A Bug in the System

Love your bacteria.” That’s the tagline for Yun Probiotherapy’s line of skin cosmetics directed at those who have acne or athlete’s foot or who just want to keep their skin looking healthy. Yun’s product line, now entering the personal care market, incorporates “friendly” bacteria to help correct skin microbe imbalances.

“Love your bacteria.” That’s the tagline for Yun Probiotherapy’s line of skin cosmetics directed at those who have acne or athlete’s foot or who just want to keep their skin looking healthy. Yun’s product line, now entering the personal care market, incorporates “friendly” bacteria to help correct skin microbe imbalances.

Scientists have known for some time that the skin, like the human gut, is teeming with bacteria, fungi, yeast, and viruses, all actors in what is known as the microbiome. Some are beneficial, others are not, and some considered “good” may become harmful under the right conditions.

There’s also long-standing evidence of a connection between a healthy gut and the consumption of Lactobacillus-containing supplements and foods such as yogurt. Research firm Global Market Insights estimates that the food market for the beneficial microorganisms known as probiotics exceeded $36 billion in 2015.

However, little was known about the diversity of the “bugs” among us or their impact on human health until the Human Microbiome Project, a five-year, $157 million endeavor launched in 2008 and overseen by the National Institutes of Health. The effort teased out tantalizing details on the astounding variety of microbial communities living in our guts and on our bodies.

Now, cosmetic formulators are taking tentative first steps toward applying some of the lessons learned from the project to develop their own microbiome franchises. They are designing health-enhancing skin care products that contain live bacteria, bacteria extracts, or ingredients meant to enhance skin microbe activity.

Skeptics say not enough evidence exists to verify the benefits of creams and butters meant to farm the bugs living on human skin. They especially question the benefit of placing live microorganisms on the body without thorough testing, and they wonder how formulations containing live actors can even exist when regulations generally forbid the sale of “contaminated” products.

Personal care product formulators like Yun aren’t put off by such questions about the skin microbiome. They see many opportunities emerging from research that suggests a strong connection between a balanced microbiome and healthy skin.

Others targeting consumers with skin-microbiome-enhancing formulas include start-up firms such as AOBiome, maker of skin care products containing the ammonia-oxidizing bacteria Nitrosomonas eutropha, and Gallinée, a supplier of products containing probiotics as well as so-called prebiotics that feed skin microorganisms.

And the small innovators are not alone. Some of the big personal care firms are staking out a claim to the microbiome. Johnson & Johnson, for instance, is helping the biotech firm S-Biomedic develop a bacterial treatment for both therapeutic and cosmetic applications. The firm is now a resident of J&J’s JLINX start-up incubator in Beerse, Belgium.

Procter & Gamble has taken an interest in the skin microbiome, applying for a patent on a prebiotic composition to “improve the health of the skin microbiome.” L’Oréal, meanwhile, has patented the bacteria-derived ingredient vitreoscilla ferment, intended to “balance” the microbiome of dry skin. The firm has incorporated it into cosmetics sold under its La Roche-Posay label.

Forward-looking personal care ingredient makers are also looking into what could be the next big thing in cosmetics. For instance, prominent ingredient suppliers such as BASF and Givaudan have introduced products to enhance the microbiome and, along with it, skin health. Smaller firms such as Azitra, Greenaltech, and Vantage Specialty Ingredients are also looking to provide microbiome-focused ingredients.

Microbiome skeptics

Not surprisingly, the concept of microbiome-enhancing cosmetics has its doubters. Wilfried Petersen, managing director of the German preservatives specialist Dr. Straetmans, wonders if the developing fascination with the skin microbiome will amount to more than a hill of beans. “The story of the microbiome sounds nice, but the proof of benefit is lacking,” he says.

European Union regulations, Petersen points out, don’t allow for the intentional addition of bacteria to cosmetics. In addition, he asks, if beneficial bacteria are added, how do you preserve the formula and how can you be sure it won’t become unstable and spoil?

Dermatologist Patricia K. Farris points out that skin microbiome imbalances, such as the overgrowth of Propionibacterium acnes, are prevalent in many skin diseases. Correcting those conditions, perhaps with lactic acid or other bacterial derivatives, can provide relief for people with those conditions.

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A graphic showing relative abundance of bacteria, fungi, and other skin microbial residents depending on their location on the human body.

Skin deep

The composition of the microbiome varies widely depending on location.
Note: Microbes named represent the most common types.
Credit: Darryl Leja/National Human Genome Research Institute

“But can we make people look 20 years younger by putting probiotics on their face? I’m not sure we’re there yet,” says Farris, who is on the board of the American Academy of Dermatology. More study is needed to determine if pre- and probiotics are worthy of the hype they are getting, she says.

Studies carried out as part of the Human Microbiome Project suggest that a person isn’t so much an individual as a complex organism composed of both human and microbial cells. Trillions of microorganisms inhabit the body, outnumbering human cells by 10 to 1. In all, those microorganisms make up 1 to 3% of the body’s mass, or anywhere from 1 to 3 kg on the body of a 100-kg adult.

The Human Microbiome Project by the numbers


$157 million: Amount invested by the National Institutes of Health in microbiome research between 2008 and 2013

2 kg: Average weight of microorganisms living in and on a 100-kg human body

10 to 1: The ratio of microorganisms to human cells in the body

10,000: Number of microbial species inhabiting the human body

8 million: Number of microbial protein-coding genes found in the body, 360 times the number of human genes

But the challenge is to translate that general knowledge into health and disease conditions and then to specific treatments. Mapping out and sequencing the genetic identity of microbes at various locations on the skin is a complex undertaking, notes Nava Dayan, a skin research consultant to pharmaceutical and personal care firms. Even with the work undertaken to date, “we don’t fully understand the baseline of what a healthy skin microbiome is because it varies from person to person and even differs depending on a person’s age and environment,” she says.

Without a full understanding of what the baseline is, developing a personal care product to influence the skin microbiome “is like shooting a moving target,” Dayan says. Even if scientists learn how the skin microbiome changes and shifts over time, they are still missing a lot of information about how microbes influence human cells.

Testing personal care formulations for their effects on the skin poses another problem, Dayan says. Cultured human cell models now used in labs “are inherently sterile.” It will be some time before scientists can develop a human cell model that also incorporates skin microbes.