Cranberries are called a superfood for a reason. Reportedly packed with fibre and more antioxidants than any other fruits and berries, cranberries are lauded for their many health benefits. They are said to boost your immune system, help prevent gum disease, reduce bad cholesterol, improve digestion and prevent urinary tract infections. However, up to now, their impact on gut microbiota – the name given to the tens of trillions of microorganisms living in our intestines – hadn’t been tested in any randomised controlled feeding trial.