Effects of Probiotic Supplementation on Gastrointestinal and Urinary Outcomes in Patients with Spinal Cord Injury: A Systematic Review

Abstract

Introduction: Spinal cord injury (SCI) often leads to autonomic dysfunction, increasing susceptibility to antibiotic-associated diarrhea (AAD) and recurrent urinary tract infections (UTIs). Gut microbiota alterations post-SCI contribute to immune dysregulation. Although probiotics reduce AAD and infections in non-SCI populations, evidence in SCI remains limited. This systematic review evaluates probiotic effects on gastrointestinal and urinary outcomes in adults with SCI.   

Methods: Following PRISMA guidelines, we searched PubMed, Scopus, ProQuest, and the Cochrane Library from January 2010 to December 2024 (final search completed June 2025). The protocol was registered in PROSPERO (CRD420261417485). Randomized controlled trials (RCTs) and prospective interventional studies in adults with SCI receiving probiotics were included. Two reviewers independently performed study selection and data extraction. Risk of bias was assessed using Cochrane RoB 2.0, and GRADE was used for evidence certainty.    

Results: Five studies (3 RCTs, 2 controlled intervention analyses) met inclusion criteria (total N = 217 participants; range 24–98 per study). Two RCTs reported significantly reduced AAD incidence during antibiotic exposure with Lactobacillus rhamnosus GG and a multi-strain probiotic (p<0.05). Three studies evaluated urinary outcomes; one large RCT (n=98) demonstrated a lower incidence of UTIs and reduced colonization with multidrug-resistant organisms. No serious adverse events were reported.   

Conclusion: Probiotic supplementation in adults with SCI was associated with reduced AAD and lower urinary infection burden in selected trials. These findings are strain-specific and limited to infection-related outcomes. They may support probiotics as a potential adjunctive strategy for managing secondary complications of SCI.