John-Paul J. Yu1
1University of Wisconsin-Madison, Madison, WI, United States
Synopsis
With well-established associations
between gut microbiome populations, brain structure and function, and neurological
disease and neuropsychiatric illness, the concomitant changes in neural tissue
microstructure occurring parallel to these changes in the composition of the gut
microbiome remain poorly characterized. We present new evidence for the
neural microstructural correlates underpinning these mechanistic changes, the
association between specific gut microbiome populations and brain
microstructure, and the role of the human gut microbiome in the microstructural
complexity of the developing brain.
Altered gut microbiome
populations are associated with a broad range of neurodevelopmental disorders
including autism spectrum disorder and mood disorders. In animal models,
modulation of gut microbiome populations via dietary manipulation influences
brain function and behavior and has been shown to ameliorate behavioral symptoms.
With striking differences in microbiome-driven
behavior, we explored whether these behavioral changes are also accompanied by
corresponding changes in neural tissue microstructure. Utilizing diffusion
tensor imaging, we identified global changes in white matter structural
integrity occurring in a diet-dependent manner. Analysis of 16S ribosomal RNA sequencing of gut
bacteria also showed changes in bacterial populations as a function of diet. Changes
in brain structure were found to be associated with diet-dependent changes in
gut microbiome populations using a machine learning classifier for quantitative
assessment of the strength of microbiome-brain region associations. Additional work exploring the contribution of the human gut microbiome in germ free and gnotobiotic mice demonstrate the critical contribution of the human gut microbiome in neurodevelopment and its role in fostering complex neural microstructure. These
associations allow us to further test our understanding of the gut-brain-microbiota
axis by revealing possible links between altered and dysbiotic gut microbiome
populations and changes in brain structure, highlighting the potential impact
of diet and metagenomic effects in neuroimaging. Acknowledgements
No acknowledgement found.References
Ong IM, Gonzalez JG, McIlwain SJ, Sawin EA, Schoen AJ,
Adluru N, Alexander AL, Yu JJ.
Gut microbiome populations are associated with structure-specific changes in
white matter architecture. Transl
Psychiatry. 2018. Jan 10;8(1):6. PMID: 29317592
Torres-Velazquez M,
Sawin EA, Anderson JM, Yu JJ.
Refractory Diet-Dependent Changes in Neural Microstructure: Implications for
Microstructural Endophenotypes of Neurologic and Psychiatric Disease. Magn Reson Imaging. 58 (2019) 148-155.
PMID: 30776455
Yi SY, Barnett BR, Zhang
Y, Hurley SA, Torres-Velazquez M, Rowley PA, Hernando D, Yu JJ. Detecting Changes in Microglial Density with
Quantitative Multi-Compartment Diffusion MRI. Front Neurosci. 2019 Feb 19;13:81. PMID: 30837826