Four out of five people suffer from acne at some point in their life, and yet acne treatment hasn't improved in decades. But now researchers have found intriguing clues that may soon lead to new treatments that will stop acne before it ever has a chance to get established.

They didn't have to look much further than the tip of the nose, but they did have to dig a little deeper than they thought they would.

Researchers first compared the bacteria from the faces--the pores of the nose--of people with and without acne, paying special attention to one particular bacterium: Propionibacter acnes. They were surprised to find no difference in the amount of P. acnes from people with acne and people without it.

The study results suggest several new approaches to treating acne. If the good strain of P. acnes is policing the skin and preventing bad strains from setting up shop and causing zits, a probiotic cream enriched in the good strain might restore order to blemished skin.

They hit the jackpot though when they used genetic analysis to divide the P. acnes into different strains (variants) and looked for differences in which strains were present on people with and without acne.

Healthy people had a strain of P. acnes in their pores that the people with acne lacked, suggesting that this strain protects the skin from acne-causing strains or from other bacteria such as Staphylococcus aureus. And about 20% of the people with acne had one of two P. acnes strains on their skin that weren't found on healthy skin.

The findings echo the situation in the gut, where beneficial bacteria fight disease and help keep unhealthy microbes in check.

In this age of hand sanitizers and antibacterial cleansers, people often forget that it's normal to have bacteria on their skin. And just like in the gut, it makes a big difference which bacteria are living in the neighborhood.

The study results suggest several new approaches to treating acne. If the good strain of P. acnes is policing the skin and preventing bad strains from setting up shop and causing zits, a probiotic cream enriched in the good strain might restore order to blemished skin. A simple skin test could predict who's most at risk for developing acne later on in their life. And with good and bad strains identified, it may be possible to develop targeted drugs that kill the bad strain while leaving the good ones alone.

Though P. acnes has been associated in some way with acne development for over a century, its precise role in acne formation has always been unclear. That role may just have gotten a bit clearer. And because of that, people's skin may get clearer too.

The study is published online in the Journal of Investigative Dermatology.