion of goblet cells, expansion of proliferative compartments, and active inflammation in the lamina propria. Without intervention, systemic inflammation associated with sepsis ensues and results in high mortality. Furthermore, we demonstrate the utility of this model for therapeutic testing by showing a strong effect of a probiotic cocktail comprising lactobacilli, bifidobacteria, streptococci, and enterococci. Treatment with this cocktail promoted mucosal healing, restored intestinal homeostasis, and exerted an anti-inflammatory effect. Taken together, we establish the NMR as a translatable model for investigating disease mechanisms in infectious colitis, including disruptions in mucosal barrier permeability, gut microbial ecology, and local and systemic immune regulation, as well as for testing functional probiotic strains as potential therapeutics. © 2026 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.