The skin is an external barrier protecting us from the effects of potentially damaging physical conditions, microbes, and chemicals. It is also the largest organ of detoxification, releasing and excreting waste products and toxins from within our body. 1
What does the gut have to do with the skin?
Hippocrates, the father of modern medicine, stated, “All disease begins in the gut.”
99 percent of human bacteria reside in the gut. Bacteria break down our food, manufacture vitamins and hormones, break down toxins and drugs, prevent colonisation by harmful microbes, and play an important role in our immune system. 2
An imbalanced state of bacteria in the gut, termed dysbiosis, may result in inflammatory and immunological responses.
Gut bacteria also maintain the integrity of the intestinal barrier. This barrier is a chemical and physical protective component of the gut, safeguarding us against the invasion of harmful bacteria and toxins. 3 Impaired intestinal barrier can result in intestinal permeability, also known as leaky gut, a condition that allows toxic substances to leak into the bloodstream.
Evidence suggests that both dysbiosis and intestinal permeability are associated with a growing number of inflammation-related disorders, 4 which might also contribute to inflammatory skin conditions, such as acne vulgaris, acne rosacea, psoriasis and atopic dermatitis, and indeed, some evidence exists that there is a link between gut disorders and skin conditions.
Skin disorders are often seen in inflammatory bowel diseases including Crohn’s disease and ulcerative colitis.5
Small intestine bacterial overgrowth (SIBO), a condition involving the excessive growth of bacteria in the small intestine, was found in one study to be 10 times more prevalent in those with acne rosacea than healthy controls. SIBO has been shown to be associated with increased intestinal permeability. 6
Other studies found that patients with acne and seborrheic dermatitis may have disrupted gut bacteria. (6), and coeliac patients have skin manifestations of dermatitis herpetiformis. 7
Diet is the most important factor in shaping the composition, diversity, and richness of our gut bacteria.
It appears that diet can influence both the composition and diversity of intestinal bacteria. It has been suggested that reduced microbial diversity, seen in Western dietary patterns, which is high in animal protein, sugar, starch, and fat and low in fibre, has a negative impact on health, and has been linked to obesity and inflammatory diseases. 8
In contrast, great numbers and diverse bacteria are found in traditional fermented foods and beverages.
What exactly is fermentation and why is it good for you?
Fermentation is as old as humanity!
Fermentation is one of the oldest forms of food preservation technologies in the world, dating back to the beginning of human civilisation, long before technologies such as canning food or refrigeration were available.
It is primarily a biochemical process in which microorganisms (such as bacteria, yeasts, and moulds) or enzymes convert sugar and starch to alcohol or lactic acid, which help preserve the foods. 9
Fermented foods are significant economical and cultural staples of the diet in many developing countries, where the knowledge of fermentation has been handed down for generations. Fermentation of foods is an inexpensive, low energy process, which increases the shelf life of perishable foods and provides food security to many in areas of famine and food shortage, as well as opportunities for employment and income. 9
Examples of fermented foods around the world
|Fermented Food||Country of Origin|
|Grains and Legumes|
|Kombucha||Russia and China|
Fermented foods are palatable and safe
Fermentation creates new and desirable tastes and textures that are completely different from those in the starting materials. 10 Fermented foods also reduce the risk of food contamination due to the production of antimicrobial compounds.
Fermented foods provide health benefits well beyond the starting food constituents
You have probably heard of the term ‘probiotics’ – the type of good bacteria defined by the World Health Organization (WHO) as ‘Live microorganisms which when administered in adequate amounts confer a health benefit on the host’. 11
Enhanced digestibility. Fermented foods are often more easily digestible than unfermented foods.
Lactose. Lactose intolerant individuals who cannot tolerate the lactose in milk can usually tolerate yoghurt, kefir, and most cheeses where the lactose has been broken down by the bacteria in them.
Phytic Acid. Phytic acid is an anti-nutrient compound in grains, legumes, and nuts, which is known to bind to minerals such as iron, zinc, calcium, magnesium and manganese, and inhibit their absorption in the body. Fermentation reduces the amount of phytic acid and increases the bioavailability of the mineral, and thus the nutritional value of meals.
Gluten and FODMAPS (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols). Fermentation of sourdough bread allows bacteria to break down the carbohydrates and gluten in the wheat and make it easier to digest by people with gluten sensitivity and/or irritable bowel syndrome (IBS).
Increase nutritional value of a food. Through the greater production of B-vitamins, vitamins C and K, amino acids, and increasing the bioavailability of minerals.
Weight management. Through altering the composition of the gut bacteria and enriching its diversity
Reduce the risk of cancer, type 2 diabetes, and cardiovascular disease. Because the vast majority of our immune system is located in the gut, fermented foods rich in bacteria could affect inflammation, and reduce the risk of these inflammation-related chronic diseases.
Protection from osteoporosis. Through the production of vitamins and absorption of minerals that stimulate the formation of bone.
Fermented foods and your skin
Hydration. A study involving 65 healthy volunteers investigated the effects of drinking a formula of fermented barley and soybean for 8 weeks and found a significant increase in hydration in the participants receiving the fermented formula compared with the participants ingesting a placebo. The same effect was noted in healthy adult women who drank probiotic and prebiotic fermented milk daily for 4 weeks, with a significant increase in their skin hydration levels when compared with the placebo.
Atopic Dermatitis. Daily intake of fermented citrus juice has been found to alleviate symptoms of atopic dermatitis (eczema).
Anti-ageing. 60 healthy non-smoker males and females aged 40–65 years were divided into two groups. One group received an oral supplement of fermented papaya formula, while the other received an antioxidant formula. After 90 days, the group who took the fermented papaya showed a significant improvement in markers of skin ageing, such as skin evenness, the level of moisture and elasticity.
Food and cosmetics
In the quest for natural, chemical-free anti-ageing skin products, the convergence of foods and cosmetics, often called nutri-cosmetics, has been a growing trend. 19 Many natural skincare products now include food ingredients that have been hiding in your kitchen.
The idea is that these food ingredients contain antioxidants. Antioxidants are substances that protect your cells against the damage done by free radicals – molecules produced by our body when breaking down food or from external sources such as to tobacco smoke, air pollutants, industrial chemicals, and exposure to X-rays.
A balance between free radicals and antioxidants is necessary for proper cell function. An imbalance, whereby antioxidant defence systems cannot protect us from free radical generation, may lead to a condition known as oxidative stress, which among other things is associated with ageing. Antioxidants have been shown to protect our skin from sunlight-induced damage and may increase skin elasticity and hydration. 19
More recently, fermented skincare, a concept thought to originate in Korea, has become popular around the world.
If fermented foods are so good for our health, can using them in cosmetics work on the outer layers of our skin the way they work in our gut?
In theory, we know that fermentation breaks down the molecular structure of substances into smaller and simpler compounds. It is possible that these compounds may be able to penetrate the skin more deeply and be easily absorbed.
In addition, fermented skincare may introduce beneficial bacteria to the skin, as well as increased levels of anti-ageing antioxidants and vitamins.
The jury is still out and more research is warranted, but in the meantime, more and more consumers prefer natural ingredients and are opting for natural skincare.
References and Sources:
- Jones, D. (2010). Textbook of functional medicine. 1st ed. Gig Harbor, WA.: Institute for Functional Medicine.
- Enders, G. (2015). GUT. 1st ed. Germany: Greystone Books.
- Bischoff, S. C., Barbara, G., Buurman, W., et al. (2014). Intestinal permeability–a new target for disease prevention and therapy. BMC Gastroenterology, 14, 189. http://doi.org/10.1186/s12876-014-0189-7
- Schippa, S., & Conte, M. P. (2014). Dysbiotic events in gut microbiota: impact on human health. Nutrients, 6(12), 5786–805. http://doi.org/10.3390/nu6125786
- org. (2017). Skin Complications of IBD | Crohn’s & Colitis Foundation. [online] Available at: http://www.ccfa.org/resources/skin-complications-of-ibd.html [Accessed 6 Mar. 2017].
- Bowe, W. P., & Logan, A. C. (2011). Acne vulgaris, probiotics and the gut-brain-skin axis – back to the future? Gut Pathogens, 3(1), 1. http://doi.org/10.1186/1757-4749-3-1
- Coeliac UK. (2017). About coeliac disease and dermatitis herpetiformis. [online] Available at: https://www.coeliac.org.uk/coeliac-disease/about-coeliac-disease-and-dermatitis-herpetiformis/dermatitis-herpetiformis/ [Accessed 6 Mar. 2017].
- Albenberg, L. G., & Wu, G. D. (2014). Diet and the intestinal microbiome: associations, functions, and implications for health and disease. Gastroenterology, 146(6), 1564–72. http://doi.org/10.1053/j.gastro.2014.01.058
- Battcock, M., Azam-Ali, S., & Food and Agriculture Organization of the United Nations. (1998). Fermented fruits and vegetables?: a global perspective. Food and Agriculture Organization of the United Nations. Retrieved from http://www.fao.org/docrep/x0560e/x0560e00.htm
- Marco, M. L., Heeney, D., Binda, S., et al. (2017). Health benefits of fermented foods: microbiota and beyond. Current Opinion in Biotechnology, 44, 94–102. http://doi.org/10.1016/j.copbio.2016.11.010
- Health and Nutritional Properties of Probiotics in Food Including Powder Milk with Live Lactic Acid Bacteria. Available online: ftp://ftp.fao.org/docrep/fao/009/a0512e/a0512e00.pdf(accessed on 5 March 2017).
- Chilton, S., Burton, J., & Reid, G. (2015). Inclusion of Fermented Foods in Food Guides around the World. Nutrients, 7(1), 390–404. http://doi.org/10.3390/nu7010390
- Tamang, J. P., Shin, D.-H., Jung, S.-J., & Chae, S.-W. (2016). Functional Properties of Microorganisms in Fermented Foods. Frontiers in Microbiology, 7, 578. http://doi.org/10.3389/fmicb.2016.00578
- Gupta, R. K., Gangoliya, S. S., & Singh, N. K. (2015). Reduction of phytic acid and enhancement of bioavailable micronutrients in food grains. Journal of Food Science and Technology, 52(2), 676–84. http://doi.org/10.1007/s13197-013-0978-y
- Lee, S., Kim, J.-E., Suk, S., et al. (2015). A fermented barley and soybean formula enhances skin hydration. Journal of Clinical Biochemistry and Nutrition, 57(2), 156–63. http://doi.org/10.3164/jcbn.15-43
- Kano, M., Masuoka, N., Kaga, C., et al. (2013). Consecutive Intake of Fermented Milk Containing Bifidobacterium breve Strain Yakult and Galacto-oligosaccharides Benefits Skin Condition in Healthy Adult Women. Bioscience of Microbiota, Food and Health, 32(1), 33–9. http://doi.org/10.12938/bmfh.32.33
- Harima-Mizusawa, N., Kamachi, K., Kano, M., et al. (2016). Beneficial effects of citrus juice fermented with Lactobacillus plantarum YIT 0132 on atopic dermatitis: results of daily intake by adult patients in two open trials. Bioscience of Microbiota, Food and Health, 35(1), 29–39. http://doi.org/10.12938/bmfh.2015-010
- Bertuccelli, G., Zerbinati, N., Marcellino, M., et al. (2016). Effect of a quality-controlled fermented nutraceutical on skin aging markers: An antioxidant-control, double-blind study. Experimental and Therapeutic Medicine, 11(3), 909–916. http://doi.org/10.3892/etm.2016.3011
- Taeymans, J., Clarys, P., and Barel, A. O. (n.d.). Use of Food Supplements as Nutricosmetics in Health and Fitness A Review. Retrieved from https://www.researchgate.net/profile/Jan_Taeymans/publication/261993501_Use_of_Food_Supplements_as_Nutricosmetics_in_Health_and_Fitness_-_A_Review/links/02e7e53627dc243b84000000.pdf