Fermented hair care hits shampoo aisle: What to know and is it worth the hype?

"Think of it like a garden, and the soil is the scalp."

Since the pandemic, concerns over personal health have been at the forefront of consumers' minds. One of the concerns that took flight was gut health and the microbiome, with a rise in sales for products like probiotics, greens powder, and digestive sodas (like Poppi and Olipop).

But conversations around microbiome health aren't exclusive to just the gut. The same interest has moved into beauty, with brands touting the importance of maintaining a healthy skin microbiome to prevent premature aging and acne. The Rootist, a new hair-care line launched in April, is introducing fermented ingredients as the next wave of innovation in the shampoo aisle with promises of "anchored, active roots, a hydrated, balanced scalp, and strong, healthy hair."

Clare Hennigan, principal analyst - Beauty & Personal Care at Mintel, says these brands have already piqued consumer interest.

"In hair care from 2022 to 2023, the number of products that feature microbiome in the product description have actually increased 52.3%," Hennigan told ABC News. "We really see, especially in hair care, the momentum stirring and the demand growing for microbiome hair care solutions."

But what are these fermented ingredients, how do brands claim they work and are they worth the hype?

What are fermented ingredients and how can they help maintain and balance the microbiome?

Very simply put, fermented ingredients are bacteria, says Dr. Mona Gohara, MD, a board-certified dermatologist and associate clinical professor at Yale School of Medicine.

"If you leave something out long enough, things kind of grow out of it. One of the things that grows is bacteria," Gohara told ABC News.

Not all bacteria are bad, however, think of yogurt and kombucha for instance, which are made through fermentation.

The Rootist says that it's this fermenting process that makes their products "easily recognized and received by roots, scalp, and hair." Just like skin and the gut, the scalp has its own bacteria and types of fungi which together create its microbiome. According to Gohara, the presumption here is that the fermented ingredients in products like that of The Rootist help feed the bacteria on our scalps which in turn supports the health of our pre-existing scalp microbiome.

And maintaining a balanced scalp microbiome is crucial to keeping hair healthy, says Dr. Jeannette Graf, MD, a board-certified dermatologist and assistant clinical professor of dermatology at the Mount Sinai School of Medicine. Conditions like dandruff or acne can be influenced by the microbiome.

"If we have an imbalance of our microbiome or a microbiome is not working correctly, we need to create an environment on the skin of the scalp, on the skin of face, where they can exist," Graf told ABC News.

"Think of it like a garden, and the soil is the scalp. If the soil is healthy, the plants and the flowers are going to blossom," explained Gohara. "If the scalp is compromised or inflamed or irritated, it's less healthy soil, right? And that, and then leads to less healthy, bountiful garden."

Are they worth the hype?

While in theory fermented hair care ingredients may be beneficial to the scalp microbiome, the bottom line is that there is that there's still more research that needs to be done.

"Within the personal care industry - there are many new ingredient technologies being developed," Graf said. "So studies are done by these biotech companies- and good ones. But that is where most of the research and literature is published."

"It's safe to say that at a minimum, the product will support a healthy scalp microbiome," Gohara added, who draws a line at claiming these products will lead to increased hair growth. "It means that in me, whatever my biological potential as a 48-year-old woman at this point, if I use this, it'll make my hair grow as optimally as it would biologically at this point."

And while experts say there is still research to be done, Hennigan says the industry is all in on fermented hair.

"This signals broader industry trends overall, where we'll see how we can really personalize our products specific to even perhaps our own personal microbiomes, to better target and pinpoint our specific needs," Hennigan said.