This gut-brain crosstalk, we’ve learned, is governed by something called the vagus nerve, which is considered the main channel of communication between the GI tract and the brain (and which sends signals in both directions). As the longest nerve in your body, the vagus nerve runs from the base of the brain through the neck and then branches out in the chest stretching all the way down to the abdomen, touching the heart and almost all major organs on its way—and its effects on both physical and mental health are extensive. All of which is to say, how well the vagus nerve is functioning—and thus, how well the gut and the brain are communicating—can have an effect on everything from anxiety levels to heart rate to digestion to weight gain, and much more. Among other things, this poor vagal functioning can lead to stagnation and bacterial overgrowth in the GI tract, and, in turn, these “bad” gut microbes may influence the activity of the hypothalamus-pituitary-adrenal (HPA) axis via the vagus nerve, which can affect important neuronal cellular activity in the brain and lead to inflammation and neurodegeneration. Which goes to show you how it’s all connected. But that’s not all. Here are some other problems associated with low vagal tone, or an underperforming vagus nerve: These are just a few things you can do to improve brain function, gut function, and everything in between. Sometimes complex pathways can respond to simple interventions.
