Good bacteria of the skin vs. skin disease causing bacteria

Nakatsuji T et al Science Translational Medicine  22 Feb 2017: Vol. 9, 4680

In this study Nakatsuji et al. report that strains of Staphylococcus (S. epidermidis and S. hominis) residing on the skin of healthy individuals produce a novel antimicrobial peptide (AMT) that can inhibit S. aureus that is known to aggravate symptoms of atopic dermatitis/eczema. They developed a probiotic lotion/cream of these good Staphylococcus strains. When applied to the fore arm of volunteers, within 24 hours, the probiotic lotion nearly eliminated S. aureus from their skin. Nonspecific antibacterial action by common pharmaceutical antibiotics could kill protective strains of Staphylococcus  and might therefore enhance the potential for recolonization by S. aureus. The selective activity of antimicrobials derived from normal flora would avoid this nonspecific effect and illustrates why bacteriotherapy that kills S. aureus but does not inhibit other beneficial strains could be superior. It remains to be seen how important this concept is in other skin diseases!