Intestinal Bacteria May Be Key to Autism
- Minhoo Jeong
- 2 hours ago
- 2 min read
Aug 22, 2025
Minhoo Jeong
ASD is a typical developmental disorder affecting sociality, communication, and behavioral development. Although the prevalence rate is so high that one in 30 children suffers from the disease, the exact cause of the disease has not been identified yet. This means that there is no fundamental treatment. Until now, it has been known that ASD is caused by genetic factors, but recently, the 'intestinal brain axis' theory that intestinal microorganisms and immune responses affect brain function and behavior has attracted attention. There are 10 times more bacteria in the human body than in human cells. According to clinical studies, ASD patients tend to have a different intestinal microbial composition than the general public. About 90% of ASD patients suffer from gastrointestinal disease.
The research team developed the world's first genetically modified ASD mouse model that was grown aseptically. Analysis of the mouse model showed no abnormalities in ASD-specific behaviors in the absence of intestinal microbes. The research team said it proved that intestinal microbes are essential factors in the development of autism symptoms. The research team revealed that intestinal microorganisms promote the inflammatory response of immune cells in the brain and that certain inflammatory T cells play an important role in autism. Blocking the inflammatory immune pathway has reduced neuroinflammation and alleviated behavioral abnormalities, proving to be a new mechanism linking the intestinal-immune-brain.
According to the research team's detailed analysis, intestinal microorganisms affected brain function by changing the balance of neurotransmitters glutamate and GABA. Glutamate and GABA balance is essential for brain stimulation and inhibition signal harmony. When the balance is broken, abnormalities in behavior and cognitive functions occur.
The research team developed an artificial intelligence (AI) based metabolite prediction model that predicts metabolite production and absorption capacity by analyzing probiotic (beneficial microorganism) candidate genomes. Through this, they discovered "L. reuteri IMB015," a probiotic strain that absorbs glutamate and produces Gabba. Administration of Lactobacillus reuteri to rats restored metabolic balance, reduced neuroinflammation, and prevented ASD-related behavioral abnormalities.
Professor Im Jae-hyuk said, "We have set a turning point in looking at autism as an immune-nervous system disease that can be managed through intestinal microbial control, not just a genetic disease." The findings were published in the international journal Nature Communications.
