A symposium at Weill Cornell Medicine-Qatar (WCM-Q) explored the impact on health of the complex interactions between the nervous system, the gut and the microbiota – the micro-organisms living in the gut.
The activity, directed by Dr Ghizlane Bendriss, visiting lecturer in biology, focused in particular on the vagus nerve and its role as a mediator of microbiota-gut-brain communication. 
As the longest cranial nerves in the human body, the two vagus nerves run from the brainstem, through the neck and into the abdomen, connecting the brain with many disparate organs, muscles and structures, including the colon. 
A growing body of research suggests that the complex interactions between the microbiota, the gut and the brain are important determinants of human health, and that an imbalance in the gut microbiota could be a causal factor in a variety of conditions, including ulcerative colitis, irritable bowel syndrome, Crohn’s disease, diabetes, obesity, Parkinson’s disease and many other neurodegenerative diseases and neuropsychiatric disorders. 
As the conduit for many of these interactions, the vagus nerve is a logical target for researchers. 
Dr Bendriss said, “This symposium aims to provide an update on one of the key routes that allows the bidirectional communication between the gut and the brain: the vagus nerve. This is a very exciting area of research that holds a lot of potential for enhanced understanding of chronic inflammatory diseases and other conditions that we hope will lead to improved or novel treatments and preventative measures.”
The workshop heard a presentation by Dr Riham Shadid, a diabetes educator and health coach, who defined the gut microbiota and the main mechanisms involved in the gut-brain axis and explained the role of antibiotics, probiotics and lifestyle on microbiota diversity and inflammatory processes. 
Dr Mehdi Djelloul, a postdoctoral researcher, described the anatomical connection between the gut and the brain and presented concrete studies that illustrate the role of the vagus nerve under inflammatory conditions and how the microbiota is involved in this process, while giving clinical examples that could benefit from modulating the gut-brain-axis. 
There were also question-answer sessions to allow participants to discuss the topics raised at the event, which had the full title, ‘The vagus nerve as a key mediator of the microbiota-gut-brain axis: from research to clinical implications’.