Gut Microbiome Composition Mediates the Association of Left Inferior Parietal Lobule and Personality Traits.

Although numerous studies showed the linkage of microbiome-gut-brain interaction with psychological traits, the underlying mechanisms on how brain anatomy and gut microbiome profile jointly influence personality traits remain unclear. Here, we collected structural magnetic resonance imaging data, together with stool samples and assessment of personality traits of 61 healthy adults. Voxel-based morphometry was applied to estimate gray matter (GM) volumes, and 16s sequencing was used for gut microbiome analysis. We conducted correlation and mediation analysis to evaluate the relationships among brain structure, composition of gut microbiome and personality traits. Besides, mediation analysis revealed the mediation of genus Alistipes on the association of inferior parietal lobule GM volume on trait agreeableness. Our findings provide potential evidence of the composition of gut microbiome as a mediator that influences the association of brain morphometry and personality traits.