Some gut feelings are a red flag, according to research

March 21, 2018 by Dave Heller, Florida State University
Credit: CC0 Public Domain

Are you guided by gut feelings?

A Florida State University neuroscientist concludes you are, if not by choice then perhaps subconsciously. Research by psychology professor Linda Rinaman finds gut-to- signals are a powerful influence on emotions, mood and decisions—typically by prompting you to avoid certain situations.

The paper, published in Physiology and co-authored by James Maniscalco, a postdoctoral research associate at the University of Illinois at Chicago, advances scientists' understanding of how the gut-to-brain circuit operates.

"We are excited about the animal research reviewed here, including our own work, because it potentially translates to humans," Rinaman said. "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."

Rinaman said the gut and brain are constantly talking to each other via the vagus . It's a sprawling two-way network connecting the brain to the gastrointestinal tract, which has an enormous surface area and a lot of "sensors." The GI tract is more than 100 times larger than the surface of the skin, and it sends more signals to the brain than any other organ system in the body.

The vagus nerve is known as the "wandering nerve" because it wanders throughout the chest and abdomen, monitoring and controlling digestion, heart rate, blood pressure, immune function and hormone levels. It's the longest of a dozen cranial nerves and operates as a two-way circuit that carries top-down messages from the brain to the body, as well as bottom-up messages commonly described as .

Those gut-to-brain signals are a powerful influence on emotions and behavior, especially in response to worrisome or threatening stimuli and events. The nerve is part of an elaborate protective system that helps shape decisions, typically by prompting us to slow down and evaluate a situation, or avoid it altogether.

"Vagal feedback signals are very protective and encourage caution," Rinaman said.

Scientific and anecdotal evidence suggests a poor diet can cause those protective, cautionary signals to get out of whack, leading to altered mood and behavior. For example, Rinaman said, a high-fat diet can promote a low-grade inflammatory response in the GI tract, changing vagal signals and possibly exacerbating symptoms of anxiety, depression or other disturbed mental states.

Rinaman said the types of bacteria within your gut are shaped by your diet, and those bacteria can affect your emotional and cognitive state.

"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," Rinaman said. "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."

It's also unclear why a treatment using electrical stimulation of the vagus nerve helps alleviate clinical depression. Approved for patients who don't respond well to prescription drugs or other therapies, vagal nerve stimulation changes the signals received by the brain and can have a positive impact.

Scientists don't understand how or why it works, but its effectiveness generates more motivation for researchers like Rinaman.

"The neuroscience of gut feelings has come a long way in my lifetime," Rinaman said, "and we are learning more valuable lessons every day."

Explore further: Boosting neural pathway from gut to brain could play part in weight control

Related Stories

Boosting neural pathway from gut to brain could play part in weight control

July 31, 2014
A Purdue University study found an increase in sensory nerve fibers that send signals from the gut to the brain reduces the time spent eating a meal, which could help regulate body weight.

Targeting neurotransmitter may help treat gastrointestinal conditions

December 4, 2012
Selective targeting of the neurotransmitter that differentially affects brain cells that control the two distinct functions of the pancreas may allow for new medication therapies for conditions like diabetes, dyspepsia and ...

Vagus nerve stimulation promising in Crohn's disease

May 3, 2017
(HealthDay)—Vagus nerve stimulation may represent a new therapeutic option for patients with Crohn's disease (CD), according to a report published online April 18 in the Journal of Internal Medicine.

Vagus nerve stimulation therapy shows progress in battling PTSD symptoms

October 23, 2017
Researchers at The University of Texas at Dallas are exploring how mild stimulation of the vagus nerve could help alleviate symptoms of post-traumatic stress disorder (PTSD), a complex condition that can cause debilitating ...

Even without nudging blood pressure up, high-salt diet hobbles the brain

January 16, 2018
A high-salt diet may spell trouble for the brain—and for mental performance—even if it doesn't push blood pressure into dangerous territory, new research has found.

How the gut feeling shapes fear

May 22, 2014
We are all familiar with that uncomfortable feeling in our stomach when faced with a threatening situation. By studying rats, researchers at ETH Zurich have been able to prove for the first time that our 'gut instinct' has ...

Recommended for you

FDA approves brain stimulation device for OCD

August 17, 2018
(HealthDay)—A brain stimulation device to treat obsessive-compulsive disorder (OCD) has received approval for marketing Friday by the U.S. Food and Drug Administration.

People are more honest when using a foreign tongue, research finds

August 17, 2018
New UChicago-led research suggests that someone who speaks in a foreign language is probably more credible than the average native speaker.

Research eyes role of stress in mental illnesses

August 17, 2018
We all face stress in our lives. Even researchers seeking to understand why some people shrug it off while others face battles against disorders like depression or PTSD.

16 going on 66: Will you be the same person 50 years from now?

August 17, 2018
How much do you change between high school and retirement? The answer depends on whether you're comparing yourself to others or to your younger self.

Men and women show surprising differences in seeing motion

August 16, 2018
Researchers reporting in the journal Current Biology on August 16 have found an unexpected difference between men and women. On average, their studies show, men pick up on visual motion significantly faster than women do.

It's okay when you're not okay: Study re-evaluates resilience in adults

August 16, 2018
Adversity is part of life: Loved ones die. Soldiers deploy to war. Patients receive terminal diagnoses.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.