A new study has revealed consistent biological signals in the human microbiome and other physiological signals associated with autism.
The research highlights the need for long-term studies to determine autism’s underlying causes.
Taking a new computational approach to the problem, a study published in Nature Neuroscience has shed new light on the relationship between the microbiome and autism.
The research – which originated at the Simons Foundation’s Autism Research Initiative (SFARI) – aligns with a recent, long-term study of autistic individuals that centred on a microbiome-focused treatment intervention.
“We were able to harmonise seemingly disparate data from different studies and find a common language with which to unite them. With this, we were able to identify a microbial signature that distinguishes autistic from neurotypical individuals across many studies,” said Jamie Morton, one of the study’s corresponding authors.
With 43 authors, this study brought together leaders in computational biology, engineering, medicine, autism and the microbiome who hailed from institutions in North America, South America, Europe and Asia.
“The sheer number of fields and areas of expertise in this large-scale collaboration is noteworthy and necessary to get a new and consistent picture of autism,” says Rob Knight, the Director of the Center for Microbiome Innovation at the University of California San Diego and a study co-author.
The computational study
In the new study, the research team developed an algorithm to re-analyse 25 previously published datasets containing microbiome and other ‘omic’ information – such as gene expression, immune system response and diet – from both autistic and neurotypical cohorts.
Within each dataset, the algorithm found the best matched pairs of autistic and neurotypical individuals in terms of age and sex, two factors that can typically confound autism studies. Their approach enabled them to reliably identify microbes that have differing abundances between ASD and neurotypical individuals.
Analysis identified autism-specific metabolic pathways associated with particular human gut microbes. Importantly, these pathways were also seen elsewhere in autistic individuals, from their brain-associated gene expression profiles to their diets. “We hadn’t seen this kind of clear overlap between gut microbial and human metabolic pathways in autism before,” said Morton.
The research showed an overlap between microbes associated with autism, and those identified in a recent long-term faecal microbiota transplant study at Arizona State University’s Biodesign Center for Health Through Microbiomes.
“Before this, we had smoke indicating the microbiome was involved in autism, and now we have fire. We can apply this approach to many other areas, from depression to Parkinson’s to cancer, where we think the microbiome plays a role, but where we don’t yet know exactly what the role is,” said Knight.