We’re often told to trust our intuition and “go with our gut.” Why? Where did this saying come from? Well, it’s actually quite literal: when we find ourselves in an uncomfortable or potentially troublesome situation, we get “butterflies,” or a nervous feeling in the “pit of our stomach.” In this case, we’re programmed to put up our guard and react with fight or flight—hence, to “go with our gut.”
But is this really an effective decision-making tool? Not always, according to researchers from Florida State University. Their study, which will be published in Physiology, says that gut-to-brain signals have a significant impact on our emotions, our moods, and our decisions, and are designed to be cautionary and protective; however, these protective signals can’t always be trusted. They can go awry and alter our mood and behavior for the worst if we don’t maintain a healthy diet, possibly worsening feelings of anxiety, depression, and other serious mental illnesses or states.

The researchers reached these findings by studying gut-to-brain circuit operations in animals. “We are excited about the animal research viewed here, including our own work, because it potentially translates to humans,” explained lead researcher and psychology professor Linda Rinaman. “We know the gut-brain pathways are very similar across mammalian species—from mouse to human. We expect these lines of research will help us better understand how gastrointestinal functions contribute to both normal and disordered mental function.”

According to Rinaman, the brain and gut are in constant communication via the vagus nerve, or the “wandering nerve,” which connects the brain to the gastrointestinal tract. The GI tract has an incredibly large surface area and sends more signals (including those messages we call gut feelings) to the brain than any other organ system. These signals have a powerful impact on our emotions, our moods, and our behavior, particularly when we are faced with a potential threat. Most often, it prompts us to calm down and think over the situation, or to run from it.

However, there is evidence to suggest that a poor diet can cause these signals to go a little haywire and lead to troublesome changes in mood and behavior. For instance, a diet high in fat can affect inflammatory responses in the GI tract, alter vagal signals, and in turn, possibly worsen symptoms of mental disorders and states, like anxiety and depression. In sum, the type of bacteria in your gut depends heavily on your diet and can affect you both emotionally and mentally.

Rinaman concludes that there’s still a plethora of research to be done in this area; however, strides are being made: “Evidence shows that modifying the diet, perhaps by consuming probiotics, can impact your mood and behavioral state. That’s very clear in animal and human studies. But how does that work? Does it involve the microbiome that you feed in your gut and how those bacteria send signals back to the brain through the vagus nerve? That area of research has exploded in the last few years and, currently, there are many more questions than answers.”

Florida State University (2018, March 21). Some Gut Feelings Are A Red Flag. NeuroscienceNews. Retrieved March 21, 2018 from http://neurosciencenews.com/gut-emotion-behavior-8682/