Researchers have launched a pioneering study aimed at finding ways to type individuals according to the bacteria in their guts. The aim is to discover if some people's microbial makeup makes them more susceptible to the side effects of radiotherapy for bowel, prostate and other cancers.

"If we can do that — if we can pinpoint those whose gut bacteria makes them more at risk of side effects than others — then we might be able to think of ways of intervening with various treatments that will boost their gut bacteria's ability to withstand radiotherapy," said one of the project's leaders, professor David Dearnaley, of the Institute of Cancer Research in London.

"In the long term, we could develop a range of new treatments for many different conditions."