Research has confirmed the gut-brain connection in autism.

People with autism often suffer from gut problems, but nobody has known why. A new study has now discovered the same gene mutations – found both in the brain and the gut – could be the cause.

The discovery confirms a gut-brain nervous system link in autism, opening a new direction in the search for potential treatments that could ease behavioural issues associated with autism by targeting the gut.

Associate Professor Elisa Hill-Yardin from RMIT University said scientists trying to understand autism have long been looking in the brain, but the links with the gut nervous system have only been recently explored.

“We know the brain and gut share many of the same neurons and now for the first time we’ve confirmed that they also share autism-related gene mutations,” Hill-Yardin said.

“Up to 90 per cent of people with autism suffer from gut issues, which can have a significant impact on daily life for them and their families.

“Our findings suggest these gastrointestinal problems may stem from the same mutations in genes that are responsible for brain and behavioural issues in autism.

“It’s a whole new way of thinking about it - for clinicians, families and researchers - and it broadens our horizons in the search for treatments to improve the quality of life for people with autism.”

The study found that a gene mutation that affects neuron communication in the brain, and was the first identified as a cause of autism, also causes dysfunction in the gut.

The mutation affects communication by altering the “velcro” between neurons that keeps them in close contact.

While earlier studies focused on identifying the genetic basis for autism, Gillberg and Råstam also took detailed clinical notes of the brothers’ significant gastrointestinal problems.

Researchers in the Gut-Brain Axis team at RMIT have built on the previous clinical work with a series of studies on the function and structure of the gut in mice that have the same “velcro” gene mutation.

The team found this mutation affects:

  • gut contractions
  • the number of neurons in the small intestine
  • the speed that food moves through the small intestine
  • responses to a critical neurotransmitter important in autism (well known in the brain but not previously identified to play any major role in the gut)

The full study is accessible here.