# Probiotic and Prebiotic Supplementation for Gastrointestinal Discomfort in Chronic Spinal Cord Injury (PRO-GIDSCI): A Randomized Controlled Crossover Trial Protocol

## TL;DR

This study tests if probiotics and prebiotics can improve gut health and quality of life in people with chronic spinal cord injuries.

## Contribution

The study introduces a randomized crossover trial protocol to evaluate prebiotic and probiotic effects on gastrointestinal discomfort in chronic spinal cord injury patients.

## Key findings

- The trial will assess changes in gastrointestinal quality of life using a standardized index.
- Gut microbiome composition and inflammatory markers will be analyzed as secondary outcomes.
- A four-week washout period will separate the two supplement phases to minimize carryover effects.

## Abstract

Background: Gastrointestinal discomfort affects up to 70% of individuals with spinal cord injury (SCI), largely due to gut dysbiosis caused by altered transit time and reduced gastrointestinal motility from autonomic disruption. Emerging evidence links prebiotics and probiotics to improved microbiome balance and reduced inflammation, yet data in SCI remain limited. Methods: Individuals aged ≥ 18 years, with a chronic SCI (≥1 year) experiencing significant gastrointestinal symptoms, will be invited to participate in this single-center randomized controlled crossover trial. Persons currently taking antibiotics, who have relevant eating or digestive disorders, or who have undergone a recent diet change will be excluded from the study. Participants will be randomized (1:1) into two groups. The first group will take a probiotic (Biotics-G, Burgerstein AG, Rapperswil-Jona, Switzerland) supplement for eight weeks, then after a four-week washout period, they will take a prebiotic (Oat Bran, Naturaplan, manufactured by Swissmill, Zurich, Switzerland) supplement for another eight weeks. The second group will receive the supplements in reverse order. The primary outcome is the Gastrointestinal Quality of Life Index, a questionnaire to assess quality of life related to gastrointestinal disorders. Secondary outcomes consist of gastrointestinal transit time, inflammatory blood markers, and gut microbiome composition. Ethics: The study will be conducted in accordance with the Declaration of Helsinki. The study was approved by the Ethics Committee for Northwest/Central Switzerland (EKNZ, ID: 2025-00238, 24.02.2025, Version 2.0). The study is registered at ClinicalTrials.gov (ID: NCT06870331, 02.04.2025). Written informed consent will be obtained from all participants involved in the study.