Autism Linked to Gut and Probiotics
Dietetics researchers from Poland’s Wroclaw Medical University have recently released a study finding that autism is often related to the parent’s or the child’s early nutritional status, along with gastrointestinal issues.
Their extensive study resulted in their advice:
“A properly designed elimination diet adapted to the patient’s individual may also lead to relief of the autism symptoms and the occurrence of gastrointestinal disorders.”
Studies link autism with gut issues
Other research has determined that autistic children have more gastrointestinal issues. Researchers from New York’s Children’s Evaluation and Rehabilitation Center found, in a study of 50 autistic children and two control groups found that 70% of the children had some form of gastrointestinal issues. This was compared to only 28% of the normal children.
Other studies have also found this correlation between autistic children and gastrointestinal problems. A study from the Arizona State University found that 63% of autistic children had chronic diarrhea and/or constipation, compared to 2% of the control group studied. (This study also revealed that autistic children also have low levels of important minerals such as potassium, lithium, iodine and others.)
Clostridium and autism
Multiple studies have also revealed that autistic children tend to have higher levels of Clostridium species in their GI tracts than normal children. One study found that autistic children had 10 times the levels of Clostridium than the control group, and 9 of these Clostridium species were not found among the control group.
A 2010 study from the Veteran’s Administration Center researchers in Los Angeles found that that autism was associated with multiple types of GI infections, including species of Bacteroidetes, Actinobacterium and Proteobacterium. Bacteroides vulgatus levels were particularly higher among the autistic children compared to the control group.
Yeast and autism
Higher levels of yeast – and increased yeast sensitivity – have also been found among autistic children. A 2002 study from the University of Maryland School of Medicine found that 43% of autistic children had positive yeast cultures in digestive juices – double that of the control group.
In a 2010 survey by the Autism Research Institute of more than 25,000 parents of autistic children, antifungal medications were reported as significantly improving symptoms among their children.
Autism and gut bacteria
A study from Chicago’s Rush Medical College gave 11 autistic children an antibiotic aimed at their digestive flora and found that during the treatment period, the autistic symptoms of 8 of the 10 children completing the trial were dramatically improved. This improvement, however, reversed once the children stopped taking the antibiotic.
A study from Arizona State University in 2011 analyzed stool samples of 58 children with some form of autism and compared these with 39 healthy children. The tests analyzed bacteria, yeast, IgA, fatty acids, pH, and many other digestive factors.
This study found that the autistic children on average had 44% lower levels of Bifidobacterium in their stools compared to the healthy children. The autistic children also had an average of 16% less species of Enterococcus in their stools.
The autistic children also had over 430% higher levels of Bacillus species of bacteria in their stools, and 21% of the autistic children were infected with Baccillu spp. Bacillis is a spore-forming gram-positive range of species that include many pathogenic species, such as B. cereus – involved in foodborne infections.
Autism and SCFAs
The autistic children also had significantly lower levels (27% less on average) of short chain fatty acids (SCFAs) in their stools. Lower levels of SCFAs can result from either lower levels of fiber and/or less fermentation of fiber by probiotic bacteria in the gut. Even those children who were supplementing with probiotics had lower levels of short chain fatty acids in their stools.
The researchers also investigated GI symptom severity together with autistic severity. They found a significant correlation between the severity of GI symptoms and the severity of autistic symptoms among the children. In their discussion, they said:
“The very strong correlation of the 6-GSI with the ATEC and its subscales indicates that there is a very strong association of gastrointestinal symptoms and autistic symptoms.”
They added: “we hypothesize that gastrointestinal problems may significantly contribute to autistic symptoms in some children.”
The researchers also commented on the significantly lower levels of short chain fatty acids in the children:
“This suggests that there are either lower amounts of beneficial bacteria which produce SCFA’s, a lower intake of soluble fiber, a longer transit time, and/or increased absorption due to increased gut permeability.”
Probiotic supplementation improves moods
Meanwhile, probiotic supplementation has been shown to improve moods. In a study of 132 people from the University of Wales, those who consumed a probiotic drink for three weeks reported significantly better moods than the placebo group.
As to whether probiotic supplementation will significantly help an autistic child, this has yet to be thoroughly researched. A 2011 University of California/David review of the research did find promise in such a strategy, as did the Wroclaw Medical University researchers. The University of California researchers wrote in their conclusion:
“There is a range of indications that alterations in the intestinal microbiota in the gut might contribute to the disorder in a substantial number of individuals. Probiotics can be useful to restore the microbial balance in the intestine, to relieve gastrointestinal problems and to attenuate immunological abnormalities. Whether the use of probiotics by children with autism can lead to improvements in behaviors needs to be established in well-controlled trials with sufficient group sizes.”
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