New Study Reveals Details of Gut Diversity in Children With Autism

New research shows clear different in gut bacteria between pediatric patients with autism spectrum disorder (ASD) and pediatric patients without ASD.

A team, led by Xinyan Xie, Department of Maternal and Child Health and MOE (Ministry of Education) Key Lab of Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, identified the taxonomic composition and evaluate the changes in the fecal microbiota in Chinese children with ASD.

Unclear Research

While it is known that ASD is linked to altered gut microbiota, there is little research into the altered bacterial species. The majority of studies in this space have been plagued by small sample sizes. The overall etiology of ASD is also unclear.

“Long-range interactions between the gut microbiota and the central nervous system indicate the existence of a microbiome-gut-brain axis, which may affect brain function and behavior through neural, immune and endocrine pathways,” the authors wrote.

In the new study, the investigators examined 101 pediatric patients with ASD to go along with a 103 participant control group from the Maternity and Children Health Care Hospital of Luohu district.

Sample Collection

The investigators collected fecal samples and demographic information for each participant and sequenced the V3-V4 hypervariable regions of the bacterial 16S ribosomal RNA (rRNA) gene.

The team also collected scores from the medical record system of the Childhood Autism Rating Scale (CARS), with an average score for pediatric patients with ASD of 35.22 ± 3.92

“In the present study, there was no significant difference of alpha and beta diversity between children with ASD and the control group,” the authors wrote. “We also did not observe gender-related differences in the diversity of gut microbiota among children with ASD.”

Differences

Patients with ASD had significantly higher relative abundance of Enterobacteriaceae (FDR-P <0.001) at the family level, but a significant reduction of the taxa Monoglobaceae (FDR-P = 0.009).

There were also 12 taxa peculiar in the ASD group, including Hungateiclostridiaceae, Caldicoprobacteraceae, and norank_o__norank_c__Clostridia belonging to the class Clostridia.

For the genera level, Bifidobacterium, Bacteroides, Blautia, Faecalibacterium, and Anaerostipes made up the main part of the gut microbiota in both groups.

However, after correcting for multiple comparisons, the relative abundances at the phylum level of Actinobacteria and Proteobacteria in the study group was significantly higher than those in the control group.

There was also a relative abundance of the Escherichia-Shigella genus in the case group that was significantly higher than the control group. In addition Blautia and unclassified_f__Lachnospiraceae was actually higher in the control group.

“Phylogenetic Investigation of Communities by Reconstruction of Unobserved States analysis showed that children with ASD may have disturbed functional pathways, such as amino acid metabolism, cofactor and vitamin metabolism, and the AMP-activated protein kinase signaling pathway,” the authors wrote. “This study revealed the characteristics of the intestinal flora of Chinese children with ASD and provided further evidence of gut microbial dysbiosis in ASD.”

The study, “Alteration of the fecal microbiota in Chinese children with autism spectrum disorder,” was published online in Autism Research.