The probiotic strains found to regulate skin physiology include Nitrobacter, Lactobacillus, and Bifidobacterium.
The researchers implied a link between intestinal microbiota disorder and inflammatory skin conditions, that include acne, atopic dermatitis, psoriasis, and rosacea.
Probiotics are known for its value in improving the microbiome and treating inflammatory skin disorders.
The paper explained the benefits of oral probiotics: “Oral probiotics are a kind of live microbiota that modify the intestinal microbe and can have direct photoprotective influences on special skin cells via regulating immune responses and inflammation factors.
“In addition, they can increase the serum contents of short-chain fatty acids (SCFAs), which induce a range of immune and inflammatory responses.”
Funded by the Education Ministry of China and the National Natural Science Foundation, researchers from Beijing, China, investigated the effectiveness of oral administration of probiotics on skin conditions via intestinal homeostasis.
Limitations of topical probiotics
There is an array of topical skin care with added probiotics in the market addressing anti-ageing, whitening, moisturizing, and body odour concerns. However, the beneficial effects of the probiotic strains in these products are limited, said the researchers.
Firstly, the antiseptics found in cosmetics – known for its antibacterial properties – have been shown to affect the viability of probiotic strains.
Secondly, microbial stabilisation is more difficult to achieve in topical products than “products containing only smaller molecules” such as dietary supplements. Other factors affecting microbial control include pH, osmolarity contents, temperature, and humidity levels of storage environment.
Thirdly, the stratum corneum in the skin “regulates the absorption of effective substances into the deeper layers of the skin, thus also limiting the choice of treatments.”
Mechanism at work
Previous studies reported the ability of probiotic strains like Lactobacillus and Bifidobacterium to reduce ultraviolent (UV) damage, rough, dry, and saggy skin, promote antioxidant capacity, and the collagen and elasticity function of the skin.
Aside from the visible benefits, it has also been shown to also boost the immune response to inhibit pathogens.
Notably, only orally administered probiotics interacts with the gastrointestinal muscosa and gut-associated lumphoid tissue (GALT) – where 70% of our immune cells are located.
“It inhibits unwanted immunological effects to maintain immune homeostasis against chronic inflammation diseases. It may be due to the modulation of the regulatory T-cells (Tregs) number by probiotics.
“Treg exerts a vital effect on the immunosuppression caused by skin photoaging. Lactobacillus johnsonii suppressed UV-caused decrease in epidermal Langerhans cell density and promoted the restoration of skin immune homeostasis after UV-caused immunosuppression.”
The researchers concluded the paper by saying that more research in the field of internal probiotics would be needed to promote it as a novel therapeutic approach in treating skin disorders.
“The Role of Probiotics in Skin Health and Related Gut–Skin Axis: A Review”
Authors: Gao, T., et al.