Gut microbiota composition and phylogenetic analysis in autism spectrum disorder: a comparative study

Area of Science:

• Microbiome research
• Neurogastroenterology
• Metabolomics

Background:

• Autism spectrum disorder (ASD) is linked to gastrointestinal (GI) issues, with the gut microbiota and short-chain fatty acids (SCFAs) playing a potential role via the gut-brain axis.
• The exact relationship between gut microbes and SCFAs in ASD is debated, requiring integrated analysis to understand these connections.
• This study investigates gut microbiota composition and its impact on SCFA production in children with ASD compared to controls, exploring links to GI symptoms and neurodevelopmental outcomes.

Purpose of the Study:

• To analyze the intestinal microbiota composition in children with autism spectrum disorder (ASD).
• To assess the influence of gut microbiota on short-chain fatty acid (SCFA) production in ASD.
• To explore the relationship between gut microbial profiles, SCFA production, GI symptoms, and neurodevelopmental outcomes in ASD.

Main Methods:

• 16S rRNA gene sequencing was used to analyze fecal samples from 38 children with ASD and 33 controls (aged 4-12 years).
• Microbial diversity, taxonomy, and predicted functions were assessed using QIIME2, MetagenomeSeq, and LEfSe.
• Short-chain fatty acid (SCFA) production was inferred from taxonomic composition and microbial abundance analysis.

Main Results:

• Children with ASD exhibited reduced microbial alpha diversity and distinct beta diversity compared to controls.
• ASD samples showed a depletion of Firmicutes and an enrichment of Bacteroidetes.
• Predicted metabolic pathways indicated lower butyrate and higher acetate/propionate production in ASD, with diminished microbial connectivity.

Conclusions:

• Microbial dysbiosis in ASD appears to alter SCFA profiles, potentially increasing butyrate and propionate levels.
• These microbial and metabolic shifts may contribute to gastrointestinal and neurological symptoms in ASD.
• Findings support microbiota-targeted interventions, such as probiotics, as potential therapeutic strategies for ASD.