We will be able to conquer fear by manipulating the bacteria in our gut, according to pioneering Irish research.
In the future, doctors may even be able to successfully treat conditions like post traumatic stress disorder by controlling the type of bacteria in a patient's gastro-intestinal tract.
Studies carried out with mice show that the rodents' gut bacteria trigger fear via a region of the brain known as the amygdala - and it is believed this may also happen in humans.
Eventually, scientists may be able to 'manipulate' gut bacteria to control the fear response - not just in mice, but in humans.
Research at University College Cork has shown that the microbiome, the collective trillions of bacteria within the gastrointestinal tract, works to regulate fear responses and modifies the brain function of adult mice.
"The amygdala is a part of the brain present in both mice and humans and has been shown to be important for the expression of fear and anxiety in both mice and men," said Dr Gerard Clark, of the Science Foundation Ireland-funded APC Microbiome Institute at UCC.
The institute is carrying out the research, whose latest findings are published in the latest issue of 'Nature Journal Molecular Psychiatry'.
"The fact that we can pinpoint this to the amygdala in these animals is very important.
"What we did not know is that we could target the gut bacteria to control the brain response in a mouse.
"Our research shows the gut bacteria trigger fear via the amygdala in mice.
"Therefore, we might extrapolate that a similar situation may pertain in humans and that we may target the microbiota with prebiotics which could increase the growth of beneficial bacteria.
"Our next step is to see if we can control the fear response by manipulating the bacteria in the gut of the mouse," he explained, emphasising, however, that the research was still only at a preliminary stage.
"We are at a very early stage in animal testing, but down the road the hope is that we would be able to manipulate the gut bacteria to try to control excessive fear such as in the case of post traumatic stress disorder.
"Essentially we would bring our research from the laboratory to the bedside," he observed.
Fear is a normal response that allows an individual to deal with an impending threat.
The neurobiology of fear is evolutionarily hardwired and regulated by the amygdala.
"Understanding the factors that regulate fear and fear-associated memories is an important step towards developing therapies for disorders where excessive brain responses to fear memories are manifested, such as post traumatic stress disorders," Dr Clarke added.
Over the past decade, he said, it had become increasingly clear that the microbiome plays a clear role in our health and well-being.
"Perhaps most surprising of all is the realisation that gut bacteria influence brain function and behaviour by manipulating bacteria in our gut," he said.