Individuals with substance use disorders have a distinct oral microbiome pattern

Area of Science:

• Microbiome research
• Neuroscience
• Addiction science

Background:

• Substance use disorder (SUD) arises from complex genetic and environmental interactions.
• The human microbiome, particularly the oral microbiome, is increasingly recognized for its role in brain health.
• Oral microbiome composition is influenced by lifestyle, diet, and hygiene.

Purpose of the Study:

• To investigate differences in oral microbiome patterns between individuals with SUD and healthy comparison (HC) subjects.
• To determine if oral microbiome patterns can accurately distinguish between SUD and HC groups.
• To explore the relationship between oral microbiome diversity and negative reinforcement in SUD.

Main Methods:

• Analysis of a sub-sample (N=177) from the Tulsa 1000 project.
• 16S rRNA marker gene sequencing to characterize oral microbiomes of 123 SUD and 54 HC subjects.
• Machine learning approach combining microbiome features and socio-demographic variables for group classification.

Main Results:

• Significant differences in oral microbiome beta diversity (UniFrac distance) between SUD and HC groups.
• Machine learning models achieved 87%-92% accuracy in categorizing group membership, controlling for external factors.
• Lower oral microbiome diversity in SUD individuals correlated with higher negative reinforcement experiences.

Conclusions:

• Oral microbiome features effectively differentiate individuals with SUD from HC subjects.
• An impoverished oral microbiome may be associated with SUD driven by negative reinforcement.
• The oral microbiome shows potential as a biological marker for SUD risk or severity.