The goal of this clinical trial is to learn whether consuming a high fermented food diet improves bowel function and gut health in adults with chronic spinal cord injury (SCI). The study will also evaluate the feasibility and tolerability of consuming fermented foods daily for 10 weeks. The main questions it aims to answer are:

1. Does a high fermented food diet improve neurogenic bowel dysfunction symptoms and colonic transit in adults with SCI?
2. Does fermented food intake change gut microbiome composition, short-chain fatty acid production, and intestinal inflammation?

Researchers will compare a high fermented food diet to a control diet to evaluate effects on bowel health and gut microbiome outcomes.

Participants will:

• Consume study foods daily for 10 weeks
• Attend 2 in-person study visits
• Collect stool samples at home and ship them overnight to the research team using provided collection kits and prepaid shipping materials
• Complete bowel health questionnaires and dietary recalls
• Undergo Sitz marker testing with abdominal X-rays to assess colonic transit
• Participate in biweekly monitoring contacts throughout the study period

Inclusion Criteria:

• Adults aged 18-70 years

• At least 1 year post-onset of spinal cord injury, consistent with chronic spinal cord injury

• Traumatic spinal cord injury involving cervical or thoracic levels

• American Spinal Injury Association Impairment Scale classification A-D

• Medically stable, with no recent hospitalizations or acute illnesses

• Able to safely consume study foods, including fermented and control food products

• Experiencing neurogenic bowel dysfunction, defined by at least one of the following:

  1. Three or fewer bowel movements per week
  2. More than 60 minutes required per bowel care routine
  3. Symptoms of incomplete evacuation
  4. Abdominal distension
  5. Fecal incontinence

• Established and stable bowel program, defined as a consistent individualized routine of timing, frequency, and evacuation methods that has remained unchanged for at least 4 weeks before enrollment

Exclusion Criteria:

• Antibiotic use within the past 4 weeks

• Active gastrointestinal disease, including Crohn's disease, ulcerative colitis, celiac disease, or gastrointestinal obstruction

• Current intake of probiotics or fermented foods exceeding 3 servings per day

• Pregnancy or breastfeeding

• Recent major bowel surgery within the past 12 weeks

• Unresolved fecal impaction

• Unstable bowel regimen that could interfere with accurate motility assessment

• Inability to safely undergo Sitz marker testing, including any of the following:

  1. Inability to swallow the capsule
  2. Pregnancy, due to radiation exposure
  3. Contraindication to abdominal X-ray procedures

De-identified individual participant data (IPD) underlying published results, including clinical, dietary, bowel function, metabolomic, and microbiome-derived datasets, will be shared within 12 months of primary publication or study completion, whichever occurs first. Processed clinical and omics datasets will be shared through the Open Data Commons for Spinal Cord Injury (ODC-SCI) and Vivli.

Data will be available beginning 12 months after publication of the primary study results or 12 months after study completion, whichever occurs first, and will remain available indefinitely.

De-identified data will be available to qualified investigators for scientifically sound research purposes. Requests will be reviewed by the study investigators and/or repository governance committees. Data will be provided under applicable data use agreements and in accordance with institutional and federal human subjects protections.