Can gut bacteria impact autism symptoms?

How common is Autism?

Autism is much more common than many people think. According to the National Autistic Society (NAS) – around 700,000 people in the UK (more than 1%) are on the autism spectrum2.

Approximately 1 in 160 children in the UK has an ASD (Autism Spectrum Disorder)3.  With most cases of autism being diagnosed after the age of 44.

Are children with Autism more likely to suffer with gut issues?

Children with autism are nearly 8 times more likely to suffer from one or more chronic gastrointestinal (GI) disorders than other children5. GI problems have been linked to behavioural issues, especially among autistic children with a difficulty communicating stress and pain5.

There is also a study that suggests children with autism are more likely to suffer with IBS symptoms compared to children without ASD6.  Researchers mention that it may be aggravated by diets that provide insufficient fibre, which can be common in gluten-free and other restrictive diets.

Gluten-free casein-free (GFCF), also known as gluten-free dairy-free diet does not include the proteins gluten and casein. Despite a lack of scientific evidence, there have been advocates for the use of this diet to alleviate physical symptoms and behavioural problems in some autistic children. A 2014 survey indicated that 25% of parents of autistic children were implementing a restrictive GFCF diet5.

The GFCF diet seeks to heal the gut and calm down the immune system, by excluding these ingredients, it is thought that there may be improvements in digestion and cognitive function.

New research shows a link between prebiotic supplementation and Autistic symptoms

A new study, published in Microbiome, suggests that combining an exclusion diet (gluten-free casein-free) with a specific prebiotic supplement containing GOS may be effective in improving GI aspects and behaviour in autistic children.

The study, led by Dr Roberta Grimaldi at the University of Reading, is the first of its kind to compare the impact of diet and prebiotics on the gut microbiota composition, GI dysfunction, mood, behaviour and sleep. The results showed that a combined dietary approach with the prebiotic supplement resulted in significant changes in gut microbiota composition and metabolism. Perhaps more importantly, the study showed a significant improvement in social behaviour scores after prebiotic intervention in autistic children following exclusion diets. The new study suggests that multiple interventions may be more relevant for the improvement of the GI aspects as well as psychological traits.

The study also showed that almost 1 in 4 (23%) of the study participants benefited from improved sleep. Parents reported that children slept 1 hour longer than usual and noticed children had less problems falling asleep. There was a general trend of the reduction of GI symptoms reported after prebiotic supplement, but differences were not significant. 

While the study is small in scale, the results pave the way for more research into the relationship between gut microbiota composition and behavioural traits in autistic children. Autism spectrum disorders are very complicated and can’t be treated with one solution due to the nature of the disorder. This post has been developed with the intent to present findings from a study that has explored the link the effects of prebiotics on autism sufferers on a tailored diet and not offer a cure.

The supplement used in the study was Bimuno®.