Clinical trial · Pharmacological research · 2020Abstract onlyConflicts declared

Fructooligosaccharide with probiotics in children with autism

What it found

In children with autism, a mix of probiotics and fructo-oligosaccharide changed gut bacteria and gut acids, and eased autism and gut symptoms.

The same changes did not appear in children given a placebo.

What they found

Studies in people

Gut bacteria at start

Children with autism had out-of-balance gut bacteria, with clearly lower levels of Bifidobacteriales and Bifidobacterium longum than the other children.

Gut acids at start

Children with autism had clearly lower levels of acetic acid, propionic acid and butyric acid than the children without autism.

Brain chemicals at start

Children with autism had higher serotonin and lower homovanillic acid, which the authors describe as a hyper-serotonergic state and a dopamine metabolism disorder.

After probiotics plus FOS

Beneficial bacteria (Bifidobacteriales and B. longum) rose and suspected harmful Clostridium fell, and autism and gut symptoms were clearly less severe.

Gut acids after treatment

The short-chain fatty acids in the children with autism rose clearly after probiotics plus FOS and came close to the levels in the children without autism.

Brain chemicals after treatment

Serotonin fell and homovanillic acid rose after probiotics plus FOS. These changes did not appear in the children with autism who took the placebo.

What the authors conclude

“Probiotics + FOS intervention can modulate gut microbiota, SCFAs and serotonin in association with improved ASD symptoms, including a hyper-serotonergic state and dopamine metabolism disorder.”
Wang Y, Li N, Yang JJ, et al, 2020

Also in their conclusions

  • They conclude that probiotics plus FOS can change gut bacteria, short-chain fatty acids and serotonin in ways that go with improved autism symptoms.
  • They say this includes the hyper-serotonergic state and the dopamine metabolism disorder.

How it was done

Autism is becoming more common, but its cause is still unknown and there is no effective treatment. Earlier animal studies pointed to the gut bacteria and the gut-brain axis, and the authors say more research in people was needed.

First they compared gut bacteria, fecal short-chain fatty acids and blood neurotransmitters in 26 children with autism and 24 children without it. Then all 26 children with autism took part in the next stage, where 16 received probiotics plus FOS and 10 received a placebo, with the same measurements taken before and after.

What it can’t tell you

  • We summarised it from the abstract only.
  • This was a small trial, with 16 children taking probiotics plus FOS and 10 taking a placebo.
  • It cannot show whether the same changes would happen in other children with autism, or last beyond the study.

The paper

Title
Probiotics and fructo-oligosaccharide intervention modulate the microbiota-gut brain axis to improve autism spectrum reducing also the hyper-serotonergic state and the dopamine metabolism disorder
Type
Clinical trial
Evidence
Studies in people
Summarised from
Abstract only
Cite
Wang Y, Li N, Yang JJ, et al (2020). Probiotics and fructo-oligosaccharide intervention modulate the microbiota-gut brain axis to improve autism spectrum reducing also the hyper-serotonergic state and the dopamine metabolism disorder. Pharmacological research. doi:10.1016/j.phrs.2020.104784PubMed 32305492DOI

Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error