NCT07086157

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

Effects of Low-FODMAP Diet and Probiotics on Gastrointestinal Symptoms, Behavior Problems, and Microbiota in Children With Autism Spectrum Disorder and Gastrointestinal Symptoms

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: 16 (actual)
• Sponsor: Marmara University Pendik Training and Research Hospital · Academic / Other
• Sex: All
• Age: 6 Years – 12 Years
• Healthy volunteers: Not accepted

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

Interventions

Type	Name	Description
DIETARY_SUPPLEMENT	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. .
OTHER	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.

Timeline

• Start date: 2023-12-01
• Primary completion: 2024-03-01
• Completion: 2024-03-01
• First posted: 2025-07-25
• Last updated: 2025-07-25

Locations

1 site across 1 country: Turkey (Türkiye)