Vagotomy and insights into the microbiota-gut-brain axis

•Surgical vagotomy has a long history of use in studies of physiology.•Vagotomy has identified multiple roles for the vagus nerve in gut-brain signalling.•The vagus nerve mediates bi-directional communication between the immune and central nervous systems.•The vagus nerve may be a major facilitator of neuro-immune communication along the microbiota-gut-brain axis. The Microbiota-gut-brain axis describes the bidirectional communication between central nervous system and microorganisms in the gastrointestinal tract. Increasing evidence has suggests that the vagus nerve, a major neural connection between the gut and brain, plays a key role in facilitating signaling along the microbiota-gut-brain axis. Much of this evidence has come from studies employing surgical subdiaphragmatic vagotomy. Here we provide a review of the use of vagotomy as a tool to explore the role of the vagus nerve in gut to brain signaling and the knowledge this approach has provided. We also examine how, more recently, vagotomy has contributed to the understanding of the vagus nerve as a bridge for multi-systemic communication; linking microbiota, immune and central nervous systems. Finally, we address limitations to surgical vagotomy and identify such limitations may be mitigated in future studies.