Journal of Inflammation Research (Mar 2022)
Gut Microbiota Mediates the Susceptibility of Mice to Sepsis-Associated Encephalopathy by Butyric Acid
Abstract
Huidan Zhang,1– 3,* Jing Xu,1,2,4,* Qingrui Wu,3,* Heng Fang,1,2,4 Xin Shao,1,2 Xin Ouyang,1 Zhimei He,2 Yiyu Deng,2– 4 Chunbo Chen1,3,4 1Department of Intensive Care Unit of Cardiovascular Surgery, Guangdong Cardiovascular Institute, Guangdong Provincial People’s Hospital, Guangdong Academy of Medical Sciences, Guangzhou, 510080, People’s Republic of China; 2Department of Critical Care Medicine, Guangdong Provincial People’s Hospital, Guangdong Academy of Medical Sciences, Guangzhou, 510080, People’s Republic of China; 3School of Medicine, South China University of Technology, Guangzhou, 510006, People’s Republic of China; 4The Second School of Clinical Medicine, Southern Medical University, Guangzhou, 510515, Guangdong, People’s Republic of China*These authors contributed equally to this workCorrespondence: Yiyu Deng; Chunbo Chen, Tel +86-20-83827812 ext. 61526, Fax +86-20-83827712, Email [email protected]; [email protected]: Neuroinflammation plays an important part in the pathophysiology of sepsis-associated encephalopathy (SAE). Gut microbiota and gut brain axis are considered as important mediators in the development of neurological diseases. The aim of this study was to investigate the role of intestinal microbiota in sepsis-related brain injury and to explore the underlying mechanisms.Methods: Mouse model of SAE was established using cecal ligation and puncture (CLP). Based on the mouse mortality and the associated time of death, light SAE (LSAE) and severe SAE (SSAE) were classified. Fecal microbiota transplantation (FMT) was performed to verify the role of intestinal microbiota. Feces of mice in the two groups which collected before operation were sequenced for 16S and targeted short chain fatty acids.Results: Intestinal microbiota from SSAE and LSAE mice displayed diverse functions. Interestingly, LSAE mice produced more butyric acid compared with SSAE mice. In the in vivo experiments, sodium butyrate (NaB) reduced the high oxidative stress levels in mice hippocampus and conferred a marked survival superiority to sepsis mice. In addition, NaB prevented the increase in intracellular reactive oxygen species (ROS) generation and inducible nitric-oxide synthase expression in LPS-stimulated primary microglia. The GPR109A/Nrf2/HO-1 signaling pathway was found to be involved in the activation of antioxidant response of primary microglia induced by sodium butyrate.Conclusion: Our findings indicate a crucial role of gut microbiota in the susceptibility to SAE. Butyrate, a metabolite of intestinal microbiota, may have a neuroprotective effect in the process of sepsis by GPR109A/Nrf2/HO-1 pathway.Keywords: gut microbiome, butyrate, sepsis-related brain injury, primary microglia, oxidative stress
