Study Compares Effects of Fecal Microbiota Transplantation and Ketogenic Diet on Children with Autism Spectrum Disorder

September 3, 2026 2 Min Read

New Research Explores Gut-Focused Treatments for ASD

A recent clinical study investigated the impact of two gut microbiota-targeted interventions—Fecal Microbiota Transplantation (FMT) and the Ketogenic Diet (KD)—on children diagnosed with Autism Spectrum Disorder (ASD). The research aimed to compare the clinical efficacy and changes in gut microbial communities following these treatments.

Study Design and Participants

The study enrolled 30 children diagnosed with ASD based on the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), and the Autism Diagnostic Observation Schedule, Second Edition (ADOS-2). Core ASD symptoms were assessed using the Childhood Autism Rating Scale (CARS) and the Autism Behavior Checklist (ABC). To analyze gut microbiota composition, researchers employed shotgun metagenomic sequencing.

Clinical Outcomes

Both treatment groups showed significant improvements in core ASD symptoms after intervention. In the FMT group, the average CARS score decreased from 34.87 to 33.53, a statistically significant change (p < 0.01). Similarly, the KD group’s mean CARS score dropped from 35.13 to 33 (p < 0.01). Regarding the ABC scores, the FMT group experienced a reduction from 79.93 to 69.33, although this change did not reach statistical significance (p = 0.064). The KD group showed a significant decrease in ABC scores from 63.07 to 42.73 (p < 0.01).

Gut Microbiota Changes

Despite clinical improvements, no significant changes were observed in overall microbial diversity (α-diversity or β-diversity) within either group after treatment. However, detailed microbial analyses revealed distinct shifts in specific bacterial taxa. The FMT intervention notably increased butyrate-producing bacteria such as Wujia chipingensis, Eubacterium sp. MSJ-33, and Butyrivibrio crossotus. In contrast, the KD group showed an increase in Blautia massiliensis and a decrease in bacteria associated with propionate metabolism, including Veillonella sp. S12025-13 and Veillonella nakazawae.

Metabolic Pathway Insights

Further functional analysis using KEGG enrichment indicated that the ketogenic diet enhanced pathways related to propionate metabolism and aromatic compound degradation. These metabolic changes could be linked to the observed clinical benefits, although the exact mechanisms remain to be clarified.

Implications for Families and Care Providers

This study suggests that both FMT and KD may offer symptom improvements for children with ASD, potentially through different modifications of the gut microbiota. Families considering such interventions should consult healthcare professionals to weigh benefits and risks, as these treatments are still under investigation and not standard care.

Limitations and Future Directions

The study’s small sample size and short-term follow-up limit the generalizability of the findings. Additionally, while associations between microbiota changes and symptom improvements were observed, causality cannot be established. Larger, longer-term studies are needed to confirm these results and to better understand how gut microbiota modulation may influence ASD symptoms.

For more detailed information, see the original study published in BMC Psychiatry: Comparison of clinical efficacy and gut microbiota characteristics in children with ASD treated with fecal microbiota transplantation and ketogenic diet.