How To Eat Yourself Happy

Your body hosts a colony of creatures that build their lives around you. Now, scientists are beginning to see that not only do they influence your health, they can even change your mind, too. Welcome to the world of psychobiotics

- Simon Crompton

There’s a school of thought that says you are not one single organism, but rather a superorganism made up of many. Human cells make up less than half of what you call ‘you’ – the rest are trillions of bacteria, fungi, and viruses in your gut, on your skin and throughout your tissues. You need them because of the role they play in digesting your food and maintaining a healthy immune system. They need you because they need somewhere to live.

Now, research is providing evidence that you have an extra reason to treasure the microbes living in the depths of your bowels: if they’re happy, you’re happy too. The hitherto ludicrous-sounding idea that what happens in your intestines affects your mood, has now got scientific backing. And it’s become clear that it’s your gut bacteria that are doing the communicating with your brain and affecting your state of mind.

Scientists are providing evidence for this link, which they refer to as the ‘microbiome-gut-brain axis’. Not only that, but they are showing that altering your gut bacteria (microbiota) by administering probiotics (live bacterial supplements) and prebiotics (dietary fibre supplements that encourage bacterial growth), you can actually improve stress response, reduce anxiety and mitigate the effects of other mental health problems.

These findings are giving rise to a whole new class of medicines: psychobiotics. The hope is that they will eventually provide powerful new treatments for depression and other mental health conditions, as well as helping us to deal with everyday stress and anxiety.

In 2019, a large review of studies found that probiotics yielded a small but significant effect in reducing anxiety and depression. A smaller study, published in the journal Translational Psychiatry, found that introducing a