Autism rates have jumped from 1 in 10,000 people 50 years ago, to 1 in 68 today.

Research at Western University and around the world, is closing in on the complexities of autism.

A large international study published Tuesday has some intriguing findings on autism and the age of the parents at the time of the child's birth.

As well, Western research is showing promise in a different area.

The international autism study looked at five million kids from Denmark to Australia, building on previous research showing a link with children of older parents. About 30,000 of the children had autism.

Researchers found autism rates were higher in kids born to dads over the age of 50 than those born to men in their 20s.

The rate was 15 per cent higher in children born to mothers in their 40s, compared to women in their 20s.

The study also found the rate was 18 per cent higher among kids born to teen mothers than those in their 20s.

It also found rates were highest when the fathers’ ages were between 35 and 44 and their partners were 10 or more years younger.

Rates were also high when the mothers were in their 30s and their partners were 10 or more years younger.

But factors like genetics and parental age are only part of the equation. 

“What we're trying to do is bring together all this different, disparate views of autism – immune, imflammation, gene expression, brain development, behaviour, early risk factors – into something cohesive to work with everyone else,” says Derrick MacFabe, director of the Kilee Patchell-Evans Autism Research Group in London.

He’s also looking at another factor – bacteria.

“What we've initially been working with are the products of the gut bacteria that are associated with autism. And the fermentation products, believe it or not, in our 10 years of work, we've shown that they produce all the behaviours of autism in animals, but they also cause all the brain immune inflammatory changes and even turn on and off autism related genes.”