Eradication of Gut Microbiota

Study Overview
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Brief Summary
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The aim of the study is to assess the effect of eradication of gut microbiota on 1) glucose metabolism including postprandial plasma responses of the incretin hormones GIP and GLP-1, insulin, C-peptide and glucagon, 2) metabolomic profiles and resting energy expenditure (REE) 3) appetite, satiety, food intake, gastric emptying and gall bladder emptying, 4) levels of markers of bone formation and resorption as well as serotonin, 5) markers of systemic inflammation, and 6) on the (prospective) composition of bacteria in faeces, blood and saliva. Thus, the overall objective is to provide detailed knowledge on the physiological role of gut microbiota combined with bioinformatic analyses of the functional implications of changes in bacteria composition on the level of both species and phylum.

Official Title
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Eradication of Gut Microbiota - Effects on Postprandial Gut Hormone Secretion, Glucose Metabolism, Bone Metabolism and Gut Microbiome

Conditions
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Diabetes, Obesity, Osteoporosis, Inflammation

Intervention / Treatment
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* Drug: meropenem, gentamicin, vancomycin (together)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: danish caucasian ethnicity informed consent normal fasting plasma glucose normal HbA1c (<6 %) normal serum lipids normal thyroid function normal danish diet non-smoking normal stool habits Exclusion Criteria: known bone disease liver disease (ALAT or ASAT >2 upper normal value) kidney disease (serum creatinine >130 μM) anaemia BMI <18.5 kg/m2 or BMI >25 kg/m2 known gastrointestinal disease (including prior bariatric surgery,lactose -intolerance, celiac disease, inflammatory bowel disease) or known familial disposition for lactose intolerance, celiac disease, inflammatory bowel disease antibiotic treatment within 6 months prior to study including malaria prophylaxis medication which cannot be on hold for the study period contraindications against/allergy towards the used antibiotics (including prior allergic reactions related to beta-lactam antibiotics, aminoglycosides or vancomycin)

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 40 Years

Sexes Eligible for Study
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Male

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: meropenem, gentamicin, vancomycin<br> | Drug: meropenem, gentamicin, vancomycin (together)<br>* 4 days antibiotic treatment, per oral, once daily: vancomycin 500 mg (Vancomycin Hospira), powder for concentrate; gentamycin 40 mg (Hexamycin®), solution; meropenem 500 mg (Meropenem Hospira), powder for concentrate; The three drugs are dissolved and combined to a cocktail (with approximately 100 ml of apple juice)<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| changes in postprandial GLP-1 secretion | plasma level of GLP-1 at baseline and during a 4 hour-meal test | 0, 4 and 42 days after antibiotic eradication of gut bacteria | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| changes in postprandial insulin/c-peptide secretion | plasma level of insulin/C-peptide at baseline and during a 4 hour-meal test | 0, 4 and 42 days after antibiotic eradication of gut bacteria | 
| changes in postprandial glucose levels | plasma level of glucose at baseline and during a 4 hour-meal test | 0, 4 and 42 days after antibiotic eradication of gut bacteria | 
| changes in postprandial GLP-2, glucagon, PYY, oxyntomodulin, gastrin, CCK, GIP, leptin, adiponectin and ghrelin secretion | plasma levels of GLP-2, glucagon, PYY, oxyntomodulin, gastrin, CCK, GIP, leptin, adiponectin and ghrelin at baseline and during a 4 hour-meal test | 0, 4 and 42 days after antibiotic eradication of gut bacteria | 
| changes in markers of bone formation and resorption | fasting plasma levels of osteocalcin, P1NP, CTX, 1CTP, sklerostin and serotonin | 0, 4, 8, 42 and 180 days after antibiotic eradication of gut bacteria | 
| gut microbiome composition | faecal bacterial composition determined from microbiological cultures and deep metagenomic next-generation sequencing of bacterial DNA in feces | 0, 4, 8, 42 and 180 days after antibiotic eradication of gut bacteria | 
| changes in markers of systemic inflammation | plasma levels of high sensitive CRP, LPBP, TNF-alfa, IL-6 and PAI | 0, 4, 42 and 180 days after antibiotic eradication of gut bacteria | 
| changes in glycated hemoglobin (HbA1c) | plasma level of glycated hemoblobin | 42 days after antibiotic eradication of gut bacteria | 
| changes in body weight |  | 0, 4, 8, 42 and 180 days after antibiotic eradication of gut bacteria | 
| changes in basal metabolic rate and respiratory quotient | indirect calorimetry measurements (210 minutes postprandial) | 0, 4 and 42 days after antibiotic eradication of gut bacteria | 
| changes in gastric emptying | 1,5 grams of paracetamol will be added to a standardized meal, plasma paracetamol will be measured at baseline and succeeding 4 hours postprandial | 0, 4 and 42 days after antibiotic eradication of gut bacteria | 
| changes in gall bladder emptying | ultrasonic determination of gall bladder dimensions at baseline and during a 4 hour-meal test (expressed as gall bladder ejection fraction) | 0, 4 and 42 days after antibiotic eradication of gut bacteria | 
| appetite, satiety and food intake | the impact of eradication on alimentary processes and appetite regulation will be measured using questionnaires and food intake measures | 0, 4, 8, 42 and 180 days after antibiotic eradication of gut bacteria | 
| changes in ketone metabolism | measurement of fasting plasma beta-hydroxybutyrate level | 0, 4, 8, 42 and 180 days after antibiotic eradication of gut bacteria | 
| changes in bile acid deconjugation | measurement of feces bile acid (conjugated and deconjugated) concentration to study the effect of gut microbiome presence on bile acid deconjugation | 0, 4, 8, 42 and 180 days after antibiotic eradication of gut bacteria | 
| changes in plasma lipid levels | fasting plasma levels of triglyceride, VLDL, LDL, HDL, total cholesterol, in addition: measurements of free fatty acids during a 4 hour meal 0, 4 and 42 days after eradication (not on day 8 and 180) | 0, 4, 8, 42 and 180 days after antibiotic eradication of gut bacteria | 
| microbiome in blood, urine and saliva | measurements on bacteria or bacterial components in blood, urine and saliva to study the effects of gut eradication on blood, urine and saliva microbiome | 0, 4, 8, 42 and 180 days after antibiotic eradication of gut bacteria | 
| adverse effects of the used antibiotics | standardized questionaries regarding gastointestinal function are filled out at each study visit (0, 4, 8, 42 and 180 days after antibiotic eradication of gut bacteria) to detect possible adverse effects of antibiotics. In addition, subjects are given a calendar and informed to write down any symptom or illness during the study period. | up to 180 days after antibiotic eradication of gut bacteria | 
| changes in metabolomic profile | plasma and urine samples for metabolomic analysis | 0, 4, 8, 42 and 180 days after antibiotic eradication of gut bacteria |