People with autism often suffer from gut problems, but nobody has known why. Researchers have 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.
The study reveals 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The research brings together new results from pre-clinical animal studies with previously unpublished clinical work from a landmark 2003 study led by Swedish researchers and a French geneticist.
The study of two brothers with autism by Professor Christopher Gillberg (University of Gothenburg), Professor Maria Råstam (Lund University) and Professor Thomas Bourgeron (Pasteur Institute) was the first to identify a specific gene mutation as a cause of the neurodevelopmental disorder.
This mutation affects communication by altering the ‘velcro’ between neurons that keeps them in close contact.
While the 2003 study was 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 this 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 research, with collaborators from University of Gothenburg and Lund University (Sweden), Baylor College of Medicine (US), University of Minho (Portugal), La Trobe University, The University of Melbourne, Florey Institute of Neuroscience and Mental Health and Monash University (Australia), is published in a forthcoming edition of Autism Research (DOI: 10.1002/AUR.2127).
The work was supported with funding through an Idea Development Award from the United States Department of Defense (DoD) Congressionally Directed Medical Research Programs (CDMRP) Autism Research Program, the Victorian Government through the Operational Infrastructure Scheme, the National Health and Medical Research Council (NHMRC), and the Royal Melbourne Hospital Neuroscience Foundation.