Effect of Gluten-free Casein-free Diet on Serum Zonulin and Claudin-5 Levels and Some Clinical Symptoms in Children With Autism Spectrum Disorder

NCT07274930 | Completed

• 1 other identifier: 223S497
• Study Type: interventional
• Target: 21
• Locations: 1 country
• Sites: 1

Brief Summary

This study will investigate the effects of a gluten-free casein-free diet (GFCF) on serum zonulin and claudin-5 levels in children diagnosed with ASD, in relation to intestinal permeability and blood-brain barrier permeability, and on electroencephalography (EEG) findings, autism symptoms, and some clinical symptoms. The study also included EEG findings to measure brain cortical activity in children diagnosed with autism before and after the diet. Purpose: This study aimed to investigate the effects of the GFCF dietary model on serum zonulin and claudin-5 levels, autism spectrum disorder parameters, gastrointestinal symptoms, and some clinical symptoms. Objectives:

1. 1.Examination of serum zonulin and claudin-5 levels in the GFCF group compared to the control group.
2. 2.Examination of EEG findings in the GFCF group compared to the control group.
3. 3.Examination of Childhood Autism Assessment Scale scores in the GFCF group compared to the control group.
4. 4.Examination of Autism Behavior Checklist scores in the GFCF group compared to the control group.
5. 5.Examination of gastrointestinal sensitivity index scores in the GFCF group compared to the control group.
6. 6.Examination of the diet quality index in individuals diagnosed with GFCF at the end of the study.

Conditions

Autism Spectrum Disorder (ASD); Nutrition

Keywords

autism specktrum disorder; gluten-free casein-free diet; intestinal permeability; zonulin; claudin-5

Outcome Measures

Primary Outcomes (2)

• The effect of the GFCF diet on blood zonulin level

  The effect of the GFCF diet on blood zonulin level

  3 months

• The effect of the GFCF diet on blood claudin-5 level

  The effect of the GFCF diet on blood claudin-5 level

  3 months

Study Arms (2)

Gluten Free Casein Free Diet

EXPERIMENTAL

The group following a ASD

Other: Gluten Free Casein Free Diet

Normal Diet

ACTIVE COMPARATOR

Normal Diet

Other: Normal Diet

Interventions

Gluten Free Casein Free Diet OTHER

Gluten Free Casein Free Diet

Gluten Free Casein Free Diet

Normal Diet OTHER

Participants follow a normal diet

Normal Diet

Eligibility Criteria

• Age: 3 Years - 6 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17)

You may qualify if:

• Children diagnosed with ASD will undergo general examinations by a pediatric neurologist, psychiatrist, and dietitian, and eligible participants will be included in the study. All children will be evaluated by a child and adolescent psychiatrist according to DSM-5 diagnostic criteria, and all will have their neurological evaluations completed by a pediatric neurologist. Children diagnosed with autism spectrum disorder who receive at least two hours of regular special education per week will be included in the study.
• Special education is crucial for every child diagnosed with ASD. The project team considers the importance of special education for children with ASD. It has been stated that participants who do not receive special education or are not continuing their education will be excluded. However, children's special education hours vary widely. The state provides two hours of special education for diagnosed children. Further hours of education may vary based on family requests. Because each child in this study will be evaluated after three months based on their individual development, it is expected that their education hours will remain constant throughout the study. If each participating child receives two hours of special education during the study, the continuity of these two hours will be monitored. If a change in training hours is detected, participants will be excluded from the study. Analysis will be conducted by adjusting for the effect of training hours to determine the effect of the diet.
• Individuals who meet the study criteria and voluntarily agree to participate in the study will be provided with an informed consent form. The Childhood Autism Rating Scale (CARS) and the Problem Behavior Checklist (ABC) will be used in the clinical evaluation of all children. These scales will be completed by the same clinician during the initial psychiatric evaluation and immediately after completing the 12-week diet program.
• Blinding will be applied to the CARS, ABC, gastrointestinal sensitivity index, Bristol stool scale, and serum zonulin and claudin-5 analyses administered to the participants at the beginning and end of the study. Except for the dietitian researcher responsible for explaining and monitoring the nutrition education and diet plan, all other researchers will evaluate the participants in accordance with the blinding principle.

You may not qualify if:

• Those under three years of age and over six years of age; Those unable to be fed orally; Patients with height-for-age, weight-for-age, and BMI-for-age Z scores above +2 SD and below -2 SD for their age and gender using World Health Organization growth references; those diagnosed with neurometabolic diseases such as epilepsy, Fragile X syndrome, or Williams syndrome; those who do not continue their special education or do not accept special education; those who are on any dietary treatment, using nutritional supplements and/or medication in the last 2 months; those with diet compliance less than 80%; and those diagnosed with celiac disease and gluten intolerance will be excluded from the study.

Sponsors & Collaborators

• Karadeniz Technical University: lead
• The Scientific and Technological Research Council of Turkey: collaborator

Study Sites (1)

Karadeniz Teknik Üniversitesi

Trabzon, Ortahi̇sar, 61080, Turkey (Türkiye)

Location

Related Links

• The Efficacy of the Gluten-free Case in-free Diet for Moroccan Autistic Children
• Serum zonulin level in autistic children and its relation to severity of symptoms a case-control study

MeSH Terms

Conditions

Autism Spectrum Disorder

Condition Hierarchy (Ancestors)

Child Development Disorders, Pervasive; Neurodevelopmental Disorders; Mental Disorders

Study Officials

• Aslı Akyol

  Hacettepe Univercity

  STUDY CHAIR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: SUPPORTIVE CARE
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Research Assistant (PhD Student)

Study Record Dates

• First Submitted: November 28, 2025
• First Posted: December 10, 2025
• Study Start: August 1, 2024
• Primary Completion: May 1, 2025
• Study Completion: August 1, 2025
• Last Updated: December 10, 2025

Record last verified: 2025-11

Locations

TU (1)