Chapter 5 Microbiota influence behavior—Work in animal models

In the past decade, evidence has accumulated using animal models to show that the microbiome influences behavior. Studies using germ-free mice have demonstrated an important role for the microbiota–brain axis in anxiety-like, depressive-like, exploratory, social, and cognitive behavior. Manipulating the microbiome with antibiotics provides additional evidence of these associations. The bidirectional interactions between the microbiome and stress using a variety of animal models of stress have revealed key bacterial taxa that influence behavior and provide evidence of the importance of microbiota-immune signaling to behavior, as well as other microbiota–brain signaling pathways. To demonstrate a role for microbiota in clinical symptoms, researchers have used fecal matter transplantation of clinically derived samples to rodents across a broad range of clinical brain disorders. This combined work provides a strong foundation for ongoing and future translational efforts to understand the mechanisms by which the microbiota regulates brain function and behavior.