Skin Microbiota and Good Bacteria

Skin Microbiota and Beneficial Bacteria The sum of all microorganisms and genomes in and on the human body is called "microbiota," while the genetic material possessed by the microbiota is called "microbiome." However, these two terms are often used interchangeably. In today's world, factors such as stress, hormonal changes, antibiotic use, cleansers incompatible with skin pH, air pollution, and UV rays can disrupt the balance of skin microbiota and negatively affect the microbiome. (1) As a result, problems such as allergies, sensitivity, irritation, redness, and dryness can develop on the skin. Atopic dermatitis (AD; eczema) is a common inflammatory skin disorder affecting 10 to 30 percent of children in industrialized countries. (2) In skin microbiota, benign and pathogenic bacteria exist in balance. The skin barrier and microbiota protect the body against a wide variety of external threats. The use of probiotic, prebiotic, and postbiotic components, which are known to have skin-renewing, healing, and nourishing properties, is increasing in personal care products. The definition of probiotics according to the United Nations Food and Agriculture Organization (FAO) and the World Health Organization (WHO) is as follows: "Living microorganisms that, when administered in adequate quantities, confer health benefits to the host." Probiotics help strengthen the microbiome ecosystem. Probiotics are natural bacterial cultures and are also called "good bacteria." These bacteria maintain the microbiota—that is, the balance of beneficial and pathogenic bacteria on the skin surface—strengthen barrier functions, and help overall body functions by reducing the risk of allergies on the skin. Prebiotics are the nutrient source for probiotics. Inulin, oligosaccharides, and glucono delta lactone are prebiotic components. (3) Prebiotics positively affect microbiota activity by preventing the proliferation of pathogenic bacteria and stimulating the proliferation of skin-friendly bacteria. When the number of pathogenic bacteria (such as Staphylococcus aureus) exceeds the number of beneficial bacteria (such as Staphylococcus epidermidis)—that is, when skin microbiota becomes unbalanced—skin problems such as irritation and atopic dermatitis (allergic eczema) emerge. (4) [caption id="attachment_158210" align="aligncenter"] Table 1. Skin Problems Related to Microbiome Imbalances (5,6)[/caption] In situations where pathogenic bacteria increase relative to beneficial bacteria and skin microbiota becomes unbalanced, it helps alleviate the irritation and redness that may occur. Due to the increase in beneficial bacteria, it supports the skin's epidermal defense mechanism and thereby helps protect the skin against external factors. Postbiotics are end products produced by probiotic bacteria. Lactic acid and butyric acid (short-chain fatty acid) are postbiotic components. They increase immune system tolerance. Imbalances in skin microbiota can lead to various skin problems. Dermatologists are aware of the importance of addressing skin microbiota dysfunction (dysbiosis) for the effective treatment of conditions such as eczema, acne, and allergies. To restore balance, scientists and skin care specialists are developing products containing components such as prebiotics and probiotics. These products aim to nourish and support beneficial microorganisms on the skin, potentially improve skin health, and alleviate certain conditions. With advancing research and personalized approaches, skin care will be promoted. (7)   References (1) Draelos ZD. The science behind skin care: Cleansers. J Cosmet Dermatol.,17(1):8-14 (2018) (2) K. Eyerich, S. Eyerich, T. Biedermann, The multi-modal immune pathogenesis of atopic eczema. Trends Immunol. 36, 788–801 (2015). (3) S. Wichienchot and W.Ishak, Prebiotics and Dietary Fibers from Food Processing By-Products, IFST, p.137 (2018) (4) A.L. Byrd, C. Deming, S.K.B. Cassidy, O.J. Harrison, Staphylococcus aureus and Staphylococcus epidermidis strain diversity underlying pediatric atopic dermatitis, Science Translational Medicine, 5 Jul 2017, Vol 9, Issue 397 (5) Grice EA, Segre JA. The human microbiome: Our second genome. Annual review of genomics and human genetics. 2012;13:151-170. doi: 10.1146/annurev-genom-090711-163814 (6) Dréno B, Araviiskaia E, Berardesca E, et al. Microbiome in healthy skin, update for dermatologists. J Eur Acad Dermatol Venereol. 2016;30(12):2038-2047. https://doi. org/10.1111/jdv.13965. doi: 10.1111/jdv.13965 (7) DeAnna Diaz, MS, MBS, OMS-III, and Chérie M. Ditre, MD, The Effect of Cleansers on the Skin Microbiome; April 2020, Practical Dermatology 65   Didem Bilir Research and Development Project Manager, Personal Care Evyap Sabun Yağ Gliserin San. ve Tic. A.Ş.