Trayt Community Perspective: Autism and the Brain-Gut Connection

April Hishinuma, Trayt Cognitive Scientist and Research Analyst

April Hishinuma, Trayt Cognitive Scientist and Research Analyst

“Some medical experts are starting to call the gut the “second brain”, and with good reason. Not only do the tens of trillions of microorganisms in the gut weigh roughly the weight of a human brain (2-5 pounds), but these important, tiny microbiota also influence our health and mood in ways we never understood before. One condition in particular that has shown a causal relationship between the brain-gut connection is Autism Spectrum Disorder (ASD).

Currently about one child in 59 is diagnosed with ASD, and the prevalence of ASD in America is still on the rise. Researchers think that the gut may be a main culprit. Children with autism are missing hundreds of thousands of bacterial species compared to “neurotypical” children. This may explain why roughly 30-50% of children with ASD have chronic gastrointestinal (GI) problems, which can negatively impact behavior due to discomfort.  A research group at Arizona State University restored the balance in the gut biome of 18 children with severe ASD using microbiota transfer therapy (MTT). MTT is a process that delivers prepared doses of fecal bacteria from a healthy individual to a patient either orally or rectally. The drastic change in gut bacteria after ten weeks of treatment led to significant behavioral changes, and gradually reduced autistic symptoms. After two years, 8 of the 18 original study participants were no longer considered on the spectrum. A recent study led by a team at California Institute of Technology also demonstrated this behavioral link between the gut biome and autism in rodents. It further showed that it was the lack of gut bacteria that aided in the production of the neurotransmitter gamma-aminobutyric acid (GABA) which increased the severity of autistic symptoms. However, the exact mechanism still remains a mystery. 

Whether or not the gut-brain connection can alleviate certain autistic behaviors is still unclear, but the evidence is growing. Specific diets in the future may be able to target and treat neurodevelopmental, anxiety, and stress-related symptoms. What is certain is that every individual has a unique gut microbiota, which may affect behavior and emotion. By eating a balanced diet full of whole grains, lean meats, fish, fruits, vegetables, and probiotics, we can better manage our gut health and increase our well being. Although more research is needed to be done, we can take still steps to feed our “second brain” a nutrient rich diet to grow a healthy mind.”  

-April Hishinuma, Trayt Cognitive Scientist and Research Analyst