Neurometabolic adaptations to intestinal inflammation in a mouse model of colitis

The inflammatory process is a conserved and adaptive biological response to infection or tissue damage. Despite its substantial energy demands, inflammation triggers centrally regulated changes in behavior, commonly referred to as sickness behavior, which includes anorexia and consequent negative energy balance. While these responses have been extensively modeled through infection or cytokine administration, they remain less explored in a more dynamic spectrum of clinical conditions, such as inflammatory bowel disease (IBD). In this study, we utilized the dextran sodium sulfate (DSS) model of colitis, which mimics key features of human IBD. We assessed food and water intake, locomotor activity, and body composition over the disease progression. We further assessed neuronal activation and transcriptional changes in metabolic-sensing brain regions at key disease stages. Acute DSS-induced disease progression was associated with metabolic alterations, including anorexia, energy conservation, reduced physical activity, and changes in body mass composition. A positive correlation between disease severity and neuronal activation in the hypothalamus and the caudal brainstem was also found. Transcriptomic analysis revealed changes in hypothalamic gene expression associated with the immune response. Furthermore, targeted co-localization studies identified the activation of hypothalamic hunger-promoting AgRP/NPY-expressing neurons as a neuronal population recruited during colitis, suggesting a role for these neurons in coordinating allostatic metabolic adaptations to intestinal inflammation. This study provides evidence that the DSS model is a clinically relevant, dynamic and tractable tool for studying the progression of sickness-like behavior in IBD, as well as the underlying neurometabolic adaptations that extend beyond the gut.