Teen Years Open Brief Window For Skin Microbiome Reset

Hormonal changes during adolescence provide a rare opportunity for new beneficial bacteria to colonize facial skin, potentially offering a critical window for acne treatments, according to new research from MIT scientists.

The study, published May 1 in Cell Host & Microbe, reveals previously hidden dynamics between the two dominant bacterial species on human faces – Cutibacterium acnes and Staphylococcus epidermidis – which together comprise about 80 percent of the average adult’s facial microbiome.

“We found that there are some surprising dynamics, and these dynamics provide insights for how to design probiotic therapy,” says Tami Lieberman, associate professor at MIT and senior author of the study. “If we had a strain that we knew could prevent acne, these results would suggest we should make sure we apply them early during the transition to adulthood, to really get them to engraft.”

Jacob Baker, lead author and now chief scientific officer at Taxa Technologies, led a team that collected microbiome samples from 30 children at a Boston-area school and 27 of their parents. By isolating individual bacterial cells, growing them into colonies, and sequencing their genomes, the researchers identified 89 distinct C. acnes lineages and 78 S. epidermidis lineages.

What makes this research groundbreaking is the discovery that these bacterial communities aren’t as stable as previously thought. During early adolescence, when hormone production increases oil secretion on skin, bacterial density skyrockets by approximately 10,000-fold. This dramatic expansion creates a unique opportunity for new C. acnes strains to establish themselves.

“For C. acnes, what we were able to show was that people do get strains throughout life, but very rarely,” Lieberman explains. “We see the highest rate of influx when teenagers are transitioning to a more adult-like skin microbiome.”

After this transitional period, C. acnes populations become remarkably stable, with minimal turnover even between family members living in close proximity. This stability suggests that introducing beneficial probiotic strains of C. acnes during early adolescence could provide lasting effects.

The research also revealed stark differences between the two dominant facial bacteria. While C. acnes communities remain stable throughout adulthood, S. epidermidis strains are far more transient, with an average lifespan of less than two years on any individual’s face. Curiously, despite this high turnover rate, family members maintain unique S. epidermidis communities, suggesting unknown barriers to strain homogenization.

“That suggests that something is preventing homogenization between people,” says Lieberman. “It could be host genetics or host behavior, or people using different topicals or different moisturizers, or it could be active restriction of new migrants from the bacteria that are already there at that moment.”

The findings have significant implications for treating conditions like acne, eczema, and psoriasis. Although C. acnes has been implicated in acne development, its lower relative abundance in several skin conditions suggests some strains may actually benefit skin health. The researchers note that introducing probiotics during the critical adolescent transition could enhance their effectiveness.

Future research will investigate how the timing of bacterial acquisition affects immune system responses and explore the mechanisms behind the unique microbiome compositions maintained by individuals despite close contact with family members.

“We want to understand why we each have unique strain communities despite the fact that there is this constant accessibility and high turnover, specifically for S. epidermidis,” Lieberman says. “What’s driving this constant turnover in S. epidermidis, and what are the implications of these new colonizations for acne during adolescence?”