The Microbial Profile of Keloid Tissue: A Potential Biomarker for Lesion Activity

Background: Keloids can extend beyond the boundaries of the original wound and often cause itching or pain. Although the skin microbiome is known to influence various skin conditions, it is still unclear how the microbiota inside keloid tissues differ between active and inactive stages. Methods: We enrolled 43 patients with active keloids and 20 patients with inactive lesions. Tissue samples were collected from keloids and from nearby normal skin. In active lesions, both the relatively unstable and stable regions were also sampled. Microbial composition and predicted functions were analyzed using 16S Ribosomal RNA (rRNA) sequencing and standard bioinformatic approaches. Results: Active keloids exhibited a distinct microbial profile compared to normal skin. Acinetobacter and Pseudomonas were more abundant in active lesions, while Cutibacterium was more common in normal skin. Functional prediction also indicated changes in lipid-related pathways in active lesions. In contrast, inactive keloids showed no significant differences from normal skin, and different regions within active lesions had similar microbial features. Conclusions: This study indicates that alterations in the microbiota are linked to the activity of keloids. Potential microbiome-based translational pathways should be explored for monitoring and managing keloid activity in the future.