Shifts in the Skin Microbiota after UVB Treatment in Adult Atopic Dermatitis

Abstract

<b><i>Background:</i></b> The pathophysiology in atopic dermatitis (AD) is not fully understood, but immune dysfunction, skin barrier defects, and alterations of the skin microbiota are thought to play important roles. AD skin is frequently colonized with <i>Staphylococcus aureus</i> (<i>S. aureus</i>) and microbial diversity on lesional skin (LS) is reduced compared to on healthy skin. Treatment with narrow-band ultraviolet B (nb-UVB) leads to clinical improvement of the eczema and reduced abundance of <i>S. aureus</i>. However, in-depth knowledge of the temporal dynamics of the skin microbiota in AD in response to nb-UVB treatment is lacking and could provide important clues to decipher whether the microbial changes are primary drivers of the disease, or secondary to the inflammatory process. <b><i>Objectives:</i></b> To map the temporal shifts in the microbiota of the skin, nose, and throat in adult AD patients after nb-UVB treatment. <b><i>Methods:</i></b> Skin swabs were taken from lesional AD skin (<i>n</i> = 16) before and after 3 treatments of nb-UVB, and after 6–8 weeks of full-body treatment. We also obtained samples from non-lesional skin (NLS) and from the nose and throat. All samples were characterized by 16S rRNA gene sequencing. <b><i>Results:</i></b> We observed shifts towards higher diversity in the microbiota of lesional AD skin after 6–8 weeks of treatment, while the microbiota of NLS and of the nose/throat remained unchanged. After only 3 treatments with nb-UVB, there were no significant changes in the microbiota. <b><i>Conclusion:</i></b> Nb-UVB induces changes in the skin microbiota towards higher diversity, but the microbiota of the nose and throat are not altered.

The Influence of Microbiome Dysbiosis and Bacterial Biofilms on Epidermal Barrier Function in Atopic Dermatitis—An Update

“…Lastly, it was shown that systemic treatment with dupilumab reduced the proportion of S. aureus on both the lesional and nonlesional skin and caused the increase in the population of coagulase-negative staphylococci, such as S. epidermidis, S. hominis, and S. saprophyticus on the nonlesional skin [166]. A study by Lossius et al revealed that bacterial diversity was also increased on the lesional skin of patients treated with UVB therapy [167]. Such observations reflect the close relationship between the inflammatory cascade and the microbial dysbiosis, underlying the need to diversify the therapeutic process in AD.…”

The effects of exposure to solar radiation on human health

“…UV irradiation of the skin causes changes in the skin microbiome [ 25 ] and transcriptome (the set of coding and non-coding RNA in cells) [ 26 ]. In people with atopic dermatitis (the most common type of eczema), 12–25 treatments over 6–8 weeks with narrowband UV-B radiation caused a shift to greater microbial diversity accompanied by reduced skin inflammation [ 25 ].…”

“…UV irradiation of the skin causes changes in the skin microbiome [ 25 ] and transcriptome (the set of coding and non-coding RNA in cells) [ 26 ]. In people with atopic dermatitis (the most common type of eczema), 12–25 treatments over 6–8 weeks with narrowband UV-B radiation caused a shift to greater microbial diversity accompanied by reduced skin inflammation [ 25 ]. Irradiation of the skin of seven healthy male volunteers (skin type II) using solar-simulated UV radiation and doses equivalent to 0, 3 and 6 standard erythemal doses (SED) led to altered expression, mainly upregulation, of multiple genes (primarily related to DNA repair and apoptosis, immunity and inflammation, pigmentation, and vitamin D synthesis) [ 26 ].…”

Microbioma cutâneo e dermatite atópica

“…por sua vez, conduziu um ensaio com 16 adultos com DA sob fototerapia UVB três vezes por semana, durante seis a oito semanas, verificando -se um aumento significativo da diversidade microbiana (p=0,013) nas regiões com lesões ativas (57) . Não existem dados, até à data, dos efeitos no microbioma cutâneo da fototerapia com PUVA (Psoralen plus ultraviolet light therapy).…”