Spatial mapping of dextran sodium sulphate-induced intestinal inflammation and its systemic effects.

Inflammatory bowel disease (IBD) is a multifactorial disease, and patients frequently experience extraintestinal manifestations affecting multiple sites. Causes of systemic inflammation remain poorly understood, but molecules originating from the intestine likely play a role, with microbial and host small molecules polarizing host immune cells towards a pro- or anti-inflammatory phenotype. Using the dextran sodium sulfate (DSS) mouse model, which mimics the disrupted barrier function, microbial dysbiosis, and immune cell dysregulation of IBD, we investigated metabolomic and phenotypic changes at intestinal and systemic sites. Using spatial biology approaches, we mapped the distribution and relative abundance of molecules and cell types across a range of tissues, revealing significant changes in DSS-treated mice. Molecules identified as contributing to the statistical separation of treated from control mice were spatially localized within organs to determine their effects on cellular phenotypes through imaging mass cytometry. This spatial approach identified both intestinal and systemic molecular drivers of inflammation, including several not previously implicated in inflammation linked to IBD or the systemic effects of intestinal inflammation. Metabolic and inflammatory pathway interplay underpins systemic disease, and determining drivers at the molecular level may aid the development of new targeted therapies.