Associations Between Gut Microbes and Social Behavior in Healthy 2-Year-Old Children.

Objective: Emerging research has connected abundances of specific bacteria to differences in psychosocial behaviors in animals and adult humans. However, research assessing mind-microbiome associations in children is sparse with extant work primarily focused on populations with autism, making it unclear whether links are also present in typically developing children. The current study fills this gap by examining associations between prosocial-self-regulating temperaments (effortful control; EC) and the gut microbiome in typically developing children.

Methods: Maternal ratings of temperament were assessed in 77 toddlers 18 to 27 months of age (46.7% female, mean age = 23.14 months). Next-generation pyrosequencing of the V1-V3 region of the 16S rRNA gene was used to classify children's gut microbial composition from fecal samples. EC included the following subcategories: cuddliness, attentional focusing, attentional shifting, inhibitory control, and low-intensity pleasure.

Results: After adjusting for covariates, EC was positively associated with relative abundances of Akkermansia (Δ R2 = 0.117, b = 0.022, SE = 0.007, p = .002), with cuddliness (i.e., joy and ease of being held) driving the relation. Furthermore, attentional focusing was negatively associated with Alistipes (Δ R2 = 0.062, b = -0.011, SE = 0.005, p = .028). Permutational analysis of variance revealed no significant differences in community structure between high and low EC groups on the phylum level ( R2 = 0.00372, p = .745) or the genus level ( R2 = 0.01559, p = .276).

Conclusions: Findings suggest that certain microbes may be linked to prosocial behaviors used to regulate emotion in typically developing children. Further research is needed to test whether these observations replicate in larger samples.