Study Says Gut Bacteria Could Influence Toddler Temperament


New research from Ohio State University suggests that certain types of gut bacteria could influence a toddler’s behavior, especially pertaining to boys, by interacting with stress hormones and resulting in the manifestation of behavioral and physical problems.

According to the study, microbes that live in a person’s gastrointestinal tract go through considerable changes in the first two years of life, more so after solid foods are introduced.  Scientists believe this unstable “gut microbiome” to be connected to a toddler’s attitude.

“Although we predicted we would observe an association between temperament variables and measures of the gut microbial community, we didn’t know how strong those associations would be,” Dr. Michael Bailey, associate professor of pediatrics at The Ohio State University and co-author of the study, told The Huffington Post in an email. “We do not yet know if these two factors are directly linked, and if so, in which direction the link occurs (i.e., gut to brain or brain to gut). It could be either, or it could be both.”

Researchers looked at microbes taken from the gastrointestinal tracts of children between the ages of 18 and 27 months.  Also used were responses to surveys taken by parents of the children concerning their child’s temperaments and eating habits.  Scientists did admit that the study did not look deeply into each child’s individual diet, but rather more at when food types were introduced, and the type and frequency of food that a child ate each day.

As a result of the study, scientists found a consistent connection between gut bacteria and behavior, even after having factored in individual histories of breastfeeding, diet, and method of childbirth.  Each of these factors are known to play a role in the type of microbes that are found in a child’s gut.  The effects were particularly noted in toddler boys.  However, girls with a lower diversity of gut bacteria were found to display behaviors such as self-restraint, cuddliness and focused attention.

Extroverted children were found to have more diverse bacteria, causing scientists to believe that there could be a link between microbial diversity and a more positive temperament, writes Jacqueline Howard for The Huffington Post.

“We really are just beginning to realize that gut microbes can impact the brain and impact behavior,” Bailey said in the email. “Until we know the extent to which this occurs, and the mechanisms by which this occurs, we really have no reliable way to predict how changes in diet, and thus changes to the microbiome, might impact toddler behavior.”