The human body carries trillions (10¹²) of microorganisms. The highest density is in our gastrointestinal tract (gut), which includes the mouth and throat and is estimated at approximately 100 trillion (100 × 10¹²). The second highest density of microorganisms is found on the epidermal barrier—our skin. The community of bacteria, viruses, fungi, and other microorganisms is known as the microbiome, which includes both the microorganisms themselves and their metabolites. It forms an interdependent, diverse, complex, and dynamic ecosystem. This ecosystem is sensitive, adaptable, and shaped by internal and external factors over time. How these microorganisms assemble into a community is also complex and dynamic, categorised into four distinct processes: dispersal, selection, drift, and diversification. When this system becomes imbalanced—through either a loss or gain of microorganisms, or changes in their relative numbers—it is known as dysbiosis, which leads to bodily function dysregulation and disease. Bacteria are the most abundant microorganism in our microbiome, and the ratio of bacteria to human cells is approximately 1:1: 38 trillion (38 × 10¹²) bacteria to 30 trillion (30 × 10¹²) human cells. Regardless of the exact number, the microbiome is a vital, underestimated, and not yet fully understood contributor to our health.
The human body hosts diverse and functionally important communities of symbiotic microbes. These communities vary by location in or on the body, depending on the roles they perform and the environment they inhabit. They are influenced by where we live (temperature, humidity, pollution, population density, etc.), our diet, exercise, stress, antibiotics, exposure to sunlight, how hot and how often we wash, and even the clothes we wear. Basically, anything we do to our body—internally or externally—can and does influence our microbiome. It is constantly altering, adapting, and changing as we age. The microbiome is a dynamic living system that interacts with other microbiome communities and with our organs, such as the brain and skin (the skin being the largest organ of the body). This interconnectedness is key to understanding the full impact of skincare on our overall health.
Our gut microbiome and skin microbiome are connected through our systemic circulation, which delivers blood to all body tissues. This is known as the gut-skin axis. The gut-skin axis acknowledges a bidirectional relationship between the gut microbiome and skin health—and vice versa. This relationship influences the microbiomes in both locations, including the composition of their members and the immune response. Our microbiome is a key regulator of the immune system, and imbalances in the skin and/or gut microbiomes can alter our immune responses. This is why changes in the gut microbiome are responsible for promoting and developing skin diseases such as atopic dermatitis, psoriasis, and acne.
“The gut microbiome plays an important role in a wide variety of skin disorders. Not only is the skin microbiome altered, but also, surprisingly, many skin diseases are accompanied by an altered gut microbiome.”
—Gut–Skin Axis: Current Knowledge of the Interrelationship between Microbial Dysbiosis and Skin Conditions
One way, research has shown the skin directly influences the gut microbiome composition is through exposure to UVB, which increases our vitamin D concentration. This, in turn, increases the diversity of the gut microbiome. UVB light can rapidly modify gut microbiota profiles. Sun exposure contributes to seasonal variations in microbiome composition, and several inflammatory diseases such as irritable bowel syndrome are strongly associated with vitamin D levels.
The gut microbiome is the largest endocrine organ, producing at least 30 hormone-like compounds—such as short-chain fatty acids (SCFAs), secondary bile acids, cortisol, and signalling molecules including gamma-aminobutyric acid (GABA), serotonin, dopamine, and tryptophan. (SCFAs are produced when gut bacteria ferment dietary fibre, and they regulate inflammation and immune response.) The endocrine system is a messenger system: hormones carry information and instructions from one set of cells to another. The compounds produced by the gut microbiome are released into the bloodstream, where they target and regulate distant organs and systems—such as the skin and the brain. This is the gut-brain-skin axis.
A complex and dynamic relationship exists between us—the human host—and our microbiome, which is mostly symbiotic, meaning mutually beneficial. Our microbiome is critical for digestion, synthesis of essential vitamins K and B12, immune system regulation, and defence against pathogenic microorganisms. Disrupting this delicate balance is implicated in gastrointestinal disorders, skin conditions, and even our mood—where the gut microbiome and its metabolites influence brain function and behaviour.
Importantly, our gut microbiome is not independent of our skin microbiome—or of our brain function. These systems form a connected network. The compounds produced by our microbiome are circulated systemically and influence, regulate, and affect all bodily functions—including mood.
There are several mechanisms through which commercial skincare products disrupt, compromise, damage, or alter our skin microbiome—which, in turn, affects the gut microbiome and subsequently the compounds that influence our brain and mood. This is why skincare that respects the microbiome—like Vitis V Face TonIQ—matters.
Preservatives are chemicals added to prevent spoilage by microorganisms. A preservative's role is to kill, prevent, or slow the growth of microorganisms in the product to extend shelf life. Your skin’s microbiome is a community of microorganisms—and preservatives in skincare do not differentiate between beneficial skin microorganisms and product-spoiling microorganisms.
Any skincare product containing water or water-based ingredients—including hydrosols, fruit extracts, juice extracts, flower water, Aloe vera, and glycerin (with the exception of soap)—will contain preservatives.
Anything that changes the local environment of the skin will alter the microbiome.
“Selection refers to the process whereby species better adapted to their environment tend to survive better and produce more offspring.”
—The Microbiome: Composition and Locations
Habitat changes from skincare can result from alterations in skin pH, affecting the acid mantle and therefore which microorganisms survive and thrive.
Slugging—or the thick application of any occlusive—changes the oxygen availability, favouring the growth of anaerobic over aerobic microorganisms.
Exfoliation not only damages the skin barrier by causing micro-tears, it also physically removes microorganisms from the skin.
Surfactants that emulsify water and oil together often have antimicrobial activity.
In a 2019 study, The Impact of Skin Care Products on Skin Chemistry and Microbiome Dynamics , researchers found:
“Many of the molecules associated with our personal skin and hygiene products had a half-life of 0.5 to 1.9 weeks—even though the volunteers regularly showered, swam, or spent time in the ocean. Thus, a single application of some of these products has the potential to alter the microbiome and skin chemistry for extensive periods of time. One ingredient that lasts on the skin is propylene glycol.”
When our skin microbiome is altered, it changes the way it functions and the metabolites it produces. This impacts the gut microbiome, which also responds by altering its composition and metabolite output—affecting brain function, behaviour, and ultimately, mood.
Research has shown that while it’s important to understand the role of individual members of the skin microbiome:
“A full community of microbes has unique and pronounced effects on the skin. Thus, in its impacts on the host, the skin microbiome is more than the sum of its parts.”
—Microbiome Journal
Vitis V Face TonIQ contains only naturally occurring ingredients, meeting the legal definition of AICIS:
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An unprocessed chemical occurring in a natural environment; or
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A chemical occurring in a natural environment that is extracted without chemical change.
It contains no surfactants, no preservatives, does not alter skin pH, and is not occlusive. It does, however, contain naturally occurring linoleic acid, the predominant polyunsaturated fatty acid in human skin, which plays a direct and critical role in maintaining a healthy skin barrier. A healthy skin barrier supports a thriving, balanced skin microbiome. Linoleic acid is bio-essential, meaning our bodies cannot produce it from precursors and must obtain it through either diet or topical application.
Our microbiome is a complex, interdependent network with bidirectional communication and it is critical to our health. Respect it. Support it. Protect it—because it is doing the same for you.
When Vitis V claims “achieve your most nourished and radiant skin and feel your finest,” we meant it in the sense of confidence. Now, this statement may actually be literal—by protecting your skin’s microbiome using Vitis V Face TonIQ, you will also be supporting your mood and genuinely feeling your finest. You’re not just nourishing your skin—you’re nourishing your entire system, from barrier to brain.
Image credit - Tania Malrechauffe on Unsplash
Revised Estimates for the Number of Human and Bacteria Cells in the Body
The microbiome: composition and locations
Skin Exposure to Narrow Band Ultraviolet (UVB) Light Modulates the Human Intestinal Microbiome
The Gut-Brain Axis: Influence of Microbiota on Mood and Mental Health