Probioitcs are beneficial bacteria living in the intestines while prebiotics, which are sometimes called "fermentable fiber," serve as their food supply. According to Mayo Clinic nutritionist Katherine Zeratsky, probiotics may improve digestion and aid immunity, but their numbers can be decreased by stress, a poor diet and certain medications. Recent research discovered that some probiotics, either taken orally or applied topically, may reduce the number of acne lesions.
In-Vitro Studies of Probiotics
The link between skin and intestinal health has been a source of speculation for at least 70 years, when two dermatologists, John Stokes and Michael Pillsbury, recommended acidophilus preparations. Modern research has confirmed this relationship. An April 2010 study published in the "International Journal of Cosmetic Science" tested several types of probiotics and found that all of them inhibited the growth of the bacterium responsible for acne. The inhibitory effects of the probiotics were enhanced by the presence of prebiotics called konjac glucomannan hydrolysates.
Internal Applications of Probiotics
According to a 2011 article in "Gut Pathogens," a 2001 study in Italy found that administering 250 mg daily of L. acidophilus and B. bifidum improved acne and also reduced the side effects of the antibiotics. A Russian study found that patients given probiotics in addition to standard clinical care improved more rapidly than patients who weren't given the probiotics. The theory underlying this treatment is that probiotics reduce inflammation and oxidative stress, two important causes of acne.
External Application of Probiotics
The idea that topical applications of probiotics might reduce acne lesions goes back to at least 1912 when researchers discovered the beneficial effects of Lactobacillus bulgaricus, the bacterium most commonly found in yoghourt. Another helpful bacteria found in most yoghourts is Streptococcus thermophilus, which can increase the skin's production of a substance called phytosphingosine, which has been shown to reduce acne lesions by 89 percent during a two-month trial, according to this same article in "Gut Pathogens."
A number of different probiotics may reduce the number of acne lesions. Many of them are found in yogurt: Lactobacillus bulgaricus, lactobacillus acidophilus, Lactobacillus casei and Streptococcus thermophilus. If you want to add more probiotics to your diet, consume more yogurt, whether made from cow's milk, soy milk or even coconut milk. Because foods that trigger insulin release are associated with acne, these products should be unsweetened. There are also a number of probiotic supplements containing these substances.