Submission + - SPAM: Gut bacteria may contribute to autism symptoms, mouse study finds
Suren Enfiajyan writes: Genetic factors play an important role in Autism but some researchers suspect that gut bacterias also have a significant influence. It reveals that mice develop autism-like behaviors when they are colonized by microbes from the feces of people with autism. The result doesn’t prove that gut bacteria can cause autism. But it suggests that, at least in mice, the makeup of the gut can contribute to some hallmark features of the disorder.
Many studies have found differences between the composition of the gut microbiomes in people with and without autism. But those studies can’t determine whether a microbial imbalance is responsible for autism symptoms or is a result of having the condition.
To test this, researchers put fecal samples from children with and without autism into the stomachs of germ-free mice, which had no microbiomes of their own. The researchers then mated pairs of mice colonized with the same microbiomes, so their offspring would be exposed to a set of human microbes early in development. Compared with mice colonized with bacteria from children without autism, the mice that inherited a microbiome from a child with autism were less social and showed more repetitive behavior.
When the researchers looked at the contents of the mouse guts, they found differences between the two groups in the levels of 27 metabolites. In particular, mice harboring microbes from people with autism had lower levels of taurine and 5-aminovaleric acid (5AV), molecules that are known to bind to neurons and inhibit their activity. That finding fits with the theory that an imbalance between excitatory and inhibitory signals in the brain might underlie autism.
These results are unlikely to yield new microbiome-based treatments right away. The two metabolites highlighted in this study might turn out to be irrelevant to autism in people. Still, the research justifies a hunt for other metabolites deficient in the gut or brain of people with the disorder, he says. “This will give encouragement to the field that there is something there.”
Link to Original Source
Many studies have found differences between the composition of the gut microbiomes in people with and without autism. But those studies can’t determine whether a microbial imbalance is responsible for autism symptoms or is a result of having the condition.
To test this, researchers put fecal samples from children with and without autism into the stomachs of germ-free mice, which had no microbiomes of their own. The researchers then mated pairs of mice colonized with the same microbiomes, so their offspring would be exposed to a set of human microbes early in development. Compared with mice colonized with bacteria from children without autism, the mice that inherited a microbiome from a child with autism were less social and showed more repetitive behavior.
When the researchers looked at the contents of the mouse guts, they found differences between the two groups in the levels of 27 metabolites. In particular, mice harboring microbes from people with autism had lower levels of taurine and 5-aminovaleric acid (5AV), molecules that are known to bind to neurons and inhibit their activity. That finding fits with the theory that an imbalance between excitatory and inhibitory signals in the brain might underlie autism.
These results are unlikely to yield new microbiome-based treatments right away. The two metabolites highlighted in this study might turn out to be irrelevant to autism in people. Still, the research justifies a hunt for other metabolites deficient in the gut or brain of people with the disorder, he says. “This will give encouragement to the field that there is something there.”
Link to Original Source
