Maintaining a Healthy Microbiome
Probiotics And Skin Health
The skin is home to a large and diverse microbiome that impacts skin health and has body-wide effects on health. The skin microbiome varies in the same individual across body site and also between individuals. It is shaped by both external and internal factors (Prescott 2017; Barnard 2017; SanMiguel 2015; Grice 2011). Yet, even with its exposure to constantly changing conditions, the skin microbiome appears to be largely stable within individuals over time (Oh 2016). Skin dysbiosis has been noted in an array of skin conditions, including atopic dermatitis (eczema), acne, seborrhea, psoriasis, rosacea, and dandruff (Barnard 2017; Abdallah 2017; Paulino 2017).
Probiotic bacteria can have local and systemic effects that support skin barrier function, regulate immune activity, and control microbial populations (Al-Ghazzewi 2014; Wong 2013; Lew 2013). Probiotic supplements may be beneficial in several infectious and inflammatory skin disorders, as well as sun-induced and trauma-related skin damage (Notay 2017; Roudsari 2015; Kober 2015). Most clinical trials have used oral probiotics, but emerging research suggests the topical application of probiotic bacteria may also be useful for promoting skin healing (Zoccali 2016; Lopes 2017).
Oral probiotics such as Lactobacillus acidophilus and Bifidobacterium bifidum have shown positive effects in people with acne in early clinical research (Bowe 2014). In a controlled trial in 20 subjects with acne, supplementing with L. rhamnosus SP1 at a dose of 3 billion CFUs per day led to greater improvement in skin condition than placebo after 12 weeks (Fabbrocini 2016). Other evidence suggests a combination of oral probiotics and antibiotics may be more effective than either alone for adults with mild-to-moderate acne (Jung 2013). Additional clinical studies found that a 5% L. plantarum topical solution, but not a 1% solution, reduced acne lesion size and redness (Muizzuddin 2012).
The probiotic strain Enterococcus faecalis SL-5, applied as a lotion, demonstrated antibacterial activity against bacteria associated with acne and improved the appearance of acne lesions (Kang 2009). Other probiotic bacteria, including L. reuteri, B. longum, B. adolescentis, and Streptococcus salivarius, have demonstrated similar antibacterial effects and have potential as topical agents for treating acne (Bowe 2014).
Factors that shape the intestinal microbiome early in life can influence risk of childhood allergic conditions, such as atopic dermatitis, a skin disorder commonly referred to as eczema (Zheng 2016; Marrs 2016). Atopic dermatitis is associated with impaired skin barrier function, inflammation, and loss of diversity in the skin microbiome (Wollina 2017).
Probiotic supplements may help prevent atopic dermatitis, especially if used during pregnancy and given in the first years of life (Zukiewicz-Sobczak 2014; Kim 2013; Elazab 2013; Pelucchi 2012). In a systematic review and meta-analysis on preventing eczema in infants and children, most studies that were examined used supplements with Lactobacillus species, Bifidobacterium species, or both, and both strains showed protective effects (Mansfield 2014).
According to recent meta-analyses, probiotics may be beneficial for treating atopic dermatitis in adults and in children older than one year (Kim 2014; Huang 2017). Probiotics with Bifidobacterium species alone appear to be less effective than those with mixed species and with Lactobacillus species (Kim 2014; Chang 2016). Three studies showed that L. acidophilus L-92 ameliorated atopic dermatitis in three human studies (Torii 2011; Yamamoto 2016; Inoue 2014).
For more information about acne, atopic dermatitis, and other skin conditions, please see the Skin Disorders health protocol.