A meta-analysis found that for every 4 children with autism spectrum disorders at least 1 was found to have some sort of gastrointestinal symptom and this was lower in children without ASD.
The most common symptoms were increased gas at 60% Bloating, diarrhea, acid reflux under 50%, and constipation the least common symptom found in 10% of participants. It's thought that through the gut & brain axis, gut health could affect Asperger's.
The Microbiome of Autistic Children
Through stool & urine samples it is possible to test the bacteria makeup of the microbiome and see if there is dysbiosis or not. This first study from 2010 found that children with Autism had a higher concentration of Clostridium genus pathogenic bacteria in their gut.
A second 2012 study started by saying that gastrointestinal disturbances were more common in children with autism possibly due to changes in microbiome flora. The researcher's previous work found more pathogenic Alcaligenaceae bacteria in autistic children and none in non-autistic control children.
In further testing, they found Sutterella bacteria in 12 children with autism and none of these same bacteria in a testing group of 9 children who did not have autism. The specific strains found were Sutterella wadsworthensis and Sutterella stercoricanis. It's thought that because these bacteria were found in over 50% of children there could be some significance.
Can Probiotics Help with Asperger's or Not?
To help answer the question of whether probiotic supplements can help with Asperger's and autism spectrum disorder we will take a look at this incredible study carried out by Professor Glenn Gibson, published in 2007.
The study started by once again confirming that the intestines of autistic children were likely to have higher amounts of Clostridium histolyticum bacteria compared to non-autistic children and that autistic children were also more likely to experience gastrointestinal symptoms like bloating and gas.
Researchers from the Food Microbiology Sciences Unit at Reading University created a probiotic containing Lactobacillus Plantarum probiotic bacteria and their theory was that this specific strain could potentially destroy clostridia pathogenic bacteria by making it a hostile environment for the bad bacteria to grow.
To test this theory a straightforward placebo trial was set up with 40 children 4 to 8 years old recruited. At random, half were asked to take the L. Plantarum probiotic once per day in powdered form for 3-weeks. The other 20 were given a placebo probiotic that contained NO bacteria.
The results were so clear in that when the time came for the 20 children to switch from real probiotics to fake, the parents refused to do it because of the benefits they had noticed in their children. The parents wanted their children to continue taking a probiotic supplement.
The study was lacking details and the results were not definitive because many of the parents refused to continue with the placebo but some interesting effects were shared. The parents noted that their children had fewer IBS symptoms, better-formed stools, improved concentration, more calmness, and less stress. When they stopped taking the L. Plantarum probiotic it was noted that these symptoms all returned.
Dr. Qinrui Li's Thoughts on Probiotics for Autism & Asperger's
This huge 2017 review looked at over 100 papers on probiotics and autism, we got some valuable insight from one Bejing Doctor called Qinrui Li and some other Doctors from Sacramento California.
In her conclusion, she said that abnormal gut flora was linked to ASD and that modulating the gut flora with probiotics, prebiotics and a gluten-free diet could potentially be cheap safe therapy.
She did also however claim that more "well designed" studies with "more participants" were needed to make any sure gone conclusions on the role between gut microbiota & autism spectrum disorders.
Closing Thoughts: More High-Quality Studies are Needed
It's clear through numerous studies that the microbiome seems to be altered in children with Asperger's because of Dysbiosis which leads to an imbalance in good and bad bacteria. It seems that this contributes to digestive symptoms similar to IBS that negatively impact the lives of children with Asperger's.
Studies into whether probiotics can help with Asperger's are inconclusive and there is no definitive study that proves probiotics can treat, cure or help all children with ASD. Different probiotic strains have different effects and every child has their unique microbiome regardless if they have Asperger's or not. More studies like the one Professor Gibson conducted are needed to prove whether or not probiotic supplements can help or not.