Effects of Photobiomodulation on Gut Microbiota: A Meta-analysis Based on 16S rRNA Sequencing Data

Abstract Photo-biomodulation (PBM) can affect the gut microbiome, which may be one of the important mechanisms by which such therapy exerts its effects. However, with the burgeoning interest in the gut microbiome, differences in research methods and conditions among independent studies make it a challenge to fully understand the impact of the gut microbiome on the health of organisms. Therefore, we conducted a meta-analysis of 16S rRNA gene datasets generated by 8 published studies about the effects of PBM on the gut microbiome to investigate how the gut microbiome is altered across wave bands (infrared [IR], ultraviolet [UV] and visible light [VIS]), species (human, rat and mouse), and physique (healthy and unhealthy). Our results show that PBM can significantly affect the community diversity, species composition, and overall expression of metabolic pathways of the gut microbiome. VIS and UV can enrich key probiotics, such as Akkermansia muciniphila, in the gut microbiome while IR leads to a decrease of probiotics and an increase in harmful bacteria. In summary, we systematically analyzed the changes in the gut microbiome under different light conditions, providing a theoretical basis for the clinical application of PBM to regulate human health.