Microbes Modulate Microglia during Malnutrition

Special series of External and Friday Seminars
Wednesday, October 16, 2019

Kylynda C. Bauer, Finlay Lab, Microbiology and Immunology, University of British Columbia, Vancouver, CA

Fecal-oral contamination contributes to the persistence of malnutrition. Lasting consequences of early malnutrition include physical stunting, metabolic alterations, and impaired nervous function. We hypothesize that specific microbial exposures disrupt gut-systemic interactions, contributing to metabolic and neurological features of malnutrition. Poor diet and fecal-oral contamination (Escherichia coli/Bacteroidales exposure) trigger malnutrition features in C57BL/6 mice (MAL-BG mice). Exposure to gut microbes altered exploratory behaviour and exacerbated cognitive deficits in malnourished mice. To explore an underlying driver, we assessed microglia, neuroimmune cells that modulate brain plasticity through phagocytic processes. We propose that fecal-oral contamination alters microglial phagocytosis via oxidative stress, contributing to neurological consequences of early malnutrition. This work reveals a significant influence of gut microbes on neurometabolic function and cognition, providing insight into the complex gut-brain axis.