Mediterranean Diet and Gut Microbiota in Children With Systemic Lupus Erythematosus

Effects of a Mediterranean Diet-Based Nutritional Intervention on Gut Microbiota, Disease Activity, and Nutritional Status in Children With Systemic Lupus Erythematosus

The goal of this clinical trial is to learn if a Mediterranean diet can improve gut microbiota, disease activity, and nutrition in children with systemic lupus erythematosus (SLE). The study will include children with SLE and healthy family members living in the same home.

The main questions it aims to answer are:

Does a Mediterranean diet improve gut microbiota in children with SLE? Does the diet help reduce disease activity? Does the diet improve overall nutrition? Researchers will compare children with SLE to healthy family members to better understand how diet, gut microbiota, and health are related.

Participants will:

Give stool samples at the beginning and end of the study to analyze gut microbiota.

Have body measurements taken. Record what they eat for 3 days (2 weekdays and 1 weekend day). Answer questions about their diet, physical activity, sleep, and health. Children with SLE in the intervention group will receive nutrition counseling based on the Mediterranean diet for 12 weeks. The counseling will focus on increasing foods rich in polyphenols and reducing processed foods to improve overall diet quality. They will also receive advice on physical activity.

At the end of the study, some participants will join a group discussion to share their experiences.

This study aims to evaluate the relationship between diet, gut microbiota, and clinical outcomes by comparing children with systemic lupus erythematosus (SLE) and healthy individuals living in the same household. The study will be conducted at the Pediatric Nephrology and Rheumatology Department of Erciyes University, including approximately 30 children diagnosed with SLE and 30 healthy family members.

The study will include an intervention group and a control group. Participants in the intervention group will receive individualized nutrition counseling based on the principles of the Mediterranean diet, provided by a registered dietitian. The intervention will focus on increasing dietary polyphenol intake, reducing dietary inflammatory potential, and limiting the consumption of ultra-processed foods. The counseling program will last for 12 weeks and include a total of 12 sessions. The first, sixth, and twelfth sessions will be conducted face-to-face, while the remaining sessions will be conducted via phone or online communication. The control group will not receive any dietary intervention.

At baseline and at the end of the study, stool samples will be collected from all participants for gut microbiota analysis. Anthropometric measurements and body composition analysis will be performed, and 3-day dietary records (including 2 weekdays and 1 weekend day) will be obtained. Diet quality, physical activity level, and sleep quality will be assessed using the Mediterranean Diet Quality Index for children and adolescents (KIDMED), the International Physical Activity Questionnaire-Short Form (IPAQ), and the Pittsburgh Sleep Quality Index (PSQI), respectively.

In addition, children with SLE will be evaluated using the Childhood Health Assessment Questionnaire (CHAQ), the Systemic Lupus Erythematosus Disease Activity Index-2000 (SLEDAI-2K), and the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SLICC/SDI). Biochemical parameters routinely collected during clinical follow-up will be obtained from patient records.

Dietary intake data will be analyzed using the BeBiS software. The dietary inflammatory index (DII), dietary polyphenol content (based on the Phenol-Explorer database), and the level of food processing (according to the NOVA classification) will be evaluated.

At the end of the intervention, a focus group discussion will be conducted with a subset of participants from the intervention group to explore their experiences and perceptions of the dietary intervention. Qualitative data obtained from these discussions will be analyzed using content analysis methods.

Inclusion Criteria:

For participants with Systemic Lupus Erythematosus (SLE):

• Diagnosis of SLE according to the SLICC classification criteria.
• SLE diagnosis established at least 6 months prior to enrollment.

For healthy controls (household members):

• Living in the same household as participants with SLE.
• Body mass index (BMI) within the normal range.

Exclusion Criteria:

For participants with SLE:

• Presence of active infection.
• Renal failure, or history of major trauma or surgery within the past 6 months.
• Presence of additional chronic diseases other than SLE.
• Use of antibiotics or probiotics within the past 4 weeks.
• Following a specific or restrictive diet.
• Illiteracy or cognitive impairment that may limit understanding of the intervention.

For healthy controls (household members):

• Presence of active infection
• Presence of any chronic disease
• Use of antibiotics or probiotics within the past 4 weeks
• Following a specific or restrictive diet
• Illiteracy or cognitive impairment that may limit understanding of study procedures