Your toddler’s unique gut microbiome may contribute to those mood swings associated with the “terrible twos.”

There may be more going on besides fussy behavior, according to researchers at Ohio State University’s Center for Clinical and Translational Science.

Those mood swings may provide indicators for early stages of chronic diseases, like allergies, asthma, bowel disease and even obesity, according to a recent study appearing in the journal Brain, Behavior, and Immunity.

Evidence has shown that intestinal bacteria interact with stress hormones, the very same ones linked to chronic illnesses like obesity and asthma, says Dr. Lisa Christian, 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,” Dr. Christian explained.

Based on an analysis of 77 stool samples taken from young boys and girls ages 18-27 months old, there were signs of activity in the gut-brain axis, says Dr. Michael Bailey, study co-author, microbiologist and member of the Institute for Behavioral Medicine Research.

“There is definitely communication between the bacteria in the gut and the brain, but we don’t know which one starts the conversation.”

No matter which side “started the conversation,” evidence appears to link young temperaments to the amount and diversity of gut bacteria, even after taking into account their diets, the mother’s birthing method and whether or not they were breast fed.

Matching gut bacteria to behaviors

Mothers were asked to assess their child’s behaviors using questionnaires that gauged 18 specific traits that fed into specific scales of emotional reactivity.

Based on those reports, researchers analyzed the different genetic types and quantities of gut bacteria in those stool samples (along with diets).

With improvements in DNA testing, which enable scientists to spot individual bacteria and concentrations in stool samples, “All of the predominant bacteria we found in our study have been previously linked to either changes in behavior or immune responses,” says Dr. Bailey, according to a press release.

Girls vs. boys

Generally, children who had the most genetically diverse gut bacteria more often displayed the behaviors connected with positive mood, impulsivity, sociability and curiosity.

Scientists have also been able to link extroverted personality traits in boys to an abundance of gut microbes from specific families (Ruminococcaceae and Rikenellaceae) and genera (Parabacteroides and Dialister).

“It’s possible that more outgoing kids could experience less trouble due to fewer stress hormones in their guts than those who are shy. Healthy guts regulate the production of stress hormones better or it could be a bit of both,” Dr. Bailey says.

The links between gut bacteria and temperament were less consistent in girls according to the study. Still, scientists linked some traits in girls — focused attention, self-restraint and cuddliness — to a less diverse microbiome.

Also, girls who had more of one particular family of gut bacteria (Rikenellaceae) experienced more fear than others with better balance in their gut health.

What makes a real difference?

Although researchers concluded diets didn’t make a difference in the behaviors and gut health of the toddlers they examined, they left room for the possibility that they could.

“It is certainly possible that the types or quantities of food that children with different temperaments choose to eat affect their microbiome,” says Dr. Christian.

Despite the findings in this study, evidence points to the method of birth — vaginal delivery versus caesarean — being a huge factor. Babies born via C-section had less gut diversity than those who were born naturally.

What’s more, the growing immune systems of small children aren’t nearly as prepared for challenges to come if they don’t have the right balance of gut bacteria. That’s where probiotics can help your child, whether he or she is a newborn, toddler or school age child.

That’s why EndoMune Junior now comes into two varieties: a powdered formula, ideal for mixing into food or drinks and a delicious chewable berry-flavored tablet that will leave them wanting more.

Each dose of EndoMune Junior contains 10 billion CFUs, including four species of proven health-promoting bacteria, and a prebiotic that feeds the good bacteria already in your child’s gut.