Analysis of the biological diversity of the skin and oropharyngeal microbiota depending on various treatment methods for psoriasis

Introduction. Psoriasis is a chronic inflammatory systemic disorder of a multifactorial origin, characterized by accelerated keratinocyte proliferation and impaired differentiation. Recently, the potential role of the human microbiota in the emergence of various chronic conditions, including psoriasis, has become a popular area of research. At the same time, no specific microbiological markers have been identified that could be used to accurately evaluate treatment effectiveness. The aim of the study was to assess the biological diversity of microbial communities of the skin and oropharynx in patients receiving different psoriasis treatment regimens, and to investigate an association between the incidence of isolated individual microorganisms and the applied treatment method. Materials and methods. The study included 155 male and female patients, aged > 18 years old, with psoriasis vulgaris of varying severity. All patients were divided into three groups. Group 1 — patients receiving topical corticosteroids (N = 52); group 2 — patients receiving methotrexate (N = 51); Group 3 — patients receiving IL-17 inhibitors (N = 52). Microbiological examination of skin and oropharynx swabs was conducted for all patients. The identification of microorganisms was performed using MALDI-ToF mass spectrometry. Results. In general, 109 and 139 individual species were isolated from oropharynx and skin, respectively. Analyzing biological diversity of the oropharyngeal microbiota revealed that the following microbial species are referred to resident microbiota in patients from all three groups: Streptococcus salivarius, Neisseria subflava, Streptococcus vestibularis. Differences in the microbiological diversity between the studied groups were only revealed due to an additional oropharyngeal microbiota. Analysis of the microbial diversity of the skin microbiota showed, that none of the isolated microorganisms was a resident part of the microbiota in all patients. Statistically significant differences were obtained for skin microorganisms, such as Staphylococcus hominis (p = 0.047) and Enterococcus faecalis (p = 0.013), as well as oropharyngeal microorganisms, including Neisseria flavescens (p = 0.022), Micrococcus luteus (p = 0.048) and Acinetobacter ursingii (p = 0.040). Conclusion. Thus, there has been revealed significant differences between studied groups in isolating individual microorganisms, which may potentially show varying effectiveness for different approaches to manage psoriatic patients.