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Completed

NCT Number: NCT02546050

The Effect of Metformin on Composition of Human Gut Bacteria

OBJECTIVE: Investigate structural changes in the human gut microbiota and associated changes in metabolic markers in urine, saliva, blood and fecal samples following metformin treatment.

DESIGN: An, 18 week, one-armed cross over intervention trial consisting of a 6-week pre-intervention period, 6-week intervention period and a 6-week post-intervention period. 25 healthy young men will be included in the trial.

INTERVENTION: Six-week Metformin treatment to young healthy men.

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Key information

Conditions

Healthy

Age range

18 year–35 year

Sex eligibility

Male

Study type

Interventional

Phase

Phase 1

Primary location

The Novo Nordisk Foundation Center of Basic Metabolic Research, Section for Metabolic Genetics, University of Copenhagen

Copenhagen, Copenhagen Ø, 2100, Denmark

About this study

An, 18 weeks, one-armed cross over intervention trial consisting of a 6-weeks pre-intervention period, 6-weeks intervention period and a 6-weeks post-intervention period. 25 healthy young men will be included in the trial. The pre-intervention period is the control period with no treatment. During the intervention period participants will receive 500 mg of metformin once daily the 1st week, then 500 mg twice daily the 2nd week, 1000 mg + 500 mg daily the 3rd week and 1000 mg + 1000 mg daily the remaining three weeks. Post-interventional investigators will examine gut microbiota of the participants 6 weeks after completion of the intervention period.

MESUREMENTS: Altered composition of gut microbiota as investigated by 16S rRNA sequencing is the primary outcome of this study. Secondary outcomes are to investigate changes in metabolic and inflammatory markers in blood and fecal samples. Blood, urine, saliva and fecal samples will be stored for future studies.

Who can participate

Healthy volunteers accepted: Yes

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

Inclusion criteria

  • Male
  • HbA1c < 5.7 % (39 mmol/mol)
  • Caucasian (self-report of parental ethnicity)
  • Weight stabile with 18.5 kg/m2 < BMI < 27.0 kg/m2
  • Normal kidney function as evaluated by normal p-creatinine for age

Exclusion criteria

  • Oral intake of any form of prescribed medication two months prior to recruitment
  • Chronic or acute illness
  • Previous gastro-intestinal operation excluding appendicitis
  • Any other significant medical reason for exclusion as determined by the investigator
  • Unable to give informed consent
  • Need of medical treatment during the study period

Treatment and study plan

metformin

Drug

Primary outcomes

  1. Structural changes in the human gut microbiota.

    Time frame: Baseline, 4 , 7, 8, 10, 11 , 13, 16, and 18 weeks

    Fecal samples are collected in order to characterize the gut microbiota composition.

    Microbial DNA will be subjected to sequencing, microbial gene analyses, including taxonomic and functional annotation.

Secondary outcomes

  1. Changes in plasma glucose and HbA1c levels

    Time frame: Baseline and at week 7,10,13 and 18

    Venous blood will be collected. The samples will be analyzed for plasma glucose and HbA1c, and correlated to changes in gut microbiota composition

  2. Changes in insulin metabolism

    Time frame: Baseline and at week 7,10,13 and 18

    Venous blood will be collected. The samples will be analyzed for serum insulin and C-peptide levels. Changes will be correlated to changes in gut microbiota composition.

  3. Changes in inflammatory markers in blood samples.

    Time frame: Baseline and at week 7,10,13 and 18

    Venous blood will be collected. The samples will be analyzed for markers of inflammation such as high sensitive C-reactive protein.

  4. Changes in kidney function tests.

    Time frame: Baseline and at week 7,10,13 and 18

    Venous blood will be collected. The samples will be analyzed for plasma creatinine and correlated to gut microbiota changes

  5. Changes in liver function tests.

    Time frame: Baseline and at week 7,10,13 and 18

    Venous blood will be collected. The samples will be analyzed for liver function test and correlated to gut microbiota changes

  6. Serum Cobalamin

    Time frame: Baseline and at week 7,10,13 and 18

    Venous blood will be collected. The samples will be analyzed for serum cobalamin and correlated to gut microbiota changes

  7. Metformin plasma level

    Time frame: At week 10 and 13.

    Plasma levels of metformin will be measured at visits 3 and 4 in order to test for compliance. Plasma metformin concentrations will be correlated to changes in gut microbiota composition and function

  8. Blood pressure

    Time frame: Baseline and at week 7,13 and 18

    Systolic and diastolic blood pressure are measured in the inclined position after a five minute rest using an automated sphygmomanometer. The measurement is repeated three times. Participants are instructed not to talk during the measurements.

  9. Heart rate

    Time frame: Baseline and at week 7,13 and 18

    Heart rate is measured in the inclined position after a five minute rest using an automated sphygmomanometer. The measurement is repeated three times. Participants are instructed not to talk during the measurements.

  10. Anthropometrics characteristics

    Time frame: Baseline and at week 7,13 and 18

    Weight is measured using standardized procedures.

  11. Anthropometrics characteristics

    Time frame: Baseline and at week 7,13 and 18

    Height is measured using standardized procedures.

  12. Anthropometrics characteristics

    Time frame: Baseline and at week 7,13 and 18

    Waist- and hip circumference are measured using standardized procedures.

  13. Bio-electrical impedance.

    Time frame: Baseline and at week 7,13 and 18

    Body composition will be measured through bio-electrical impedance

  14. GI symptoms

    Time frame: Baseline and at week 7, 10, 13 and 18.

    Changes in gastrointestinal symptoms of participants by validated VAS-questionnaire concerning following parameters: Overall abdominal symptoms, abdominal pain, bloating, flatulence, satisfaction with stool consistence, constipation, diarrhea, tiredness, nausea, metallic taste.

Sponsors and collaborators

Lead sponsor

Oluf Borbye Pedersen

Other

Registry information

Official study title

Effects of Metformin on Human Gut Microbiota

Important dates

Study start
2015
Primary completion
2016
Study completion
2016
First posted
Sep 10, 2015
Registry last updated
Feb 17, 2016

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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