FRIDAY, Oct. 31, 2025 (HealthDay News) — A child’s future risk of depression and anxiety might be tied to their gut health.

Young children whose gut microbiomes contained certain bacteria were more likely to develop a mood disorder as tweens, researchers reported Oct. 30 in the journal Nature Communications.

Researchers discovered that the kids’ gut bacteria were tied to differences in connectivity between emotion-related brain networks – and that those differences, in turn, were linked to anxiety and depression later in childhood.

The results suggest that gut bacteria could play a role in programming a child’s brain circuits, particularly those related to emotion, researchers said.

“By linking early-life microbiome patterns with brain connectivity and later symptoms of anxiety and depression, our study provides early evidence that gut microbes could help shape mental health during the critical school-age years,” senior researcher Bridget Callaghan, chair of developmental psychology at UCLA, said in a news release.

For the new study, researchers analyzed data from 55 children in Singapore participating in a long-term health study. The children provided stool samples at age 2 and MRI brain scans at age 6, and caregivers filled out surveys about the kids’ behavioral problems at 7-1/2.

The team found that children whose gut microbiomes with higher levels of Clostridiales and Lachnospiraceae bacteria were at higher risk of symptoms of depression and anxiety.

These two bacterial groups have been linked to stress response and depression in adults, Callaghan noted. Clostridiales bacteria in particular tend to be harmful, with certain strains linked to tetanus, gangrene and botulism.

Future research will drill down into exactly which bacteria are linked to mood problems and whether the observed link is a direct cause-and-effect relationship, she said.

“We need to figure out what species within these larger groups are driving the findings,” Callaghan said. “Once we have that information, there are relatively straightforward ways to change the microbiome, like probiotics or diet, that we could use to address issues.”

More information

The Cleveland Clinic has more on the gut microbiome.

SOURCE: UCLA, news release, Oct. 30, 2025