Wow. This is so interesting. Another really fascinating piece of the puzzle highlighting how gut bacteria could be really important for neurodevelopment.

Infant girls are more likely to have higher proportions of a gut bacteria species called Bacteroidetes. Infant girls also tend to score higher (at early stages) when it comes to cognition and language.

Now new research by Tamana SK et al., (2021) finds that if infant boys have higher levels of Bacteroidetes in their gut composition, those boys have more advanced cognitive and language skills one year later. This is compared to boys with lower levels of the bacteria.

One of the study team is Professor Anita Kozyrskyj, a professor of pediatrics at the University of Alberta and the principal investigator of the SymBIOTA (Synergy in Microbiota) laboratory.

Dr Kozyrskyj is also featured in our Microbirth film and is one of the 11 professors featured in our Infant Microbiome & Epigenetics online course.

In an article released by the University of Alberta, Professor Kozyrskyj says:

“It’s well known that female children score higher (at early ages), especially in cognition and language,” She continues. “But when it comes to gut microbial composition, it was the male infants where we saw this obvious connection between the Bacteroidetes and the improved scores.”

What's special about Bacteroidetes?

According to Dr Kozyrskyj, Bacteroidetes are a type of bacteria (and very few bacteria can do this) that produce metabolites called sphingolipids.

It seems sphingolipids are really important for the formation and structure of neurons in the brain.

In the article, Dr Kozyrskyj says:

“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".

So what factors could affect Bacteroidetes in the infant gut?

According to Dr Kozyrskyj:

Factors that could deplete the proportion of Bacteroidetes in the infant gut include if a baby is born by C-section.

Factors that could positively influence the amount of Bacteroidetes in the infant gut include breastfeeding, eating a high-fibre diet, living with a dog, and having lots of exposure to nature and green spaces.

What does this study mean?

This study doesn't necessarily mean infants with a lower proportion of Bacteroidetes will remain behind in cognition and language in later childhood or adulthood.

But this type of research (and others in this area) could potentially help identify those infants that may be at higher risk of neurodevelopmental disorders.

More research is needed, and the team are going to look at other factors that could impact neurodevelopment in infants, including stress and the colonisation of the gut by Clostridium difficile.

These future studies will no doubt reveal more important pieces of the complex puzzle about how gut bacteria affect neurodevelopment in early life.

My take-home message:

This research indicates that higher proportions of Bacteroidetes in the infant gut is linked to advanced cognitive and language skills.

If C-section depletes the proportion of Bacteroidetes in the infant gut, and if breastfeeding positively influences the amount of Bacteroidetes - then this is a great argument to support vaginal birth and exclusive breastfeeding.

Clearly what is needed is more research on birth and breastfeeding.

And I would love to see more funding to support vaginal birth and exclusive breastfeeding, whenever possible.

In my mind, that means changes to maternity systems. I would love to see more respect, appreciation and higher wages for trained midwives, more funding for highly skilled lactation experts (IBCLCs, CLCs etc) and more appreciation for the work of doulas (who provide practical and emotional support to expectant and new parents during and after birth).

I would also love to see all childbirth education programmes include an explanation of the infant microbiome for expectant parents, including how vaginal birth and breast milk seem are so important for the development of the infant immune system and, as this new study provides compelling new evidence for, potentially also to infant neurodevelopment.

What do you think?

Article and Science reference:

University of Alberta article:

Tamana SK, Tun HM, Konya T, Chari RS, Field CJ, Guttman DS, Becker AB, Moraes TJ, Turvey SE, Subbarao P, Sears MR, Pei J, Scott JA, Mandhane PJ, Kozyrskyj AL. Bacteroides-dominant gut microbiome of late infancy is associated with enhanced neurodevelopment. Gut Microbes. 2021 Jan-Dec;13(1):1-17. doi: 10.1080/19490976.2021.1930875. PMID: 34132157; PMCID: PMC8210878.


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