Effect of a Low-calorie Diet With a Prebiotic Supplement on Health of Overweight-obese Subjects. (POSTBIOTICS)

Effect of a Low-calorie Diet With a Prebiotic Supplement on Health of Overweight-obese Subjects: a Randomized Controlled Trial

The main objective of this project is to evaluate the effect of prebiotic supplementation on weight loss and other physiological and metabolic parameters related to excess weight in overweight/obese adult men and women, as well as to determine the changes in the gut microbiota associated with these changes. Specific objectives are focus on evaluate the effect of the intervention on the following parameters:

• Weight and body composition.
• Changes in the gut microbiota (metagenomics).
• Changes in urinary and serum metabolites.
• Complete blood count, routine biochemical variables related to glucose and lipid metabolism, as well as liver health parameters.
• Specific markers involved in obesity pathology (insulin, leptin, adiponectin, and cytokines MCP1, TNF, CRP, and IL10).
• Satiety-related variables using a visual analog scale.
• Adherence to the assigned intervention, both to the hypocaloric diet and to the supplement provided in the study.
• Physical activity level.
• Changes in gastrointestinal health through self-reported questionnaires.
• Mental health and quality of life of participants through self-reported questionnaires.
• Chronotype of participants through a self-reported questionnaire. For this purpose, a randomized, double blind parallel study has been designed.

Target sample size is 156 subjects.

Participants will be allocated in two groups for 8 weeks:

• Experimental group (n=104): hypocaloric diet + prebiotic supplement.
• Placebo group (n=52): hypocaloric diet + placebo supplement.

Participants will visit nutritional intervention unit at week 1 and week 8. At week 4 they will receive a phone control call.

Study Overview

• Status: Completed
• Conditions: Obesity; Weight Loss; Polyphenols
• Intervention / Treatment: Dietary supplement: Prebiotic + hypocaloric diet; Dietary supplement: Placebo + hypocaloric diet

Detailed Description

Volunteers who wish to participate in the study will be interviewed by phone to verify that they meet the main inclusion criteria. Volunteers who meet the main inclusion criteria will be invited to an information and screening visit to resolve any doubts. Volunteers who agree to participate in the study will sign the informed consent and will be randomly allocated to one of the two arms of the study and will be provided with any required material.

During the intervention, volunteers will attend 2 Clinical investigation visits. The first one will be carried out on the first day of the study and the last one will take place at the end of the 8 weeks. In both visits anthropometric and body composition measurements, blood pressure, stool and blood, urine and stool samples, as well as data about dietary, physical activity, sleep and gastrointestinal symptoms will be taken.

Inclusion criteria

• Men and women aged 18 to 70 years.
• Volunteers with overweight or obesity (BMI: 25.0-39.9 kg/m²) and body fat percentage > 30% for women / > 20% for men.
• Stable weight (+/- 5%) in the last three months prior to the start of the study.
• Normal physical examination and vital signs, or clinically insignificant findings for the experiment (those not related to metabolic health).
• Subjects must be able to understand and be willing to sign the informed consent form, agreeing to comply with all study procedures and requirements.
• Continued pharmacological/hormonal treatment will be allowed as long as it does not affect the study parameters and the dosage has been stable for at least 3 months. Exclusion will apply to treatments with insulin or any drug with hypoglycemic effects.
• Willingness to undergo each of the procedures involved in the study (including consuming a sweetened yogurt).
• Availability to attend the two in-person clinical evaluation sessions at the scheduled times and locations.

Exclusion criteria

• Volunteers undergoing pharmacological treatment if the treatment is not stable (at least 3 months before the start of the study), with exclusion of treatments:
• That alter gastrointestinal function.
• Stomach protectants.
• Hypoglycemic drugs.
• Insulin (under no circumstances).
• Subjects with relevant functional or structural abnormalities of the digestive system, such as malformations, angiodysplasias, active peptic ulcers, chronic inflammatory or malabsorption diseases, hiatal hernia, reflux, etc.
• Subjects who have undergone surgical interventions with permanent sequelae in the digestive system (e.g., gastroduodenostomy) or bariatric surgery.
• Suffering from any chronic metabolic disease or obesity-related disease, or any systemic intestinal, liver, or kidney disease: type 1 or 2 diabetes, severe dyslipidemia, uncontrolled thyroid dysfunction, cirrhosis, inflammatory bowel disease, untreated anemia, etc. (non-alcoholic fatty liver will not be an exclusion criterion).
• Exceeding the alcohol consumption limit for the corresponding sex (more than 14 units per week for women and 20 units per week for men).
• Pregnant, breastfeeding, or planning to become pregnant.
• Taking nutritional supplementation (weight loss supplements, fiber supplements, probiotics, multivitamins, etc.) that contains compounds that may affect the study outcomes, unless the person is willing to stop these supplements during the 8-week intervention period and ensures a minimum washout period of 30 days before baseline measurements.
• Having donated blood in the 14 days prior to the start visit.
• Subjects with any type of cancer or undergoing cancer treatment, or who have not been free of cancer for at least 5 years since eradication.
• Subjects with an allergy to any component of the study product or any other food that interferes with and complicates following the study protocol.
• Subjects with any cognitive and/or psychiatric impairment.
• Subjects who are expected to have poor cooperation or, in the investigator's opinion, have difficulty following the study procedures.
• Subjects currently undergoing treatment for weight loss/body composition modification.
• Subjects who are taking or have taken antibiotics within 30 days before the initial visit.

• Study Type: Interventional
• Enrollment (Actual): 156
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Spain
  • Navarra
    • Pamplona, Navarra, Spain, 31008
      • Center for Nutrition Research

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Men and women aged 18 to 70 years.
• Volunteers with overweight or obesity (BMI: 25.0-39.9 kg/m²) and body fat percentage > 30% for women / > 20% for men.
• Stable weight (+/- 5%) in the last three months prior to the start of the study.
• Normal physical examination and vital signs, or clinically insignificant findings for the experiment (those not related to metabolic health).
• Subjects must be able to understand and be willing to sign the informed consent form, agreeing to comply with all study procedures and requirements.
• Continued pharmacological/hormonal treatment will be allowed as long as it does not affect the study parameters and the dosage has been stable for at least 3 months. Exclusion will apply to treatments with insulin or any drug with hypoglycemic effects.
• Willingness to undergo each of the procedures involved in the study (including consuming a sweetened yogurt).
• Availability to attend the two in-person clinical evaluation sessions at the scheduled times and locations.

Exclusion Criteria:

• Volunteers undergoing pharmacological treatment if the treatment is not stable (at least 3 months before the start of the study), with exclusion of treatments:
• That alter gastrointestinal function.
• Stomach protectants.
• Hypoglycemic drugs.
• Insulin (under no circumstances).
• Subjects with relevant functional or structural abnormalities of the digestive system, such as malformations, angiodysplasias, active peptic ulcers, chronic inflammatory or malabsorption diseases, hiatal hernia, reflux, etc.
• Subjects who have undergone surgical interventions with permanent sequelae in the digestive system (e.g., gastroduodenostomy) or bariatric surgery.
• Suffering from any chronic metabolic disease or obesity-related disease, or any systemic intestinal, liver, or kidney disease: type 1 or 2 diabetes, severe dyslipidemia, uncontrolled thyroid dysfunction, cirrhosis, inflammatory bowel disease, untreated anemia, etc. (non-alcoholic fatty liver will not be an exclusion criterion).
• Exceeding the alcohol consumption limit for the corresponding sex (more than 14 units per week for women and 20 units per week for men).
• Pregnant, breastfeeding, or planning to become pregnant.
• Taking nutritional supplementation (weight loss supplements, fiber supplements, probiotics, multivitamins, etc.) that contains compounds that may affect the study outcomes, unless the person is willing to stop these supplements during the 8-week intervention period and ensures a minimum washout period of 30 days before baseline measurements.
• Having donated blood in the 14 days prior to the start visit.
• Subjects with any type of cancer or undergoing cancer treatment, or who have not been free of cancer for at least 5 years since eradication.
• Subjects with an allergy to any component of the study product or any other food that interferes with and complicates following the study protocol.
• Subjects with any cognitive and/or psychiatric impairment.
• Subjects who are expected to have poor cooperation or, in the investigator's opinion, have difficulty following the study procedures.
• Subjects currently undergoing treatment for weight loss/body composition modification.
• Subjects who are taking or have taken antibiotics within 30 days before the initial visit.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Prebiotic group; Natural yogurt with prebiotic formula	Dietary supplement: Prebiotic + hypocaloric diet; Study participants will add prebiotic formula in a natural yogurt every day to be consumed within a hypocaloric diet.
Placebo Comparator: Placebo group; Natural yogurt with placebo formula	Dietary supplement: Placebo + hypocaloric diet; Study participants will add placebo formula in a natural yogurt every day to be consumed within a hypocaloric diet.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Fecal microbiota	Fecal microbiota of participants will be analyzed by bacterial 16S or Shotgun gene sequencing technology.	Clinical Investigation Day 1 and Clinical Investigation Day 2

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Height	Height of participants will be measured by stadiometer and reported in m.	Clinical Investigation Day 1
Body weight	Weight of participants will be measured by bioimpedance and reported in kg	Clinical Investigation Day 1 and Clinical Investigation Day 2
Body mass index	Body mass index will be calculated as follows: weight (kilograms)/ height (cm)2	Clinical Investigation Day 1 and Clinical Investigation Day 2
Body fat percentage	Body fat of participants will be analyzed by bioimpedance and reported in percentage and kilograms.	Clinical Investigation Day 1 and Clinical Investigation Day 2
Body muscle mass	Body muscle mass of participants will be analyzed by bioimpedance and reported in kilograms.	Clinical Investigation Day 1 and Clinical Investigation Day 2
Body lean mass	Body leen mass of participants will be analyzed by bioimpedance and reported in kilograms.	Clinical Investigation Day 1 and Clinical Investigation Day 2
Body water mass	Body water mass of participants will be analyzed by bioimpedance and reported in kilograms.	Clinical Investigation Day 1 and Clinical Investigation Day 2.]
Body bone mass	Body bone mass of participants will be analyzed by bioimpedance and reported in kilograms.	Clinical Investigation Day 1 and Clinical Investigation Day 2
Gastrointestinal symptoms	Gastrointestinal symptoms will be registrated through Gastrointestinal Symptoms Rating Scale questionnaire, which is a questionnaire of 15 items. The questionnaire has a seven-point graded likert-type scale, where 1 represents absence of troublesome symptoms and 7 represents very troublesome symptoms.	Clinical Investigation Day 1 and Clinical Investigation Day 2
Dietary intake	Dietary intake (energy, macronutrients and micronutrients) will be analysed by food frequency questionnaire.	Clinical Investigation Day 1 and Clinical Investigation Day 2
Physical activity	Physical activity will be evaluated by the reduced version of the International Physical Activity Questionnaire, which estimates the total physical activity in MET-min/week, time spent sitting and classifies subjects based on their physical activity	Clinical Investigation Day 1 and Clinical Investigation Day 2
Adherence to capsule consumption	Adherence will be assessed using the capsule consumption record form.	Clinical Investigation Day 1 and Clinical Investigation Day 2
Waist circumference	Waist circumference of participants in fasting condition will be analyzed by measuring tape and reported in centimeters.	Clinical Investigation Day 1 and Clinical Investigation Day 2
Hip circumference	Hip circumference of participants in fasting condition will be analyzed by measuring tape and reported in centimeters.	Clinical Investigation Day 1 and Clinical Investigation Day 2
Neck circumference	Neck circumference of participants in fasting condition will be analyzed by measuring tape and reported in centimeters.	linical Investigation Day 1 and Clinical Investigation Day 2
Systolic blood pressure	Systolic blood pressure of participants in fasting condition will be analyzed by electronic tensiometer and reported in mmHg	Clinical Investigation Day 1 and Clinical Investigation Day 2
Diastolic blood pressure	Diastolic blood pressure of participants in fasting condition will be analyzed by electronic tensiometer and reported in mmHg	Clinical Investigation Day 1 and Clinical Investigation Day 2
Heart rate	Heart rate of participants in fasting condition will be analyzed by electronic tensiometer and reported in pulses/min.	Clinical Investigation Day 1 and Clinical Investigation Day 2
Glucose concentration	Blood glucose levels of participants in fasting condition will be analyzed by biochemical autoanalyzer and reported in mg/dL.	Clinical Investigation Day 1 and Clinical Investigation Day 2
Insulin concentration	Blood insulin concentration will be analyzed after an overnight fast by ELISA kit.	Clinical Investigation Day 1 and Clinical Investigation Day 2
Blood glycated hemoglobin	Fasting blood glycated hemoglobin will be reported in percentage.	Clinical Investigation Day 1 and Clinical Investigation Day 2
HOMA index	HOMA index will be calculated as follows: HOMA-IR = [fasting glucose (mmol/L) x fasting insulin (μU/ml)] / 22.5.	Clinical Investigation Day 1 and Clinical Investigation Day 2
Total cholesterol	Blood total cholesterol levels of participants in fasting condition will be analyzed by biochemical autoanalyzer and reported in mg/dL	Clinical Investigation Day 1 and Clinical Investigation Day 2
HDL cholesterol	Blood HDL cholesterol levels of participants in fasting condition will be analyzed by biochemical autoanalyzer and reported in mg/dL	Clinical Investigation Day 1 and Clinical Investigation Day 2
LDL cholesterol	LDL cholesterol levels of participants in fasting condition will be analyzed by Friedewald formula and reported in mg/dL.	Clinical Investigation Day 1 and Clinical Investigation Day 2
Triglyceride concentration	Triglyceride levels of participants in fasting condition will be analyzed by biochemical autoanalyzer and reported in mg/dL.	Clinical Investigation Day 1 and Clinical Investigation Day 2
Hemogram concentration	Hemogram levels of participants in fasting condition will be analyzed by biochemical autoanalyzer.	Clinical Investigation Day 1 and Clinical Investigation Day 2
Leptine	Blood leptine concentration will be analyzed after an overnight fast by ELISA kit.	Clinical Investigation Day 1 and Clinical Investigation Day 2
Adiponectin	Blood adiponectin concentration will be analyzed after an overnight fast by ELISA kit.	Clinical Investigation Day 1 and Clinical Investigation Day 2
MCP1	Blood MCP1 concentration will be analyzed after an overnight fast by ELISA kit.	Clinical Investigation Day 1 and Clinical Investigation Day 2
Tumor necrosis factor alpha (TNF-alpha)	Blood TNF-alpha concentration will be analyzed after an overnight fast by ELISA kit.	Clinical Investigation Day 1 and Clinical Investigation Day 2
C Reactive protein (CRP)	Blood CRP concentration will be analyzed after an overnight fast by ELISA kit.	Clinical Investigation Day 1 and Clinical Investigation Day 2
Albumin concentration	Albumin levels of participants in fasting condition will be analyzed in urine by biochemical autoanalyzer.	Clinical Investigation Day 1 and Clinical Investigation Day 2
Creatinine concentration	Creatinine levels of participants in fasting condition will be analyzed in urine by biochemical autoanalyzer and reported in μmol/L.	Clinical Investigation Day 1 and Clinical Investigation Day 2
Life quality	Life quality of participants will be evaluated by SF-36 questionnaire.	Clinical Investigation Day 1 and Clinical Investigation Day 2
chronotype	Morningness-Eveningness Questionnaire (MEQ)	Clinical Investigation Day 1 and Clinical Investigation Day 2
Level of hunger	Hunger of participants will be analyzed by Hunger-Satiety Visual Analogue Scale (VAS). The minimum value of the scale is 0 mm and the maximum value is 100 mm. A reduction in hunger scale means better outcome.	Clinical Investigation Day 1 and Clinical Investigation Day 2
Level of fullness	Fullness of participants will be analyzed by Hunger-Satiety Visual Analogue Scale. The minimum value of the scale is 0 mm and the maximum value 100 mm. An incrementation in fullness scale means better outcome	Clinical Investigation Day 1 and Clinical Investigation Day 2
Level of satisfaction	Satisfaction sensation of participants will be analyzed by Hunger-Satiety Visual Analogue Scale. The minimum value of the scale is 0 mm and the maximum value 100 mm. An incrementation in satisfaction scale means better outcome.	Clinical Investigation Day 1 and Clinical Investigation Day 2
Want to eat something else	Want to eat something else sensation of participants will be analyzed by Hunger-Satiety Visual Analogue Scale. The minimum value of the scale is 0 mm and the maximum value 100 mm. A reduction in want to eat something else scale means better outcome.	Clinical Investigation Day 1 and Clinical Investigation Day 2
Thirst	Thirst sensation of participants will be analyzed by Hunger-Satiety Visual Analogue Scale. The minimum value of the scale is 0 mm and the maximum value 100 mm.	Clinical Investigation Day 1 and Clinical Investigation Day 2
Blood untargeted metabolomics	Untargeted metabolomics will be analyzed in plasma and serum.	Clinical Investigation Day 1 and Clinical Investigation Day 2
Urine untargeted metabolomics	Untargeted metabolomics will be analyzed in urine.	Clinical Investigation Day 1 and Clinical Investigation Day 2
Lipidomic	Lipidomic will be analyzed in plasma and serum.	Clinical Investigation Day 1 and Clinical Investigation Day 2
Depression	Depression will be evaluated by Beck questionnaire.	Clinical Investigation Day 1 and Clinical Investigation Day 2
Anxiety	Anxiety will be evaluated by Stai questionnaire.	Clinical Investigation Day 1 and Clinical Investigation Day 2
Interleukin 10 (IL10)	Blood IL10 concentration will be analyzed after an overnight fast by ELISA kit.	Clinical Investigation Day 1 and Clinical Investigation Day 2

Collaborators and Investigators

• Sponsor: Clinica Universidad de Navarra, Universidad de Navarra
• Investigators: Study Chair: Idoia Ibero, PhD, Center for Nutrition Research; Study Chair: María Hernández, Center for Nutrition Research; Study Chair: Blanca Martínez, Center for Nutrition Research; Study Chair: Verónica Ciaurriz, Center for Nutrition Research; Study Chair: Carlos González, PhD, Center for Nutrition Research; Study Chair: Salomé Pérez, Center for Nutrition Research; Study Chair: Marta Cuervo, PhD, Center for Nutrition Research; Study Chair: Ana Lorente, Center for Nutrition Research; Study Chair: María Goñi, Center for Nutrition Research

Study record dates

Study Major Dates

• Study Start (Actual): December 13, 2024
• Primary Completion (Actual): May 23, 2025
• Study Completion (Actual): May 23, 2025

Study Registration Dates

• First Submitted: November 25, 2024
• First Submitted That Met QC Criteria: November 25, 2024
• First Posted (Actual): November 29, 2024

Study Record Updates

• Last Update Posted (Actual): May 30, 2025
• Last Update Submitted That Met QC Criteria: May 26, 2025
• Last Verified: May 1, 2025

More Information

Terms related to this study

• Keywords: obesity; prebiotic; polyphenols; supplement; microbiota
• Additional Relevant MeSH Terms: Nutrition Disorders; Overnutrition; Body Weight; Body Weight Changes; Overweight; Weight Loss
• Other Study ID Numbers: POSTBIOTICS (2024.154)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No