Acne vulgaris (zits) are a common teen affliction; however, one of five individuals go through their teen years with only a rare appearance of them. The bacteria that cause acne live on everyone’s skin, so why do some teens never experience a zit crop on the eve of the senior prom? UCLA researchers have discovered the reason; they found that acne bacteria contain “bad” strains associated with zits, and “good” strains that may protect the skin. The research could lead to a host of new therapies to prevent and treat the condition. They published their findings on the February 28 edition of the Journal of Investigative Dermatology.
“We learned that not all acne bacteria trigger pimples; one strain actually may help keep skin healthy,” explained lead author Huiying Li, an assistant professor of molecular and medical pharmacology at the David Geffen School of Medicine at UCLA. She added, “We hope to apply our findings to develop new strategies that stop blemishes before they start, and enable dermatologists to customize treatment to each patient’s unique cocktail of skin bacteria.”
The researchers looked at a tiny bacterium with a big name: Propionibacterium acnes; the organism thrives in the oily depths of our pores. When the bacteria aggravate the immune system, they cause the swollen, red bumps associated with acne. Using over-the-counter pore-cleansing strips, LA BioMed and UCLA researchers lifted P. acnes bacteria from the noses of 49 pimply and 52 clear-skinned volunteers. After extracting the microbial DNA from the strips, Dr. Li’s laboratory tracked a genetic marker to identify the bacterial strains in each volunteer’s pores and recorded whether the person suffered from acne.
The researchers next cultured the bacteria from the strips to isolate more than 1,000 strains. Washington University scientists sequenced the genomes of 66 of the P. acnes strains, enabling UCLA co-first author Shuta Tomida to focus on genes unique to each strain. “We were interested to learn that the bacterial strains looked very different when taken from diseased skin, compared to healthy skin,” noted co-author Dr. Noah Craft, a dermatologist and director of the Center for Immunotherapeutics Research at LA BioMed at Harbor–UCLA Medical Center. He added, “Two unique strains of P. acnes appeared in one out of five volunteers with acne but rarely occurred in clear-skinned people.”
Dr. Li noted, “We were extremely excited to uncover a third strain of P. acnes that’s common in healthy skin yet rarely found when acne is present. We suspect that this strain contains a natural defense mechanism that enables it to recognize attackers and destroy them before they infect the bacterial cell.” She explained, “This P. acnes strain may protect the skin, much like yogurt’s live bacteria help defend the gut from harmful bugs. Our next step will be to investigate whether a probiotic cream can block bad bacteria from invading the skin and prevent pimples before they start.” If the research pans out, it will offer new hope to acne sufferers with a simple cream or lotion that will increase the body’s friendly strain of P. acnes through the use of a simple cream or lotion may help calm spotty complexions.
“Our research underscores the importance of strain-level analysis of the world of human microbes to define the role of bacteria in health and disease,” noted co-author George Weinstock, associate director of the Genome Institute and professor of genetics at Washington University in St. Louis. He added, “This type of analysis has a much higher resolution than prior studies that relied on bacterial cultures or only made distinctions between bacterial species.”
The investigators plan further studies that will focus on: exploring new drugs that kill bad strains of P. acnes while preserving the good ones; the use of viruses to kill acne-related bacteria; and a simple skin test to predict whether a person will develop aggressive acne in the future.
Acne affects 80% of Americans at some point in their lives; however, scientists know little about what causes the disorder and have made limited progress in developing new strategies for treating it. Dermatologists’ arsenal of anti-acne tools (i.e., benzoyl peroxide, antibiotics and Accutane (isotretinoin) ) has not expanded in decades. Most severe cases of acne do not respond to antibiotics, and Accutane can produce serious side effects and can cause birth defects if taken during pregnancy.