ABSTRACT Support is requested for a Keystone Symposia conference entitled Gut-Brain Axis, organized by Drs. Ann Weber, Sarkis Mazmanian and Scott Sternson. The conference will be held in Banff, Canada from March 20- 23, 2022. The gut-brain axis encompasses bidirectional communication between the gastrointestinal tract and the central nervous system (CNS). This is mediated via the autonomic nervous system, including the vagus nerve and enteric nervous system (ENS), and endocrine, immune, and metabolic pathways. These systems coordinate physiology and behavior in health and disease. The underlying mechanisms and pathways are now being elucidated in this emerging area of scientific interest. Understanding the gut-brain axis augments neurobiological mechanisms and provides opportunities to treat CNS disorders from the periphery as well as metabolic and immunologic diseases, including diverse conditions ranging from obesity to nonalcoholic steatohepatitis to neurologic and neuropsychiatric disorders. This meeting will bring together basic and applied scientists from across academia and industry to advance our understanding of gut-brain signaling. By highlighting the latest research across the components of the gut-brain axis, including vagal and ENS circuits and gut hormone and immune signaling, the role of the microbiome, and the gut-brain axis in health and disease, this meeting will catalyze increased interest, investment and cross-disciplinary collaborations to advance promising new approaches to improving human health. Finally, this meeting is being paired with the Keystone Symposia conference, Neuronal Control of Appetite. The meetings will share sessions and provide an optimal venue for participants across both conferences to interact and develop new collaborations in these fields.