P08 Developing a rapid ATP assay to understand skin and hair follicle microbiome and assess skin microbiome dysbiosis

Abstract Introduction and aims Disruption to the complex ecosystem of microorganisms on the skin’s surface, known as dysbiosis, has implications for skin health. However, current methods to assess microbiome dysbiosis are costly and time-consuming; thus, they are not integrated into clinical workups. This study aims to develop a rapid ATP assay to assess skin dysbiosis on the skin surface and niches. Methods Five healthy volunteers participated in the study. Skin microbiome samples were collected from the dorsal forearm using swabbing (0.25 cm² area) and a noninvasive skin stretch-activated device (−4.5 psi, 10 min). Dysbiosis was induced via tape stripping on one arm and ethanol wiping on the other. Samples were taken at 0, 3, 6, and 24 h postdysbiosis. The total microbial count was determined using an ATP assay. Results The ATP assay was verified as fit for purpose, providing linearity over the range of 0.00511 AU to 0.000011476 AU (r2 = 0.98). The amount of microbial DNA on the skin’s surface was 0.002 ng uL−1; within the appendages, it was 0.009 ng uL−1. There was a statistical difference between the baseline (control) and t = 0 h and t = 3h for both treatments, indicating that both tape stripping and ethanol wipes induced microbiome dysbiosis. The dysbiosis recovered over the 24-h period in both groups, but the ethanol-cleansed skin took longer to recover compared with the tape-stripped skin (at t = 3 h and t = 6 h, the ethanol skin had statistically lower levels of ATP compared with tape-stripped skin). Conclusions The ATP assay measured microbial populations on the skin and tracked changes after dysbiosis. It could serve as a clinical tool to assess microbiome recovery rates. Further research is needed to determine whether this approach helps compare diseased skin and whether a handheld ATP machine could provide clinicians with a point-of-care analysis.