Résumé
Depression affects more than 280 million people worldwide. This disease alone cost 6.2 billion euros in healthcare expenses in 2016 for France. Reasearch into this disorder is essential, and represents a public health concern. The World Health Organization considers depression to constitute the first cause of disability in the world, which highlights the importance of developing our knowledge of this neuropsychotic pathology. The complexity of diagnosis and the poor tolerance of current treatments (numerous adverse effects reported) offer few therapeutic alternatives, resulting to resistance to the pharmacological treatments available. The pathophysiology of depression remains poorly understood, and researchs suggests that the monoaminergic axis may not be the only treatment option. Indeed, investigations into the gut-brain axis are proving a great potential as a new therapeutic alternative. It has been discovered that bidirectional communication is possible between the gut and the brain, thanks to the vagus nerve and its digestive afferents. The intestinal microbiota is therefore in direct contact with the central nervous system. Research into the gut microbiota has shown that dysbiosis has a signficant impact on the human organism, and in particular on the central nervous system. The aim of this paper is to review current knowledge of the gut-brain axis in depression, and to offer an opening to new therapeutic approach, with stimulation of the vagus nerve to treat depressive disorder resulting from dysbiosis.