If you’re already plotting your baby’s admission into Harvard, don’t neglect her microbes. Gut microbiota may be your child’s best teacher.
A little background: 100 trillion microbes share your body. Their move-in date is now thought to have begun when you were under construction in the womb. During and after birth and with those first months of rich nutrition, the microbiota amasses at a furious pace. Gut microbiota may play a role in how the brain develops in the first years of life.
Microbes in the gut impact neurodevelopment. Studies in rodents show that changing those microbes also changes behaviors. Could humans benefit also? Experts suggest that the template for future microbiota composition may be locked in at as early as 3 years of age. These first years of life are a vigorous time in both gut colonization and brain development; the nature of the link has received more attention of late.
Alexander L. Carlson and colleagues at University of North Carolina School of Medicine sought to determine whether there might be a relationship between the gut microbiome and brain development in infants.
Their findings were reported in Infant Gut Microbiome Associated with Cognitive Development in the Biological Psychiatry journal in July 2017.
Stool samples were collected from 89 healthy one-year olds, a task easier than such collections in most age groups. 16S rRNA sequencing was used for analysis of bacterial taxa. MRIs and cognitive outcomes using the Mullen Scales of Early Learning (a series of tests that examine fine and gross motor skills, perceptual abilities, and language development) were conducted at 1 and 2 years of age.
- The infants clustered into 3 groups by bacteria types.
- Mullen scores at age 2 differed significantly between clusters.
- Higher alpha diversity was linked with lower scores on the overall composite score, visual reception scale, and expressive language scale at age 2.
Infants in the cluster with relatively high levels of the bacterial genus Bacteroides had better cognitive scores compared to the other two clusters. In addition, babies with highly diverse gut microbiomes didn’t perform as well as those with less diverse microbiomes.
The latter was surprising, given that less diversity is usually linked with negative outcomes including type 1 diabetes and asthma. In other words, optimal microbiota may vary depending on the desired outcome.
How this all plays out is not known. Is it signalling or something below the radar such as nutrient changes, the researchers asked.
“This is the first study to show that cognitive development is associated with the microbiome, and so it’s the very first step,” said Alexander Carlson. “We’re not really at the point where we can say, ‘Let’s give everyone a certain probiotic.’ But we did have a few big takeaways from what we found. One was that when measuring the microbiome at age one, we already see the emergence of adult-like gut microbiome communities — which means that the ideal time for intervention would be before age 1.”
In the future, parents may be able to alter their infant’s microbiome to enhance brain development or reduce the risk for disorders like autism.
While an Ivy League college may not be in the cards, a good mind is one of nature’s treasures. If our microbes can assist in cognitive development, more research will hopefully zero in on an optimum mix. In the meantime, a good rule for new parents is to both deliver vaginally and breast feed if possible. Then feed them well.