Background: Understanding the dynamics of the gut-brain axis has clinical implications for physical and mental health conditions, including obesity and anxiety. As such disorders have early life antecedents, it is of value to determine if associations between the gut microbiome and behavior are present in early life in humans. Methods: We used next generation pyrosequencing to examine associations between the community structure of the gut microbiome and maternal ratings of child temperament in 77 children at 18-27. months of age. It was hypothesized that children would differ in their gut microbial structure, as indicated by measures of alpha and beta diversity, based on their temperamental characteristics. Results: Among both boys and girls, greater Surgency/Extraversion was associated greater phylogenetic diversity. In addition, among boys only, subscales loading on this composite scale were associated with differences in phylogenetic diversity, the Shannon Diversity index (SDI), beta diversity, and differences in abundances of Dialister, Rikenellaceae, Ruminococcaceae, and Parabacteroides. In girls only, higher Effortful Control was associated with a lower SDI score and differences in both beta diversity and Rikenellaceae were observed in relation to Fear. Some differences in dietary patterns were observed in relation to temperament, but these did not account for the observed differences in the microbiome. Conclusions: Differences in gut microbiome composition, including alpha diversity, beta diversity, and abundances of specific bacterial species, were observed in association with temperament in toddlers. This study was cross-sectional and observational and, therefore, does not permit determination of the causal direction of effects. However, if bidirectional brain-gut relationships are present in humans in early life, this may represent an opportunity for intervention relevant to physical as well as mental health disorders.
Bibliographical noteFunding Information:
This study was supported by an Innovative Initiative Award to M.T.B. and L.M.C. from the Food Innovation Center at The Ohio State University . This study was also supported by awards from NINR ( R01 NR01366 ) and NICHD ( R21 HD067670 ) to L.M.C., NCCAM ( R01 AT006552 ) to M.T.B. and NIDCR ( T32 DE014320 ). This study was supported by the Ohio State University Center for Clinical and Translational Sciences (CCTS), funded by UL1TR001070 from the National Center for Advancing Translational Sciences . The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Center for Research Resources or the National Institutes of Health.
- Early life
- Gut microbiome
- Gut-brain axis