The vagus nerve provides a bi-directional link between the brain and the gastrointestinal tract, and as such, is involved in maintaining gut functions such as sensitivity, motility, and immunity. Being a major component in the control of upper gastrointestinal motility, low vagal tone has been associated with gastrointestinal motility disturbances.

In preclinical models, electrical stimulation of the vagus nerve accelerates the recovery of gastrointestinal transit. This is facilitated through vagal afferents targeting the hypothalamic–pituitary–adrenal axis and vagal efferent fibres targeting the cholinergic anti-inflammatory pathway (CAP) (Chapman et al., 2021). Targeting CAP in the gut affects the pro-inflammatory macrophages in the myenteric plexus, a network of nerves that controls the movement of food through the digestive tract (Gottfried-Blackmore et al., 2020).