Ever wondered why some people are at higher risk of contracting life-threatening infection by a dangerous bacterium? It may be the result of excess calcium found in their guts, a finding that may lead to better treatment for the most vulnerable patients, scientists say.

The study showed that increased levels of calcium in the gut, because of certain medications or supplements, triggers Clostridium difficile (C. diff) -- a bacterium that chiefly affects older patients living in nursing homes, or those who have been confined to a hospital environment for a long time.C. diff can recognise this extra calcium, along with a substance called bile salt called taurochlorate produced in the liver, to trigger its awakening and the breaking of its shell.In the study, mouse gut contents that were depleted of gut calcium had a 90 per cent lower rate of C. diff spore germination, the researchers said.

"These spores are like armored seeds, and they can pass through the gut's acidic environment intact," said Philip Hanna, Professor at the University of Michigan."Much of the spore's own weight is made of calcium, but we've shown that calcium from the gut can work with bile salts to trigger the enzyme needed to activate the spore and start the germination process," Hanna added, in the paper published in the journal PLoS Pathogens.However, for human patients, instead of cutting on calcium, adding more to the system may help.This could awaken all the dormant C. diff spores in a patient's gut at once, and make them vulnerable to antibiotics that can only kill the germinated form and could also prevent the transmission of more spores as well as slow or stop the cycle of transmission that could threaten them or other patients in the future, the researchers noted.But, Hanna cautions that the new findings should not cause any patients to stop taking their medications or doctor-recommended supplements, or to start taking new ones.