RESUMO
The role of Malassezia yeasts in dandruff and seborrheic dermatitis is unclear; however, antifungal therapy with ketoconazole is commonly used. We propose that ketoconazole shifts skin lipid profile, affects Malassezia lipid metabolism and favours biotin-producing bacteria. Biotin regulates inflammatory response and cell proliferation, contributing to symptom improvement.
Assuntos
Caspa , Dermatite Seborreica , Malassezia , Antifúngicos/farmacologia , Biotina , Biologia Computacional , Caspa/tratamento farmacológico , Caspa/microbiologia , Dermatite Seborreica/tratamento farmacológico , Dermatite Seborreica/microbiologia , Humanos , Cetoconazol/farmacologia , Metabolismo dos LipídeosRESUMO
The human body is inhabited by complex microbial communities, which positively impact different aspects of our health, and might also be related to the development of diseases. Progress in technologies, particularly sequencing methods and bioinformatics tools, has been crucial for the advances in this field. Microbial communities from skin can modulate immune response and protect the host against pathogens, and there are also data supporting their association with several skin conditions; including dandruff and seborrheic dermatitis. For decades, they have been thought to be related to Malassezia yeasts; however, the microbial role has not been elucidated, and their etiology remains poorly understood. This review discusses the recent findings in dandruff and seborrheic dermatitis and their relation to the skin microbiota. Data provided new perceptions to aid in the understanding of these skin disorders, broadening our view of their etiology and the possible roles of microbial communities in symptom development.
Assuntos
Caspa/microbiologia , Dermatite Seborreica/microbiologia , Microbiota , Pele/microbiologia , Humanos , Malassezia/isolamento & purificaçãoRESUMO
Dandruff is a prevalent chronic inflammatory skin condition of the scalp that has been associated with Malassezia yeasts. However, the microbial role has not been elucidated yet, and the etiology of the disorder remains poorly understood. Using high-throughput 16S rDNA and ITS1 sequencing, we characterized cutaneous bacterial and fungal microbiotas from healthy and dandruff subjects, comparing scalp and forehead (lesional and non-lesional skin sites). Bacterial and fungal communities from dandruff analyzed at genus level differed in comparison with healthy ones, presenting higher diversity and greater intragroup variation. The microbial shift was observed also in non-lesional sites from dandruff subjects, suggesting that dandruff is related to a systemic process that is not restricted to the site exhibiting clinical symptoms. In contrast, Malassezia microbiota analyzed at species level did not differ according to health status. A 2-step OTU assignment using combined databases substantially increased fungal assigned sequences, and revealed the presence of highly prevalent uncharacterized Malassezia organisms (>37% of the reads). Although clinical symptoms of dandruff manifest locally, microbial dysbiosis beyond clinically affected skin sites suggests that subjects undergo systemic alterations, which could be considered for redefining therapeutic approaches.