Study shows autism spectrum disorder is related to changes in the gut microbiome

According to a new study, autism spectrum disorder is associated with changes in the gut microbiome. The results of the study were published this week in mSystems, an open-access journal from the American Society for Microbiology.

Longitudinally, we were able to see that within an individual, changes in the microbiome were associated with changes in behavior. If we are going to understand the link between the gut microbiome and autism, we need more collaborative efforts across different regions and centers to get really thorough generalizable information about this relationship.”

Dr Catherine Lozupone, PhD, Study Principal Investigator and Microbiologist, Department of Medicine, University of Colorado

As part of the study, standardized DNA extraction and sequencing techniques were used to compare the composition of the gut microbiome between individuals with autism spectrum disorder and neurotypical controls in Arizona and Colorado.

The team discovered that the composition of the gut microbiome varied between individuals in Arizona and those in Colorado. Moreover, gastrointestinal symptoms were considerably higher in those with autism than those without autism in Arizona but not Colorado. The composition of the gut microbiome was largely related to autism when controlled for study-site location but not for gastrointestinal symptoms.

In addition, the team longitudinally assessed the relationship between the gut microbiome and autism behavioral severity, diet, and gastrointestinal symptoms in the individuals from Colorado.

We reached out to study participants every three months or so and had them fill out a number of checklists, one being the aberrant behavior checklist which looks at behaviors that are associated like inappropriate speech and repetitive motions.”

Dr Catherine Lozupone, PhD, Study Principal Investigator and Microbiologist, Department of Medicine, University of Colorado

“A food frequency questionnaire asked participants what they were eating in the past week. We also asked what types of GI symptoms participants were experiencing. We obtained fecal samples to look at the microbiome. We collected all this data to see how it related to each other,” added Dr Lozupone.

As part of the longitudinal analysis, the team identified that variation in the levels of lethargy/social withdrawal quantified in individuals at various time points corresponding with the degree of variation in gut microbiome composition and that a decline of inappropriate speech between time points was related to decreased gut microbiome diversity.

We need more research, but our work shows that the gut microbiome is playing a role in the provocation of symptoms in kids with autism spectrum disorder. This further supports the fact that the gut microbiome could be a valuable therapeutic target for children with autism spectrum disorders. I know that some labs have been exploring things like fecal microbiome transplant in these children and having some promising results.”

Dr Catherine Lozupone, PhD, Study Principal Investigator and Microbiologist, Department of Medicine, University of Colorado

More studies to unravel the mechanisms at play could result in new therapies for children with autism.