Ask an expert

Professor Barry Marshall, microbiologist at the University of Western Australia

Q

Does the human appendix have a function?

A

For most of history we had no idea what the appendix was for. Recently, however, it has been linked to maintaining a healthy gut. Before antibiotics, an infection could cause lots of diarrhoea, flushing out ‘good’ gut flora in our intestines. The shape and position of the appendix makes it ideal as a reservoir of healthy bacteria to repopulate the gut after these episodes. This theory is supported by a 2012 study, which found that people without an appendix were four times more likely to suffer recurrent infections. Scientists have found that it has evolved independently at least 30 times in mammals, suggesting it’s important.