"If those [substances] are exacerbating the problem, what if we took them out of the gut and prevented them from getting to the brain and wreaking havoc," he said.
"We think there's an underlying anxiety component that seems to be operating in a lot of kids with autism. When anybody gets anxious it manifests in all types of behaviours. In autistic kids it seems to come out in classic autism behaviours of repetitive motion and social withdrawal and things like that.
"So we think that if we can just damp down the anxiety level maybe it would have a downstream impact where some of these other manifestations are damped down as well."
Campbell said reducing anxiety had the potential to help children focus better at school and help them interact more comfortably with others.
"Maybe hold down a job. Just things that would really make a difference to their families."
But, he stressed, they were not trying to change who the kids were.
"They are very unique, special people and they have these really unique personalities but some of the symptoms just make it hard for them and we want to make that a little easier for them. "There are many parents out there who say, 'My kid doesn't need a cure. I just want to manage some of their symptoms to make my life easier and make their life easier.' "
Paediatrician and study lead Dr Rebecca Griffith said the drugs also had the potential to improve the gut function in autistic children and deal with the abdominal pain, diarrhoea and constipation which were common characteristics of the condition.
Campbell said both drugs, which came in powder form and were mixed in with food, were believed to be safe.
The probiotic was a bacteria found in the gut of half of the general population and the sponge-like medicine had been used in a similar function to treat other issues.
Autism New Zealand said very little was known about the condition so they supported exploratory research such as this which could help families.
But Altogether Autism national manager Catherine Trezona said she warned parents to treat drugs and supplements which claimed to help autistic kids to tread with caution. So far there was nothing that had been proven to work, she said.
The study would begin by testing the sponge-like drug in 25 Auckland children.
Griffith said they were still recruiting participants and anyone interested could contact Optimal Clinical Trials by emailing info@optimalclinicaltrials.com, calling 0800 RESEARCH or by clicking here to apply online.
Trial could have huge impact: parent
"Every parent [of an autistic child] is reaching for anything that's going to improve their quality of life."
That was Bridget Carter's reaction to news of the drug trial.
While her sons, Nathan, 17, and Cameron, 21, were not taking part in this trial, Carter said she supported any natural trial or development which could help autism sufferers.
Both young men were on the autism spectrum and she said anything that could help reduce the anxiety they experienced would be of huge benefit.
"It would have a high positive impact. Their anxiety manifests in different ways. People don't understand," she said.
For Nathan, less anxiety would help him be more focused on learning and be less "terrified" of leaving the house.
"I think people would be very interested, especially if it's on the natural side like a probiotic."
For many autistic children, food could have a massive effect, Carter said.
Many other parents she knew said it seemed some foods could make symptoms worse but cutting them out could be very effective so she was not surprised researchers were looking at the substances in the gut.
Her boys had never been on medication for the condition because they could not communicate when something was wrong.
But, she would consider a more natural product and said she would be interested to see the results of the trial.
Autism
• Autism is a neurodevelopmental condition that affects cognitive, sensory, and social processing, changing the way people see the world and interact with others.
• It is estimated to be present in one in 59 people.
• A person living with autism may experience challenges with social communication and interaction, have intense interests and a strong need for routines and predictability, and be hyper or hyporeactive to sensory input.
• The cognitive differences associated with autism may also contribute to specific skills such as superior visual memory, attention to detail, and pattern recognition.
Source: Autism NZ
