What is already known
Several studies have found a link between gut microbes and neurodevelopmental conditions such as autism. However, little is known about how a child’s brain development is interconnected with gut microbial diversity in early life.
What this research adds
Researchers analyzed the gut microbiota of 381 healthy children aged 40 days to 10 years, each within a week of various age-appropriate cognitive assessments. By 18 months of age, a child’s cognitive-function scores were associated with variations in specific gut microbes and microbial metabolites such as short-chain fatty acids (SCFAs). For example, high levels of Alistipes obesi and of SCFAs-producing bacteria such as Eubacterium eligens and Faecalibacterium prausnitzii were associated with higher cognitive function in children older than 18 months.
Conclusions
The findings may inform efforts to detect neurodevelopmental conditions and develop new interventions.
For years, scientists have investigated the link between the brain and the gut microbiota. Now, an analysis involving more than 380 children shows that specific gut microbes are associated with higher cognitive function.
The findings, published in Science Advances, may inform efforts to detect neurodevelopmental conditions and develop new interventions. “Although we did not directly test the causal relationships between gut microbial taxa and their genes, the gut, and the brain, this study provides clear and statistically significant associations that could serve as targets for future efforts in preclinical models,” the authors say.
Previous studies have shown that gut microbes are associated with the development of autism and other conditions that affect brain development and function. However, little is known about how a child’s brain development is interconnected with gut microbial diversity in early life.
Kevin Bonham at Wellesley College in Massachusetts and his colleagues set out to analyze the gut microbiota of 381 healthy children aged 40 days to 10 years, each within a week of various age-appropriate cognitive assessments. The researchers also used brain scans to assess the structure of the children’s brains.
Microbial metabolism
By 18 months of age, a child’s cognitive-function scores were associated with variations in specific gut microbes and microbial metabolites such as short-chain fatty acids (SCFAs), the researchers found.
Among children older than 18 months, those with higher cognitive-function scores showed increased levels of several gut bacteria, including Alistipes obesi and Asaccharobacter celatus, as well as SCFA-producing microbes such as Eubacterium eligens and Faecalibacterium prausnitzii. The microbe Sutterella wadsworthensis was associated with lower cognitive-function scores.
The production of the amino acid glutamate — a neurotransmitter with several types of receptors found throughout the brain — was enriched in children with higher cognitive-function scores. “These results suggest that microbial metabolic activity, particularly the metabolism of neuroactive compounds, may have effects on cognitive development,” the researchers say.
Neurodevelopment biomarkers
Using machine-learning models, the researchers showed that gut microbial profiles in the first year of life could predict future cognitive function and brain structure. The analysis identified F. prausnitzii, E. eligens, Parasutterella excrementihominis, A. obesi and an additional 48 microbial species as important for discriminating cognitive-function scores.
The team also found that specific microbes were associated with distinct cognitive functions. “Bifidobacterium pseudocatenulatum, Blautiawexlerae and E. eligens are substantially more important for the prediction of expressive language, while Roseburia faecis, Streptococcus salivarius and Fusicatenibacter saccharivorans are distinctly predictive of gross motor, and Clostridium innocuum and Bacteroides vulgatus stand out on models targeting visual reception,” the researchers say.
By examining the gut-brain-microbiota axis in typical neurodevelopment, the findings could pave the way for identifying biomarkers for cognition and brain development, the authors say.
