In a new study, researchers led by a team at Columbia University have found that emotional deprivation early in life is tied to a higher rate of gastrointestinal problems, along with disruption of the gut microbiome and patterns of brain activity that may indicate a higher mental health risk.
These findings are among the first in humans to show a link between emotional trauma, gut bacteria, gastrointestinal issues and brain activity.
They also mean, according to one of the study’s senior authors, that gastrointestinal problems in children may indicate a higher risk for future mental health problems.
Study compared foreign adoptees with other children
The study, published on March 29, 2019, in the journal Development and Psychopathology, compared 115 children adopted from orphanages or foster care in foreign countries before age 2 with 229 children raised by at least one biologically related caregiver.
As noted in a Columbia University press release on the study, the adoptees all endured an extended period early in life separated from any parental figure, which is known to be a strong predictor of mental health problems in humans. Similar treatment in rodents has been shown to trigger fear and anxiety and harm neurological development.
In the current study, the adoptee group had higher rates of gastrointestinal symptoms like stomach aches, nausea, vomiting, and constipation. The researchers also closely examined a smaller group of 16 children — half of them adoptees and half raised by their biological parents — by collecting stool samples, behavioral information, and brain images.
The researchers found a number of patterns in the data collected from this smaller group. One result is that the adoptees had a distinctly different makeup of their gut bacteria, with less diversity in these microorganisms. Brain activity patterns were correlated with the makeup of gut bacteria, and showed a potentially greater risk of mental health issues in children who were already shown to be at greater risk for gastrointestinal issues.
Implications for mental health screening
The researchers note that while their study couldn’t determine a cause-and-effect relationship among the associations it found, it’s further evidence that gut health and brain health are closely related.
Moreover, the study suggests 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,” according to Nim Tottenham, a professor of psychology at Columbia and senior author of the study. This means, she says, that “gastrointestinal symptoms in young children could be a red flag for future emotional health problems.”
The researchers note that certain animal studies suggest it may be possible to manipulate the gut microbiome, by making dietary changes and taking probiotics, to reduce the negative neurological effects of trauma and adversity, especially early in life. But right now, there’s not enough evidence to draw this conclusion in humans.
For now, the researchers are focused on a larger-scale version of the current study to see if their findings hold up, with results expected later this year.