Characterization and analysis of the skin mycobiome in keloid: A case-control study

Altered skin bacteriome has been associated with keloid, yet the relation of fungal community to this disease remains unclear. This study aimed to characterize the skin mycobiome in patients with keloid and its correlation to disease severity. A case-control study was designed to investigate the fungal landscape in participants with keloid and healthy controls. Disease severity was assessed using Vancouver Scar Scale. Swabs of the keloid lesion (KL) and non-lesional (KNL) skin of keloid patients and corresponding skin sites of healthy controls (C) were obtained for ITS rRNA sequencing. Our findings revealed decreased richness and evenness in the fungal community within the KL as well as KNL groups compared to C (P < 0.01). Notably, fungal composition was more similar between KNL and C compared to KL (KL-C, ANOSIM: R=0.12, P = 0.004; KL-KNL, ANOSIM: R=0.10, P = 0.021; KNL-C, ANOSIM: R=0.03, P = 0.215). Skin mycobiome in KL was more enriched with Malassezia (P < 0.05), and depleted in Cladosporium, Alternaria, Aspergillus and Debaryomyces (P < 0.05). Correlation analysis identified a positive association between the relative abundance of Malassezia and disease severity (r_s=0.56, P = 0.007). The present study shows a decreased fungal diversity and altered fungal composition structure in keloid lesions. The overabundance of Malassezia and its correlation to disease severity highlight a potential role of these fungi in the pathogenesis of keloid and offer insights into novel disease-management approaches.