Oral microbial profiles in young adults with cannabis use disorder

With increasing legalization and rising potency of cannabis products, cannabis use disorder (CUD) is a growing public health concern, particularly among young adults, who have the highest rates of CUD. While substance use is known to be associated with the oral microbiome, the impact of CUD remains understudied. Given the oral microbiome's role in overall health, identifying microbial signatures associated with CUD, relative to other substance use disorders (SUDs), may provide insight into its biological mechanisms and potential therapeutic targets.

Saliva samples were collected from young adults (ages 18-25; N = 192) with CUD (n = 129) and non-CUD SUD (n = 63). The non-CUD SUD control group allowed for isolation of CUD-related associations in a population that often uses multiple substances. Using 16S rRNA gene sequencing, we examined alpha diversity, beta diversity, and taxa abundance between the groups and in relation to cannabis use patterns (frequency and amount; CUD group only), controlling for sequencing batch, age, sex, race, body mass index (BMI), and alcohol use.

Compared to the non-CUD SUD group, the CUD group exhibited significantly lower alpha diversity, distinct beta diversity, and differences in taxa abundance. Among those with CUD, greater cannabis use frequency was linked to lower diversity, while both frequency and amount were associated with higher abundances of strict anaerobes.

CUD is associated with specific alterations in the oral microbiome, including lower diversity and taxonomic shifts. Associations with cannabis use patterns underscore the relevance of frequent and heavy use. Future research should explore the functional implications of these findings for CUD-related outcomes.