Evaluation of the effect of microbiota on brain neural fiber bundles in germ-free common marmosets by structural connectome analysis

This study aimed to investigate the brain–gut correlation in common marmosets. We examined germ-free (GF) common marmoset in terms of brain connectivity between brain regions using magnetic resonance imaging. We performed three-dimensional diffusion-weighted imaging, generated whole-brain tractography, and created connectome weighted by mean fractional anisotropy (FA). We compared the difference between GF and control. In GF mice, mean FA between regions showed little difference; however, these were reduced in common marmoset compared with conventional ones. Studying the effect of microbiota on common marmoset brain might capture primate-specific characteristics and would help in exploring the microbiota effects on the human brain.