Feasibility of a Diet Intervention for Juvenile Arthritis (DIGEST-JA)

The Role of Diet, as Mediated by the Gut Microbiome, on Childhood Arthritis Disease Activity: a Feasibility Intervention Study

Families of children with arthritis are highly interested in the benefits of diet to improve their child's disease and future health outcomes. Previous research shows that the germs - bacteria and other organisms - that live in the intestines (gut microbiome) are important to how well immune systems work, and that what people eat changes their gut microbiome. The investigators want to study whether a certain diet - based on the principles of the Mediterranean Diet - will improve arthritis for children and whether it was changes in the microbiome that led to improvement.

Fifty-four participants in this study will change their diet for an 8-week period, and will have the option of remaining on the diet for an additional 4 weeks. At three time points during the study (beginning, 8 weeks, and 12 weeks), participants will provide stool and blood samples, will complete questionnaires about diet and other aspects of lifestyle and health, and will complete a disease assessment by a clinician. From collecting all these samples and information, the investigators will be able to determine if the diet was successful in improving disease activity in children with arthritis and if the gut microbiome was changed as well.

This study will help the investigators figure out if a larger, and more definitive, study like this is possible to do in children with arthritis and will help the investigators design a bigger multinational study to confirm how diet affects disease outcomes and the microbiome in children with arthritis. If successful, this research will provide scientific knowledge to help families make their way through this difficult to- navigate topic.

Study Overview

• Status: Recruiting
• Conditions: Arthritis, Juvenile; Juvenile Idiopathic Arthritis; Arthritis, Childhood
• Intervention / Treatment: Other: Diet intervention

• Study Type: Interventional
• Enrollment (Estimated): 54
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Hayyah Clairman; Phone Number: 416-813-7979; Email: hayyah.clairman@sickkids.ca

Study Locations

• Canada
  • Manitoba
    • Winnipeg, Manitoba, Canada, R3E 3P4
      • Not yet recruiting
      • University of Manitoba
      • Contact: Lily Lim, MBBS, MRCPCH, FRCPC, PhD
      • Principal Investigator: Lily Lim, MBBS, MRCPCH, FRCPC, PhD
  • Ontario
    • Hamilton, Ontario, Canada, L8N 3Z5
      • Recruiting
      • McMaster Children's Hospital
      • Contact: Tania Cellucci, MD, MScCH, FRCPC
      • Principal Investigator: Tania Cellucci, MD, MScCH, FRCPC
    • London, Ontario, Canada, N6A 5W9
      • Recruiting
      • London Health Sciences Centre
      • Contact: Roberta Berard, MD, FRCPC, MSc
      • Principal Investigator: Roberta Berard, MD, FRCPC, MSc
    • Ottawa, Ontario, Canada, K1H 8L1
      • Recruiting
      • Children's Hospital of Eastern Ontario (CHEO)
      • Contact: Roman Jurencak, MD
      • Principal Investigator: Roman Jurencak, MD
    • Toronto, Ontario, Canada, M5G 1X8
      • Active, not recruiting
      • The Hospital for Sick Children
  • Quebec
    • Montreal, Quebec, Canada, H3T 1C5
      • Not yet recruiting
      • Centre Hospitalier Universitaire Sainte-Justine
      • Contact: Jean Jacques De Bruycker, MD, FRCPC
      • Principal Investigator: Jean Jacques De Bruycker, MD, FRCPC
  • Saskatchewan
    • Saskatoon, Saskatchewan, Canada, S7N 0W8
      • Recruiting
      • Jim Pattison Children's Hospital
      • Contact: Mehul Jariwala, MD
      • Principal Investigator: Mehul Jariwala, MD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Ages 8-18 years
• Diagnosis of JIA (excluding systemic JIA, enthesitis-related arthritis, and rheumatoid factor (RF) positive polyarthritis) as per International League of Associations for Rheumatology (ILAR) criteria. (For this feasibility study, there will be no requirement for any particular level of disease activity.)
• Subjects on stable treatment - i.e., any medical treatment with disease-modifying antirheumatic drugs (DMARDs) and/or systemic or intraarticular corticosteroids, has been unchanged for 8 weeks, and is unlikely to change for 12 weeks as judged by the treating physician.
• Willingness to provide stool samples.
• English or French fluency adequate to answer the study questionnaires, and participate in diet instruction, as judged by the enrolling physician.

Exclusion Criteria:

• Documented specific food allergies, celiac disease.
• Co-morbidities that might impact the tolerability of the study diet, e.g., type I diabetes, peptic ulcer disease, etc.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Supportive Care
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Intervention; Diet (MedDiet)

Other: Diet intervention; A diet based on the principles of the Mediterranean Diet (MedDiet): consists of an abundance of plant foods - unrefined cereals, fruit, vegetables, and extra-virgin olive oil - a moderate consumption of poultry, dairy products, eggs, and low consumption of sweets and red meats. All subjects will be instructed to follow the MedDiet for 8 weeks by the study team. Families will be given the option to continue for 12 weeks if they wish to do so.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
(Feasibility 1) Participant accrual rate:	The proportion of all subjects who are approached that enroll and the accrual frequency at each site.	8-12 weeks
(Feasibility 2) The proportion of subjects who complete all the various measurement steps	Including return of the fecal samples, gender identification, completion rate of the food diary, etc. The proportion of subjects who continue in the 12-week extension will be recorded.	8-12 weeks
(Feasibility 3) Nutrient intake	Measured by the participants completing an ecologic momentary assessment (EMA) food diary and the corresponding Prospective Urban Rural Epidemiology (PURE) scores. The PURE score is calculated based on what the subjects entered in their EMA food diary. The score is from 0-6, with a higher score representing a healthier diet.	8-12 weeks
(Feasibility 4) Adherence to the MedDiet	Measured by Mediterranean Diet Quality Index in children and adolescents (KIDMED) a questionnaire that measures adherence to the MedDiet scores. The index ranges from 0-12. The values are classified into three levels: > 8 is optimal MedDiet, 4-7 means improvement needed to adjust intake to MedDiet patterns, and ≤ 3 is low diet quality.	8-12 weeks
(Mediator 1) Changes in the microbiome	Measured by intestinal microbial ⍺-diversity (a measure representing the number of microbial groups and how evenly balanced they are within the gut), the individual species and functions of gut organisms (through shotgun metagenomics), and short chain fatty acids (SCFAs).	8-12 weeks
(Mediator 2) Changes in juvenile arthritis disease activity score	Measured by the Juvenile Arthritis Disease Activity Scale (cJADAS10). This includes the 1) physician's global assessment of disease activity measured on a 10cm visual analog scale (VAS), (2) parent/patient's global assessment of well-being measured on a 10cm VAS, (3) count of joints with active disease up to 10 active joints. The total score ranges from 0-30 with higher number representing a higher juvenile arthritis disease activity score.	8-12 weeks
(Mediator 3) Changes in functional status	Measured by the Childhood Health Assessment Questionnaire (CHAQ) (self/parent report scale that is widely used to measure functional status in children with arthritis). The score ranges from 0-3, with a 0 representing no functional disability and 3 representing severe disability.	8-12 weeks
(Mediator 4) Changes in quality of life	Measured by the Quality of My Life (QoML) questionnaire (a validated questionnaire to measure well-being). QoML consists of 3 visual analog scales each scored out of 10. Higher scores indicate better quality of life.	8-12 weeks
(Mediator 5) Changes in gut inflammation	Measured by fecal calprotectin.	8-12 weeks
(Mediator 6) Changes in systemic inflammation	Measured by a blood biomarker panel, a composite measure of immune activation comprising 49 analytes: (sCD40L, EGF, Eotaxin, FGF-2, Flt-3 ligand, Fractalkine, G-CSF, GM-CSF, GROα, IFNα2, IFNγ, IL-1α, IL-1β, IL-1ra, IL-2, IL-3, IL-4, IL-5, IL-6, IL-7, IL-8, IL-9, IL-10, IL-12 (p40), IL-12 (p70), IL-13, IL-15, IL-17A, IL-17E/IL-25, IL-17F, IL-18, IL-22, IL-27, IP-10, MCP-1, MCP-3, M-CSF, MDC (CCL22), MIG, MIP-1α, MIP-1β, PDGF-AA, PDGF-AB/BB, RANTES, TGFα, TNFα, TNFβ, VEGF-A, YKL40)	8-12 weeks
(Feasibility 5) Tolerability of diet intervention	Tolerability will be measured by the Gastrointestinal Symptom Scale for Kids (GISSK), a well-validated and simple questionnaire, designed for use in juvenile idiopathic arthritis (JIA). There are 2 parts to the scale. A visual analog scale (VAS) from 0-100 where the higher score represents the higher severity of gastrointestinal symptoms. And a 8-part questionnaire that ranges from 0-8 where 0 represents no gastrointestinal symptoms.	8-12 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
(Confounder 1) Sleep quality	Measured by FitBit accelerometry	8-12 weeks
(Confounder 2) Patient-reported Sleep Quality	Measured by Patient-Reported Outcomes Measurement Information System (PROMIS) sleep disturbances questionnaire. The total score ranges from 0-40 with a higher score representing a poor sleep quality.	8-12 weeks
(Confounder 3) Physical activity	Measured by the Godin-Shephard Leisure-Time Physical Activity Questionnaire (GODIN) exercise questionnaire. A total score of 24 or more is active, 14 - 23 is moderately active, and less than 14 units is sedentary.	8-12 weeks
(Confounder 4) Sex	Results will be stratified by sex at birth.	8-12 weeks
(Confounder 5) Gender	Gender will be collected using the Perceived Similarity to Gender Groups Measure for children and youth.	8-12 weeks
(Confounder 6) Medication use	Will be abstracted from the patient chart. Results will be stratified by medication use.	8-12 weeks
(Confounder 7) Age	Stratify data by age group (8 - 12 and 13 - 18)	8-12 weeks

Collaborators and Investigators

• Sponsor: The Hospital for Sick Children
• Collaborators: Canadian Institutes of Health Research (CIHR)
• Investigators: Principal Investigator: Brian M. Feldman, The Hospital for Sick Children

Study record dates

Study Major Dates

• Study Start (Actual): April 7, 2025
• Primary Completion (Estimated): August 1, 2028
• Study Completion (Estimated): October 1, 2028

Study Registration Dates

• First Submitted: June 5, 2024
• First Submitted That Met QC Criteria: June 19, 2024
• First Posted (Actual): June 25, 2024

Study Record Updates

• Last Update Posted (Actual): May 5, 2026
• Last Update Submitted That Met QC Criteria: April 29, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: diet; microbiome; arthritis
• Additional Relevant MeSH Terms: Musculoskeletal Diseases; Joint Diseases; Rheumatic Diseases; Connective Tissue Diseases; Autoimmune Diseases; Immune System Diseases; Skin and Connective Tissue Diseases; Arthritis; Arthritis, Juvenile
• Other Study ID Numbers: 1000080845

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No