Bacteroides-dominant gut microbiome linked to better neurodevelopment in boys: Study

"The differences between male and female gut microbiota are very subtle, but we do know from CHILD Cohort Study data that girls at early ages are more likely to have more of these Bacteroidetes. So perhaps most girls have a sufficient number of Bacteroidetes and that's why they have improved scores over boys," added Kozyrskyj.

The researchers, led by Kozyrskyj and associate professor of pediatrics Piush Mandhane, studied bacteria found in fecal samples from the infants and identified three different groups exhibiting similar dominant clusters of bacteria. They then evaluated the infants on a variety of neural developmental scales. Of those groups, only the male infants with Bacteroidetes-dominant bacteria showed signs of enhanced neurodevelopment.

The research replicates similar findings from a U.S. study that also showed an association between Bacteroidetes and neural development.

"It makes sense that if you have more of these microbes and they produce more sphingolipids, then you should see some improvement in terms of the formation of neuron connections in our brain and improved scores in cognition and language," she said.

According to Kozyrskyj, cesarean birth is one factor that can significantly deplete Bacteroidetes. Factors that positively influence gut microbiota composition in infants include breastfeeding, having a high-fiber diet, living with a dog, and being exposed to nature and green spaces.

While the findings don't necessarily mean children with a lower proportion of Bacteroidetes will remain behind their peers in later childhood or adulthood, the researchers believe the study offers early promise as a way to potentially identify children at risk of neurodevelopmental disorders.

The team will continue to follow the infants participating in CHILD to determine whether the findings can be predictive of autism or attention-deficit/hyperactivity disorder. Moving forward, the researchers are also examining several other factors that may have an impact on neurodevelopment in infants, including stress and gut colonization by the bacterium Clostridium difficile.

"Over the first one to two years of life, your brain is very malleable," said Kozyrskyj. "Now we're seeing a connection between its malleability and gut microbiota, and I think that is very important."

Reference:

The study titled, "Bacteroides-dominant gut microbiome of late infancy is associated with enhanced neurodevelopment," is published in the journal Gut Microbes.