The gut microbiota modulates brain network connectivity under physiological conditions and after acute brain ischemia

Aswendt, Markus; Green, Claudia; Sadler, Rebecca; Llovera, Gemma; Dzikowski, Lauren; Heindl, Steffanie; Aguero, Mercedes Gomez de; Diedenhofen, Michael; Vogel, Stefanie; Wieters, Frederique; Wiedermann, Dirk; Liesz, Arthur and Hoehn, Mathias (2021): The gut microbiota modulates brain network connectivity under physiological conditions and after acute brain ischemia. In: Iscience, Vol. 24, No. 10, 103095

Abstract

The gut microbiome has been implicated as a key regulator of brain function in health and disease. But the impact of gut microbiota on functional brain connectivity is unknown. We used resting-state functional magnetic resonance imaging in germ-free and normally colonized mice under naive conditions and after ischemic stroke. We observed a strong, brain-wide increase of functional connectivity in germ-free animals. Graph theoretical analysis revealed significant higher values in germ-free animals, indicating a stronger and denser global network but with less structural organization. Breakdown of network function after stroke equally affected germ-free and colonized mice. Results from histological analyses showed changes in dendritic spine densities, as well as an immature microglial phenotype, indicating impaired microglia-neuron interaction in germ-free mice as potential cause of this phenomenon. These results demonstrate the substantial impact of bacterial colonization on brain-wide function and extend our so far mainly (sub) cellular understanding of the gut-brain axis.

• Item Type: Journal article
• Faculties: Medicine; Medicine > Munich Cluster for Systems Neurology (SyNergy)
• Subjects: 600 Technology > 610 Medicine and health
• Language: English
• DFG: Gefördert durch die Deutsche Forschungsgemeinschaft (DFG) - 390857198