In the medical world, it’s not so simple. Leaky gut doesn’t actually exist as a diagnosis, but something called ‘intestinal permeability’ does. This is the same concept – that the lining of the gut thins or contains ‘holes’ that let through bacteria. Only, intestinal permeability is a symptom of rare and more sinister illnesses, rather than its own medical problem.

In a 2019 review of the literature from Gut by the British Medical Journal, researchers said that it’s true that there’s evidence for “barrier dysfunction in diseases resulting in intestinal inflammation and damage such as coeliac or Crohn’s disease or ulceration from non-steroidal anti-inflammatory drugs (NSAIDs)”.

However, they state that changes to the intestinal barrier are an epiphenomenon – a by-product of these illnesses, rather than a condition that can exist on its own within healthy populations.

Leaky gut syndrome: is your gut lining really a problem?