Early life adversity is linked to increased gastrointestinal symptoms in children that may have an impact on the brain and behavior as they grow to maturity, according to a new study published online in the journal Development and Psychopathology.
“One common reason children show up at doctors’ offices is intestinal complaints,” said senior author Dr. Nim Tottenham, a professor of psychology at Columbia University. “Our findings indicate that gastrointestinal symptoms in young children could be a red flag to primary care physicians for future emotional health problems.”
A growing body of scientific evidence shows a strong connection between the gut and brain. Research also shows that a history of trauma or abuse is present in up to half of adults with irritable bowel syndrome (IBS), at a prevalence twice that of patients without IBS.
“The role of trauma in increasing vulnerability to both gastrointestinal and mental health symptoms is well established in adults but rarely studied in childhood,” said study lead author Dr. Bridget Callaghan, a post-doctoral research fellow in Columbia’s psychology department.
In addition, she said, animal studies have shown that adversity-induced changes in the gut microbiome — the bacteria community that regulates everything from digestion to immune system function — influence neurological development, but no human studies have done so.
“Our study is among the first to link disruption of a child’s gastrointestinal microbiome triggered by early-life adversity with brain activity in regions associated with emotional health,” Callaghan said.
The research team focused on children who experienced extreme psychosocial deprivation due to institutional care before international adoption. Separation of a child from a parent is known to be a powerful predictor of mental health issues in humans. That experience, when modeled in rodents, induces fear and anxiety, hinders neurodevelopment and alters microbial communities across the lifespan.
The researchers looked at data from 115 children adopted from orphanages or foster care on or before they were 2 years old, and from 229 children raised by a biological caregiver. The children with past caregiving disruptions showed higher levels of symptoms that included stomach aches, constipation, vomiting and nausea.
From that sample of adoptees, the researchers then chose eight children, ages 7 to 13, from the adversity-exposed group and another eight who’d been in the group raised by their biological parents.
The team collected behavioral information, stool samples and brain images from all the children. They used gene sequencing to identify the microbes present in the stool samples and evaluated the abundance and diversity of bacteria in each child’s fecal matter.
The results show that children with early caregiving disruptions had distinctly different gut microbiomes compared to kids raised with biological caregivers from birth.
Brain scans of all the children also revealed that brain activity patterns correlated with certain bacteria. For example, the children raised by parents had increased gut microbiome diversity, which is linked to the prefrontal cortex, a region of the brain associated with regulating emotions.
“It is too early to say anything conclusive, but our study indicates that adversity-associated changes in the gut microbiome are related to brain function, including differences in the regions of the brain associated with emotional processing,” said Tottenham, an expert in emotional development.
Source: Columbia University