Probiotics have been known to man for centuries. The term probiotics means “for life," and the beneficial bugs come from two groups of bacteria, Lactobacillus or Bifidobacterium. Probiotics were taken orally in the past only to reestablish the state of equilibrium among naturally occurring bacteria in the body, especially in the gastrointestinal (GI) tract. Now they have also been discovered to aid in beauty and skin health. With the recent explosion of interest and research on the human microbiome, especially in the gut, there has been a corresponding multitude of research, as well as theories and products containing different species of probiotics for various indications.
In a 2013 study, lead author Tatiana Levkovich stated: “Skin and mucosal surfaces of mammalian species are populated by millions of bacteria that impart diverse metabolic effects. These host-associated microbes play a well-established role in homeostasis in the gastrointestinal (GI) tract … There is now substantial evidence linking various gut microbiota and local immunity networks with systematic effects on the immune system. Disruption of the normal balance between microbial communities in the intestine is associated with allergic, autoimmune, metabolic and neoplastic pathologies in the GI tract and other distant tissues. Along these lines, experimental and clinical studies have shown that the dietary enrichment with certain ‘probiotic’ organisms activates immune and metabolic pathways that restore tissue homeostasis and promote overall health."
Probiotics have been commonly ingested as a beauty food in India and China for centuries. Recently, oral probiotics have gone mainstream in the United States for digestive health, but it is only a matter of time before their use for skin health is realized, branded and widely marketed.
Oral probiotics have gone so mainstream in the United States that Readers Digest last year featured a slide show of the 13 most common foods naturally containing probiotics. The focus was on GI health, but the same list could have focused on the youthful health of the skin. Probiotic-containing foods include some types of milk, natural yogurts, kefir, soft cheese, soy burgers and miso soup, which is popular in Japan. In addition, fermented products such as kimchi, a spicy fermented and pickled cabbage dish popular in Korea, sour pickles, and the brine of olives are also naturally rich in probiotics. Kombucha tea, a fermented tea popular in the Orient and full of probiotics, has recently been introduced into mainstream American grocery stores and has rapidly become popular with the health-conscious crowd.
There are many strains and strengths of oral probiotic supplements, which are now widely available in mainstream American groceries and pharmacies, as well as health food stores. Also, increasingly, foods such as yogurt and milk are supplemented with active strains of probiotics. Most people are familiar with Jamie Lee Curtis and her Activia commercials. The same fortified yogurt not only helps support the GI tract, but also helps skin maintain its healthy glow and youthful beauty. More natural probiotic foods are likely to be supplemented with probiotic actives and heavily marketed and branded as being beneficial for youthful skin.
Oral probiotics have been scientifically shown to balance the microflora and pH of the skin, returning it to a naturally healthy state. When the skin is out of balance, there is destruction of the skin barrier, leading to greater dispersion of harmful foreign substances and bacteria, in turn flaring skin conditions such as wrinkles, rosacea, acne, psoriasis and dermatitis.
Oral probiotics reduce inflammation and redness and are thought to have a long-term effect against the premature formation of wrinkles. Rosacea can be reduced or controlled when the skin is no longer too acidic or too base. Acne and dermatitis can also be reduced when skin is brought back to its natural state. Recent animal and human clinical controlled studies have shown oral probiotics contribute to the reinforcement of skin barrier function, decrease skin sensitivity and modulate the skin immune system, leading to the preservation of skin homeostasis.
Levkovich’s study revealed feeding probiotic bacteria to aged mice induced fur and skin changes mimicking peak health and reproductive fitness characteristics of much younger animals, or the “glow of health." Eating probiotics yielded luxuriant fur only in probiotic-fed male mice as compared to controls. Female animals displayed probiotic-induced shinier hair, a feature that also aligns with fertility in human females. This data confirms the strategy of eating probiotic bacteria for integumentary health.
In a study funded by Nestle in Switzerland, researchers investigated whether oral probiotics are able to modulate the immune system of the skin using mice exposed to an acute dose of ultraviolet radiation (UVR). They showed that nutritional supplementation with Lactobacillus johnsonii for 10 days was able to protect against the UVR-induced decrease in skin immune capacity by three measures. In the absence of UV-exposure, probiotic bacteria had no detectable effects on the immune system of the skin. In conclusion, data demonstrated ingested probiotic bacteria can maintain cutaneous immune capacity after UV exposure.
In another randomized, double-blind, placebo controlled clinical trial, 54 healthy volunteers supplemented with either Lactobillus johnsonii or placebo during six weeks prior to solar-simulated UV irradiation. For the first time, the results provided scientific evidence that ingested probiotic bacteria accelerate the recovery of skin immune homeostasis after UV-induced immunosuppression.
Based on a 2009 study, researchers concluded several lines of evidence suggest some probiotic bacteria can modulate the immune system both at the local and systemic levels, thereby improving immune defense mechanisms and/or downregulating immune disorders. These properties show that, beyond the gut, probiotics might exert their benefits at the skin level.
Dermatologist Whitney Bowe reviewed how the old gut-brain-skin theory has been validated via modern scientific investigations. In the article, Bowe stated it is evident gut microbes and oral probiotics could be linked to the skin by their ability to influence systemic inflammation, oxidative stress, glycemic control, tissue lipid content and even mood. Bowe said it makes sense that this intricate relationship between gut microbiota and the skin may also be influenced by diet.
A 2013 article published in Current Opinion in Microbiology correctly predicted that although probiotics were mainly used for GI applications, their use can easily be extended to skin, oral and vaginal health. While most probiotics currently belong to food-grade species, the future may offer new functional microorganisms in food and pharma.
Prebiotics have also been added to probiotics or used alone to support a youthful, healthy appearance of the skin. Prebiotics were first identified and named in 1995 and are considered functional foods. Typically, prebiotics are carbohydrates such as fructo-oligo-saccharides (FOS) or gluci-oligo-saccharides and inulin. They are non-digestible food ingredients that increase the number and/or activity of the helpful bifidobacteria and lactic acid bacteria in the body. The harmful organisms in the body cannot use prebiotics as food supplements, so the friendly bacteria can grow faster than the harmful ones with this ingredient. While probiotic foods contain live bacteria, prebiotic foods feed the good bacteria already living in the digestive system. Prebiotics exist in foods such as asparagus, onions, garlic, bananas, oatmeal, red wine, honey and maple syrup. Other of the foods naturally high in prebiotics include tomatoes, artichokes, legumes, flax seed, chicory and berries.
Prebiotic supplemental powders and prebiotics added to foods such as bread are now becoming more commonplace, but they will probably demand even greater shelf space in the future as the skin health properties of prebiotics become more widely known. Oatmeal, honey and maple syrup, as well as probiotics, could certainly be supplemented with more prebiotics by manufacturers.
Plenty of research and cultural history support the fact that both probiotics and prebiotics can help the skin look healthier and more beautiful.
Jeanette Jacknin, M.D., is a board certified dermatologist, author, national speaker and consultant with expertise in holistic dermatology and natural cosmeceuticals.
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