New hope for autism

The incidence of autism in the US has increased by 78 per cent in the past decade, affecting one in 88 children nationwide. Traditional research has studied autism as a genetic disorder affecting the brain, but recent studies have demonstrated links between various physiological markers and the condition.

In 2009, studies at Arizona State University showed a correlation between the severity of autistic symptoms and levels of toxic heavy metals, including lead, thallium, tin and tungsten, in the urine of children aged three to eight years. Symptoms reduced after the metals were removed from the body by treatment with dimercaptosuccinic acid.

More recent research has shown that many autistic patients suffer gastrointestinal disorders. Studies in a mouse model of autism, published recently in the journal Cell, showed that autistic mice exhibited gastrointestinal abnormalities, in particular a condition known as intestinal permeability, which allows abnormal passage of substances through the gut wall and into the bloodstream.

The mice were treated with oral doses of Bacteroides fragilis, a bacterium used in probiotic therapy, which alters the gut flora. It was found that after treatment, the permeability was corrected. Furthermore, the mice’s behaviour was also altered. In particular, they were more likely to communicate with each other, and less likely to display repetitive behaviour such as digging. In other words, behaviour associated with autism was reduced.

The researchers are now planning to trial a form of this probiotic treatment on behavioural symptoms in human autism within the next two years.

Autism is a heterogeneous disorder, and the ratio between genetic and environmental factors will differ between patients. Diagnosis and treatment may not be universal, but by studying various physiological markers, treatments could be developed which improve the quality of patients’ lives after the onset of symptoms in childhood.