Researchers Identify Links Between Gut Microbiome and Autism, Potentially Paving the Way for New Diagnostics

A new study has identified associations between the gut microbiome and autism spectrum disorder (ASD) that may pave the way for noninvasive diagnostic options for patients with ASD. The findings, published by authors from the Microbiota I-Center (MagIC) at the Chinese University of Hong Kong (HKU) in China, indicate that the observed reduced microbial diversity in patients with ASD may help to identify biomarkers that strengthen the abilities of genetic and behavioral tests.

The ability to identify ASD through a fecal sample paves the way for the development of noninvasive diagnostic options, acknowledging the complex characteristics and needs of children with ASD to receive compassionate care. Image Credit: © Alexis Scholtz/peopleimages.com - stock.adobe.com

ASD is a bio-neurological developmental disorder that alters the functioning of various brain regions involved in cognitive processes, social interactions, and communication. Patients with ASD may present with various comorbidities such as feeding disorders, behavioral disorders, sensory integration dysfunction, epilepsy, and autoimmune disorders, which greatly impact quality of life. Despite the developmental, social, and cognitive disruptions faced by patients with ASD, they typically excel in learning and remembering detailed information and are especially strong visual and auditory learners.^1,2

The underlying cause of ASD is unknown; however, studies suggest it is a combination of genetic and environmental factors that impact development. Researchers have even identified potential associations between genetic risk and cellular activity in the brain. Although incurable, ASD is very treatable with therapeutic interventions, such as behavioral and occupational therapies, paired with medications to help regulate symptoms and existing comorbidities.^1,2

Gastrointestinal (GI) issues are common in individuals with ASD, potentially due to the strong associations between GI issues and seizures, sleep disorders, and psychiatric problems, which are other prevalent comorbidities in these patients. Prior studies investigating the link between the gut microbiome and ASD have focused on the bacterial content of the microbiome; however, the investigators from HKU expanded their assessment to include archaea, fungi, viruses, microbial genes, and metabolic pathways to better understand the complex associations between gut health and ASD.^3,4

In the study, the investigators performed metagenomic sequencing on fecal samples from 1627 children aged 1 to 13 years with or without ASD. Of the participants, 24.4% were female. Their 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 single-kingdom panels achieved area under the curve (AUC) values ranging from 0.68 to 0.87 in distinguishing children with ASD from children without ASD.⁴

Additionally, a panel of 31 multi-kingdom and functional markers demonstrated high diagnostic accuracy, achieving an AUC of 0.91, with similar performances observed among boys and girls. The model’s accuracy was driven by the biosynthesis pathways of ubiqional-7 or thiamine diphosphate, which were less prevalent in children with ASD. These findings support the potential application of multi-kingdom and functional gut microbiota markers as diagnostic tools for ASD.⁴

ASD diagnosis can be an invasive and extensive process, often involving medical and neurological exams, behavioral observations, and cognition and language assessments, as well as blood tests, to identify potential comorbidities. This process may be difficult and overwhelming for young children with limited communication capabilities and sensory sensitivities, resulting in elevated stress, physical discomfort or pain, and emotional distress. The ability to identify ASD through a fecal sample paves the way for the development of noninvasive diagnostic options for young patients, acknowledging the complex characteristics and needs of children with ASD to receive compassionate care.

REFERENCES

1. Autism spectrum disorder. National Institute of Mental Health. Accessed July 11, 2024. https://www.nimh.nih.gov/health/topics/autism-spectrum-disorders-asd
2. Understanding the connection between genetic risk and brain cell activity in autism spectrum disorder. Pharmacy Times. June 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 and the gut-brain connection. Autism Research Institute. Accessed July 11, 2024. https://autism.org/nutrition-gut-brain-connection/
4. Su Q, Wong O.W.H., Lu W, et al. Multikingdom and functional gut microbiota markers for autism spectrum disorder. Nat Microbiol. July 8, 2024. doi: 10.1038/s41564-024-