Methamphetamine induces intestinal injury by altering gut microbiota and promoting inflammation in mice

Methamphetamine (METH) is a psychostimulant abused worldwide. Its abuse induces intestinal toxicity. Moreover, the gut microbiota is altered by drugs, which induces intestinal injury. Whether gut microbiota mediates METH-induced intestinal toxicity remains to be validated. In the present study, wild-type and TLR4-/- mice were treated with METH. Gut microbiota was determined using 16S rRNA gene sequencing. Transcriptomics of the intestinal mucosa was performed by RNA-Sequencing. Blood levels of pro-inflammatory cytokines and lipopolysaccharide (LPS), the intestinal barrier, and inflammation were also assessed. METH treatment weakened the intestinal barrier and increased pro-inflammatory cytokines and LPS levels in the blood. Moreover, METH treatment significantly decreased the diversity of probiotics but increased the abundance of pathogenic gut microbiota, contributing to the over-production of LPS and disruption of intestinal barrier. Inflammatory pathways were enriched in the intestinal mucosa of METH-treated mice by KEGG analysis. Consistently, activation of the TLR4 pathway was determined in METH-treated mice, which confirmed intestinal inflammation. However, pretreatment with antibiotics or Tlr4 silencing significantly alleviated METH-induced gut microbiota dysbiosis, LPS over-production, intestinal inflammation, and disruption of the intestinal barrier. These findings suggested that the gut microbiota and LPS-mediated inflammation took an important role in METH-induced intestinal injury. Taken together, these findings suggest that METH-induced intestinal injury is mediated by gut microbiota dysbiosis and LPS-associated inflammation.