Effect of a Probiotic on the Glycemic Profile and the Fecal Microbiota of Prediabetic Subjects (PREDIABETCARE)

Study Overview
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Brief Summary
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According to the data from the Di@bet.es study, which is part of the National Diabetes Strategy, the prevalence of type 2 diabetes among Spanish population is 13.8%. Diabetic patients suffer from several short and long term complications, which are related to a significant worsen of quality of life and a substantial increase in death rate. In this sense, it is important to prevent the development of Type 2 diabetes. Therefore, it is of high relevance to identify and to treat prediabetic subjects prior to the development of the disease. Many strategies have been implemented to reverse this situation, such as changes in diet and lifestyle, among others. However, it is hard to achieve changes in lifestyle and despite the use of some drugs in this phase of the disease, the problem continues growing. For this reason, new strategies to combat the development of type 2 diabetes are been investigated, such as the use of probiotic formulations. However, at the moment, few studies evidence the effect of probiotics on glycemic regulation. Therefore, an interesting opportunity arises according to the potential ability of probiotic formulation for the control of prediabetes. Considering this background, the main objective of this research is to assess the effect of a new probiotic formulation on glycemic control, insulin resistance and the composition of the fecal microbiota in prediabetic subjects.

Detailed Description
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This study is designed as a 12-week, double-blind, randomised, placebo-controlled parallel study. It is focused on prediabetic overweight / obese men and women between 18 and 70 years old. All participants attend the Nutrition Intervention Unit of the Center for Nutrition Research in the University of Navarra for the screening visit and 4 more times during the intervention (week 1, 4, 8 and 12 of study). Screening visit: evaluation of the inclusion criteria. Volunteers who meet the inclusion criteria are provided with a stool collection kit and a 72 h food record questionnaire. Moreover, they are randomly assigned to one of the two intervention groups: Control group: placebo supplemented; Experimental group: probiotic supplemented. Clinical investigation day 1 (day 1): The volunteer attend the Nutrition Intervention Unit in fasting state. Each volunteer is asked to provide the stool sample and the 72-hour food record questionnaire. Then, anthropometric, body composition and blood pressure measurements are taken and the gastrointestinal symptoms questionnaire is completed. After that, volunteer is provided with the capsules of the study for one month. Finally, fasting blood samples are collected and then an oral glucose tolerance test is carried out and blood samples are taken at 30, 60, 90 and 120 minutes after the ingestion of the glucose solution. Clinical investigation day 2 (week 4): The volunteer attend the Nutrition Intervention Unit in fasting state. The gastrointestinal symptoms questionnaire is completed and the adherence to the study and to the capsule consumption is assessed. After the measurement of anthropometric, body composition and blood pressure a blood sample is collected. Finally, volunteer is provided with capsules for the next month. Clinical investigation day 3 (week 8): The volunteer attend the Nutrition Intervention Unit in fasting state. The gastrointestinal symptoms questionnaire is completed and the adherence to the study and to the capsule consumption are assessed. After the measurement of anthropometric, body composition and blood pressure, a blood sample is collected. Finally, the stool collection kit, 72h food record questionnaire and capsules for one month are given to the volunteer. Clinical investigation day 4 (week 12): The volunteer attend the Nutrition Intervention Unit in fasting state. Each volunteer is asked to provide the stool sample and the 72-hour food record questionnaire. Then, anthropometric, body composition and blood pressure measurements are taken and the gastrointestinal symptoms questionnaire are completed. Finally, fasting blood samples are collected and then an oral glucose tolerance test is carried out and blood samples are taken at 30, 60, 90 and 120 minutes after the ingestion of the glucose solution. One month later, the online version of the gastrointestinal symptoms questionnaire is send to each volunteer in order to asess any gastrointestinal symptom after stopping capsule consumption.

Official Title
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Evaluation of the Effect of the Administration of a Probiotic Formulation on Glycemic Control, Insulin Resistance and the Composition of the Microbiota in Subjects With Prediabetes

Conditions
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PreDiabetes, Overweight and Obesity

Intervention / Treatment
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* Dietary Supplement: Probiotic
* Dietary Supplement: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Men and women aged between 18 and 70 years. Prediabetic subjects: glycosylated hemoglobin (HbA1c) between 5.7% and 6.4%. Body Mass Index (BMI) between 25 and 39.9 kg / m2. No weight changes (± 3 kg) during the last 3 months. The subjects must be in general physical and psychological conditions in accordance with the objective of the study. Subjects must be able to understand and sign the informed consent. Exclusion Criteria: To be in continuous pharmacological / hormonal treatment, especially those that could affect blood glucose concentration. Suffering from a chronic metabolic disease, or from a systemic intestinal, liver or kidney disease: type 1 or 2 diabetes, severe dyslipidemia, uncontrolled thyroid function disorders, cirrhosis, inflammatory bowel disease, etc. Subjects suffering from severe hyperlipidemia, severe hypertension or hypothyroidism without treatment or treated for less than 3 months. Presence of relevant functional or structural abnormalities of the digestive system, such as malformations, angiodysplasia, active peptic ulcers, chronic inflammatory diseases or malabsorption. Subjects who have undergone gastrointestinal surgery with permanent sequelae (for example, gastroduodenostomy). Chronic treatment with stomach protectors. Subjects suffering from some type of cancer or being in treatment for it or with a period less than 5 years since its eradication. Presence of some type of mental impairment such as depressive pathology, anxiety or untreated bipolar disorder. They will be able to participate if they have stable treatment for at least 3 months prior to the begining of the trial. Allergy or intolerance to any food or food group that is likely to manifest during the study. Be on a special diet (Atkins, vegetarian, etc.) during the 3 months prior to the start of the study. Weight variations (± 3 kg) during the last 3 months. Suffering from eating disorders or eating restrictive behaviors (score on the EAT-26 questionnaire equal or greater than 20). Subjects who have undergone surgical treatment for obesity. Being pregnant or breastfeeding. Abuse of alcohol (more than 14 units in women and 20 units in men) and / or drugs. Show poor collaboration or, in the opinion of the investigator, have difficulties in following the study procedures. Take some type of nutritional supplementation that can affect blood glucose and / or microbiota. If they take it, in order to be included in the study, they will have to stop the supplement, with a washout period of at least 14 days before starting the study. People who are positive for Covid-19 will not be able to participate in the study.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 70 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
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Group receiving the probiotic capsules<br>Experimental group will consume one probiotic capsule every day during 12 weeks at breakfast. | Dietary Supplement: Probiotic<br>* Experimental group will consume one probiotic capsule every day during 12 weeks at breakfast.<br>|
| Placebo Comparator: Group receiving the placebo capsules<br>Placebo group will consume one placebo capsule every day during 12 weeks at breakfast. | Dietary Supplement: Placebo<br>* Placebo group will consume one placebo capsule every day during 12 weeks at breakfast.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change of blood glycated hemoglobin (HbA1c) concentration from baseline to week 12. | Fasting blood glycated hemoglobin (HbA1c) concentration will be reported in % and in mmol/mol. | The Time Frame contains two time points: Clinical Investigation Day 1 (at baseline) compared to Clinical Investigation Day 4 (after 12 weeks of intervention). | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change of metagenomic analysis of intestinal microbiota composition from baseline to week 12. | Measured by analyzing the variable regions V3-V4 of the prokaryotic 16S rRNA (ribosomal ribonucleic acid) gene sequences. | The Time Frame contains two time points: Clinical Investigation Day 1 (at baseline) compared to Clinical Investigation Day 4 (after 12 weeks of intervention). | 
| Change of fasting blood glucose concentration from baseline to week 4. | Blood glucose concentration will be analyzed after an overnight fast. | The Time Frame contains two time points: Clinical Investigation Day 1 (at baseline) compared to Clinical Investigation Day 2 (after 4 weeks of intervention). | 
| Change of fasting blood glucose concentration from baseline to week 8. | Blood glucose concentration will be analyzed after and overnight fast. | The Time Frame contains two time points: Clinical Investigation Day 1 (at baseline) compared to Clinical Investigation Day 3 (after 8 weeks of intervention). | 
| Change of fasting blood glucose concentration from baseline to week 12. | Blood glucose concentration will be analyzed after an overnight fast. | The Time Frame contains two time points: Clinical Investigation Day 1 (at baseline) compared to Clinical Investigation Day 4 (after 12 weeks of intervention). | 
| Oral glucose tolerance test | Blood glucose will be reported in mg/dl at 30, 60, 90 and 120 minutes as part of the oral glucose tolerance test | The Time Frame contains two time points: Clinical Investigation Day 1 (at baseline) compared to Clinical Investigation Day 4 (after 12 weeks of intervention). | 
| Change in the Area under the curve for glucose from baseline to week 12. | Area under the curve will be calculated using glucose levels after oral glucose tolerance test. | The Time Frame contains two time points: Clinical Investigation Day 1 (at baseline) compared to Clinical Investigation Day 4 (after 12 weeks of intervention). | 
| Change of fasting blood insulin concentration from baseline to week 12. | Blood insulin concentration will be analyzed after an overnight fast by ELISA kit. | The Time Frame contains two time points: Clinical Investigation Day 1 (at baseline) compared to Clinical Investigation Day 4 (after 12 weeks of intervention). | 
| Change of HOMA index from baseline to week 12. | HOMA index will be calculated to analyze insulin resistance | The Time Frame contains two time points: Clinical Investigation Day 1 (at baseline) compared to Clinical Investigation Day 4 (after 12 weeks of intervention). | 
| Change of blood glucagon like peptide-1 (GLP-1) concentration from baseline to week 12. | Blood GLP-1 concentration will be analyzed after an overnight fast with ELSA kit. | The Time Frame contains two time points: day 1 (at baseline) compared to day 4 (after 12 weeks of intervention). | 
| Change of Blood peptide-C concentration from baseline to week 12. | Blood peptide-C concentration will be analyzed after and overnight fast. | The Time Frame contains two time points: Clinical Investigation Day 1 (at baseline) compared to Clinical Investigation Day 4 (after 12 weeks of intervention). | 
| Change of gastrointestinal symptoms from baseline to week 4. | Gastrointestinal symptoms will be analyzed by a gastrointestinal symptom questionnaire. | The Time Frame contains two time points: Clinical Investigation Day 1 (at baseline) compared to Clinical Investigation Day 2 (after 4 weeks of intervention). | 
| Change of gastrointestinal symptoms from baseline to week 8. | Gastrointestinal symptoms will be analyzed by a gastrointestinal symptom questionnaire. | The Time Frame contains two time points: Clinical Investigation Day 1 (at baseline) compared to Clinical Investigation Day 3 (after 8 weeks of intervention). | 
| Change of gastrointestinal symptoms from baseline to week 12. | Gastrointestinal symptoms will be analyzed by a gastrointestinal symptom questionnaire. | The Time Frame contains two time points: Clinical Investigation Day 1 (at baseline) compared to Clinical Investigation Day 4 (after 12 weeks of intervention). | 
| Change of blood ALT concentration from baseline to week 12. | Blood ALT concentration will be measured after an overnight fast. | The Time Frame contains two time points: Clinical Investigation Day 1 (at baseline) compared to Clinical Investigation Day 4 (after 12 weeks of intervention). | 
| Change of blood AST concentration from baseline to week 12. | Blood AST concentration will be measured after an overnight fast. | The Time Frame contains two time points: day 1 (at baseline) compared to day 4 (after 12 weeks of intervention). | 
| Change of blood total cholesterol concentratio from baseline to week 12. | Blood total cholesterol concentration will be analyzed after an overnight fast. | The Time Frame contains two time points: Clinical Investigation Day 1 (at baseline) compared to Clinical Investigation Day 4 (after 12 weeks of intervention). | 
| Change of blood HDL cholesterol concentration from baseline to week 12. | Blood HDL cholesterol concentration will be analyzed after an overnight fast. | The Time Frame contains two time points: Clinical Investigation Day 1 (at baseline) compared to Clinical Investigation Day 4 (after 12 weeks of intervention). | 
| Change of blood LDL cholesterol concentration from baseline to week 12. | Blood LDL concentration will be reported in mg/dl by Friedewald equation. | The Time Frame contains two time points: Clinical Investigation Day 1 (at baseline) compared to Clinical Investigation Day 4 (after 12 weeks of intervention). | 
| Change of blood triglyceride concentration from baseline to week 12. | Blood triglyceride concentration will be analyzed after an overnight fast. | The Time Frame contains two time points: Clinical Investigation Day 1 (at baseline) compared to Clinical Investigation Day 4 (after 12 weeks of intervention). | 
| Change of hemogram from baseline to week 12. | Blood hemogram | The Time Frame contains two time points: Clinical Investigation Day 1 (at baseline) compared to Clinical Investigation Day 4 (after 12 weeks of intervention). | 
| Change of weight from baseline to week 4. | Weight of participants in fasting condition will be analyzed by bioimpedance and reported in kg. | The Time Frame contains two time points: Clinical Investigation Day 1 (at baseline) compared to Clinical Investigation Day 2 (after 4 weeks of intervention). | 
| Change of weight from baseline to week 8. | Weight of participants in fasting condition will be analyzed by bioimpedance and reported in kg. | The Time Frame contains two time points: Clinical Investigation Day 1 (at baseline) compared to Clinical Investigation Day 3 (after 8 weeks of intervention). | 
| Change of weight from baseline to week 12. | Weight of participants in fasting condition will be analyzed by bioimpedance and reported in kg. | The Time Frame contains two time points: Clinical Investigation Day 1 (at baseline) compared to Clinical Investigation Day 4 (after 12 weeks of intervention). | 
| Change of body mass index from baseline to week 4. | Weight and height will be combined to report BMI in kg/m^2. | The Time Frame contains two time points: Clinical Investigation Day 1 (at baseline) compared to Clinical Investigation Day 2 (after 4 weeks of intervention). | 
| Change of body mass index from baseline to week 8. | Weight and height will be combined to report BMI in kg/m^2. | The Time Frame contains two time points: Clinical Investigation Day 1 (at baseline) compared to Clinical Investigation Day 3 (after 8 weeks of intervention). | 
| Change of body mass index from baseline to week 12. | Weight and height will be combined to report BMI in kg/m^2. | The Time Frame contains two time points: Clinical Investigation Day 1 (at baseline) compared to Clinical Investigation Day 4 (after 12 weeks of intervention). | 
| Change of waist circumference from baseline to week 4. | Waist circumference will be measured with a measuring tape and will be reported in cm. | The Time Frame contains two time points: Clinical Investigation Day 1 (at baseline) compared to Clinical Investigation Day 2 (after 4 weeks of intervention). | 
| Change of waist circumference from baseline to week 8. | Waist circumference will be measured with a measuring tape and will be reported in cm. | The Time Frame contains two time points: Clinical Investigation Day 1 (at baseline) compared to Clinical Investigation Day 3 (after 8 weeks of intervention). | 
| Change of waist circumference from baseline to week 12. | Waist circumference will be measured with a measuring tape and will be reported in cm. | The Time Frame contains two time points: Clinical Investigation Day 1 (at baseline) compared to Clinical Investigation Day 4 (after 12 weeks of intervention). | 
| Change of hip circumference from baseline to week 4. | Hip circumference will be measured with a measuring tape and will be reported in cm. | The Time Frame contains two time points: Clinical Investigation Day 1 (at baseline) compared to Clinical Investigation Day 2 (after 4 weeks of intervention). | 
| Change of hip circumference from baseline to week 8. | Hip circumference will be measured with a measuring tape and will be reported in cm. | The Time Frame contains two time points: Clinical Investigation Day 1 (at baseline) compared to Clinical Investigation Day 3 (after 8 weeks of intervention). | 
| Change of hip circumference from baseline to week 12. | Hip circumference will be measured with a measuring tape and will be reported in cm. | The Time Frame contains two time points: Clinical Investigation Day 1 (at baseline) compared to Clinical Investigation Day 4 (after 12 weeks of intervention). | 
| Change of body composition (fat mass, lean mass and water content) from baseline to week 4. | Body composition will be analyzed at fasting state by bioimpedance. | The Time Frame contains two time points: Clinical Investigation Day 1 (at baseline) compared to Clinical Investigation Day 2 (after 4 weeks of intervention). | 
| Change of body composition (fat mass, lean mass and water content) from baseline to week 8. | Body composition will be analyzed at fasting state by bioimpedance. | The Time Frame contains two time points: Clinical Investigation Day 1 (at baseline) compared to Clinical Investigation Day 3 (after 8 weeks of intervention). | 
| Change of body composition (fat mass, lean mass and water content) from baseline to week 12. | Body composition will be analyzed at fasting state by bioimpedance. | The Time Frame contains two time points: Clinical Investigation Day 1 (at baseline) compared to Clinical Investigation Day 4 (after 12 weeks of intervention). | 
| Change of systolic blood pressure from baseline to week 4. | Fasting systolic blood pressure will be measured by a tensiometer and reported in mmHg. | The Time Frame contains two time points: day 1 (at baseline) compared to day 2 (after 4 weeks of intervention). | 
| Change of systolic blood pressure from baseline to week 8. | Fasting systolic blood pressure will be measured by a tensiometer and reported in mmHg. | The Time Frame contains two time points: Clinical Investigation Day 1 (at baseline) compared to Clinical Investigation Day 3 (after 8 weeks of intervention). | 
| Change of systolic blood pressure from baseline to week 12. | Fasting systolic blood pressure will be measured by a tensiometer and reported in mmHg. | The Time Frame contains two time points: Clinical Investigation Day 1 (at baseline) compared to Clinical Investigation Day 4 (after 12 weeks of intervention). | 
| Change of dyastolic blood pressure from baseline to week 4. | Fasting dyastolic blood pressure will be measured by a tensiometer and reported in mmHg. | The Time Frame contains two time points: Clinical Investigation Day 1 (at baseline) compared to Clinical Investigation Day 2 (after 4 weeks of intervention). | 
| Change of dyastolic blood pressure from baseline to week 8. | Fasting dyastolic blood pressure will be measured by a tensiometer and reported in mmHg. | The Time Frame contains two time points: Clinical Investigation Day 1 (at baseline) compared to Clinical Investigation Day 3 (after 8 weeks of intervention). | 
| Change of dyastolic blood pressure from baseline to week 12. | Fasting dyastolic blood pressure will be measured by a tensiometer and reported in mmHg. | The Time Frame contains two time points: Clinical Investigation Day 1 (at baseline) compared to Clinical Investigation Day 4 (after 12 weeks of intervention). | 
| Change of heart rate from baseline to week 4. | Fasting heart rate will be measured by a tensiometer. | The Time Frame contains two time points: Clinical Investigation Day 1 (at baseline) compared to Clinical Investigation Day 2 (after 4 weeks of intervention). | 
| Change of heart rate from baseline to week 8. | Fasting heart rate will be measured by a tensiometer. | The Time Frame contains two time points: Clinical Investigation Day 1 (at baseline) compared to Clinical Investigation Day 3 (after 8 weeks of intervention). | 
| Change of heart rate from baseline to week 12. | Fasting heart rate will be measured by a tensiometer. | The Time Frame contains two time points: Clinical Investigation Day 1 (at baseline) compared to Clinical Investigation Day 4 (after 12 weeks of intervention). | 
| Change of physical activity from baseline to week 12. | Physical Activity will be analyzed by the International Physical Activity Questionnaire. | The Time Frame contains two time points: Clinical Investigation Day 1 (at baseline) compared to Clinical Investigation Day 4 (after 12 weeks of intervention). | 
| Change on food intake from baseline to week 12. | Energy and macronutrient intake will be analyzed by a 72h foor record questionnaire. | The Time Frame contains two time points: Clinical Investigation Day 1 (at baseline) compared to Clinical Investigation Day 4 (after 12 weeks of intervention). | 
| Adherence to the intervention at week 4. | Adherence to the intervention will be assessed by a capsule intake diary. | Clinical investigation day 2 (week 4). | 
| Adherence to the intervention at week 8. | Adherence to the intervention will be assessed by a capsule intake diary. | Clinical investigation day 3 (week 8). | 
| Adherence to the intervention at week 12. | Adherence to the intervention will be assessed by a capsule intake diary. | Clinical investigation day 4 (week 12). | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Prediabetes, Obesity and overweight, Glycated hemoglobin, Blood glucose, Fecal microbiota, Probiotic