Pig hearts may soon be transplanted into terminally ill people to cure their life-threatening conditions. 

The science fiction idea is now one step closer to reality since a landmark study proved it was possible to keep an animal alive with a heart from another species. 

German researchers stunned the medical and scientific world by giving a baboon a pig's heart and keeping the animal alive for 195 days.  

Scientists have praised the research and called it a 'landmark' breakthrough.