Comparison of clinical efficacy and gut microbiota characteristics in children with ASD treated with fecal microbiota transplantation and ketogenic diet.

FMT significantly reduced CARS scores in children with ASD.

• Mean CARS score decreased from 34.87 to 33.53 in the FMT group (p < 0.01)
• Sample size: 30 participants total diagnosed with ASD according to DSM-5 and ADOS-2
• CARS (Childhood Autism Rating Scale) was used to evaluate ASD core symptoms
• The FMT group was one of two intervention arms in the study

Ketogenic diet significantly reduced both CARS and ABC scores in children with ASD.

• Mean CARS score declined from 35.13 to 33.00 in the KD group (p < 0.01)
• Mean ABC score reduced from 63.07 to 42.73 in the KD group (p < 0.01)
• The ABC (Aberrant Behavior Checklist) reduction of approximately 20 points represents a substantial improvement
• Both CARS and ABC improvements reached statistical significance in the KD group

FMT did not produce a statistically significant improvement in ABC scores.

• Mean ABC score reduced from 79.93 to 69.33 in the FMT group (p = 0.064)
• The reduction of approximately 10 points did not reach statistical significance
• By contrast, the KD group showed a statistically significant ABC reduction (p < 0.01)
• The FMT group had a higher baseline ABC score (79.93) compared to the KD group (63.07)

Neither intervention produced statistically significant changes in gut microbiota diversity measures.

• No statistically significant changes were observed in α-diversity or β-diversity within either group following intervention
• Gut microbiota composition was analyzed by shotgun metagenomic sequencing
• This finding held for both the FMT and KD groups
• Despite the lack of overall diversity changes, specific taxon-level differences were identified

FMT and ketogenic diet produced distinct post-intervention microbial signatures as revealed by LEfSe analysis.

• FMT significantly enriched butyrate-producing taxa: Wujia chipingensis, Eubacterium sp. MSJ-33, and Butyrivibrio crossotus
• KD elevated Blautia massiliensis and decreased propionate metabolism-associated taxa (Veillonella sp. S12025-13 and Veillonella nakazawae)
• LEfSe (Linear discriminant analysis Effect Size) analysis was used to identify taxon-level differences
• The two interventions appeared to modulate the gut microbiota through different microbial mechanisms

Ketogenic diet enriched propionate metabolism and aromatic compound degradation pathways in gut microbiota.

• KEGG enrichment analysis revealed KD enriched propionate metabolism with Fold enrichment = 3.747, q = 0.010
• KD also enriched aromatic compound degradation with Fold enrichment = 3.591, q = 0.010
• These functional pathway changes were specific to the KD group
• The decrease in Veillonella species (propionate-associated taxa) alongside enrichment of propionate metabolism pathways suggests complex metabolic remodeling

ASD in the study population was accompanied by gastrointestinal dysfunction and gut microbiota dysbiosis, motivating the choice of both interventions.

• ASD is characterized by impairments in social communication and interaction, along with restricted, repetitive patterns of behavior
• Both FMT and KD were selected as interventions targeting the gut microbiota for ASD
• Participants were diagnosed according to DSM-5 and ADOS-2 criteria
• The study registered under NCT06348433 (03/21/2024)