Scientists have discovered the strangest aspect of stem cells. Not the most useful, not the most amazing, but – while it may be both of those – it’s probably the weirdest. As it turns out, stinky breath may be bad for your social life but good for your health.

Stem cells have been found in a place called dental pulp – that’s the inside of your tooth which likes to get infected, cause excruciating pain, and then you have to get a root canal the day before your big presentation. The weird part isn’t that they found stem cells inside your teeth; we’ve known that for a while. The strangeness starts when researchers started experimenting with bad breath.

The compound hydrogen sulfide (H2S) smells like rotten eggs, and is pretty toxic as well. It not only makes your breath smell awful, but can kill you if inhaled in high doses. Your body produces hydrogen sulfide all the time, and so people have a natural resistance to the stuff – enough so that no matter how much you may want to die, the talkative man on the subway with halitosis will not harm you.

Anyway, scientists have found that forcing stem cells to differentiate properly isn’t easy. But, a study published in the Journal of Breath Research found that dental pulp stem cells turned into liver cells at a higher rate when there was a little hydrogen sulfide around – an amount similar to that found in the human body. Apparently, stem cells just love stinky poison.

And it’s a good thing, because another study, published in the Annals of Internal Medicine, found that more people in the U.S. are dying of hepatitis C than AIDS. Not only are these rates continuing to rise, it’s estimated that there are over 800,000 undiagnosed baby boomers with hepatitis C.

Baby boomers are especially vulnerable to the disease because hepatitis C is mostly transmitted through blood contact, and high quality screening for blood transfusions wasn’t available until 1992. There is also the possibility that injection drug use may have caused a jump in infection. Over the years, the disease damages the liver, and can eventually cause cirrhosis or liver cancer.

And that’s why the strange discovery of hydrogen sulfide comes just in time. The end result of hepatitis C may mean a life-saving liver transplant and those livers may need to be grown from stem cells. Stinky breath could save lives.