Abstract: Objective To investigate the relationship between trimethylamine N-oxide(TMAO),short-chain fatty acids(SCFAs) and serum of intestinal flora metabolites in patients with traumatic brain injury(TBI) Correlation of metabolic marker levels. Methods Among 99 TBI patients admitted from September 2018 to December 2020,33 healthy subjects were selected as the control group.Detect intestinal TMAO,SCFAs levels,serum total cholesterol(TC),triglyceride(TG),and high-density lipoprotein cholesterol by high-performance liquid chromatography,gas chromatography,and automatic biochemical analyzer.(High-density lipoprotein cholesterol,HDL-C),low-density lipoprotein cholesterol(LDL-C),glycosylated hemoglobin(HbA1c) and fasting blood glucose levels. Results The intestinal TMAO levels,serum TC,TG,LDL-C,HbA1c,and fasting blood glucose levels in TBI patients were higher than those in the control group,and gradually increased with the severity of the disease(P< 0.05) ;intestinal butyric acid and serum HDL-C levels were lower than the control group,and gradually decreased with the worsening of the disease( P <0.05).Pearson correlation analysis showed that TMAO was positively correlated with HbA1c and TC,and negatively correlated with TG and LDL-C.Butyric acid was positively correlated with TG and LDL-C,and was negatively correlated with TC and fasting blood glucose.Multivariate logistic regression analysis showed that TC,LDL-C,HbA1c and fasting blood glucose levels were the risk factors for the intestinal TMAO and butyric acid levels to affect the prognosis of TBI patients. Conclusion Intestinal TMAO and butyric acid levels are closely related to serum metabolic marker levels,and are related to the progression of TBI patients.They provide possible new targets for the prevention and treatment of TBI,but their mechanisms need to be further studied.

Key words: traumatic brain injury, intestinal flora metabolites, trimethylamine oxide, short-chain fatty acids, serum metabolic markers, correlation