AAD 2026: CO2 Laser Resurfacing Linked to Transient Microbiome Shifts
New findings presented at the 2026 American Academy of Dermatology (AAD) Annual Meeting in Denver, Colorado, provide insight into dynamic microbiome changes following ablative CO2 laser resurfacing and their relationship to wound healing.
In this monocentric, double-blind, randomized intra-individual study, 25 participants underwent laser treatment on a defined skin area, with adjacent untreated skin serving as control. Microbiome samples were collected at baseline, immediately post-procedure, and on Days 1, 3, 8, and 18. Investigators also assessed clinical healing and skin barrier recovery using transepidermal water loss (TEWL) measurements over a 3-week period.
Quantitative PCR analysis demonstrated significant fluctuations in bacterial load within treated areas, with notable changes observed on Days 3 and 8. Microbial composition, assessed using 16S rRNA sequencing, revealed transient shifts in diversity during this period. These alterations normalized by approximately Day 19, coinciding with clinical healing.
A key finding was the temporary overrepresentation of Staphylococcus species in treated skin. Increased Staphylococcus abundance correlated with slower wound healing and delayed barrier recovery, as measured by TEWL. These results suggest a potential link between microbial imbalance and post-procedural recovery kinetics.
While the study was limited by its small sample size and single-center design, it offers mechanistic insight into how ablative laser procedures influence the skin microbiome.
“These findings underscore the profound, albeit temporary, disruption of microbial homeostasis by ablative laser therapy and highlight a link between specific microbial shifts and healing kinetics,” the authors wrote. “Understanding these dynamic microbial responses offers novel insights into optimizing post-procedure care and enhancing cutaneous repair quality.”