Alterations in scalp microorganisms after Er: YAG laser treatment for Shanghai androgenetic alopecia patients.

Androgenetic alopecia (AGA) is associated with the scalp microbiota, but the role of microflora during hair loss has not been fully characterized. Erbium: yttrium aluminum garnet (Er: Yag) is a microablative laser treatment for hair regeneration that can cause minimal damage to the skin surface. This investigation aimed to evaluate the effects of microtrauma caused by the Er: Yag laser of AGA on scalp microorganisms. Thirteen AGA patients in this study received Er: Yag laser treatment (3.3 Hz frequency and 7.00 J/cm pulse fluence). Scanning electron microscope (SEM) was used to observe the scalp bacteria. Before treatment, microflora samples were collected 2 hours and 48 hours after shampooing. Samples were also collected on the third, seventh, and fourteenth days following laser treatment. Scalp microorganisms coding the 16S ribosomal RNA V3/V4 region were analysed by high-throughput DNA sequencing. Globular bacteria were detected through the SEM images on the epidermis at the junction of the hair shaft and hair follicle. The results of the 16S sequencing revealed that the most abundant genera observed across all samples prior to laser treatment were Cutibacterium species (spp.) (53%) and Staphylococcus spp. (13%) in 13 AGA patients. Three days after laser treatment, Firmicutes, Staphylococcus spp., and Staphylococcus capitis were significantly more abundant at the phylum, genus, and species levels than before, respectively. These data suggest that the presence of Staphylococcus spp. significantly increased after microtrauma caused by Er: Yag laser treatment, indicating that the Er: Yag laser might play an essential role in modulating and restoring the balance of scalp microbiota.