Soluble Fiber May Improve Constipation and Irritability In Children Diagnosed With Autism Spectrum Disorder

Most children diagnosed with autism spectrum disorder (ASD) also have chronic digestive issues1 such as leaky gut and constipation – because their gut bacteria (microbiome) are out of balance.

Soluble Fiber May Improve Constipation and Irritability In Children Diagnosed With Autism Spectrum Disorder

As parents know, these gut disorders often lead to a child’s irritability. The good news is that scientists are now finding that simply increasing soluble fiber intake may improve both constipation and irritability in children diagnosed with ASD.

Soluble fiber, also known as prebiotic fiber, is found in some fruits and vegetables, as well as nuts, seeds, beans and as a dietary supplement.

I’ll talk more about how to increase soluble fiber intake later. First, let’s look at why we may be seeing this benefit in children diagnosed with ASD.

Our mood and behavior are affected by what lives in our gut

The good bacteria in your gut create most of the serotonin, dopamine and other neurotransmitters responsible for your mood. This “conversation” between the gut and brain is part of what scientists call the gut/brain axis.

Autism is a classic gut/brain dysfunction disease. When the gut has an imbalance of the wrong kinds of bacteria, it sends improper signals to the brain. That can show up as irritability and behavior issues. So, the question becomes: How can we change the gut bacteria so the child feels and behaves better?

Soluble fiber’s role in nutritional research

Researchers are excited about soluble fiber because it feeds the gut’s good bacteria. It also helps to create a healthier microbiome balance in the gut. Plus, soluble fiber helps manage occasional constipation. The theory is that when you use soluble fiber to support gut health, mood and behavior might also improve.

Ten years ago, scientists may have considered this idea absurd. Yet today, this is a promising area of clinical research. Early published studies have recently found a connection between soluble fiber intake and management of ASD symptoms.

In one pilot study published in the Journal of Clinical Biochemical Nutrition3, researchers at the Kyoto Prefectural University of Medicine supplemented the diets of 13 children diagnosed with ASD with 6 grams/day of guar fiber, a soluble fiber widely available in the US as an ingredient known as Sunfiber.

The children – one girl and 12 boys – ranged from four to nine years old. By the end of the first week, all the children experienced some constipation relief. They went from defecating once or twice a week to being able to go two to four times a week. Their irritability – measured on a standardized scale – also improved significantly.

These researchers found that this modest dose of guar fiber reduced what’s called serum inflammatory cytokines, which are one way the gut signals the brain to influence mood and behavior.

Overall, I’m excited that this one study produced results on three levels: tangible (less constipation); biomarker (fewer inflammatory cytokines) and behavioral (less irritability). Another soluble fiber, Galacto-Oligo-Saccharides, is also showing promising results in this area of study.

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How to sneak more soluble fiber into your child’s diet

Pile on the berries.

Raspberries, blackberries and blueberries are rich in fiber. Sprinkle berries on their yogurt, pudding or gelatin. Add berries to their favorite breakfast cereal to double or even triple its fiber content.

Give your child popcorn and nuts as snacks.

Two cups of popcorn contain two grams of fiber, four times the amount of fiber in their favorite cheesy crackers. Add some nuts – almonds, pecans and walnuts are highest in fiber – to really rev up this snack’s fiber content.

Add Sunfiber to their favorite recipes.

Mix a scoop or two of this soluble fiber supplement into your pancake batter, cookie dough or pasta sauce. It won’t change the food’s color, odor, flavor or texture. This helps your little ones get more fiber without any fuss. Plus, it’s all-natural and 100% gluten free. Sunfiber is available over-the-counter as a stand-alone product and in numerous non-prescription formulas including MentaBiotics and Regular Girl.

Add chia seeds to smoothies.

Chia is also high in brain-healthy omega-3s.

Involve the kids in the kitchen by making Maple Spiked Chocolate Hummus.

Even younger children can help you put all the ingredients into the food processor. The link to the recipe is below.

Remember that fiber isn’t just important for children. It is important for everyone’s overall health. Most of us only get somewhere between 15 and 18 grams of fiber daily. We should aim for at least 28 grams (and probably a lot more for optimal health). Supplementing with a well-researched fiber supplement is a smart way to increase your total fiber intake.

For a complete list of products containing Sunfiber, see Here’s the recipe for the chocolate hummus. And you can investigate the MentaBiotics formula here.

1. Gastrointestinal problems in children with autism, developmental delays or typical development

2. Dietary supplementation with partially hydrolyzed guar gum helps improve constipation and gut dysbiosis symptoms and behavioral irritability in children with autism spectrum disorder

This article was featured in Issue 100 – Best Tools And Strategies For Autism


Shawn Talbott

Shawn Talbott, PhD, is fascinated by nutritional biochemistry: the idea that what we eat changes the biochemistry of our bodies, and influences how we look, think and feel. He’s now turned his attention to the gut/brain axis. “This is the missing piece of the puzzle,” he says “Understanding the connection between our microbiome and our brain is fundamentally changing how we think about human performance.” Doc Talbott holds a MS in Exercise Science from University of Massachusetts and a PhD in Nutritional Biochemistry from Rutgers. He also holds advanced certificates in Entrepreneurship and Innovation from MIT. He is a Fellow of both the American College of Sports Medicine and the American College of Nutrition. As a Diplomate of the International Olympic Committee’s Sports Nutrition program, he has educated elite-level athletes in a variety of sports including at the United States Olympic Training Centers. He is the author of hundreds of articles and more than a dozen books on nutrition and fitness. His work has been featured in media outlets around the world, including a variety of segments on The Dr. Oz Show, as well as at the White House as part of Michelle Obama’s “Let’s Move” campaign to fight childhood obesity. Website: