Microbiota links to neural dynamics supporting threat processing

There is growing recognition that the composition of the gut microbiota influences behaviour, including responses to threat. The cognitive‐interoceptive appraisal of threat‐related stimuli relies on dynamic neural computations between the anterior insular (AIC) and the dorsal anterior cingulate (dACC) cortices. If, to what extent, and how microbial consortia influence the activity of this cortical threat processing circuitry is unclear. We addressed this question by combining a threat processing task, neuroimaging, 16S rRNA profiling and computational modelling in healthy participants. Results showed interactions between high‐level ecological indices with threat‐related AIC‐dACC neural dynamics. At finer taxonomic resolutions, the abundance of Ruminococcus was differentially linked to connectivity between, and activity within the AIC and dACC during threat updating. Functional inference analysis provides a strong rationale to motivate future investigations of microbiota‐derived metabolites in the observed relationship with threat‐related brain processes.
There is convincing preclinical evidence demonstrating the effect of the gut microbiota in altering brain mechanisms supporting threat processing. However, there remains a large gap in understanding how microbiota consortia engenders variability in neural dynamics underpinning human threat processing. Our study supports distinct interactions between microbial abundance patterns—reflected across different taxonomic scales—with neural dynamics supporting threat learning and threat updating processes in healthy individuals.