The Living Skin — the microbiome, the cleanser, inulin & Gotu Kola

CHAPTER SIX  ·  THE RESILIENCE GUIDE

The Living Skin

The microbiome, the cleanser, inulin, and Gotu Kola.

By Barbi  ·  8 min read  ·  Founder, PHILOGENI

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Why has my cleanser become the problem?

I have always loved the ritual of washing my face. The water. The cool of it on the morning skin. The rinse. The towel. For more than thirty years I had a routine I never questioned — a gentle foaming face wash, water, rinse, towel. Done.

My skin was fine. Until it wasn't.

When the dryness started, I switched to a cream cleanser. The same brand I had used for thirty years. The cream cleanser was gentler. It helped. But it never gave me the feeling of properly clean that the foaming wash had given me, and after a while I started doubting whether my face was actually clean at the end of it.

Then I tried the Korean two-step. An oil cleanse first, massaged into dry skin for a minute or two to dissolve sunscreen and sebum and the day. Then a water-based cleanser to emulsify and rinse. The principles were sound. The practice was too fussy for me. I have always been a no-fuss skincare person. I prefer the idea of skinimalism — fewer steps, smarter formulations, less stuff on the shelf. A twelve-step routine is not what I am here for. I doubt it is what you are here for either.

The real problem, I realised, was not the steps. It was that almost every cleanser on the high street had been formulated to take everything off — including the things the skin had been working hard to keep on.

Our cleansers are the first thing we do for our skin every day, and the most overlooked product on the shelf. The cleanser is doing more than removing makeup, sunscreen, and the day. It is setting the conditions every other product has to work with. A cleanser that strips the lipid environment the skin is struggling to maintain leaves every product afterwards doing extra work to compensate for the disruption the cleanse just caused.

This chapter is the cleanser's chapter — and, by extension, the chapter on the third living system we named in Chapter 2. The microbiome.

The skin as living ecology

Your skin is not a sterile surface to be sterilised. It is a living surface, populated by an ecology of bacteria, fungi, and yeasts that the body has been cultivating for as long as you have had skin. On every square centimetre of your face, somewhere between ten million and one billion microorganisms coexist. The dominant residents include Staphylococcus epidermidis, broadly beneficial; Cutibacterium acnes, useful in healthy skin and problematic when overgrown; and a population of yeasts called Malassezia. 1

These organisms produce short-chain fatty acids, antimicrobial peptides, and metabolites that the skin uses to maintain its pH, support its lipid layer, and regulate its local immune response. A healthy microbiome contributes to a healthy barrier. A disrupted microbiome contributes to inflammation, redness, and the cluster of reactive complaints menopausal skin so often presents.

Estrogen affects sebum composition, which in turn shapes the microbiome's food supply. As estrogen recedes through the hormonal transition, sebum production falls and its composition shifts. The microbiome reorganises in response. The species that were minor residents may become more prominent. The species that supported the barrier may diminish. 2 This reorganisation is part of why women in perimenopause report sudden reactivity to products they have used for years. The barrier on which the product is being used is now maintained by a different microbiome than the one that tolerated the product at thirty-five.

What disrupts it

The most common disruptor on the bathroom shelf is the foaming sulfate cleanser. Sodium lauryl sulfate (SLS) and sodium laureth sulfate (SLES) are surfactants — substances that lift oil and dirt from the surface. They are very effective at this. They are too effective on a mature barrier. Foaming sulfate cleansers strip the lipid environment the microbiome depends on, and they do so every time you use them. The disruption is cumulative. After a year of twice-daily use, a barrier that was struggling at the start is struggling worse at the end.

Other common disruptors include denatured alcohol (Alcohol Denat.) in toners and astringents, which dissolves lipids by chemistry rather than mechanics; broad-spectrum antibacterial ingredients such as triclosan and its relatives, which do not distinguish between beneficial and pathogenic species; and over-exfoliation with acids or scrubs at a frequency the skin cannot recover from. None of these is necessarily bad in its proper place. All of them, used too frequently or on a hormonally-changed barrier, push the microbiome in the wrong direction.

Inulin and the prebiotic answer

The conventional answer to a disrupted microbiome — in gut research, in food science, and increasingly in skincare — is to add bacteria. Probiotics. In skincare, this is complicated by the fact that live bacteria are difficult to keep alive in a cosmetic formulation, and the bacteria your face needs are not the same bacteria a yoghurt or a supplement carries.

The more elegant answer is prebiotic. A prebiotic is not a bacterium. It is the food that supports the beneficial bacteria already living on the skin.

Inulin — a polysaccharide extracted from chicory root — is the most commonly used skin prebiotic and the best-studied. When included in a cleanser or a leave-on formulation, inulin feeds the beneficial residents of the microbiome selectively, supporting their populations without affecting the inflammatory species the body is trying to keep in check. 3 Studies have shown improved barrier recovery time and reduced transepidermal water loss when prebiotic ingredients are added to topical formulations consistently over weeks.

Why prebiotics matter most in cleansers: the cleanser is the product that interacts with the microbiome with the highest frequency and the greatest mechanical force. A cleanser that feeds the ecology while it cleans sets a different baseline for every product that follows. A cleanser that strips the ecology, however gently, sets all subsequent products up to compensate. The difference compounds.

Gotu Kola — the structural-support botanical

Centella asiatica, commonly known as Gotu Kola, has been used in Ayurvedic and traditional Chinese medicine for over two thousand years, primarily for wound healing and skin repair. In the last forty years its chemistry has been characterised. The botanical contains four pharmacologically active triterpenoids — asiaticoside, madecassoside, asiatic acid, and madecassic acid — that have demonstrated specific and well-documented activities on skin.

The two most established activities are stimulation of Type I collagen synthesis in human fibroblasts, 4 and modulation of the inflammatory NF-κB pathway. 5 The collagen evidence dates from the 1990s; the anti-inflammatory work has accumulated more recently. Together they explain why Centella has become the active ingredient at the centre of the Korean skincare "Cica" category — short for centella, used widely in products designed for sensitive, irritated, post-procedure, or reactive skin.

For hormonally-changed skin, Gotu Kola earns its place specifically in cleansers and in leave-on creams. In a cleanser, the anti-inflammatory action supports the microbiome's recovery during the cleansing process itself — turning the moment of mechanical disruption into a moment of gentle modulation. In a cream, the collagen-supportive activity addresses the structural matrix changes that begin in perimenopause and accelerate through menopause. The two roles compound, in the same way the prebiotic and the cleanser compound.

What to look for on a cleanser label

The cleanser is the single most consequential product on your shelf at this stage of life. Get the cleanser right and every other product in your routine has a better starting position. Get the cleanser wrong and no amount of expensive serum afterwards will compensate for the disruption the cleanse causes twice a day.

What to avoid: SLS, SLES, and other foaming sulfate surfactants high in the ingredient list. Denatured alcohol (Alcohol Denat.) anywhere in the top five. Broad-spectrum antibacterials such as triclosan. Heavy synthetic fragrance.

What to look for: cream, oil, balm, or milk cleansers rather than foaming wash systems; gentler surfactants such as coco-glucoside, decyl glucoside, or lauryl glucoside (plant-derived, far gentler than sulfates); inulin or other named prebiotic ingredients; Centella asiatica or one of its triterpenoids (asiaticoside, madecassoside) in the formulation.

A cleanser that supports the microbiome is not a cleanser that does not clean. It is a cleanser that distinguishes between what should be removed — sunscreen, sebum oxidation products, the day — and what should be preserved: the lipid environment, the bacterial residents, the surface integrity. The first job of a cleanser at this stage of life is not to strip. It is to discriminate.

The cleanser is the most important product on your shelf — and almost no one is told this. Get the cleanser right and the rest of the routine becomes simpler.

Sources cited in this chapter

1. Byrd AL, Belkaid Y, Segre JA. The human skin microbiome. Nature Reviews Microbiology. 2018;16(3):143-155.

2. Sfriso R, Egert M, Gempeler M, Voegeli R, Campiche R. Revealing the secret life of skin — with the microbiome you never walk alone. International Journal of Cosmetic Science. 2020;42(2):116-126.

3. Krutmann J. Pre- and probiotics for human skin. Clinics in Plastic Surgery. 2012;39(1):59-64.

4. Bonté F, Dumas M, Chaudagne C, Meybeck A. Influence of asiatic acid, madecassic acid, and asiaticoside on human collagen I synthesis. Planta Medica. 1994;60(2):133-135.

5. Bylka W, Znajdek-Awiżeń P, Studzińska-Sroka E, Brzezińska M. Centella asiatica in cosmetology. Postępy Dermatologii i Alergologii. 2013;30(1):46-49.

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