A Pilot Study of the Gut Microbiota in Spine Fusion Surgery Patients

Background: The microbiome has been identified as a contributor to bone quality. As skeletal health is critical to success of orthopedic surgery, the gut microbiome may be a modifiable factor associated with postoperative outcomes. For spine fusion surgery in particular, de novo bone formation and sufficient bone mineral density are essential for successful outcomes. Given the prevalence and complexity of these procedures, the identification of novel factors that may be related to operative success is important. Questions/purposes: We sought to investigate how the composition of the microbiota related to bone health in a focused spinal fusion surgery cohort. Methods: We investigated the composition of the microbiome in a cohort of 31 patients prior to spinal fusion surgery, as well as changes in the microbiome over 6 weeks postoperatively. Preoperative areal bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry. Results: Composition of gut microbiota differed among spinal fusion patients with low bone mass ( T-score ≤ −1.0) and those with normal BMD ( P = .03). There was no significant change in composition of the gut microbiota between preoperative evaluation and 6 weeks postoperatively. Conclusions: Our findings in this small sample suggest there may be a relationship between BMD and composition of the gut microbiome in patients who undergo spinal fusion surgery. Further work is needed to investigate these relationships as well as potential interventions to foster a favorable microbial composition in spinal fusion surgery patients.