Altered Gut Microbiota in Chinese Children with Autism Spectrum Disorders

Background: The results from previous studies of the link between gut microbes and autism spectrum disorders (ASD) were controversial and have not been explored in the Chinese population.

Objectives: To assess whether gut microbiota dysbiosis was associated with children with ASD in China.

Methods: We enrolled 45 children with ASD (6 to 9 years of age; 39 boys and 6 girls) and 45 sex- and age-matched neurotypical children. Dietary and other sociodemographic information was obtained via questionnaires. The composition of the fecal microbiota was characterized by bacterial 16S ribosomal RNA (16S rRNA) gene sequencing.

Results: The ASD group showed less diversity and richness of gut microbiota than the neurotypical group. The analysis of beta diversity showed an altered microbial community structure in the ASD group. After adjustment for confounders and multiple testing corrections, no significant group difference was found in the relative abundance of microbiota on the level of the phylum. At the family level, children with ASD had less richness of Acidaminococcaceae than the healthy controls (0.16% vs. 0.44%, P_FDR=0.029). Fewer organisms of the genera Lachnoclostridium (2.25% vs. 3.55%, P_FDR=0.005), Tyzzerella_4 (0.13% vs. 0.50%, P_FDR=0.002), Flavonifractor (0.08% vs. 0.16%, P_FDR=0.002), and unidentified_Lachnospiraceae (0.06% vs. 0.13%, P_FDR=0.002) were found in the ASD group than in the neurotypical group. At the species level, Clostridium_clostridioforme were more abundant in the ASD group (0.22% vs. 0.10%, P_FDR=0.005).

Conclusions: This study provides further evidence of intestinal microbial dysbiosis in ASD and sheds light on the characteristics of the gut microbiome of autistic children in China.