A new study associates autism spectrum disorder with an alteration of the intestinal microbiome in children

Researchers in China have looked at the role in autism of a broader range of gut microorganisms, such as archaea, fungi and viruses, beyond the bacteria studied. The work reveals specific metabolic changes and identifies 31 markers for early diagnosis, paving the way to develop personalized treatments.

The relationship between intestinal microbiome and autism spectrum disorder (TORCH) is not new, but previous research has focused on changes in the composition of intestinal bacteria in affected people compared to individuals considered neurotypical.

In fact, until now it was unclear whether other members of the gut microbiome, such as archaea, fungi and viruses, as well as the specific role of this flora (or the genes present), were altered.

Now, a new study developed at the Chinese University of Hong Kong points out how certain bacterial and non-bacterial components of the intestine and their certain functions could contribute to this disorder in the pediatric population. The results, published in Nature Microbiology, coincide with those of previous works and show a lower microbial diversity in autistic people.

"Understanding which microbes are imbalanced in the affected childhood population could pave the way for developing non-invasive diagnostic tools and personalized treatments"

Qi Su (Hong Kong University)

“This study sheds light on how the intestinal microbiome – made up not only of bacteria, but also fungi and viruses – can influence autism,” he explains to SINC. Qi Su, author of the work, who adds: “By identifying specific changes in children, possible early markers are suggested to diagnose it.”

The researchers performed metagenomic sequencing of fecal samples from 1.627 boys and girls with or without ASD between 1 and 13 years old from five cohorts from China, and analyzed these data along with additional factors such as diet, medication, and comorbidity.

After evaluating all the information, the authors identified 14 archaea, 51 bacteria, 7 fungi, 18 viruses, 27 microbial genes and 12 altered metabolic pathways, offering significant improvements over previous studies that adjusted for bacterial components.

“Simple tests such as analyzing stool samples could help doctors diagnose ASD in the future,” says Su, “and understanding which microbes are imbalanced in the affected child population could pave the way to developing non-invasive diagnostic tools –essential for the little ones– and custom treatments".

Great potential for diagnosis

In this work we used automatic learning, specifically a method called Random Forest, to analyze data collected from children with and without ASD. “Imagine you have a big puzzle, and each piece represents different aspects of the gut microbiome, such as bacteria, viruses and fungi. Random Forest tries to find patterns or differences between children,” says Su.

“Through its use, we were able to identify specific microbial markers, which helps us understand how the gut microbiome could be related to ASD and opens new possibilities for diagnosing and potentially treating it in the future,” he continues.

The team created a model based on a panel of 31 microbes and functions, which had greater diagnostic accuracy in identifying affected boys and girls compared to those that included a single kingdom (such as bacteria or archaea).

"The authors suggest that these 31 markers could have clinical diagnostic potential given their reproducibility."

The authors suggest that these 31 bookmarks could have clinical diagnostic potential given their reproducibility in multiple cohorts. “Early detection would allow earlier intervention strategies, crucial to improve outcomes in children with autism by starting therapies and treatments at younger ages, when brain plasticity is greater,” says the expert.

These markers could also serve as indicators to monitor the effectiveness of treatments. By monitoring changes in the composition of the intestinal microbiome Over time, doctors could evaluate whether individual interventions such as dietary changes or probiotic (beneficial bacteria) supplements effectively restore a healthy balance of the microbiota.

“If these microbial markers are further investigated, more details could be uncovered about the mechanisms linking gut flora and ASD, leading to the development of new therapies targeting the gut-brain axis. These advances promise to achieve earlier diagnosis, personalized treatments and better monitoring of results,” Su insists.

More research to validate the findings

Although these results could represent a great step towards improving diagnostic methods for ASD, the authors emphasize that they cannot be evaluated no causal role of the microbiota in the development of autism.

Furthermore, it is necessary to repeat the study in other groups and populations around the world to validate the results. “While our model shows good performance across all ages, genders and cohorts, there could be the possibility of unmeasured factors potentially leading to inflated performance, so independent validation needed by third parties before clinical application,” concludes Su.

«Although these results could represent a great step towards improving the diagnosis for ASD, no causal role of the microbiota in the development of autism can be evaluated»

Source: Travel SINC

Reference: Qi Su et al. 'Multityping and functional gut microbiota markers for autism spectrum disorder'. Nature Microbiology (2024)