Researchers identify link between gut microbiome and autism, potentially paving the way for new diagnostic methods

A new study uncovers a link between the gut microbiome and autism spectrum disorder (ASD), potentially paving the way for non-invasive diagnostic options for ASD patients. The reduced microbial diversity found in ASD patients may help identify biomarkers to enhance the power of genetic and behavioral tests, according to the findings published by authors from the Microbiology I Centre (MagIC) at the Chinese University of Hong Kong (HKU), China.

The ability to identify ASD from stool samples has paved the way for the development of non-invasive diagnostic options and recognized the complex characteristics of children with ASD and the need for compassionate care. Image credit: © Alexis Scholtz/peopleimages.com – stock.adobe.com

ASD is a bioneurological developmental disorder that alters the functioning of various brain regions involved in cognitive processes, social interaction, and communication. Individuals with ASD may present with a variety of comorbid conditions that significantly affect their quality of life, including feeding disorders, behavioral disorders, sensory integration dysfunction, epilepsy, and autoimmune diseases. Although individuals with ASD face developmental, social, and cognitive disabilities, they are typically good at learning and remembering detailed information, especially visual and auditory learners.^1,2

While the underlying causes of ASD are unknown, research suggests it is a combination of genetic and environmental factors that influence development. Researchers have even identified a potential link between genetic risk and cellular activity in the brain. Although incurable, ASD is highly treatable through a combination of therapeutic interventions such as behavioral and occupational therapy, along with medications that help regulate symptoms and existing comorbidities.^1,2

Gastrointestinal (GI) problems are common in patients with ASD, likely due to a strong association between GI problems and other common comorbidities in these patients, including seizures, sleep disorders and psychiatric disorders. While previous studies investigating the relationship between the gut microbiome and ASD have focused on the bacterial content of the microbiome, the HKU researchers expanded their assessment to include archaea, fungi, viruses, microbial genes and metabolic pathways to better understand the complex association between gut health and ASD.^3,4

In this study, researchers performed metagenomic sequencing of fecal samples from 1,627 children aged 1-13 years with and without ASD. 24.4% of participants were female. Findings revealed 14 Archaea, 51 Bacteria, 7 Fungi, 18 Viruses, 27 microbial genes, and 12 metabolic pathways that were altered in children with ASD. Machine learning using a single kingdom panel yielded area under the curve (AUC) values ​​ranging from 0.68 to 0.87 for distinguishing children with ASD from those without ASD.^Four

Furthermore, the panel of 31 multi-kingdom and functional markers showed high diagnostic accuracy, achieving an AUC of 0.91, with similar performance observed in boys and girls. Model accuracy was driven by the ubiquinone-7 or thiamine diphosphate biosynthesis pathways, which are less common in children with ASD. These results support the potential application of multi-kingdom and functional gut microbiota markers as diagnostic tools for ASD.^Four

Diagnosing ASD can be an invasive and extensive process, often involving medical and neurological testing, behavioral observations, cognitive and language assessments, and even blood tests to identify potential comorbid conditions. This process can be difficult and burdensome for young children with limited communication skills and sensory sensitivities, resulting in increased stress, physical discomfort and pain, and psychological distress. The ability to identify ASD in stool samples paves the way for the development of non-invasive diagnostic options for young children patients, recognizing the complex characteristics and needs that children with ASD have to receive compassionate care.

References

1. Autism spectrum disorder. National Institute of Mental HealthAccessed July 11, 2024. Autism spectrum disorder
2. Understanding the relationship between genetic risk and brain cell activity in autism spectrum disorder. Pharmacy TimesJune 6, 2024. Accessed July 11, 2024. https://www.pharmacytimes.com/view/understanding-the-connection-between-genetic-risk-and-brain-cell-activity-in-autism-spectrum-disorder
3. Nutrition, the gut-brain connection. Autism Research InstituteAccessed July 11, 2024. Treatment for Autism
4. Su Q, Wong OWH, Lu W, et al. “Multi-domain and functional gut microbiota markers in autism spectrum disorders” Nut MicrobiologyJuly 8, 2024. doi:10.1038/s41564-024-