I first heard about the work of Dr. Derrick MacFabe in 2009, and was immediately fascinated. I’d been curious about autism for a while, having read reports on the drastic increase in diagnoses, and a medical community that shared little agreement about why this was happening. The challenges of severe and regressive autism seemed to be a particular mystery, and I wondered where we were in finding answers. Gut bacteria was a compelling new perspective.

I reached out to Dr. MacFabe and began sifting through the first portion of giant amounts of research. Looking back, I might have been a bit naive about venturing into a documentary on autism. The core difficulty in tackling this issue lies in its name: “Autism Spectrum Disorder”. As a spectrum, autism covers a vast territory. For people who live with it, autism ranges from being just one aspect of their personality, to representing a life of considerable struggle, and everything in between. What’s more, the science is just as broad; autism’s enormous complexity is worthy of a weekly program, rather than a single one-hour show, and information changes almost daily.

But, more than the challenge of the content, there was the emotion of the thing. Some of the families of those with autism struggle to understand the whys and hows, often passionately embracing theories that explain their own circumstances. And those theories are legion.

Even so, we moved forward. I may have been naive as I waded in, but I never thought there was a definitive answer. With its wide-reaching physiological symptoms touching immune-system, cell function, brain inflammation, genetic expression, metabolism, and of course gastroenterology (to name but a few), autism is a slippery fish. A film on the subject couldn’t possibly cover everything – but it could introduce a new lens through which to examine the problem. So, discovering the work around gut bacteria was a captivating way in.

And as it turned out, despite the Niagara Falls of material to wrap my head around, I really loved the science. It was, quite literally a whole new world. A bacterial cause of some forms of autism demands that we consider the humble microbe in a much grander way than most of us ever have. Research around the gut microbiome shines a light on the living creatures on us and in us that need consideration and attentive care; an entirely new eco-system whose health and balance is integral to our own. A system that, as one scientist explained, was not unlike the population of a typical big city: there are good and bad elements, and generally the good elements keep the bad in check and everything runs pretty well (in a comforting cliché, the good will always trump the bad – there just has to be enough of it). A city with more bad elements than good is dysfunctional. And so, the gut. And, so too, the rest of the body.

What got me most was that this was a fresh path in medicine; one that is so novel, yet somehow so intuitive. After all, haven’t we always known that we are what we eat? That we have to listen to our gut? All those old adages are actually somewhat revolutionary, reminding us that there is and always has been a gut-brain connection. G.I. symptoms are very common in autism, but it’s traditionally been the behaviours of autism that medicine has focused on. Now, publications are exploding with links between gut bacteria unbalance and all sorts of problems: inflammatory bowel disease, ulcerative colitis, obesity, and neuropsychiatric disorders like depression, schizophrenia, and now autism. Our “world within” is offering some incredible insights into causation, and maybe even hope for improvement.

In the end, it is the parents who have pushed this hope forward. The remarkable mothers in the film are the ones who have driven much of this bacterial theory. They represent countless other parents who have agitated for research. For me, this may have been the biggest revelation: parents who educate themselves to the highest degree so they can do the best for their kids. Ellen Bolte’s extraordinary scientific work based on her own son’s case continues to be cited in academic papers and has prompted new work on bacterial connections in autism. Never mind that she conducted her research while raising four children, one of whom is severely autistic.

These bold steps into uncharted territory – by scientists and lay people alike – were the most amazing part of working on this film, and what I think will be a crucial part of untangling the enigma that is autism.