Research Summary

Gut Microbiota Profiles Differentiate ADHD and ASD in Children

Miranda Manier, BA

Key Highlights

  • Distinct gut microbiota profiles differentiate Attention Deficit Hyperactivity Disorder  (ADHD) from Autism Spectrum Disorder (ASD) with high accuracy (AUC = 0.939).
  • Probiotic supplementation significantly increased microbial diversity in children with ASD but not in those with ADHD.
  • In ASD, probiotic use reduced taxa associated with gastrointestinal symptoms and anxiety.
  • Microbiota-based therapies may offer novel interventions for managing neurodevelopmental disorders.

A recent study published in Research in Developmental Disabilities demonstrated significant differences in gut microbiota composition between children with Attention Deficit Hyperactivity Disorder (ADHD) and Autism Spectrum Disorder (ASD). Probiotic supplementation modulated the gut microbiota, particularly in children with ASD, where diversity metrics improved and potentially harmful taxa were reduced. These findings suggest the microbiome may play a distinct role in the pathophysiology and potential treatment response of these two neurodevelopmental disorders.

With increasing evidence pointing to the influence of the gut-brain axis on neurodevelopment, the gut microbiome has emerged as a potential therapeutic target for conditions like ADHD and ASD. However, comparative studies examining microbiota differences between these disorders and their response to probiotics remain limited. This study addresses that gap by investigating both baseline microbial differences and the effects of probiotic therapy.

Researchers conducted a 12-week randomized, double-blind, placebo-controlled trial involving 80 children aged 5 to 14 years (39 with ADHD and 41 with ASD). Fecal samples were collected at baseline and after intervention, and microbial analysis was performed using 16S rRNA gene sequencing to assess changes in microbiota composition. The trial aimed to determine distinguishing microbial features between ADHD and ASD and to evaluate the effects of probiotic supplementation on microbial diversity and taxa abundance.

The analysis identified 22 microbial taxa that clearly distinguished ADHD from ASD, achieving an area under the curve (AUC) of 0.939. In children with ADHD, increased levels of Clostridia, Ruminococcaceae, and Lachnospiraceae were observed, while Bacteroides, Bacilli, and Actinobacteria were more prominent in those with ASD. These microbial differences persisted even after controlling for potential confounding factors. Probiotic treatment led to significant increases in alpha diversity (Chao 1, Fisher's alpha, and Shannon indices) in children with ASD, but no significant changes were noted in alpha or beta diversity in the ADHD group. Additionally, in the ASD group, probiotics decreased the abundance of Eggerthellaceae and other taxa associated with gastrointestinal symptoms and anxiety.  Children with ADHD exhibited a reduced presence of bacteria with potential adverse effects even before intervention.

“Probiotic supplementation favorably altered gut microbiota composition, offering insights for future therapeutic strategies targeting the microbiome in neurodevelopmental disorders,” the study authors concluded.

Reference:
Novau-Ferré N, Papandreou C, Rojo-Marticella M, Canals-Sans J, Bulló M. Gut microbiome differences in children with Attention Deficit Hyperactivity Disorder and Autism Spectrum Disorder and effects of probiotic supplementation: A randomized controlled trial. Res Dev Disabil. 2025;161:105003. doi:10.1016/j.ridd.2025.105003