Gut microbiota-derived short-chain fatty acids ameliorate methamphetamine-induced depression-and anxiety-like behaviors in a Sigmar-1 receptor-dependent manner

Methamphetamine(Meth)abuse can cause serious mental disorders,including anxiety and depression.The gut microbiota is a crucial contributor to maintaining host mental health.Here,we aim to investigate if microbiota participate in Meth-induced mental disorders,and the potential mechanisms involved.Here,15 mg/kg Meth resulted in anxiety-and depression-like behaviors of mice successfully and suppressed the Sigma-1 receptor(SIGMAR1)/BDNF/TRKB pathway in the hippocampus.Mean-while,Meth impaired gut homeostasis by arousing the Toll-like receptor 4(TLR4)-related colonic inflammation,disturbing the gut microbiome and reducing the microbiota-derived short-chain fatty acids(SCFAs).Moreover,fecal microbiota from Meth-administrated mice mediated the colonic inflam-mation and reproduced anxiety-and depression-like behaviors in recipients.Further,SCFAs supple-mentation optimized Meth-induced microbial dysbiosis,ameliorated colonic inflammation,and repressed anxiety-and depression-like behaviors.Finally,Sigmarl knockout(Sigmar1^(-/-))repressed the BDNF/TRKB pathway and produced similar behavioral phenotypes with Meth exposure,and elim-inated the anti-anxiety and-depression effects of SCFAs.The activation of SIGMAR1 with fluvoxamine attenuated Meth-induced anxiety-and depression-like behaviors.Our findings indicated that gut microbiota-derived SCFAs could optimize gut homeostasis,and ameliorate Meth-induced mental disorders in a SIGMAR1-dependent manner.This study confirms the crucial role of microbiota in Methrelated mental disorders and provides a potential preemptive therapy.