The Terrible Twos and the Gut Microbiome
It seems not a week goes by without some surprising news hinting at the role our gut bacteria play in shaping our lives in unexpected ways. This week is no different. According to researchers at the Ohio State University Center for Clinical and Translational Science, the makeup of the diverse communities of microorganisms living in the gut (the “microbiome”) may have an important influence on how toddlers behave.
That’s right. If you’re struggling with a toddler who seems determined to give new meaning to the “terrible twos,” you may want to consider what he or she may be harboring in the digestive tract. Investigators say they’ve discovered a link between toddlers’ temperaments and the presence of certain intestinal bacteria. The finding evidently applies to both boys and girls.
Investigators weren’t looking for ways to improve toddlers’ behavior. Rather, they’re interested in illuminating the possible links among the microbiome and the risk of chronic illnesses, such as obesity, asthma, allergies, and bowel disease. Almost by accident, they discovered there appears to be a link between having certain strains of bacteria in the gut and having a stormy temperament.
“There is substantial evidence that intestinal bacteria interact with stress hormones—the same hormones that have been implicated in chronic illnesses like obesity and asthma," said Lisa Christian, PhD, a researcher with Ohio State's Institute for Behavioral Medicine Research. "A toddler's temperament gives us a good idea of how they react to stress. This information combined with an analysis of their gut microbiome could ultimately help us identify opportunities to prevent chronic health issues earlier.”
Previous research has demonstrated that a more diverse collection of bacteria in the gut is usually associated with better health outcomes generally. The same appears to be true when it comes to toddlers and their moods and behaviors. In short; kids with more diverse collections of microbes tended to have better mood and self-control. In boys, the presence of certain species of bacteria was even linked to more outgoing traits.
"There is definitely communication between bacteria in the gut and the brain, but we don't know which one starts the conversation,” said microbiologist Michael Bailey, PhD. ”Maybe kids who are more outgoing have fewer stress hormones impacting their gut than shy kids. Or maybe the bacteria are helping mitigate the production of stress hormones when the child encounters something new. It could be a combination of both.”
Previous research has shown that being delivered vaginally—and breastfeeding—are both linked to greater gut microbiome diversity. And evidence is mounting that greater diversity is a good thing, for numerous reasons. Although the differences noted in the present Ohio State study were not necessarily due to differences in diet, scientists think diet may play a role in gut microbiome diversity. “…It is possible that effects of diet would emerge if we used a more detailed assessment. It is certainly possible that the types or quantities of food that children with different temperaments choose to eat affect their microbiome." said Dr. Christian, in a press release.
Lisa M. Christian, Jeffrey D. Galley, Erinn M. Hade, Sarah Schoppe-Sullivan, Claire Kamp Dush, Michael T. Bailey. Gut microbiome composition is associated with temperament during early childhood. Brain, Behavior, and Immunity, 2015; 45: 118 DOI: 10.1016/j.bbi.2014.10.018