INTRODUCTION
Atopic dermatitis (AD) is a common, chronic inflammatory skin disease for which cutaneous dysbiosis is a core component of disease pathophysiology.1,2 AD-associated dysbiotic changes in the skin microbiome composition include an increased abundance of Staphylococcus aureus (S. aureus), S. epidermidis, and S. haemolyticus, decreased bacterial species diversity, and reduced colonization of the fungal genus Malassezia.3 Regulation of the skin microbiota is an emerging strategy for managing AD, and monitoring could be a biomarker for disease activity and treatment success.4-6 Cosmetic skin care products may be tools for microbial manipulation through barrier restoration and foundational support for diverse cutaneous flora. Even simpler, anti-inflammatory ingredients could theoretically augment the microbiota through this mechanism alone and enhance AD treatment and management.
Colloidal oatmeal is an often used ingredient in skin care products for AD for its anti-inflammatory, anti-pruritic, and barrier repair properties and is listed in the US Food and Administration monograph as a skin barrier protectant and irritation-relieving ingredient for skin irritation due to eczema; notably, colloidal oat also acts as a prebiotic, encouraging the balanced growth of commensal bacteria.7-10 Additionally, extracts from the plant Ophiopogon japonicus have demonstrated immunoregulatory activity in an AD mouse model11 and clinically improved AD symptoms and patient’s quality of life compared to placebo.12 Finally, filaggrin, an essential protein for maintenance of the epidermal barrier, is reduced in atopic skin.13 Reduced levels of filaggrin metabolic byproducts such as pyrrolidone carboxylic acid (PCA) correlate with disease severity,14 thus topical replenishment of PCA may improve the defective skin barrier in AD. Despite these findings, the impact of these combined ingredients on improving dysbiosis has not been well elucidated to date.
Sensitive skin syndrome (SSS) is a condition of increased skin reactivity to innocuous exposures and is associated with an impaired skin barrier like AD. Although the skin microbiome of sensitive skin is not well understood, it is suspected that this impaired skin barrier contributes to the abnormal neurosensory responses of this condition.15-17
Colloidal oatmeal is an often used ingredient in skin care products for AD for its anti-inflammatory, anti-pruritic, and barrier repair properties and is listed in the US Food and Administration monograph as a skin barrier protectant and irritation-relieving ingredient for skin irritation due to eczema; notably, colloidal oat also acts as a prebiotic, encouraging the balanced growth of commensal bacteria.7-10 Additionally, extracts from the plant Ophiopogon japonicus have demonstrated immunoregulatory activity in an AD mouse model11 and clinically improved AD symptoms and patient’s quality of life compared to placebo.12 Finally, filaggrin, an essential protein for maintenance of the epidermal barrier, is reduced in atopic skin.13 Reduced levels of filaggrin metabolic byproducts such as pyrrolidone carboxylic acid (PCA) correlate with disease severity,14 thus topical replenishment of PCA may improve the defective skin barrier in AD. Despite these findings, the impact of these combined ingredients on improving dysbiosis has not been well elucidated to date.
Sensitive skin syndrome (SSS) is a condition of increased skin reactivity to innocuous exposures and is associated with an impaired skin barrier like AD. Although the skin microbiome of sensitive skin is not well understood, it is suspected that this impaired skin barrier contributes to the abnormal neurosensory responses of this condition.15-17
