Miriam Frankel and Matt Warren write:

Your gut is a bustling and thriving alien colony. They number in their trillions and include thousands of different species. Many of these microorganisms, including bacteria, archaea and eukarya, were here long before humans, have evolved alongside us and now outnumber our own cells many times over. Indeed, as John Cryan, a professor of anatomy and neuroscience at University College Cork, rather strikingly put it in a TEDx talk: “When you go to the bathroom and shed some of these microbes, just think: you are becoming more human.”

Collectively, these microbial legions are known as the “microbiota” – and they play a well-established role in maintaining our physical health, from digestion and metabolism to immunity. They also produce vital compounds the human body is incapable of manufacturing on its own.

But what if they also had a hotline to our minds? In our new book, Are You Thinking Clearly? 29 Reasons You Aren’t And What To Do About It, we explore the dozens of internal and external factors that affect and manipulate the way we think, from genetics, personality and bias to technology, advertising and language. And it turns out the microbes that call our bodies their home can have a surprising amount of control over our brains.

Over the last few decades, researchers have started to uncover curious, compelling – and sometimes controversial – evidence to suggest that the gut microbiota doesn’t just help to keep our brains in prime working order by helping to free up nutrients for it from our food, but may also help to shape our very thoughts and behaviour. Their findings may even potentially bolster how we understand and lead to new treatments for a range of mental health conditions, from depression and anxiety to schizophrenia.

The picture is still very far from complete, but in the wake of the Covid-19 pandemic, which has had a deleterious impact on people’s mental health in many parts of the world, unpicking this puzzle could be more important than ever. [Continue reading…]