The Effect of Marijuana on The Oral Microbiome

Marijuana is the most commonly used recreational drug in the United States. In 2015, it was reported that 22.2 million U.S. individuals ≥12 years old had used marijuana in the past month. The use of marijuana has been associated with cognitive impairment, changes in heart rate, and increased risk for periodontal disease. The association between microorganisms, health, and disease, is being studied extensively, and advances in research and data analysis have brought about stronger evidence of such a relationship. External factors have proven to play a role in changes in the microbiome, which have been linked to states of disease or health. This correlation may be evident in the oral microbiome, with the use of marijuana. The aim of this study was to first see if the microbiome is distinct in marijuana users. 11 test subjects and 16 control subjects participated in the study. Bacterial swabs were taken and analyzed from two oral locations: lateral border of the tongue and the oropharynx. 16S ribosomal RNA gene targeted sequencing was carried out. The study showed that four taxa had differentially relative abundances at the lateral border of the tongue of marijuana users compared to non-users. Three organisms were identified at the genera level Rothia, Variovorax, Fusobacterium and one at the family level, Bradyrhizobiaceae (FDR ≤0.1). Of these, Rothia (FDR<0.065), Variovorax (FDR<0.065), and Bradyrhizobiaceae (FDR<0.073) were found to have higher relative abundances in the marijuana user group, while Fusobacterium (FDR<0.065), was increased in the control group. Further studies should be completed to confirm such a distinction, and this can lend to future research on the effect these changes may have in the oral cavity and the rest of the body.