Exploring the Effects of Isotretinoin on the Oral Microbiome: A Comparative Study of Microbial Diversity and Composition

Abstract

Isotretinoin, known by its brand name Accutane, is an oral medication commonly used in the treatment of moderate to severe acne. Previous research has demonstrated the antimicrobial properties of isotretinoin, particularly in modulating cutaneous colonization by the acne linked Cutibacterium acnes, however, its effects on entire microbial communities are poorly understood. Therefore, the objective of this study was to investigate the effects of isotretinoin on the beta diversity of the oral microbiome. The salivary microbiomes of 7 individuals who have previously taken isotretinoin but are no longer taking it were compared to 27 control individuals with no history of isotretinoin usage. 16S sequencing followed by non-metric multidimensional scaling showed no significant difference in oral microbiome beta diversity between individuals who have taken isotretinoin and those who have not. Differential abundance analysis revealed past isotretinoin users exhibited significantly lower abundances of Actinobacteria taxa including Actinomycetales and Micrococcaceae related species. While bacterial alpha diversity was similar between study groups, oral community richness within the Actinobacteria phylum was significantly lower among isotretinoin users. These findings provide further insight into the long-term effects of isotretinoin on the human body and characterize its impact on the oral microbiome for the first time. However, additional research is needed to explore the underlying mechanisms by which isotretinoin influences microbial diversity as well as the broader implications of such alterations in microbiome composition.