Depression, anxiety and memory impairments are associated with intestinal inflammation.42 DSS-induced colitis triggers an inflammatory response in the brain that is accompanied by anxiety-like behaviour and impaired recognition memory.43 Our results were in line with previous findings that DSS-induced colitis led to neuroinflammation, as evidenced by an increase in the production of TNF-α, IL-1β and IL-6 in the brain (Fig. 3D and E). Here, TNF is linked to major depressive disorder.