Young school-aged children with behaviour problems may have different bacteria in their guts than their well-behaved peers, new research suggests.
The study also noted that parents may play a key role in development of the particular bacteria in their child's gut (collectively known as the microbiome). That role even extends beyond the type of foods parents give their children, researchers suspect.
No cause-and-effect link
"We were interested in determining if there were aspects of the gut microbiome that explained the variation of behaviour in children," said the study's senior author, Thomas Sharpton.
And, it appeared to. For example, Sharpton said, "Children in families that demonstrated stronger caregiver bonds had differences in microbiomes than those that did not." He's an associate professor of microbiology at Oregon State University in Corvallis.
Sharpton was quick to note that the study does not prove a cause-and-effect link.
"We are not saying that the microbiome is causing the behaviour. It may be that the behaviour is causing microbiome changes. It's difficult to disentangle the confounding factors," he said.
The researchers did point out that diet didn't seem to account for the changes seen in this study.
This isn't the first study to connect the microbiome to kids' behaviour.
A team from Texas Children's Hospital in Houston reported last May that children with autism and digestive symptoms had differences in their microbiomes compared to siblings and other kids without autism. These researchers didn't find a clear microbiome pattern that would easily indicate autism, however.
The new study included 40 children between five and seven years of age. The researchers analysed stool samples from each to identify the types of bacteria in their guts.
Sharpton said if large studies confirm these findings, it might be possible to figure out a way to use microbiome information to predict how a child's behaviour might develop. Having that information might lead to earlier – and possibly more successful – interventions.
Dr Maryann Buetti-Sgouros, head of paediatrics at Northern Westchester Hospital in Mount Kisco, New York, reviewed the findings.
She said, "This study reinforces the idea that there is a brain-gut connection, but I don't think the study gives us any conclusive answer. It does give us further areas to research."
Dr Andrew Adesman, chief of developmental and behavioural paediatrics at Cohen Children's Medical Center of New York in New Hyde Park, had a similar reaction.
Research still in its infancy
"This study adds to the body of research suggesting even in young school-age children, that the microbiome has clinical implications that extend well beyond the GI [gastrointestinal] tract," Adesman said.
But, as Sharpton noted, Adesman said it's difficult in studies like this to know for sure what factor is cause and what might be an effect. He said that further study is needed.
"Research examining the clinical implications of the gut microbiome is still in its infancy, and it will likely be a decade or more before we have a full appreciation for its true importance – especially in children," Adesman said.
The findings were published in mBio. The study was done in collaboration with researchers from the University of Oregon in Eugene.
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