Intestinal bacteria may be able to overcome the symptoms of autism in mice, researchers at the California Institute of Technology have discovered. The injection of these microorganisms also made it possible to reduce gastrointestinal problems in animals, the same ones experienced by people suffering from autism.
Previous studies have shown that people with autism experience more intestinal problems and that these are linked to greater permeability of the intestinal walls. Microbiologist Sarkis Mazmanian and neuroscientist Elaine Hsiao wanted to see the role that bacteria can play in the body of people with autism.
The researchers identified the bacteria present in the intestines of mice. They then discovered that rodents with autism symptoms have less of a bacteria called Bacteroides fragilis that is found naturally in the intestines of healthy mice. When the researchers fed the mice with this bacterium, the animals behaved normally and their gastrointestinal complaints improved.
They then showed that autistic mice had an abnormally high blood level of a metabolite, an organic compound called 4-ethylphenylsulphate, compared to control mice. The researchers tested this hypothesis by administering this substance to healthy mice. These subsequently presented with symptoms associated with autism.
A link between bacteria and autism to dig
These experiments tend to prove that there is a link to be explored between bacteria, metabolite and behavioral disorders.
“Several studies have shown that the intestinal flora can influence several behaviors, from anxiety, to pain, and to emotional sensitivity, explains Elaine Hsiao. Our study is the first to establish that it can play on the behaviors associated with autism”.
Although several studies have touted the benefits of probiotics present in yoghurts for prevent autism disorders, Californian researchers remain cautious. Further studies are needed to confirm the interest of intestinal bacteria.
