HQ Team
June 29, 2023: Recent research has shed new light on the connection between autism spectrum disorder (ASD) and the body’s ‘second brain’ – the gut.
A paper, authored by a team of 43 scientists from various disciplines, has revealed the strongest link to date between gut microbes, host immunity, and genetic expression in the nervous system.
The research, which analyzed 10 existing datasets on autism and the microbiome, along with 15 other datasets on dietary patterns and gene expression profiles, reveals a consistent gut profile among individuals with ASD.
“Before this, we had smoke indicating the microbiome was involved in autism, and now we have fire,” says microbiologist Rob Knight from the University of California San Diego.
“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.”
ASD and gut issues
While the exact subtypes and underlying causes of autism are still not fully understood, the new study sheds light on a common gut profile observed among individuals with ASD. By exploring this connection, researchers hope to gain a deeper understanding of ASD and potentially develop new treatment approaches in the future for depression, Parkinson’s disease, and cancer, where the role of the microbiome is still being investigated.
Individuals with autism spectrum disorder (ASD) often face gastrointestinal issues such as constipation, diarrhea, bloating, and vomiting. Over time, researchers have been exploring the relationship between gut microbes and neurodevelopmental disorders like ASD. Some experts have argued that restricted diets due to selective eating habits in children with autism may influence the types of bacteria present in their digestive tracts.
Gut-brain axix in ASD
By analyzing a wide range of data, the study reveals significant associations among gut microbes, host immunity, brain expression, and dietary patterns in relation to ASD. The findings increase our understanding of the gut-brain axis involved in autism and provide valuable insights into the potential biological mechanisms underlying the disorder.
The gut-brain connection is still a relatively new area of research. In recent years, scientists have begun to explore the trillions of microbes residing in our guts, collectively known as the human microbiome. However, there is still much to learn about what constitutes a healthy microbiome and how it differs in atypical cases.
the current study compared existing data on the gut and ASD, using an algorithm to match autistic and neurotypical individuals based on age and sex. By considering each pair as a single data point, the researchers were able to analyze gut microbe differences across a large cohort of individuals.
The results of the study revealed significant metabolic pathways associated with diet, gene expression, and specific gut microbes that were linked to autism. Importantly, these microbial signatures aligned with those identified in a recent long-term study on fecal transplants in children with ASD, which showed sustained improvements in gastrointestinal and behavioral symptoms.
“We were able to harmonize seemingly disparate data from different studies and find a common language with which to unite them,” explains Jamie Morton, who worked on the paper as a biostatistician at the Simons Foundation, a charitable organization that funds biomedical research.
The study is published in Nature Neuroscience.