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  • Alex Cloherty

On Makeup And Microbiomes

With the coming of December, I’ve been getting a lot of targeted advertising on social media for advent calendars. It’s a case of consumerism galore! These days, there are not only advent calendars containing chocolate, but also new takes on advent calendars that come filled with tea or cosmetics. And I thought to myself, I know a little about the microbiology of chocolate. I have personally experimented with applying microbiology to tea. But I knew absolutely nothing about the microbiology of cosmetics.

So, I started reading.

In the past, the main goal for microbiology as it applies to cosmetics was to keep things like moisturisers, cleansers, and makeup as microbe-free as possible. For instance, microbes that often live on or in us, but can cause problems when they overgrow (like Pseudomonas aeruginosa, Staphylococcus aureus and Candida albicans), are expected to be absent in products, especially if they are used anywhere close to the eye. Of course, this becomes difficult to maintain when we’re sticking our fingers in pots of cream, dragging mascara wands along our eyelashes, or rubbing ‘beauty blenders’ on our faces. I had to giggle at the statistics that “ninety-three per cent of beauty blenders had not been cleaned and 64% had been dropped on the floor and continued to be used”, meaning that they hosted quite some Enterobacteriaceae and fungi. I mean, that does sound like an honest account of the average commuters’ lightning fast makeup routine to be fair. Excuse me while I go and clean my makeup brushes…

That being said, it’s become more and more popular in recent years to try to work with our microbiomes - the “good” bacteria, viruses, and fungi that colonise our bodies - rather than only working against any “bad” bugs growing on or in us. You’ve probably noticed it yourself - in the last few years, the use of probiotics - which this paper defines as “live microorganisms that, when administered in adequate amounts, confer a health benefit on the host” - has become increasingly popular in food and other consumer products, cosmetics included.

So, how far have we gotten in using the power of microbes for cleansing, beautifying, or changing our appearances?

Well, the marketing around “probiotic cosmetics” would definitely lead you to believe that we are there already. When the authors of this paper from Canada surveyed the sites of Sephora and Ulta, two major cosmetic retailers, they found over 50 products that were marketed as ‘probiotic’. But, is it just marketing, or are there really good bugs in those products?

Well, those same scientists might be inclined to say it’s the former, and they give us a warning that “many false claims and rampant misuse of the term has resulted in mainstream consumer channels providing incorrect information to consumers.” They contend that for a product to really be probiotic, it needs to:

  1. Be clear on exactly what microbe it contains, and on the science-based rationale for including microbes in the product (i.e. have a clear cosmetic effect in mind),

  2. Contain enough live microbes at the time of its use for it to be realistic that those microbes would have the intended, science-based effect, and

  3. The type of use and dosage of the cosmetic should be in line with the type of use and dosage of the microbes that was scientifically shown to have that intended effect.

And indeed, although a lot of cosmetic products that allude to their their “probioticness” in marketing, or are straight-up falsely marketed as probiotic, don’t check all of those boxes. Instead, cosmetics might use vague descriptions of the microbe that is included on the ingredients list - for instance, I do love this face cream, but always roll my eyes a bit when I read the claim that it contains “glacial glycoprotein extracted from micro-organisms”. Which ones?!? Or, products might only contain broken-down and filtered pieces of bacteria - you’ll see the word “filtrate” used on such marketing materials - meaning that no live microbes are actually present in them. That ‘filtrate’ may well be healthy for skin, but because the generally accepted definition of “probiotic” means that living bacteria are included in the product, filtrate alone doesn’t really cut it for a cosmetic to be truly “probiotic”.

Another potential red flag in “probiotic” cosmetic marketing is that the whole idea of science-based inclusion of microbial ingredients is lacking, and the focus is shifted to broad claims with no real basis in microbiological science. One popular claim along those lines is that the cosmetic in question “balances” the skin microbiome. The problem with this catchy one-liner is that we don’t really know how to “balance” skin microbiomes. For one, different people with equally healthy skin can have wildly different microbiomes, so it follows that there are probably a lot of different types of microbes in different proportions that can make skin very happy. That means that the best bacterial balance for you might be different than the best balance for your next door neighbour. In my opinion, to really know what microbes might “balance” your personal skin microbiome, it would be helpful to know if you’re actually lacking any balance in your microbiota in the first place. After all, your skin might just crave some extra hydration rather than a boost in Bifidobacteria - and a simple hydrating cosmetic might well be a fraction of the price of one marketed as “microbiome balancing”.

We’re not at the point yet where skin microbiome fingerprinting is possible for every consumer, but perhaps that is the future of cosmetics. As I read through a few different scientific articles to prepare for this piece, I had to wonder if one day we’ll see “personalised cosmetics”, just like we are starting to see the advent of “personalised medicine” in cancer therapies. Maybe in a few decades we’ll be able to take a facial swab, and then be matched to a perfect mix of truly probiotic cosmetics that really will balance our own unique skin microbiome.

In the meantime, any cosmetic that claims to balance your microbiome or the like, should at least be backed by scientific studies showing across lots of humans that its ingredients actually do have a positive effect. We actually are starting to see studies like this - for instance, L’Oreal conducted a scientific study that showed pretty convincingly that broken down pieces of Bifidobacterium longum had an antiinflammatory effect on human skin.

So, maybe the future of cosmetics will indeed involve working with, rather than against our microbes. But in order to get there, I can’t say it better than these authors:

“There is no question that the modulation of microbes can lead to novel ways to improve appearance and well-being… [but] unproven claims help no-one, whereas good scientific investigation can bring forth products of great merit to human health and well-being.”

Hear, hear.

P.S. If you want a science-based advent calendar for the rest of December, you can follow me on Twitter, Mastodon, or LinkedIn, or Microbial Mondays on Facebook, where I’m sharing a different new or old Microbial Mondays article each day until Christmas. Happy holidays!

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