• The expert urge the public to be cautious and skeptical of claims made about probiotic products. (Getty Images)Source: Getty Images
In the future, psychobiotics could be used to supplement anti-depressants and anti-psychotics and improve your brain function. SBS examines whether our gut bacteria can really affect our mental functioning.
Kemal Atlay

26 Oct 2016 - 11:51 AM  UPDATED 26 Oct 2016 - 12:12 PM

What if you could simply improve your mental health by taking a ‘psychobiotic’?

Well, there’s a growing body of evidence linking the bacteria in our guts, our ‘second brain’, with neurological disorders, such as anxiety and depression. It’s also thought that our gut microbiota can influence the neurotransmitter levels in our brain that heavily control our mood and feelings of wellbeing.

But a new paper published today in Trends in Neurosciences shows that ‘psychobiotics’ could be soon used to improve our mental health.

...Psychobiotics can potentially be used to supplement or even replace antidepressants and other anti-psychotic medications in the future.

Psychobiotics: Please explain

Psychobiotics is an emerging field of neuroscience that looks at how altering your gut microbiome, either through taking a probiotic supplement or eating foods that can exert changes once fermented in the gut, can affect our neurochemistry and, ultimately, improve our mental health.

Over the last decade or so, studies in both mice and humans have shown that taking probiotics can have beneficial psychological effects, such as reducing symptoms of anxiety and depression, reducing the stress levels by influencing the stress hormone cortisol, and even improving mood.

“Those studies give us confidence that gut bacteria are playing a causal role in very important biological processes, which we can then hope to exploit with psychobiotics,” says a neurobiology expert from the University of Oxford and the paper’s lead author, Associate Professor Philip Burnet.

This means that psychobiotics can potentially be used to supplement or even replace antidepressants and other anti-psychotic medications in the future.

However, Professor Simon Brookes, an expert in gastrointestinal physiology from Flinders University, says he’s excited by the research although he remains skeptical of the wide-sweeping claims about the promise of psychobiotics.

“The whole area is very surprising, it’s popped up relatively rapidly in the last four or five years and it’s absolutely intriguing,” he tells SBS.

Brookes explains that because there is a great deal of accumulating evidence that the nervous system and the immune system interact all over the body, and that the gut is in a constant state of low-level immune system activation, “any changes in gut bacteria are likely to have an effect on the nervous system”.

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“There’s also the possibility microbiota actually release small molecules, some of which may be absorbed and get into the bloodstream, and there’s a potential for some of those to activate pathways into the brain or to cross the blood-brain barrier and directly affect brain chemistry.”

Research has also shown that gut bacteria can produce hormones and neurotransmitters that are near identical to our own, which means they can have an impact on the nervous system in the same way.

For example, in a recent study where participants were given either a probiotic or a placebo for 30 days, those who were treated with the probiotic “showed significant declines in self-reported negative mood and distress”. Urine samples also showed a marked drop in cortisol levels, which backed up the findings that stress levels had reduced.

“Probiotics are a long way from their true translational potential."

When can we buy a psychobiotic at the pharmacy?

However, both Brookes and Burnet agree there is still a long way to go to determine conclusive results .

They urge the public to be cautious and skeptical of claims made about probiotic products.

“The effects that you see in mice in experimental conditions won’t necessarily map directly to what would be happening in intact human beings leading a normal life,” says Brookes.

More research is therefore needed before we start seeing psychobiotics at the pharmacy.

“Probiotics are a long way from their true translational potential,” says Burnet.

“The technology and resources already exist for such investigations, so though we are enthusiastic, the enthusiasm needs to be tempered and channeled toward answering the core mechanistic questions.”

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