Why you should never ignore your gut instinct

Our "gut feelings" are part of an elaborate protective system that prompts us to slow down and evaluate a situation, or avoid it completely, scientists said. Photo / Getty Images

If you're having a hard time making a decision, then trust your gut instinct.

That's the advice of scientists who claim our instinctive reactions act as a 'red signal' that stops our brain from making mistakes.

Our 'gut feelings' are part of an elaborate protective system that prompts us to slow down and evaluate a situation, or avoid it completely, scientists said.

The research, from Florida State University in Tallahassee, advances our understanding of the gut-to-brain circuit - a poorly understood part of the body, reports Daily Mail.

"The neuroscience of gut feelings has come a long way in my lifetime," said study coauthor and Florida State neuroscientist Dr Linda Rinaman.

"And we are learning more valuable lessons every day."

The gastrointestinal 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.

It talks to the brain via the vagus or "wandering" nerve, a super highway of nervous signalling that snakes up the body from organ to organ.

The nerve carries top-down messages from the brain to the body as well as bottom-up messages commonly described as "gut feelings".

While it's clear there's a lot of communication between the brain and gut, scientists have struggled to determine how much these feelings affect our decision making.

In the new study, Dr Rinaman worked with Florida State colleague Dr James Maniscalco to pull together a review of all recent research into gut feelings.

They argue signals from our gastrointestinal tract can work as a red signal to stop us from making mistakes.

The messages push us to avoid dangerous situations by cutting off reward systems in the brain.

This has a powerful influence on emotions and behaviour, especially in response to worrisome or threatening events, the researchers found.

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

Evidence suggests eating poorly can cause the gut's protective, cautionary signals to falter, leading to altered mood and behaviour.

For example, Dr Rinaman said, a high-fat diet can lead to inflammatory response in the GI tract, changing signals from the vagus nerve which can lead to symptoms of anxiety and depression.

She added that 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 behavioural state," Dr 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."