Effects of Oral Intake of Kimchi-Derived Lactobacillus plantarum K8 Lysates on Skin Moisturizing

Abstract

Skin is the soft outer covering of vertebrates that provides protection from pathogenic infection, physical damage, or UV irradiation, and controls body temperature and water content. In this study, we examined the effects of oral intake of kimchi-derived Lactobacillus plantarum K8 lysates on skin moisturizing. In an in vitro study, we observed that the hyaluronic acid content increased in HaCaT cells treated with L. plantarum K8 lysates. Oral administration of L. plantarum K8 lysates effectively attenuated the horny layer formation and decreased epidermal thickening in DNCB-treated SKH-1 hairless mice skin. The damage to barrier function was reduced after 8 weeks of oral administration of L. plantarum K8 lysates as compared with that in the atopic dermatitis mice. For the test with volunteers, we manufactured experimental candy containing 2.1% L. plantarum K8 lysates, while control candy did not contain bacterial lysate. A significant increase in hydration in the experimental candy-administered group as compared with the control candy-administered group was observed on the face after 4 and 8 weeks, and on the forearm after 4 weeks. Decreases in horny layer thickness and TEWL value were observed on the face and forearm of the experimental group. Together, the in vitro cell line and in vivo mouse studies revealed that L. plantarum K8 lysates have a moisturizing effect. A clinical research study with healthy volunteers also showed an improvement in barrier repair and function when volunteers took L. plantarum K8 lysates-containing candy. Thus, our results suggest that L. plantarum K8 lysates may help to improve skin barrier function.

Skin Protective Nutraceuticals: The Current Evidence in Brief

“…Probiotics can modify and regulate host innate immune responses for additional protection against pathogenic bacteria [ 8 ]. Probiotic lactobacilli including Lactobacillus plantarum have shown nonspecific immune system boosting and regulation [ 5 , 20 ]. Lactobacilli protect phagocytes from pathogen-directed apoptosis [ 20 ].…”

“…The skin controls body temperature and water content, which prevents dryness. The skin protects the covered body from infection, physical damage, and ultraviolet radiation (UVR) [ 5 ]. Damage to the skin occurs via several modalities including heat, moisture, UVR, and direct mechanical trauma.…”

“…Increased outer horny skin layer thickness is associated with atopic dermatitis (eczema; AD) [ 5 ]. About 14% of children under four years of age have AD [ 9 ].…”

“…Annually in the USA, AD costs about $1 billion USD [ 10 ]. Externally applied moisturizers improve dry skin’s barrier function and reduce inflammation, which forms part of AD treatment [ 5 , 9 ]. Skin barrier disorders such as AD also have immunologic components [ 5 ].…”

“…Externally applied moisturizers improve dry skin’s barrier function and reduce inflammation, which forms part of AD treatment [ 5 , 9 ]. Skin barrier disorders such as AD also have immunologic components [ 5 ]. Extrinsic or allergic AD accounts for up to 80% of AD and involves IgA, IgE, and regulatory T-cells [ 9 ].…”