Can chemicals produced by the gut microflora affect autism in children?
Autistic children have statistically significant differences in the concentration of certain chemicals (metabolites) produced by bacteria that live in the intestines, compared to healthy children.
Children with autism and autism spectrum disorders show statistically significant differences in the concentration of certain chemicals (metabolites) produced by bacteria living in the intestines compared to healthy children - such data have been presented during of the annual conference of the American Society for Microbiology. The results of this study provide additional evidence that changes in the composition of the gut microflora may play a role in the development of autism.
According to the study authors, scientists from the University of Arizona, most of the bacteria that live in the large intestine are helpful, help digestion, synthesize vitamins, and protect against harmful microorganisms. If excessive growth and reproduction of pathogenic bacteria occurs, then they produce an excessively high number of dangerous metabolites or upset the balance of metabolites, which can affect not only the intestines, but the entire body, including the brain.
Recently, there is growing evidence that children with autism have intestinal microflora disorders. To identify possible microbial metabolites associated with the development of autism, the researchers compared the components of fecal samples in autistic children and in healthy children. It turned out that in autistic children, there were statistically significant differences in the concentration of 7 of the 50 components studied in this study.
Most of the 7 metabolites can play a role in the development and functioning of the brain, being neurotransmitters or substances that control the biosynthesis of neurotransmitters. Researchers have suggested that microorganisms that live in the gut can change the levels of neurotransmitter metabolites, damaging information (or communication) transmission and / or causing brain dysfunction.
It turned out that in autistic children, the level of 2 metabolites - homovanillate and N, N-dimethylglycine - is statistically significantly lower than in healthy children. Homovanillate is the result of the breakdown of dopamine (one of the main neurotransmitters), which indicates an imbalance in the catabolism of dopamine. N, N-dimethylglycine is a building block for the synthesis of proteins and neurotransmitters, and this component is used to reduce the severity of symptoms in children with autism and epilepsy.
The glutamine / glutamate ratio was statistically significantly higher in children with autism. Glutamine and glutamate are then metabolized to gamma-aminobutyric acid (GABA), which is an inhibitory neurotransmitter. An imbalance between glutamate and GABA leads to the development of behavioral responses characteristic of autism, such as hyper-excitation.
Using modern sequencing technology, the researchers were also able to identify hundreds of unique families of microorganisms and proved that autistic children have very specific changes in the composition of the gut microflora.
The correlation between the intestinal microflora and the metabolites of neurotransmitters is a kind of bridge for a better understanding of the effect of changes in the intestinal microflora on the development of autism, and this fact can be a potentially useful aspect for diagnosis. and the treatment of neurological symptoms in autistic children.