Intestinal microbiota dysbiosis and liver metabolomic changes during brain death

Background The causative link between brain death and intestinal microbiota dysbiosis is unclear, and the distortion in liver metabolism caused by brain death requires further exploration. Material and Methods A rat model of brain death was constructed and sustained for 9 hours. Intestinal contents and portal vein plasma were collected for microbiota sequencing and microbial metabolite detection. Liver tissue was resected to investigate metabolic alterations, and the results were compared with those of a sham group. Results Microbiota dysbiosis occurred at the family and genus levels after 9 hours of brain death. Microbial metabolites remained unchanged in both the intestinal contents and portal vein plasma. Liver metabolic function deteriorated, and the levels of 80% of the differential metabolites decreased in the brain-dead rats. Most of the differential metabolites were related to energy metabolism. Conclusions Brain death resulted in microbiota dysbiosis in rats; however, this dysbiosis did not alter microbial metabolites. Deterioration in liver metabolic function during extended periods of brain death may reflect a continuous worsening in energy deficiency.