Cannabis Use Disorder Was Linked to Lower Oral Microbiome Diversity
Young adults with cannabis use disorder had significantly lower oral bacterial diversity and distinct microbial profiles compared to those with other substance use disorders, with heavier use associated with more anaerobic bacteria.
Quick Facts
What This Study Found
Compared to a non-CUD substance use disorder control group, the CUD group exhibited significantly lower alpha diversity (fewer types of bacteria), distinct beta diversity (different bacterial community composition), and differences in specific bacterial taxa. Among CUD participants, more frequent cannabis use was linked to lower diversity, and both frequency and amount were associated with higher abundances of strict anaerobes.
Key Numbers
192 participants; 129 with CUD, 63 with non-CUD SUD; CUD had lower alpha diversity; distinct beta diversity between groups; greater cannabis frequency linked to lower diversity; frequency and amount linked to higher strict anaerobe abundance; controlled for sequencing batch, age, sex, race, BMI, alcohol
How They Did This
192 young adults (ages 18-25) with CUD (n=129) or non-CUD substance use disorder (n=63) provided saliva samples for 16S rRNA gene sequencing. The non-CUD SUD control group helped isolate cannabis-specific effects in a population that commonly uses multiple substances. Analyses controlled for batch, age, sex, race, BMI, and alcohol use.
Why This Research Matters
The oral microbiome affects whole-body health, from cardiovascular disease to mental health. Finding that cannabis use disorder specifically alters oral bacterial communities could reveal biological pathways linking heavy cannabis use to broader health outcomes.
The Bigger Picture
The shift toward anaerobic bacteria in heavy cannabis users mirrors patterns seen in periodontal disease and some systemic conditions. This suggests that cannabis use may create an oral environment that promotes harmful bacteria, with potential downstream health effects beyond the mouth.
What This Study Doesn't Tell Us
Cross-sectional design cannot determine if cannabis caused the microbiome changes, all participants had substance use disorders limiting generalizability, self-reported cannabis use, saliva sampling captures only part of the oral microbiome, no longitudinal follow-up
Questions This Raises
- ?Does the altered oral microbiome contribute to the increased oral health problems seen in cannabis users?
- ?Would microbiome changes reverse with cannabis cessation?
- ?Do the same patterns appear in recreational cannabis users without CUD?
Trust & Context
- Key Stat:
- Cannabis use disorder was linked to lower oral bacterial diversity and increased anaerobic bacteria
- Evidence Grade:
- Well-controlled comparison against other SUD patients with molecular methods; moderate sample size but cross-sectional design
- Study Age:
- Published 2025
- Original Title:
- Oral microbial profiles in young adults with cannabis use disorder.
- Published In:
- Drug and alcohol dependence, 275, 112822 (2025)
- Authors:
- Browning, Brittney D(3), Tomko, Rachel L(11), Kirkland, Anna E(5), Visontay, Rachel, Ferguson, Pamela L, Alekseyenko, Alexander V, Engevik, Melinda A, Mewton, Louise, Squeglia, Lindsay M
- Database ID:
- RTHC-06124
Evidence Hierarchy
A snapshot of a population at one point in time.
What do these levels mean? →Frequently Asked Questions
Does cannabis use change mouth bacteria?
In this study, young adults with cannabis use disorder had fewer types of bacteria and different bacterial communities in their saliva compared to those with other substance use disorders. Heavier use was linked to more anaerobic bacteria.
Why does the oral microbiome matter for cannabis users?
The oral microbiome affects dental health, cardiovascular risk, and systemic inflammation. The shift toward anaerobic bacteria seen in heavy cannabis users resembles patterns in periodontal disease, suggesting a potential pathway to broader health effects.
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Cite This Study
https://rethinkthc.com/research/RTHC-06124APA
Browning, Brittney D; Tomko, Rachel L; Kirkland, Anna E; Visontay, Rachel; Ferguson, Pamela L; Alekseyenko, Alexander V; Engevik, Melinda A; Mewton, Louise; Squeglia, Lindsay M. (2025). Oral microbial profiles in young adults with cannabis use disorder.. Drug and alcohol dependence, 275, 112822. https://doi.org/10.1016/j.drugalcdep.2025.112822
MLA
Browning, Brittney D, et al. "Oral microbial profiles in young adults with cannabis use disorder.." Drug and alcohol dependence, 2025. https://doi.org/10.1016/j.drugalcdep.2025.112822
RethinkTHC
RethinkTHC Research Database. "Oral microbial profiles in young adults with cannabis use di..." RTHC-06124. Retrieved from https://rethinkthc.com/research/browning-2025-oral-microbial-profiles-in
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.