Safety and Viability of an E. Coli Nissle Colibactin Knockout in Healthy Volunteers

Study Overview
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Brief Summary
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E. coli Nissle (EcN) is a well-established human probiotic. However, it has been found that it produces colibactin, linked to colorectal cancer. In this safety trial, the safety and properties of a novel, colibactin-knockout EcN strain (EcNΔClbP) is investigated.

Detailed Description
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In this randomised controlled intervention study, the investigators will compare EcN vs. EcN colibactin-knockout (EcNΔClbP), given once daily for 7 days, in a population of healthy individuals. Safety will be established using adverse event reporting, study visits and laboratory parameters. Pharmacokinetics will be established at the beginning and the end of the study. EcN/EcNΔClbP gut engraftment properties and effects on gut microbiome composition will be assessed using fecal analyses (qPCR, shotgun metagonmics). In addition, effects on glucose homeostasis will be studied using continuous glucose monitoring.

Official Title
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Safety and Viability of an E. Coli Nissle Colibactin Knockout in Healthy Volunteers

Conditions
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Diabetes

Intervention / Treatment
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* Dietary Supplement: EcN Colibactin knockout
* Dietary Supplement: E Coli Nissle


Participation Criteria
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Eligibility Criteria
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Inclusion criteria: Healthy male or female of Caucasian descent If female, postmenopausal Age: 18-65 years old BMI: 18-25 kg/m2 Subjects should be able to give informed consent Exclusion Criteria: Use of any systemic medication (except for paracetamol), including proton pump inhibitors, antibiotics and pro-/prebiotics in the past three months or during the study period. Use of the EcN probiotic strain (Mutaflor®) in the past 12 months. (Expected) prolonged comprised immunity (e.g. due to recent cytotoxic chemotherapy or human immunodeficiency viruses (HIV) infection with a CD4-T cell count < 240/mm3). History of moderate to severe disease of the digestive tract, such as celiac disease, chronic diarrhoea (≥3 stools/day for >4 weeks), chronic obstipation (<2 defecations/week for >3 months), Irritable Bowel Syndrome (IBS) (according to Rome IV criteria) or Inflammatory Bowel Disease (IBD). Any gastro-intestinal disorder within the past 6 months Smoking or illicit drug use (e.g. amphetamine/cocaine/heroin/GHB) in the past three months or use during the study period. Use of >21 units of alcohol per week on average in the past three months or use of >2 units of alcohol during the study period. Simultaneous participation in other studies

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

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: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Double-blind, randomised, controlled, safety study
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: EcN<br>E Coli Nissle wildtype 10^11 once daily for 7 days | Dietary Supplement: E Coli Nissle<br>* E Coli wildtype strain<br>|
| Experimental: EcN colibactin-knockout<br>EcN colibactin-knockout 10^11 once daily for 7 days | Dietary Supplement: EcN Colibactin knockout<br>* E coli Nissle strain with ClbP-gene removed and therefore not producing colibactin<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Adverse events | The number, duration and severity of adverse reactions to assess the safety/tolerability of the EcNΔClbP strain compared to the wild type strain. | 3 weeks | 
| CRP | Changes in CRP (mg/L) | Weekly, during 3 weeks | 
| Leucocytes | Changes in leucocytes (10^9/L) | Weekly, during 3 weeks | 
| Renal function | Changes in renal function, expressed as kreatinin levels (micromol/L) throughout the study | Weekly, during 3 weeks | 
| Bilirubin | Changes in bilirubin in micromol/L throughout the study | Weekly, during 3 weeks | 
| alkaline phosphatase | Changes in alkaline phosphatase in U/L throughout the study | Weekly, during 3 weeks | 
| gamma-GT in U/L | Changes in gamma-GT in U/L throughout the study | Weekly, during 3 weeks | 
| AST | Changes in AST in U/L throughout the study | Weekly, during 3 weeks | 
| ALT | Changes in ALT in U/L throughout the study | Weekly, during 3 weeks | 
| Hemoglobin | Changes in hemoglobin in mmol/L throughout the study | Weekly, during 3 weeks | 
| trombocytes | Changes in trombocytes in 10^9/L throughout the study | Weekly, during 3 weeks | 
| eosinophils | Changes in eosinophils in 10^9/L throughout the study | Weekly, during 3 weeks | 
| basophils | Changes in basophils in 10^9/L throughout the study | Weekly, during 3 weeks | 
| neutrophils | Changes in neutrophils in 10^9/L throughout the study | Weekly, during 3 weeks | 
| monocytes | Changes in monocytes in 10^9/L throughout the study | Weekly, during 3 weeks | 
| Lipid profile | Changes in lipid profile throughout the study | Weekly, during 3 weeks | 
| Homeostatic model of insulin resistance (HOMA-IR) | Changes in HOMA-IR throughout the study | Weekly, during 3 weeks | 
| Gastro-intestinal quality of life - questionnaire | Changes in Gastro-intestinal quality of life (GIQLI) score. The maximum score is 155, the minimum score is 31. A higher score represents a better outcome. | Weekly, during 3 weeks | 
| Bristol Stool Chart | Changes in Bristol Stool Chart score throughout the study. Stools can be scored from 1 (hard stool) to 7 (watery stool). A score of 4 is considered ideal. | Weekly, during 3 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of copies of EcN (qPCR) | Quantification of EcN in faeces samples collected throughout the two weeks via quantitative polymerase chain reaction (qPCR) | Daily during 2 weeks | 
| Microbiome composition | Comparison of relative abundances of species throughout the study using shotgun metagenomics | Weekly during 3 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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advanced microbiome therapeutics, diabetes, safety