Bacteria connected to how babies experience fear

Bacteria connected to how babies experience fear


Even at a very early age, babies can react to perceived fear. One reason why they have that reaction may have a surprising source: gut microbes.

The human gut is home to a vast community of microrganisms, and recent research has linked gut flora to a host of health conditions — both good and bad. Now, University of North Carolina and Michigan State researchers have found that gut bacteria can also drive infants’ fear responses.

In their study, the scientists worked with 30 babies. They gauged the infants’ fear response to someone walking into a room with a Halloween mask and collected stool samples.

After analyzing the data, researchers found an association between specific features of the gut microbiome and the strength of infant fear responses. Among children with an atypical gut bacterial profile, the fear response was more pronounced.

The effects of an uneven gut microbiome on fear levels also varied by age. The researchers found that 1-month-old infants with uneven microbiomes were more fearful than children who were 1 year old.

This is why researchers say the findings are important: The gut microbiome may shed new light on how the amygdala [əˈmiɡdələ] — the part of the brain that processes emotions and assesses threats — develops and works. After doing brain scans on the infants, the scientists noted that the gut environment in the 1-year-old children was associated with the size of the amygdala.

All of this, researchers noted, raises the possibility that gut bacteria can influence how the amygdala develops and operates.

So when it comes to assessing fear, the idea of trusting your gut may be truer than ever.

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