This episode delves into the fascinating world of host-associated microbiotas with renowned scientist Dr. Eisen. His groundbreaking research uncovers how microbiotas guide the trajectory of developmental programs and influence social behavior.

Dr. Eisen's team discovered that the zebrafish microbiota is required for normal social behavior, revealing a molecular pathway that connects the microbiota, microglial remodeling of neural circuits, and social behavior. This exploration was conducted using the experimentally tractable model vertebrate, the zebrafish.

We discuss in depth how the microbiota restrains neurite complexity and targets forebrain neurons necessary for normal social behavior. We also delve into how the microbiota is crucial for localizing forebrain microglia, brain-resident phagocytes that remodel neuronal arbors.

Dr. Eisen's research indicates that the microbiota influences microglial molecular functions, promoting the expression of the complement signaling pathway and the synaptic remodeling factor c1q. He shares with us his intriguing finding that several distinct bacterial taxa are individually sufficient for normal microglial and neuronal phenotypes, suggesting that host neuroimmune development is sensitive to a feature common among many bacteria.

In this illuminating conversation, we explore how understanding the connection between microbiota and social behavior can open up pathways for new interventions in multiple neurodevelopmental disorders. Join us as we navigate this complex and intriguing interplay between our microbiota and our brains.

Key Words: Microbiota, Neurodevelopment, Social Behavior, Microglial Remodeling, Neural Circuits, Zebrafish, Neurite Complexity, Forebrain Neurons, Neuroimmune Development, Neurodevelopmental Disorders.

Eisen et al. (2022) The microbiota promotes social behavior by modulating microglial remodeling of forebrain neurons. doi:10.1371/journal.pbio.3001838