Profile of gut microbiota in patients with traumatic thoracic spinal cord injury and its clinical implications: a case-control study in a rehabilitation setting

Gut microbiota are the candidate biomarkers for neurogenic bowel dysfunction (NBD) in patients with spinal cord injury (SCI). We aimed to identify the common features between patients with varying degree of thoracic SCI and healthy individuals and subpopulations of microbiota correlated with the serum biomarkers. Twenty-one patients with complete thoracic SCI (CTSCI), 24 with incomplete thoracic SCI (ITSCI), and 24 healthy individuals (HC) were enrolled in this study. Fresh stool samples and clinical data were collected from all participants, and their bowel functions with SCI were assessed. Microbial diversity and composition were analyzed by sequencing the 16S rRNA gene. The features of gut microbiota correlated with the serum biomarkers and their functions were investigated. The mean NBD score of patients with CTSCI was higher than that of patients with ITSCI. Diversity of the gut microbiota in SCI group was reduced, and with an increase in the degree of damage, alpha diversity had decreased gradually. The composition of gut microbiota in patients with SCI was distinct from that in healthy individuals, and CTSCI group exhibited further deviation than ITSCI group compared to healthy individuals. Four serum biomarkers were found to be correlated with most differential genera. Patients with thoracic SCI present gut dysbiosis, which is more pronounced in patients with CTSCI than in those with ITSCI. Therefore, the gut microbiota profile may serve as the signatures for bowel and motor functions in patients with thoracic SCI.

肠道菌群（gut microbiota）是脊髓损伤（spinal cord injury, SCI）患者神经源性肠功能障碍（neurogenic bowel dysfunction, NBD）的潜在生物标志物。本研究旨在明确不同严重程度胸段脊髓损伤患者与健康个体之间的肠道菌群共性特征，以及与血清生物标志物相关的菌群亚群。本研究共纳入21例完全性胸段脊髓损伤（complete thoracic SCI, CTSCI）患者、24例不完全性胸段脊髓损伤（incomplete thoracic SCI, ITSCI）患者及24例健康对照（healthy individuals, HC）。收集所有受试者的新鲜粪便样本与临床资料，并评估其脊髓损伤相关肠功能。通过16S rRNA基因测序分析菌群多样性与组成结构，探究与血清生物标志物相关的肠道菌群特征及其功能。结果显示，完全性胸段脊髓损伤患者的平均神经源性肠功能障碍评分高于不完全性胸段脊髓损伤患者；脊髓损伤组肠道菌群多样性降低，且随着损伤程度加重，α多样性（alpha diversity）逐渐下降；脊髓损伤患者的肠道菌群组成与健康对照存在显著差异，且与健康对照相比，完全性胸段脊髓损伤组的菌群组成偏离程度较不完全性胸段脊髓损伤组更为显著。本研究发现4种血清生物标志物与大部分差异菌属相关。胸段脊髓损伤患者存在肠道菌群失调（gut dysbiosis），且完全性胸段脊髓损伤患者的菌群失调程度较不完全性胸段脊髓损伤患者更为显著。综上，肠道菌群特征谱可作为胸段脊髓损伤患者肠功能与运动功能的特征性生物标志物。