Researchers believe the antibacterial properties extracted from the Persian shallot could increase the effects of existing antibiotic treatment.

They said this could help "reverse the tide" of drug-resistant TB, which infected 490,000 people in 2016.

But they said the research was still in its early stages and clinical trials would need to follow. In the ongoing study, led by Birkbeck, University of London and University College London, the research team conducted tests on four different molecules from the shallots, which are a staple of Iranian cooking.