Alteration of the gut microbiota profile in children with autism spectrum disorder in China Original paper

What was studied?

This original research article examined alteration of the gut microbiota profile in Chinese children with autism spectrum disorder (ASD). The authors used 16S rRNA sequencing to compare gut microbiome composition between ASD and healthy controls, focusing on microbial diversity, taxonomic shifts, and microbial functional pathways. The study directly addresses the gut microbiota–ASD connection by identifying distinctive microbial patterns and metabolic pathway alterations that may serve as early microbial signatures of ASD. The paper provides one of the largest datasets from China, offering microbiome signatures relevant for clinical interpretation and database integration.

Who was studied?

A total of 1,118 children aged 2–12 years participated, including 957 with clinically confirmed ASD and 161 healthy controls. Children with ASD were recruited across 12 Chinese provinces, and diagnoses were based on DSM-5 criteria. Controls were drawn from local schools and screened for psychiatric conditions. No participant had taken antibiotics, probiotics, antipsychotics, or prebiotics within the month before sampling. Fecal samples were collected under standardized low-temperature conditions to preserve microbial integrity.

Most important findings

The ASD group demonstrated significantly reduced alpha diversity, highlighted by lower Shannon, Simpson, and Chao1 indices shown in the diversity plots on page 4. β-diversity analysis revealed clear group separation, indicating consistent microbiome divergence in ASD children. At the phylum level, ASD samples exhibited increased Firmicutes and reduced Bacteroidetes, resulting in a markedly lower Bacteroidetes/Firmicutes ratio (0.54 vs. 0.89). At the genus level, several taxa were significantly enriched in ASD, including Faecalibacterium, Blautia, Eubacterium_eligens_group, Parasutterella, Veillonella, and Lachnospiraceae_NK4A136_group. Conversely, Prevotella 9, Agathobacter, and Alistipes were depleted—consistent with prior associations linking lower Prevotella abundance to impaired polysaccharide fermentation and reduced succinate-mediated immune modulation. Species-level differences included higher Bacteroides fragilis and reduced B. coprocola, B. plebeius, B. stercoris, and Parabacteroides merdae. The LDA plot on page 7 highlights these taxa as potential ASD biomarkers. Co-occurrence networks showed markedly increased connectivity in ASD, suggesting an unstable microbial ecosystem with elevated cross-taxa correlation. Functionally, KEGG analysis revealed significant enrichment of metabolic pathways involved in branched-chain amino acid synthesis, fatty-acid biosynthesis, lysine biosynthesis, aromatic compound metabolism, and partial neurotransmitter-related pathways. Pathways related to one-carbon metabolism and carbon fixation were reduced. These shifts highlight metabolic environments potentially relevant to neurodevelopment.

Key implications

This study identifies a distinct gut microbiome signature in Chinese children with ASD, characterized by reduced diversity, increased Firmicutes-dominant taxa, depletion of key saccharolytic genera, and altered microbial metabolic pathways. These findings support the microbiota–gut–brain axis as a contributor to ASD-related physiology and behavior. The microbial patterns described provide potential non-invasive biomarkers for ASD screening and may guide therapeutic strategies targeting microbial restoration or metabolic modulation. The large sample size strengthens the generalizability of these microbial signatures for inclusion in clinical microbiome databases.

Citation

Li H, Guo W, Li S, Sun B, Li N, Xie D, Dong Z, Luo D, Chen W, Fu W, Zheng J, Zhu J. Alteration of the gut microbiota profile in children with autism spectrum disorder in China. Frontiers in Microbiology. 2024;14:1326870. doi:10.3389/fmicb.2023.1326870