Gut microbiota diversity and composition in children with autism spectrum disorder: associations with symptom severity.

This study looked at gut bacteria in children with autism compared to children without autism. Researchers found that children with severe autism symptoms had very different gut bacteria compared to children with mild autism or no autism. Children with mild autism had gut bacteria more similar to children without autism. The findings suggest that gut health might be connected to how severe autism symptoms are.

This cross-sectional study examined gut microbiota diversity and composition in 46 children across three groups: neurotypical, mild ASD, and severe ASD. Researchers used high-throughput sequencing to analyze fecal samples and assessed ASD symptom severity through clinical evaluation. Key findings revealed that children with severe ASD had significantly different gut microbiota patterns compared to neurotypical children and those with mild ASD. Alpha diversity differed between severe and mild ASD groups, with severe ASD showing distinct bacterial community structures.

Mild ASD children's microbiota more closely resembled neurotypical patterns. Functional predictions indicated differences in metabolic pathways, with severe ASD associated with altered amino acid and vitamin metabolism. The study suggests gut microbiota composition correlates with ASD symptom severity.

Findings suggest gut microbiota assessment might help understand ASD symptom severity. However, more research is needed before clinical applications. Results support continued investigation of microbiome-targeted interventions, particularly for children with severe ASD symptoms.

Small sample size (46 participants), cross-sectional design prevents causal inferences, single-center study may limit generalizability, symptom assessment method not fully detailed, lacks validation of functional predictions

Autism spectrum disorder (ASD) is a prevalent neurodevelopmental disorder impairing social and communication skills. Gut microbiota has become key in understanding ASD pathophysiology. However, the relationship between the ASD symptoms and alternation of gut microbiota still remains unknow. We hypothesize that the composition of gut microbiota in children with ASD may be strongly associated with the severity of their symptoms.

Here, fecal samples from children (divided in to three groups: neurotypical, severe ASD and mild ASD) at a hospital were collected. The symptoms of ASD were assessed by an experienced pediatric neurologist, and the severity of the symptoms in children with ASD was determined based on the assessment scores. Then the diversity and composition of gut microbiota were detected by high-throughput sequencing. In total, 2,021 amplicon sequence variants (ASVs) were obtained from 46 fecal samples, with highest in the neurotypical group.

Alpha diversity in bacteria differed between severe and mild ASD. Microbiota health and dysbiosis indices varied with ASD severity. Beta diversity indicated that severe ASD differed from others, and mild ASD was closer to neurotypical in community structure. At the phylum level, Firmicutes was the dominant bacteria but abundances differed in different groups, and Ascomycota increased in severe ASD fungi.

At the genus level, groups had distinct dominants, and mild ASD microbiota resembled that of neurotypical children. Function prediction revealed differences in bacteria and fungi, with severe ASD having higher amino acid metabolism, lower cofactor/vitamin metabolism, and more undefined saprotrophs. This study revealed gut microbiota differences between ASD children (varying symptoms) and neurotypical ones, showing milder ASD closer in microbiota aspects. It offers insights for exploring ASD pathogenesis and devising interventions.