Marie Hanson* was stretched to her limits dealing with her three kids, all of whom were diagnosed with autism. Eleven-year-old David* would spend his days fixated on repetitive rituals, like feverishly washing his hands for hours. When he got stuck on a word while reading, he would go back to the start of the sentence and read it over and over again, growing increasingly agitated until he had a total meltdown. His nine-year-old sister, Stacey*, would sob inconsolably and rock her body back and forth all day long. She wouldn’t make eye contact with people and couldn’t tell her mom what was bothering her. In the midst of all this chaos, eight-year-old Lydia* would charge her siblings and physically attack them, gouging them with her nails and swinging at them with her arms. She could carry on simple conversations, but when it came to more abstract thought, she wasn’t able to put her thoughts into words.
“I researched online for six months for something I could do to help my kids and bring stability and peace to our home,” says Hanson. “I finally read about a diet called Gut and Psychology Syndrome [GAPS].”
The GAPS diet is based on the idea that certain foods, like the starchy, sugary ones her kids love, can particularly affect young people with brain disorders. They can trigger digestive issues like constipation, which her kids were experiencing, and worsen autism behaviours, such as impairments in communication, difficulties in social situations and obsessive, rigid behaviours. Based on what Hanson read, it seemed like radically changing their diet could make a difference. She decided it was worth a shot.
While autism is mostly known as a brain disorder, in which kids struggle with language, social skills, communication and thought processing, some researchers in the medical community are turning to another part of the body for answers about the condition: the gut. Kids with autism often suffer from intestinal ailments, such as gruelling bouts of diarrhea, persistent constipation and agonizing cramps. Scientists looking to join the puzzle pieces believe that the problem is largely tied to an imbalance in the gut microbiome. The gut microbiome houses trillions of bacteria, which aid in digestion and nutrient absorption. When imbalanced, the microbiome can also contribute to conditions like inflammatory bowel syndrome and heart disease. Now, autism experts are asking if certain autism behaviours can be treated by balancing the gut microbiome through diet or probiotics.
Carbohydrates and gut health
To be clear, there aren’t many medical doctors who will recommend an extreme diet like GAPS yet. But the Kilee Patchell-Evans Autism Research Group, a non-profit research organization based in London, Ont., has been focusing on the gut microbiome and autism for years. (Its extensive work is listed among the top 50 scientific discoveries in Canada by the Natural Sciences and Engineering Research Council of Canada.)
The group is looking at refined carbohydrates, like processed sugars and starches, and what happens when they enter the gut. “Families report worsened autism symptoms and ongoing gastrointestinal issues that seem to occur after their kids eat refined carbohydrates,” says Derrick MacFabe, a neuroscientist and director of the research group, as well as a director of the American College of Nutrition.
His team learned that when these kids eat refined carbs, it appears that they feed specific bacteria in their gut. When the bacteria consume these carbs, they make short-chain fatty acids, particularly propionic acid (PPA). PPA is also found in wheat and dairy—foods that kids with autism often crave, which means that they can have a PPA overload.
In a series of studies, MacFabe and his colleagues injected rodents with PPA. Researchers found that the animals became hyperactive, had repetitive behaviours and stopped socializing. Subsequent research by the team shows that PPA affects mitochondria, the part of the cell that takes in nutrients, breaks them down and creates energy (essential for brain development and function). Separately, their research has found that PPA activates the immune genes of kids with autism, which MacFabe believes leads to increased inflammation in the brain and gut. “Collectively, these studies show that short-chain fatty acids, particularly PPA, appear to switch genes that affect brain development and function and immune and energy function on and off, all of which are associated with autism,” he says.
MacFabe doesn’t endorse any particular diet, like GAPS, at this stage, but he does think that parents of kids with autism would be wise to focus on what they’re eating. He recommends fewer total carbohydrates, especially refined sugars, such as sodas and store-bought baked goods, and processed foods. Instead, kids should eat whole grains, fruits and vegetables, as well as “good fats,” such as fish and avocados, and fermented foods like sauerkraut. Limiting their use of antibiotics is also important, says MacFabe. “Together, these practices appear to normalize the microbiome,” he says.
The GAPS diet
For families like the Hansons, who have decided to radically alter their diet, it’s no easy feat. Created by a neurologist-turned-nutritionist, the GAPS diet aims to accomplish two things. First, it sets out to repair the damaged gut lining, which allows harmful particles to enter the blood and reach the brain. Second, it aims to maintain the lining once it’s restored by decreasing bacteria that harm the lining and increasing bacteria that protect it.
Kate Hutchinson, a registered holistic nutritionist in Vancouver, has helped parents of several hundred kids with autism feed them the GAPS diet since 2008. Within a month or two, she usually sees a significant improvement in their language, eye contact, communication and ability to use the bathroom. “I have never not seen the toileting issue correct itself on this diet, and it’s usually within a month,” she says. It’s believed the signal that would normally tell the brain that the bladder is full gets interrupted due to inflammation and is now able to get through. Anecdotally, kids often become less picky eaters and experience fewer sensory issues.
To give the gut a chance to repair itself, kids on the GAPS diet begin with meat and fish broths, as well as soups and stews that are slow cooked, which breaks down nutrients and makes them easy to digest. More foods, such as eggs, vegetables, plain nuts and fermented foods, are slowly added. Among other things, GAPS excludes all grains, refined carbohydrates, refined sugars, prepackaged foods and oftentimes dairy from cow’s milk.
There is no solid research that proves the effectiveness of the GAPS diet specifically. However, some studies show improved autism symptoms with diets that, like GAPS, eliminate gluten from grains and casein from dairy and include a lot of essential fatty acids from foods like fish and nuts. But Evdokia Anagnostou, a child neurologist and autism researcher at Holland Bloorview Kids Rehabilitation Hospital in Toronto, cautions parents who want to go down this road. “Diets, particularly restrictive diets, are tricky,” she says. “Kids with autism are already very picky eaters. Then we impose further restrictions, so I worry about potentially causing nutritional deficiencies. We have no conclusive evidence so far that it normalizes the gut in a way that will help with brain and behaviours.”
Wendy Edwards, a paediatrician in Chatham, Ont., is more optimistic. She suggests that kids with autism and gastrointestinal issues at least cut out gluten and liquid cow’s milk (cheese and yogurt are often OK, she says) and then tweak their diets more if needed. She differs from Anagnostou in that she doesn’t think restrictive diets, such as the specific carbohydrate diet (which also eliminates refined carbohydrates and refined sugars, among other things) and GAPS, will cause nutrition problems if they are followed properly.
“I think both diets are fine, as they are nutritious and safe and can be helpful to the gut and autism,” she says. “But I seldom ask [parents] to try them because they are a big lifestyle change and may be more complicated than most children need for healthier guts.”
Probiotics and poo
The research into gut health and autism expands beyond diet. Researchers at Queen’s University in Kingston, Ont., are looking at whether probiotics play a role in autism. Xudong Liu, a genetics researcher and director of the Queen’s Partnership on Neurodevelopment, and his team are comparing stool samples of siblings where one has the disorder and one doesn’t to see if a particular bacteria profile increases the risk of autism for some individuals.
“The findings might lend support to explore if probiotics work for a particular group of people with autism,” he says. “Probiotics are one way to treat gut-bacteria-related psychiatric disorders, such as anxiety and depression. Since they show tremendous potential for these conditions, we anticipate that probiotics may be a solution for certain autism symptoms in some people.” Though skeptical about certain diets, Anagnostou believes that probiotics may positively alter the microbiome. She tells the parents of her patients that it’s “reasonable” to try them, though she cautions that they’re not all the same and it’s not yet known which ones may be effective.
There’s yet another avenue of exploration: transplanting stool that contains healthy bacteria into the intestines to restore the microbiome. MacFabe believes that fecal transplants may show promise. But he says a lot more research on animals is needed before properly controlled human studies can be done to determine if they are safe in autism.
For now, his focus remains on short-chain fatty acids. He thinks there may be potential to treat—or even prevent—autism by controlling production of these fatty acids or increasing their breakdown in the gut.
For many families, like the Hansons, there’s no time to wait for solid scientific evidence. It’s been more than seven years since her kids started on GAPS (the whole family does it, which has made it easier to stick with). She won’t lie—the complete lifestyle change was difficult in the beginning and, even when they got into a routine, staying on course wasn’t always easy. “I used to cave on holidays and birthdays,” she says, “but my kids’ behaviours regressed when they went off it.”
The Hansons have learned to eat and cook in different ways, making things like zucchini pancakes and pasta from beets and squash and using honey instead of sugar. Hanson saw improvements in the first few weeks on the diet, and her kids have continued to progress over time. David, now 18, who Hanson spent seven years trying to teach the alphabet, is now 150 pages into writing a Minecraft novel. “He is still several years behind academically,” she says. “But his extremely obsessive behaviours and meltdowns have stopped, so he can engage in his studies. He is also pushing through his social anxieties and has friends for the first time.”
Stacey, 16, is long past her day-long crying spells and much better at expressing herself now. “She writes her own music, is in a theatre program and has a job working with customers in a clothing store,” says Hanson. Lydia, now 15, is no longer physically aggressive. “Now, even when her siblings provoke her, she tells them calmly how it makes her feel and asks them to stop,” she says. “She listens well and is very engaged in conversations. She is in theatre, like her sister, rides horses and challenges herself in other activities that she never had the confidence to try before. The diet has given us focus and hope, so we keep going.”
*Names have been changed