Inulin ameliorates chronic ketamine-induced anxiety-like behaviors and impairments in spatial learning and memory: involvement of gut microbiota, microbial metabolite short-chain fatty acids, and the BDNF-TrkB-ERK1/2-CREB pathway.
📄 Abstract
Chronic ketamine exposure results in psychotic and cognitive symptoms that resemble those found in patients with schizophrenia. Emerging evidence suggests that patients with schizophrenia exhibit gut microbiota dysbiosis and decreased levels of short-chain fatty acids (SCFAs) and BDNF, which are related to the severity of psychotic and cognitive symptoms. Dietary inulin can regulate gut microbiota, SCFAs, and BDNF. However, the role of gut microbiota, SCFAs, and BDNF in chronic ketamine-induced schizophrenia-like behaviors is unclear. In this study, we found that chronic ketamine exposure for 28 days caused gut microbiota dysregulation, reduced the expression of SCFAs in serum, hippocampus, and feces, elevated gut permeability, downregulated the BDNF-TrkB-ERK1/2-CREB signaling pathway, caused neuronal damage, and decreased the expression of synaptic proteins Syn and PSD-95, which may lead to anxiety-like behaviors, prepulse inhibition (PPI) deficits, and spatial learning and memory deficits. In addition, inulin intervention reversed gut microbiota dysbiosis by decreasing the abundance of