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NCT Number: NCT06803706

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.

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Key information

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Grüner Kreis Organization Johnsdorf Facility, Fehring, Austria

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Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • diagnosis of a form of substance use disorder (F1x.x) by a licensed psychiatrist according to ICD-10
  • minimum age of 18 years
  • sufficient knowledge of the German language
  • willingness to quit smoking
  • willingness and ability to consent

Inclusion criteria

for healthy controls :

  • minimum age of 18 years
  • sufficient knowledge of the German language
  • willingness and ability to consent

Exclusion criteria

  • lack of consent, inability to provide informed consent
  • age below 18,
  • acute psychotic symptoms or acute suicidal tendencies
  • cardiovascular disease
  • pregnancy or breastfeeding
  • severe mental or organic illnesses (such as epilepsy, brain tumors, recent major surgery), tumor diseases, dementia (Mini Mental Score <20), severe autoimmune diseases or immunosuppression, acute infections, or acute diarrhea, prior gastrointestinal surgery (except appendectomy)
  • probiotic intake within the last 6 months,
  • ongoing consumtion of dietary supplements, probiotics, antibiotics, or prebiotic supplements during the study
  • prior participation in a smoking cessation programme

Treatment and study plan

6-weeks CBT smoking cessation programme

Behavioral

Held in the therapeutic community, the intervention will employ principles of cognitive-behavioural therapy (CBT) coupled with personalized recommendations for nicotine replacement. The Austrian Health Insurance standard for therapy will be guiding the program's content, which is tailored for inpatient clients. Specifically, the following interventions based on CBT techniques will be applied in the weekly group sessions consisting of 10 to 15 participants: Psychoeducation including information on tobacco addiction, health risks, advice on relapse prevention and the handling of craving, motivation building, behavioural observation.

Long-term drug therapy within a therapeutic community

Behavioral

The standard treatment within the 'Grüner Kreis' therapeutic community - which all participants will receive - consists of group therapy (once a week), individual psychotherapy (once a week), counselling by social workers, psychiatric consultations, as well as sport-, art- and work-therapy. Daily life is organized according to principles of therapeutic community-based addiction treatment.

Primary outcomes

  1. Self-efficacy

    Time frame: From enrollment to follow-up 3 months after the end of the 6-weeks treatment period

    Self-efficacy as a psychological variable and will be assessed by the Self-Efficacy Scale (SWE), a self-report instrument for measuring general optimistic self-confidence. It consists of 10 items and measures optimistic competence expectancy, i.e., confidence in solving difficult situations with one's own abilities.

  2. General substance-related craving

    Time frame: From enrollment to follow-up 3 months after the end of the 6-weeks treatment period.

    Substance related craving will be assessed by the MaCS (Mannheim Craving Scale). consists of 12 items and four additional items and is rated on a 5- point Likert scale.

  3. Tobacco dependence

    Time frame: From enrollment to follow-up 3 months after the end of the 6-weeks treatment period.

    Tobacco dependence will be assessed by The Fagerström Test for Cigarette Dependence (formerly Fagerström Test for Nicotine Dependence; FTND). It consists of 6 categorically scaled items that assess the number of smoked cigarettes per day (CPD), compulsive use, and dependence intensity.

  4. Primary Affects

    Time frame: From enrollment to follow-up 3 months after the end of the 6-weeks treatment period.

    Primary Affects, as proposed by Jaak Panksepp will be assessed by the German Version of the Brief Affective Neuroscience Personality Scales including a LUST Scale (BANPS-GL), a self-report questionnaire.

  5. Metabolome

    Time frame: From enrollment to the end of the 6-weeks treatment period.

    Metabolome will be ascertained from blood via state-of-the-art NMR (nuclear magnetic resonance).

  6. Gut microbiome

    Time frame: From enrollment to the end of the 6-weeks treatment period.

    Gut microbiome will be ascertained via 16s-rRNA sequencing from stool.

  7. Smoking behaviour

    Time frame: From enrollment to follow-up 3 months after the end of the 6-weeks treatment period.

    Participants will be asked regarding their daily smoked cigarettes in the last two weeks (interval scaled). A second single item question will be, if participants have been completely abstinent from tobacco smoking in the last two weeks (dichotome).

Secondary outcomes

  1. Psychiatric Symptoms

    Time frame: From enrollment to follow-up 3 months after the end of the 6-weeks treatment period.

    For the evaluation of psychopathology, the ICD-10 Symptom Rating (ISR) questionnaire will be utilized. In accordance with the ICD-10, this self-assessment questionnaire, comprising 30 items, is designed to comprehensively assess the status and severity of mental disturbances. Symptoms of the six symptomatic patterns - depressive, anxiety, obsessive-compulsive, eating disorders, somatoform syndrome, and post-traumatic stress disorder - are assessed.

Study contacts

Contact information is provided by the study sponsor or research team.

Human F Unterrainer, Professor

CONTACT

[email protected]

+43-699-181-95-990

Johannes Peter, MSc

CONTACT

[email protected]

+43-6606941409

Sponsors and collaborators

Lead sponsor

Sigmund Freud PrivatUniversitat

Other

Collaborators

  • Medical University of Graz

Registry information

Official study title

Metabolomic and Gut Microbial Biomarkers of Smoking Cessation Treatment in Long-term Drug Therapy: A Randomized Controlled Trial

Important dates

Study start
2025
Primary completion
2026
Study completion
2026
First posted
Jan 31, 2025
Registry last updated
May 18, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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