Pineapples are the latest - and strangest - weapon to emerge in the global battle against superbugs which are predicted to kill up to 10 million people a year by 2050.

Australian scientists have discovered that a collection of enzymes found in the stems and roots of the tropical fruit can cure diarrhoea in piglets, reducing the reliance on antibiotics.

Being able to treat farmed piglets with a natural remedy for diarrhoea also takes antibiotics out of the human food chain.

La Trobe University biochemist Rob Pike said the collection of enzymes found to treat diarrhoea in piglets would likely provide an alternative treatment for the condition in humans as well, given the similarities in physiology and anatomy between the two species.

“Indiscriminate use of antibiotics has resulted in resistant bacteria,” Professor Pike said. “And this contributes to the rise of superbugs.”

Multi-drug resistant bacteria, known as superbugs, are predicted to kill more people than cancer if left unchecked - about 10 million people a year by 2050. About 500 superbug cases are detected in Australia each year.

Developing a natural alternative to treating diarrhoea in pigs and humans would significantly add to scientists’ arsenal when tackling the global superbug problem.

Unlike antibiotics which target the bacteria, the three enzymes found in the pineapples work with the cells in the pig’s gut, making it difficult for the bacteria to attach to the cells. This means diarrhoea doesn’t take hold.

“I believe this is a whole new way of going about the treatment of diarrhoea,” Professor Pike said. “It means that the pig cells are no longer vulnerable to bacteria.”

Pig farmers rely heavily on antibiotics to treat scour, pre-weaning diarrhoea in piglets. Scour is a common cause of death in piglets, which costs the Australian pig industry more than $7 million a year.

Targeting the gut cells is key because it denies the bacteria the chance to evolve and become resistant. It is resistance which researchers and health professionals fear could eventually render antibiotics useless.

The three enzymes found in the pineapple stem and root are called bromelain, a collection of enzymes which were discovered in the 1930s. However it was only 30 years ago that their antibiotic qualities were discovered.

“The momentum to develop alternatives to antibiotics is there now because people believe antibiotics are on the way out and we need something to replace them,” Professor Pike said.

Anatara Lifesciences, which has conducted animal trials, is developing the alternative treatment with Professor Pike and colleague Lakshmi Wijeyewickrema.