Clinical Report: Adverse Allergic Reactions After FMT in Pediatric ASD

Overview

This report details two cases of pediatric patients with autism spectrum disorder (ASD) who experienced anaphylactic shock following fecal microbiota transplantation (FMT). These cases highlight the potential risks associated with FMT in children with ASD and multiple food intolerances.

Background

Fecal microbiota transplantation (FMT) is increasingly utilized in children with autism spectrum disorder (ASD) to address gut microbiota dysbiosis. However, the safety profile of FMT in high-risk subgroups, particularly those with multiple food intolerances, remains underexplored. Understanding the risks and mechanisms of adverse reactions is crucial for improving patient safety during FMT procedures.

Data Highlights

No numerical data or trial data were provided in the article.

Key Findings

• Two pediatric patients with ASD and multiple food intolerances developed anaphylactic shock after FMT.
• Case 1 experienced early-stage shock associated with IgG-mediated type III hypersensitivity.
• Case 2 exhibited classic anaphylactic shock with a biphasic course.
• Both patients improved following standardized anti-allergy and anti-shock treatment.
• One patient successfully completed subsequent FMT using a low-dose regimen.
• Refined risk stratification and close monitoring are recommended for high-risk patients undergoing FMT.

Clinical Implications

Clinicians should be aware of the potential for severe allergic reactions, such as anaphylactic shock, in pediatric patients with ASD and food intolerances undergoing FMT. Implementing individualized transplantation protocols and standardized emergency procedures may enhance safety.

Conclusion

The findings emphasize the need for careful consideration of patient selection and monitoring during FMT in high-risk pediatric populations.

Related Resources & Content

1. Shirotani M, et al., Frontiers in Pediatrics, 2026 -- Safety and efficacy of a novel fecal microbiota transplantation method using hydrogen nanobubble water without antibiotics or bowel cleansing in children with autism spectrum disorder
2. BMC Psychiatry, 2025 -- Investigation of Plasma and Urinary Neurotransmitter Levels in Chinese Pediatric Patients with Autism Spectrum Disorder
3. Frontiers in Immunology, 2026 -- Non-invasive detection of pediatric atopic dermatitis based on fecal microbiota and metabolite profiles: a diagnostic approach
4. Journal of Gastroenterology, 2025 -- Nutritional Approaches and Gastrointestinal Wellness in Autism Spectrum Disorder
5. American Gastroenterological Association, 2024 -- New AGA guideline: Use FMT for the majority of recurrent C. diff patients
6. FDA Safety Alert on Fecal Microbiota Transplantation
7. New AGA guideline: Use FMT for the majority of recurrent C. diff patients - American Gastroenterological Association
8. (PDF) Effect of oral faecal microbiota transplantation intervention for children with autism spectrum disorder: A randomised, double‐blind, placebo‐controlled trial