My research focuses on the nutrient sensing by microglia in various pathophysiological contexts. Here, I will mainly discuss a new mechanism by which low maternal omega-3 intake alters the shaping of neural networks during neurodevelopment by disrupting microglia-mediated synaptic pruning in the hippocampus. Our data show that maternal dietary omega-3 deficiency increases microglial phagocytosis of synaptic elements in the developing hippocampus, through the activation of 12/15- lipoxygenase (LOX)/12-HETE signaling, which alters neuronal morphology and affects cognition in the postnatal offspring. These findings provide new insights into the mechanisms linking maternal nutrition to neurodevelopmental disorders.