Abstract:Objective To explore the clinical predictive value of differences in gut microbiota diversity for secondary systemic inflammatory response syndrome (SIRS) in patients with acute traumatic brain injury.Methods A retrospective analysis was conducted on 60 patients with acute traumatic brain injury treated in the Emergency Intensive Care Unit (ICU) and Neurosurgical ICU of Guyuan People's Hospital from January 2022 to December 2023. Patients were divided into the simple acute traumatic brain injury group (non-SIRS group) and the post-traumatic SIRS group (SIRS group) based on the diagnostic criteria of SIRS. The general data of patients were collected and clinical indicators were detected. The gut microbiota diversity and the genus-level relative abundance were compared between the two groups using 16S rRNA gene sequencing. Pearson correlation analysis was performed to assess the relationships between gut microbiota and clinical indicators, and the diagnostic value of the gut microbiota for SIRS was evaluated using the receiver operating characteristic (ROC) curve.Results There was no statistically significant difference between the two groups of patients in terms of sex composition, age, red blood cell count, and platelet count (P > 0.05). Compared to the non-SIRS group, the SIRS group had higher body temperature, faster heart rates, higher white blood cell count, and elevated C-reactive protein levels (P < 0.05). There was no statistically significant difference in Chao1 and Shannon indices between the two groups (P > 0.05). The comparison of the relative abundances of Bacteroides, Ruminococcus, Akkermansia, and Enterococcus between the two groups showed no statistically significant differences as determined by the t-test (P >0.05). The relative abundance of Prevotella was lower in the SIRS group compared with that in the non-SIRS group (P <0.05), and the relative abundances of Escherichia-Shigella and Corynebacterium were higher in the SIRS group than in the non-SIRS group (P < 0.05). Pearson correlation analysis indicated that body temperature, heart rate, white blood cell count, and C-reactive protein levels were negatively correlated with the relative abundance of Prevotella (r = -0.574, -0.539, -0.554 and -0.572, all P < 0.05), and positively correlated with the relative abundances of Escherichia-Shigella (r = 0.751, 0.743, 0.657 and 0.770, all P < 0.05) and Corynebacterium (r = 0.782, 0.762, 0.707 and 0.799, all P <0.05). The ROC curve analysis revealed that the combined detection yielded the highest predictive efficacy, with an AUC of 0.946 (95% CI: 0.871, 1.000), a sensitivity of 96.7% (95% CI: 0.902, 0.100), and a specificity of 93.3% (95% CI: 0.844, 0.100).Conclusions Changes in the composition of the gut microbiota are closely related to the development of SIRS following traumatic brain injury, and changes in the abundance of specific bacterial genera can serve as early biomarkers for the development of SIRS.