Is Autism Caused by a Lack of Gut Bacteria?
A new study conducted on mice has found that the absence of a specific gut bacterium led to impaired social behaviors similar to those associated with autism.
No one knows for certain what causes some people to develop autism, but a new study from Baylor University points to a possible direction: the population of gut bacteria. The absence of a certain strain of gut bacteria caused social problems in mice, researchers found. However, social behavior greatly improved after the bacterium was introduced into the mice's guts.
The inspiration for the study came from documented data showing that many people on the autism spectrum also suffer from gastrointestinal issues. Given numerous recent studies on how diet can alter gut bacteria populations and the connection between gut bacteria and the brain, the researchers suspected there might be a relation between gut bacteria and autism.
To test the hypothesis, the researchers fed 60 female mice a high-fat diet, equivalent to a junk food-based diet in humans. When the mice became pregnant and gave birth, the pups stayed with them for only three weeks and were then switched to a regular diet. After a month, the young mice exhibited behavioral-social issues similar to those seen in cases of autism.
Next, the researchers examined the gut bacteria of the mice born to mothers who consumed a poor diet compared to regular mice. The examination revealed distinct differences in gut bacterial populations. "The findings were so consistent that merely by looking at the gut bacteria data of a specific mouse, we could predict whether its behavior would be problematic or not," says Dr. Shelly Buffington, a co-author of the study. The missing bacterium, it soon became apparent, was Lactobacillus(L.) reuteri . When a sample of this bacterium was emptied into the water the 'autistic' mice drank, their social behavior improved remarkably.
The missing gut bacterium is one that should naturally be found in humans as well. The researchers hope that in the future it will be possible to develop a probiotic containing this bacterium to treat neurodevelopmental disorders in humans, including autism.
The inspiration for the study came from documented data showing that many people on the autism spectrum also suffer from gastrointestinal issues. Given numerous recent studies on how diet can alter gut bacteria populations and the connection between gut bacteria and the brain, the researchers suspected there might be a relation between gut bacteria and autism.
To test the hypothesis, the researchers fed 60 female mice a high-fat diet, equivalent to a junk food-based diet in humans. When the mice became pregnant and gave birth, the pups stayed with them for only three weeks and were then switched to a regular diet. After a month, the young mice exhibited behavioral-social issues similar to those seen in cases of autism.
Next, the researchers examined the gut bacteria of the mice born to mothers who consumed a poor diet compared to regular mice. The examination revealed distinct differences in gut bacterial populations. "The findings were so consistent that merely by looking at the gut bacteria data of a specific mouse, we could predict whether its behavior would be problematic or not," says Dr. Shelly Buffington, a co-author of the study. The missing bacterium, it soon became apparent, was Lactobacillus(L.) reuteri . When a sample of this bacterium was emptied into the water the 'autistic' mice drank, their social behavior improved remarkably.
The missing gut bacterium is one that should naturally be found in humans as well. The researchers hope that in the future it will be possible to develop a probiotic containing this bacterium to treat neurodevelopmental disorders in humans, including autism.
