Impact of a High-fiber Diet on the Microbiome and Disease Activity in Patients With Rheumatoid Arthritis
NCT Number: NCT06492200
Status: RECRUITING
Study Type: INTERVENTIONAL
Phases: NA
Conditions: Arthritis, Rheumatoid
Interventions: OTHER: Psyllium husks
Sponsor: Wuerzburg University Hospital
Collaborators: RheinNatur Food GmbH
Sex: ALL
Age: ADULT, OLDER_ADULT
Enrollment: 52
Study Design: Allocation: RANDOMIZED|Intervention Model: PARALLEL|Masking: NONE|Primary Purpose: TREATMENT
Start Date: 2024-06-01
Completion Date: 2026-12-30
Locations: University Würzburg, Würzburg, 97080, Germany

Summary:
The goal of this clinical trial is to learn if increasing dietary fiber can improve the gut microbiome and reduce disease activity in adults with rheumatoid arthritis (RA). The main questions it aims to answer are:

* Can a higher fiber diet improve gut bacteria and produce beneficial short-chain fatty acids (SCFAs)?
* Does a higher fiber diet reduce RA symptoms and help with weight loss?

Researchers will compare two groups: one group will receive dietary counseling and take 10 grams of psyllium husk daily, while the other group will continue their usual diet.

Participants will:

* Complete dietary questionnaires at the start, 6 months, and 12 months.
* Provide stool samples for gut bacteria and SCFA analysis.
* Have their RA activity and body weight monitored regularly.
* Receive regular phone calls to support the dietary changes.

The study will involve adults with diagnosed RA who can provide informed consent and meet other inclusion criteria.

Primary Outcome Measures: Disease Activity Score 28 (DAS28), The Disease Activity Score 28 (DAS28) is a composite measure used to assess the activity of rheumatoid arthritis (RA). It is calculated using the number of tender and swollen joints (out of 28 specified joints) and the patient's global health assessment. The DAS28 score ranges from 0 to 9.4, with higher scores indicating higher disease activity. This measure is widely used in clinical practice and research to monitor and evaluate the effectiveness of RA treatments., Measurements will be assessed at baseline, 6 months, and 12 months.|C-Reactive Protein (CRP) Level, C-reactive protein (CRP) level is a biomarker used to measure inflammation in the body. Elevated CRP levels are indicative of inflammation and are commonly seen in rheumatoid arthritis patients. CRP levels will be measured using blood tests to assess the inflammatory status of the participants., Measurements will be assessed at baseline, 6 months, and 12 months.|Short-Chain Fatty Acids (SCFA) Levels in Stool, The concentration of short-chain fatty acids (SCFAs) in stool samples will be measured. SCFAs, such as acetate, propionate, and butyrate, are produced by the gut microbiota through the fermentation of dietary fibers. These compounds play a crucial role in maintaining gut health and modulating the immune system. The levels of SCFAs will be analyzed to determine the impact of increased dietary fiber intake on gut microbiota composition and function., Measurements will be assessed at baseline, 6 months, and 12 months.|Body Weight, Participants' body weight will be measured to assess changes over the study period. Weight measurements will be taken using a standardized and calibrated scale. Changes in body weight will help determine the effect of increased dietary fiber intake on weight management in individuals with rheumatoid arthritis., Measurements will be assessed at baseline, 6 months, and 12 months.
Secondary Outcome Measures: Patient Global Assessment of Disease Activity, The Patient Global Assessment of Disease Activity is a subjective measure where participants rate their overall disease activity on a scale from 0 (no disease activity) to 10 (maximum disease activity). This assessment provides insight into the patient's perception of their rheumatoid arthritis and its impact on their daily life., Measurements will be assessed at baseline, 6 months, and 12 months.|Health Assessment Questionnaire-Disability Index (HAQ-DI), The Health Assessment Questionnaire-Disability Index (HAQ-DI) is a self-reported questionnaire used to assess the degree of difficulty a person has in performing daily activities due to their rheumatoid arthritis. The HAQ-DI scores range from 0 (no disability) to 3 (severe disability)., Measurements will be assessed at baseline, 6 months, and 12 months.|Erythrocyte Sedimentation Rate (ESR), The Erythrocyte Sedimentation Rate (ESR) is a blood test that measures how quickly erythrocytes (red blood cells) settle at the bottom of a test tube. A faster-than-normal rate may indicate inflammation in the body, which is common in rheumatoid arthritis. ESR levels will be measured to evaluate the inflammatory status of the participants., Measurements will be assessed at baseline, 6 months, and 12 months.|Changes in Gut Microbiome Composition, The composition of the gut microbiome will be analyzed using stool samples. This analysis will focus on identifying the types and quantities of bacteria present in the gut. Changes in microbiome composition will be assessed to understand the impact of increased dietary fiber intake on gut health and its potential relationship with rheumatoid arthritis., Measurements will be assessed at baseline, 6 months, and 12 months.