Ever wondered why you get butterflies in your stomach when you’re nervous or maybe you tend to be irritable when your stomach is upset? This is because the bacterial population in your gut and the connection from your digestive tract to your vagus nerve combine to dramatically influence your central nervous system and brain function. Neurotransmitters like GABA and serotonin are even produced in the gut! Although most of the nerve signals actually travel from the gut to the brain, the relationship goes both ways, having a vital impact on our immune systems, mental health, and overall well-being.