Evaluation of the Impact of Near-Infrared Multiwavelength Locked System Laser Therapy on Skin Microbiome in Atopic Dogs

Abstract

Photobiomodulation (PBM) is a newly adopted consensus term to replace the therapeutic application of low-level laser therapy. It has been suggested that PMB influences the microbiome which, in turn, has increasingly been shown to be linked with health and disease. Even though the use of PBM has also grown dramatically in veterinary medicine, there is still a lack of evidence supporting its effect in vivo. Our objective was to investigate the impact of a dual-wavelength near-infrared laser source (Multiwavelength Locked Laser System, MLS®) on the skin microbiome in atopic dogs. Twenty adult-client-owned atopic dogs were enrolled in the study. The dogs were treated with MLS® laser therapy on one half of the abdominal region, whereas the contralateral side was left untreated and served as a control. Skin microbiome samples were collected before and after MLS® treatments, and then subjected to NGS-based ITS and 16S rRNA analysis. The results showed that while microbiome composition and diversity were not significantly affected, PBM could play a role in modulating the abundance of specific bacterial species, in particular Staphylococcus, that represent a major skin pathogenic strain. To the best of the authors’ knowledge, this is the first study to investigate the potential impact of MLS® laser therapy on the skin microbiome in atopic dogs.

Changes in the Skin Microbiome Following Dermatological Procedures: A Scoping Review

“…It is also generally understood that specific wavelengths affect bacteria in different ways, with UV and blue wavelengths generally considered to be more destructive than red or infrared light [73,[81][82][83][84]. Interestingly, the studies we reviewed suggest that overall, UV light therapy results in an increase in microbial diversity and a decrease in pathogenic bacteria such as S. aureus, whereas laser therapy, regardless of wavelength, leads to decreased bacterial densities in all species tested [40][41][42][43][44]49,[51][52][53][54]58,59,61]. The reasons for this are unclear, but may be due to the optical amplification innate in laser therapy.…”

“…It is generally associated with an increase in microbiome diversity [40][41][42][43][44][45][46][47]. However, some studies found no significant change in this regard [48,49].…”

“…More recently it has been shown to have antibacterial effects, including suppressing growth and potentially disrupting membrane integrity and potential [56,57]. Of the three studies using laser therapy, one showed limited effects on microbial diversity but noted a decrease in Staphylococcus pseudintermedius [49]. Another study reported a decrease in alpha diversity [58].…”