Metabolome and Gut Microbiome Changes During Smoking Cessation in Long-term Drug Therapy in a Therapeutic Community

Theoretical Framework: Cigarette smoking is the leading preventable cause of death worldwide, with nicotine dependence notably common among individuals with Substance Use Disorders (SUD). Smoking exacerbates both physical and mental health issues, further complicating the treatment of SUD. Current therapeutic approaches for SUD often prove inadequate, indicating a need for new strategies. Recent advancements in metabolomics and gut microbiome research have provided valuable insights into the biological mechanisms underlying addiction. Objectives: This study aims to investigate the therapeutic potential of smoking cessation for individuals with SUD, using a six-week intervention within a therapeutic community. The research specifically explores the psychobehavioral, metabolic, and gut microbiome domains. It is hypothesized that smoking cessation will improve emotional regulation, self-efficacy, and reduce substance craving, mediated by changes in metabolic and microbiome profiles linked to brain reward systems. Methods: A randomized controlled trial (N=150) will be conducted, examining outcomes such as clinical relapse rates, microbial and metabolic markers, particularly in choline and folate metabolism. Participants with SUD (n=100) will undergo a six-week smoking cessation intervention, with pre- and post-assessments, compared to a control group receiving treatment as usual. Metabolomic and microbiome analyses will be conducted using blood and stool samples, alongside psychological assessments via questionnaires. Assessments on a behavioural level will take place at a 3-months follow-up. A cross-sectional, non-interventional healthy control group (n=50) will be examined at a single timepoint with an anologous panel of psychological variables, blood and stool to ascertain differences between smokers with SUD and healthy controls.

NCT Number	NCT06803706
Lead Sponsor	Sigmund Freud PrivatUniversitat Collaborators: Medical University of Graz
Conditions	Substance Use Disorder (SUD), Alcohol Use Disorder (AUD), Nicotine Addiction, Healthy Adult Participants
Enrollment	150 participants
Start Date	2025-05-05
Primary Completion	2026-10-28 (estimated)
Study Completion	2026-10-28 (estimated)
Updated on ClinicalTrials.gov	2026-05-18