Gut Microbiota at the Age of 3 Years Predicts Problematic Behaviors at Age 5 via Explicit Emotional Regulation: A Longitudinal Study

Problematic behaviors during childhood predict an increased risk of mental health problems such as depression and developmental disorders at later stages. Recent evidence suggests that gut microbiota may affect the development of executive function (EF), mainly explicit emotion regulation (EER), contributing to behavioral problems. This longitudinal study aimed to examine whether the composition of gut microbiota at 3 years of age may predict the risk of problematic behaviors at 5 years via EER. Data from 68 typically developing preschool children of these two age groups were analyzed. The composition of their gut microbiota was profiled using 16S rRNA gene sequencing. EF development was evaluated based on the Behavior Rating Inventory of Executive Function–Preschool Version. The problematic behavioral risk in children aged 1.5–5 years was measured meanwhile, utilizing the Child Behavior Checklist. Mediation analyses were performed employing gut microbiota indices as independent variables, problematic behavioral risk as an outcome, and EF components as mediators. The results suggested that at age 5, a higher risk of externalizing and internalizing problematic behaviors could be predicted by a higher relative abundance of the genus Coprobacillus at age 3. At age 5, a lower relative abundance of the genus Granulicatella was associated with a higher risk of internalizing problematic behaviors. These findings highlighted that the composition of gut microbiota may serve as informative markers of subsequent mental health risk.