Latest News » The link between gut microbes and autism

What is the gut-brain connection with autism?

What is the gut-brain connection with autism?

Autism spectrum disorder is the overarching term for a variety of developmental disorders affecting a large number of people across the country. According to Centers for Disease Control and Prevention, estimates, 1 in 68 children fall somewhere on the ASD spectrum. As research is still ongoing, the CDC does not have definitive numbers as of yet whether ASD prevalence is stabilizing or continuing to grow.  

The crucial connection between the gut and ASD
For years, research has indicated that there may be a critical connection between gut and brain, specifically in regards to ASD. For example, gastrointestinal disorders are one of the most common medical conditions associated with ASD, and these symptoms range anywhere from inflammatory bowel conditions to chronic gut irritation. Meanwhile, the CDC found that children suffering from ASD were 3.5 times more likely to experience constipation or diarrhea than their peers.

Certain experts even suggest that toxins generated due to abnormal gut bacteria may worsen or even trigger autism symptoms in children. While this hypothesis is yet unproven, researchers continue to investigate the crucial connection between ASD and gut microbes. Many recent studies have sought to lessen – or even eradicate – autism symptoms by targeting these gut microbes.

New studies into the gut-brain connection
One recent study, "Blood–brain barrier and intestinal epithelial barrier alterations in autism spectrum disorders," published in Molecular Autism, sought to find whether an altered blood-brain barrier can "be part of the chain of events" leading to the development or worsening of ASD. The researchers concluded that in an ASD brain, there is the possibility of an altered set of genes regarding BBB integrity, along with an increase in neuroinflammation and leaky-gut syndrome. 

"This study is part of a project aimed at testing our working hypothesis about the pathophysiology of ASD, which proposes that the combination of gut microbial dysbiosis, increased gut permeability, and the passage of nonself antigens and/or activated immune complexes through an impaired BBB interferes directly with the function of the central nervous system of ASD," Dr. Fiorentino explained to MedScape.

In another study published recently in Microbiome, the authors based their research on previous studies that found significant ties between ASD and gut microbe diversity. In the course of their work, researchers attempted to make the gut microbes of children with ASD resemble that of children without ASD. Using fecal microbial transplants, the researchers hoped the treated children's microbiome could change and certain ASD symptoms may lessen or disappear. 

The research participants involved 18 children aged seven to 16 with ASD. All children took part in the 10-week treatment course, which necessitated bowel cleansing, daily fecal microbial transplants and antibiotics. After the study, the participants experienced a 80 percent improvement of their GI symptoms and 20 to 25 percent improvement in their ASD behaviors, particularly in regard to sleeping habits or social skills. 

"This is very exciting work that illustrates how we can transition from observations relating the gut microbiome and disease toward actions that can be taken to improve human health," said Rob Knight, director of the Center for Microbiome Innovation at the University of California San Diego. However, researchers concluded that this treatment plan still has a long way to go.

Despite the promising results of the study, Rosy Krajmalnik-Brown, co-lead author of the project and associate professor at ASU, explained that parents and guardians should still consult their primary care physician, as "improper techniques can result in severe gastrointestinal infection." The study's authors concluded that further research must be conducted to determine whether this treatment could be effective for all who need it. Additionally, more testing must take place before the researchers can submit their findings for FDA approval.

To browse our selection of digestive support supplements, click here.