Is-there a place for vagus nerve stimulation in inflammatory bowel diseases?

The vagus nerve (VN), the longest nerve of the organism that innervates the gastrointestinal tract, is a mixed nerve composed of 80% of afferent and 20% of efferent fibers. The VN has anti-inflammatory properties, in particular an anti-TNFα effect through the cholinergic anti-inflammatory pathway. The VN is a key component of the autonomic nervous system, i.e. the parasympathetic nervous system. An imbalance of the autonomic nervous system, as represented by a low vagal tone, is described in many diseases and has a pro-inflammatory role. Inflammatory bowel diseases (IBD) are chronic disorders of the gastro-intestinal tract where TNFα is a key cytokine. VN stimulation (VNS), classically used for the treatment of drug resistant epilepsy and depression, would be of interest in the treatment of IBD. We have recently reported in a 6 month follow-up pilot study that VNS improves active Crohn's disease. Preliminary data of another pilot study confirm this interest. Similarly, VNS has recently been reported to improve rheumatoid arthritis, another TNFα mediated disease. Bioelectronic Medicine, as represented by VNS, opens new therapeutic avenues in the treatment of such chronic inflammatory disorders. In the present manuscript, we will focus on the interest of VNS in IBD.