How does immunotherapy influence the skin microbiota of people living with atopic dermatitis?
The human skin is an ecosystem, populated by a large variety of bacterial species, called the skin microbiota. Within the skin microbiota, one can find a large diversity of species, many of which are beneficial to humans. In the scenario of skin affected by atopic dermatitis (AD), this ecosystem can be altered. Furthermore, there can be high numbers of a type of bacteria, Staphylococcus aureus (S. aureus), especially in people living with severe AD.
Two prescribed treatments, dupilumab and cyclosporine are both effective therapies for AD leading to improved symptoms and skin appearance. However, little is known about the effects of these therapies on the human skin microbiota. We therefore set out to explore if and how these AD therapies influence the bacteria colonising the skin of people living with AD.
We analysed skin bacteria sampled from different body sites from 157 individuals affected by AD just before and 3 months after starting treatment with dupilumab or cyclosporine in order to examine the potential effects of both treatments. For comparison, we additionally assessed the skin bacteria of 258 volunteers whose skin was unaffected by AD.
We found that individuals with AD under dupilumab treatment, independent of improved AD symptoms had decreased numbers of S. aureus, resulting in the skin microbiota being of similar composition to skin microbiota in individuals unaffected by AD. In contrast, ciclosporin treatment did not affect skin bacteria despite improvement in the symptoms of AD. Treatment with dupilumab but not cyclosporine seems to restore a healthy skin microbiota largely independent of improvement in AD symptoms indicating a treatment-specific effect of dupilumab on the skin microbiota.
Dupilumab but not cyclosporine treatment shifts the microbiome toward a healthy skin flora in patients with moderate-to-severe atopic dermatitis
Jan Hartmann, Lucas Moitinho-Silva, Nicole Sander, Inken Harder, Robert Häsler, Elke Rodriguez, Eva Haufe, Andreas Kleinheinz, Susanne Abraham, Annice Heratizadeh, Elke Weisshaar, Knut Schäkel, Christiane Handrick, Matthias Augustin, Andreas Wollenberg, Petra Staubach-Renz, Konstantin Ertner, Michael Sticherling, Beate Schwarz, Sven Quist, Franca Wiemers, Florian Schenck, Julia Wildberger, Lukas Tittmann, Wolfgang Lieb, Jochen Schmitt, Thomas Werfel, Stephan Weidinger, the TREATgermany Study Group. Allergy. 2023; 00: 1–11.