If anything makes us human it’s our minds, thoughts and emotions.

And yet a controversial new concept is emerging that claims gut bacteria are an invisible hand altering our brains.

Science is piecing together how the trillions of microbes that live on and in all of us – our microbiome – affect our physical health.

But even conditions including depression, autism and neurodegenerative disease are now being linked to these tiny creatures.

We’ve known for centuries that how we feel affects our gut – just think what happens before an exam or a job interview – but now it is being seen as a two-way street.

Groups of researchers believe they are on the cusp of a revolution that uses “mood microbes” or “psychobiotics” to improve mental health.

The study that ignited the whole concept took place at Kyushu University in Japan.

The researchers showed that “germ-free” mice – those that never came into contact with microbes – pumped out twice the amount of stress hormone when distressed than normal mice.

The animals were identical except for their microbes. It was a strong hint that the […]