Low-FODMAP Diet and Probiotics: Effects on Gut, Behavior, and Microbiota in Children With Autism Spectrum Disorder

NCT ID: NCT07086157

Last Updated: 2025-07-25

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 16 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2023-12-01
• Study Completion Date: 2024-03-01

Brief Summary

The goal of this clinical trial was to evaluate whether a low-FODMAP diet and probiotic supplements could reduce gastrointestinal (GI) symptoms and behavior problems in children with autism spectrum disorder (ASD) who also experienced GI issues. The main questions it aimed to answer were:

Did a low-FODMAP diet and/or probiotics improve GI symptoms such as constipation, diarrhea, and abdominal pain?

Did these interventions help reduce behavior problems such as irritability, lethargy, stereotypy, hyperactivity, and speech disorder ?

Researchers compared two groups:

1. Children who received a daily probiotic supplement containing 4 strains for 4 weeks

2. Children who received both the probiotic supplement and followed a low-FODMAP diet

This comparison aimed to determine whether the combination of diet and probiotics had greater benefits than probiotics alone.

Participants:

Took the assigned intervention(s) for 4 weeks

Provided stool samples for gut microbiota analysis

Completed assessments of GI symptoms and behavior using validated questionnaires

Detailed Description

This randomized, controlled, parallel-group clinical trial aimed to investigate the effects of a low-FODMAP diet and multi-strain probiotic supplementation on gastrointestinal (GI) symptoms, behavioral problems, and gut microbiota composition in children with Autism Spectrum Disorder (ASD) who presented with concurrent GI complaints.

Children aged 6 to 12 years with clinically diagnosed ASD and GI symptoms were recruited. A total of 16 participants were randomly assigned into two equal groups (n=8 per group). One group received a probiotic supplement containing four bacterial strains daily for 4 weeks, while the second group received the same probiotic supplement in combination with a low-FODMAP diet over the same period. The randomization was stratified and allocation was blinded to the data analysts.

Interventions Probiotic group: A commercially available probiotic blend (containing Lactobacillus acidophilus, Bifidobacterium longum, Lactobacillus rhamnosus, and Saccharomyces boulardii) was administered once daily for 4 weeks.

Low-FODMAP + Probiotic group: In addition to the probiotic supplement, participants received individualized nutrition counseling and followed a standardized low-FODMAP diet protocol under dietitian supervision for 4 weeks.

Data Collection and Measures GI symptoms were assessed using the Pediatric Gastrointestinal Symptoms Questionnaire - Rome III Version (QPGS-RIII) and the Bristol Stool Scale (BSS).

Behavioral outcomes were evaluated using the Aberrant Behavior Checklist (ABC), focusing on subscales including irritability, lethargy-social withdrawal, stereotypy, hyperactivity, and inappropriate speech.

Dietary intake was recorded using 3-day food diaries to determine intake of daily FODMAP amount.

Microbiota composition was analyzed from fecal samples using 16S rRNA gene sequencing and LEfSe (Linear Discriminant Analysis Effect Size) for taxonomic biomarker discovery.

Quality Control and Data Validation All participants were monitored weekly to ensure adherence to interventions and assess adverse effects.

Dietary intake data were validated against food portion models and caregiver interviews.

Stool sample processing followed standardized protocols: DNA was extracted, amplified, and sequenced using Illumina platforms.

A pre-defined bioinformatics pipeline was used for quality filtering, taxonomic assignment, and alpha/beta diversity analysis.

Internal consistency checks and double data entry validation were applied to all behavioral and symptom questionnaires.

Statistical Analysis Statistical analysis was performed using SPSS v25 and R. Paired and independent-sample t-tests or Wilcoxon signed-rank tests were applied based on distribution normality. Microbiota diversity indices (Shannon, Simpson, Chao1) and taxonomic differences were compared across groups and time points. Spearman correlation analyses were used to explore associations between microbiota shifts and clinical parameters. A p-value of <0.05 was considered statistically significant.

Conditions

Autism Spectrum Disorder; Functional Gastrointestinal Disorders

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: NONE

Study Groups

Low-FODMAP Diet + Probiotic Supplement

Participants in this arm received the same probiotic supplement as the other group once daily for 4 weeks, in combination with a personalized low-FODMAP diet. The diet was planned and monitored by a registered dietitian to ensure compliance and nutritional adequacy.

Group Type: EXPERIMENTAL

Probiotic

Intervention Type: DIETARY_SUPPLEMENT

A probiotic supplement in capsule form containing 4 strains of microorganisms, with a total of 10 × 10⁹ CFU (colony-forming units) per capsule. The strain composition per capsule was:

Lactobacillus acidophilus L1 - 2.9 × 10⁹ CFU, Bifidobacterium longum LBL-01 - 2.9 × 10⁹ CFU, Lactobacillus rhamnosus - 2.9 × 10⁹ CFU, Saccharomyces boulardii - 1.3 × 10⁹ CFU. Each participant in this arm took one capsule per day in the morning on a full stomach, for a duration of 4 weeks. No other dietary interventions were applied to this group. This probiotic supplement was chosen because the strains in its content are among the most frequently researched and known strains in terms of intestinal health. Additionally, it does not contain FOS or inulin due to FODMAP restriction.

.

Low-FODMAP Diet

Intervention Type: OTHER

A structured low-FODMAP diet intervention designed to restrict intake of fermentable oligosaccharides, disaccharides, monosaccharides, and polyols. The diet was individualized and monitored by a registered dietitian over a 4-week period to ensure adherence and nutritional adequacy.

Probiotic Supplement Only

Participants in this arm received a multi-strain probiotic supplement containing four bacterial strains (Lactobacillus acidophilus L1, Bifidobacterium longum LBL-01, Lactobacillus rhamnosus, and Saccharomyces boulardii) once daily for 4 weeks. No dietary restrictions or modifications were applied in this group.

Group Type: EXPERIMENTAL

Probiotic

Intervention Type: DIETARY_SUPPLEMENT

A probiotic supplement in capsule form containing 4 strains of microorganisms, with a total of 10 × 10⁹ CFU (colony-forming units) per capsule. The strain composition per capsule was:

Lactobacillus acidophilus L1 - 2.9 × 10⁹ CFU, Bifidobacterium longum LBL-01 - 2.9 × 10⁹ CFU, Lactobacillus rhamnosus - 2.9 × 10⁹ CFU, Saccharomyces boulardii - 1.3 × 10⁹ CFU. Each participant in this arm took one capsule per day in the morning on a full stomach, for a duration of 4 weeks. No other dietary interventions were applied to this group. This probiotic supplement was chosen because the strains in its content are among the most frequently researched and known strains in terms of intestinal health. Additionally, it does not contain FOS or inulin due to FODMAP restriction.

.

Interventions

Probiotic

A probiotic supplement in capsule form containing 4 strains of microorganisms, with a total of 10 × 10⁹ CFU (colony-forming units) per capsule. The strain composition per capsule was:

Lactobacillus acidophilus L1 - 2.9 × 10⁹ CFU, Bifidobacterium longum LBL-01 - 2.9 × 10⁹ CFU, Lactobacillus rhamnosus - 2.9 × 10⁹ CFU, Saccharomyces boulardii - 1.3 × 10⁹ CFU. Each participant in this arm took one capsule per day in the morning on a full stomach, for a duration of 4 weeks. No other dietary interventions were applied to this group. This probiotic supplement was chosen because the strains in its content are among the most frequently researched and known strains in terms of intestinal health. Additionally, it does not contain FOS or inulin due to FODMAP restriction.

.

Intervention Type: DIETARY_SUPPLEMENT

Low-FODMAP Diet

A structured low-FODMAP diet intervention designed to restrict intake of fermentable oligosaccharides, disaccharides, monosaccharides, and polyols. The diet was individualized and monitored by a registered dietitian over a 4-week period to ensure adherence and nutritional adequacy.

Intervention Type: OTHER

Eligibility Criteria

Inclusion Criteria

• Diagnosed with Autism Spectrum Disorder by a specialist at Marmara University Pendik Training and Research Hospital Child and Adolescent Psychiatry Clinic
• Aged between 6 and 12 years
• Diagnosed with functional gastrointestinal symptoms according to Rome IV criteria
• Willing to participate by signing informed consent and assent forms (by both child and parent)

Exclusion Criteria

• Following any other dietary intervention at the time of study initiation
• Routine use of prebiotics or probiotics
• Use of antibiotics within the 4 weeks prior to the study
• Presence of active diarrhea due to intestinal infection or similar condition
• Diagnosis of other gastrointestinal diseases besides functional GI symptoms

• Minimum Eligible Age: 6 Years
• Maximum Eligible Age: 12 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Istanbul Saglik Bilimleri University

OTHER

Sponsor Role: collaborator

Marmara University Pendik Training and Research Hospital

OTHER

Sponsor Role: lead

Responsible Party

Pınar Polat

Doctor Dietitian

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Pınar Polat, PhD

Role: PRINCIPAL_INVESTIGATOR

Marmara University Pendik Training and Research Hospital

Neşe Perdahlı Fiş, Prof Dr

Role: STUDY_CHAIR

Marmara University Pendik Training and Research Hospital

Özlem Aytekin, AProf Dr

Role: STUDY_DIRECTOR

Saglik Bilimleri Universitesi

Fatih Özbey, Prof Dr

Role: STUDY_DIRECTOR

Saglik Bilimleri Universitesi

Locations

Marmara Univesity Pendik Training and Research Hospital

Istanbul, , Turkey (Türkiye)

Countries

Turkey (Türkiye)

References

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Reference Type: BACKGROUND

PMID: 39702309 (View on PubMed)

Iglesias-Vazquez L, Van Ginkel Riba G, Arija V, Canals J. Composition of Gut Microbiota in Children with Autism Spectrum Disorder: A Systematic Review and Meta-Analysis. Nutrients. 2020 Mar 17;12(3):792. doi: 10.3390/nu12030792.

Reference Type: BACKGROUND

PMID: 32192218 (View on PubMed)

Srikantha P, Mohajeri MH. The Possible Role of the Microbiota-Gut-Brain-Axis in Autism Spectrum Disorder. Int J Mol Sci. 2019 Apr 29;20(9):2115. doi: 10.3390/ijms20092115.

Reference Type: BACKGROUND

PMID: 31035684 (View on PubMed)

Settanni CR, Bibbo S, Ianiro G, Rinninella E, Cintoni M, Mele MC, Cammarota G, Gasbarrini A. Gastrointestinal involvement of autism spectrum disorder: focus on gut microbiota. Expert Rev Gastroenterol Hepatol. 2021 Jun;15(6):599-622. doi: 10.1080/17474124.2021.1869938. Epub 2021 Jan 5.

Reference Type: BACKGROUND

PMID: 33356668 (View on PubMed)

Socala K, Doboszewska U, Szopa A, Serefko A, Wlodarczyk M, Zielinska A, Poleszak E, Fichna J, Wlaz P. The role of microbiota-gut-brain axis in neuropsychiatric and neurological disorders. Pharmacol Res. 2021 Oct;172:105840. doi: 10.1016/j.phrs.2021.105840. Epub 2021 Aug 24.

Reference Type: BACKGROUND

PMID: 34450312 (View on PubMed)

Martinez-Gonzalez AE, Andreo-Martinez P. The Role of Gut Microbiota in Gastrointestinal Symptoms of Children with ASD. Medicina (Kaunas). 2019 Jul 26;55(8):408. doi: 10.3390/medicina55080408.

Reference Type: BACKGROUND

PMID: 31357482 (View on PubMed)

Leader G, Abberton C, Cunningham S, Gilmartin K, Grudzien M, Higgins E, Joshi L, Whelan S, Mannion A. Gastrointestinal Symptoms in Autism Spectrum Disorder: A Systematic Review. Nutrients. 2022 Apr 1;14(7):1471. doi: 10.3390/nu14071471.

Reference Type: BACKGROUND

PMID: 35406084 (View on PubMed)

Study Documents

Document Type: Individual Participant Data Set

Raw 16S rRNA sequencing data are publicly available through the National Library of Medicine's Sequence Read Archive (SRA) under accession number PRJNA1112427.

View Document

Related Links

https://tez.yok.gov.tr/UlusalTezMerkezi/

Full-text thesis record in the Turkish National Thesis Center. The thesis no is 888255.

Other Identifiers

09.2023.1132

Identifier Type: -

Identifier Source: org_study_id