Nutrition, HealthyPARABIOTICS-2NCT07165431
Effect of a Postbiotic Supplementation in Overweight and Obese Subjects: A Randomized Controlled Trial (PARABIOTICS-2).
A study testing Postbiotic + nutritional recommendations in people with Nutrition, Healthy and Weight Loss, run by Clinica Universidad de Navarra, Universidad de Navarra at 1 site in Spain.
Trial summary
The principal objective of this project is to evaluate the effect of a postbiotic supplement (inactivated microorganism) on body composition and other physiological and metabolic parameters related to excess body weight in overweight or obese adult men and women, as well as to determine changes in the gut microbiota… Read more about this study
- Who is it for?
- Ages 18 to 70 yearsHealthy volunteers can take part
- Conditions the study is for
- Nutrition, Healthy, Weight Loss, Overweight and Obesity
- What is being tested?
- Postbiotic + nutritional recommendations
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 114 participants
- Where
- 1 siteSpain
- Study dates
- 1 Dec 2025to 30 Jun 2026
- Phase
- Interventional
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 70 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Male and female participants aged 18 to 70 years.
- Volunteers with overweight or obesity (BMI: ≥ 27-39.9 kg/m²) and a body fat percentage of ≥ 30% for women and ≥ 20% for men.
- Stable body weight (±5%) for at least the three months prior to study initiation.
- Normal physical examination and vital signs, or clinically non-relevant findings for the purposes of the study (i.e., not related to metabolic health).
- Subjects must be able to understand and willing to sign the informed consent form, and comply with all study procedures and requirements.
- Continued pharmacological/hormonal treatment will be permitted provided it does not affect the study parameters and that the dosage has remained stable at least the previous three months to the start of the intervention. Treatment with insulin or any drug with a hypoglycemic effect will be excluded
- Willingness to undergo all study procedures (including the daily consumption of a 1 g gummy during the intervention).
- Time and geographic availability to attend the two on-site clinical evaluation sessions at the scheduled times (including a 3-hour session during visit 2).
Who cannot join
- Volunteers undergoing pharmacological treatment will be excluded if the treatment has not been stable for at least 3 months prior to study initiation. Excluded treatments include:
- Those that alter gastrointestinal function.
- Chronic use of stomach protectors.
- Any hypoglycemic drugs or insulin.
- Subjects with significant functional or structural abnormalities of the digestive system, such as malformations, angiodysplasias, active peptic ulcers, chronic inflammatory or malabsorption diseases, hiatal hernia, chronic reflux, etc.
- Subjects who have undergone surgical interventions resulting in permanent sequelae in the digestive tract (e.g., gastroduodenostomy) or bariatric surgery.
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- Subjects with chronic metabolic diseases or obesity-related conditions, or systemic intestinal, hepatic, or renal diseases, including type 1 or 2 diabetes, severe dyslipidemia, uncontrolled thyroid disorders, cirrhosis, inflammatory bowel disease, untreated anemia, etc. (Non-alcoholic fatty liver disease will not be an exclusion criterion).
- Exceeding the alcohol consumption limit established for each sex (more than 14 units per week for women and 20 units per week for men).
- Pregnant or breastfeeding women, or those planning to become pregnant.
- Use of nutritional supplements (such as weight loss supplements, newly initiated fiber supplements, probiotics, postbiotics, etc.) containing compounds that may affect study outcomes, unless the participant agrees to discontinue them during the 12-week intervention period and a minimum 15-day washout period prior to baseline measurements is ensured.
- Blood donation within 14 days prior to the baseline visit.
- Subjects with any type of cancer or undergoing cancer treatment, or for whom less than 5 years have passed since remission.
- Subjects allergic to any component of the study product or to any other food that could interfere with or hinder study compliance.
- Subjects presenting any type of cognitive and/or psychiatric impairment.
- Subjects anticipated to have poor compliance or who, in the investigator's opinion, may have difficulty adhering to study procedures.
- Subjects currently undergoing treatment for weight loss or body composition modification.
- Subjects who are taking or have taken antibiotics within 60 days prior to the baseline visit.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Spain1 site, 1 recruiting
- Recruiting
Center for Nutrition Research
Pamplona, Navarre
Paula Aranaz, PhD, 948425600 ext. 806390, paranaz@unav.es
Fermin Milagro, 948425600 ext. 806553, fmilagro@unav.es
About this study
Official title: Clinical Evaluation of a Postbiotic Supplement in Overweight and Obese Subjects: A Randomized Controlled Trial.
The principal objective of this project is to evaluate the effect of a postbiotic supplement (inactivated microorganism) on body composition and other physiological and metabolic parameters related to excess body weight in overweight or obese adult men and women, as well as to determine changes in the gut microbiota associated with these outcomes.
Specific objectives are focus on evaluate the effect of the intervention on the following parameters:
Read more
- Changes in body weight and composition.
- Changes in glucose tolerance.
- Changes in gut microbiota (metagenomics).
- Changes in urinary and serum metabolites.
- Changes in routine biochemical variables related to carbohydrate and lipid metabolism, as well as liver parameters.
- Changes in specific markers involved in obesity pathology, such as insulin, leptin, adiponectin, and cytokines MCP-1, TNF, CRP, and others.
- Adherence to the nutritional recommendations and the gummy containing postbiotic formula.
- Changes in the level of physical activity.
Target sample size is 114 subjects, including a 10% of drop out.
Participants will be allocated in two groups for 12 weeks:
- Experimental group (n=57): nutritional recommendations + postbiotic supplement/gummy.
- Placebo group (n=57): nutritional recommendations + placebo supplement/gummy.
Participants will visit the nutritional intervention unit at weeks 1 and 12. A follow-up phone call will be conducted at week 6.
Read the detailed description
Volunteers who wish to participate in the study will complete an online questionnaire to verify eligibility based on the main inclusion criteria. Volunteers who meet these criteria will be invited to an information and screening visit to address any questions. Those who agree to participate will sign the informed consent form, be randomly assigned to one of the two study arms, and receive the necessary study materials.
During the intervention, volunteers will attend two clinical investigation visits. The Clinical Investigation Day 1 will be conducted on the first day of the study, and the Clinical Investigation Day 2 visit will occur at the end of the 12-week intervention. At both visits, anthropometric and body composition measurements, blood pressure, and samples of blood, urine, and stool will be collected. Additionally, data on diet, physical activity, sleep, and gastrointestinal symptoms will be recorded.
- Conditions
- Nutrition, Healthy, Weight Loss, Overweight and Obesity
- Being tested
- Postbiotic + nutritional recommendations, Placebo + nutritional recommendations
- Keywords
- Postbiotic, Obesity, Nutritional advice, Microbiota, Glucose tolerance
- Medical subject headings
- Weight Loss, Overweight, Obesity
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Postbiotic + nutritional recommendationsDietary supplement
Study participants will consume daily one gummy containing a postbiotic formulation, along with adherence to healthy nutritional recommendations for 12 weeks.
Placebo + nutritional recommendationsDietary supplement
Study participants will consume daily one gummy containing a placebo formulation, along with adherence to healthy nutritional recommendations for 12 weeks.
| Study group | Role | What they receive |
|---|---|---|
| Postbiotic group | Experimental | Gummy containing postbiotic formula. Receives: Dietary Supplement: Postbiotic + nutritional recommendations |
| Placebo group | Placebo comparator | Gummy containing placebo formula. Receives: Dietary Supplement: Placebo + nutritional recommendations |
What is being measured
The primary outcome is the main question the study is designed to answer.
Body fat mass percentage
Body fat of participants will be analyzed by bioimpedance and reported in percentage and kilograms.
Measured: Clinical Investigation Day 1 and Clinical Investigation Day 2
Secondary outcomes (44)
Body weight
Weight of participants will be measured by bioimpedance and reported in kg
Measured: Clinical Investigation Day 1 and Clinical Investigation Day 2
Height
Height of participants will be measured by stadiometer and reported in m.
Measured: Clinical Investigation Day 1
Body mass index
Body mass index will be calculated as follows: weight (kilograms)/ height (cm)2
Measured: 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.
Measured: 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 and percentage.
Measured: 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.
Measured: 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.
Measured: 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.
Measured: 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.
Measured: Clinical 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
Measured: 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
Measured: 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.
Measured: 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.
Measured: Clinical Investigation Day 1 and Clinical Investigation Day 2
Insulin concentration
Blood insulin concentration will be analyzed after an overnight fast by ELISA kit.
Measured: Clinical Investigation Day 1 and Clinical Investigation Day 2
Blood glycated hemoglobin
Fasting blood glycated hemoglobin will be reported in percentage.
Measured: 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.
Measured: 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
Measured: 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
Measured: 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.
Measured: 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.
Measured: Clinical Investigation Day 1 and Clinical Investigation Day 2
Aspartate aminotransferase
Aspartate aminotransferase levels of participants in fasting condition will be analyzed by biochemical autoanalyzer and reported in mg/dL.
Measured: Clinical Investigation Day 1 and Clinical Investigation Day 2
Alanine aminotransferase
Alanine aminotransferase levels of participants in fasting condition will be analyzed by biochemical autoanalyzer and reported in mg/dL.
Measured: Clinical Investigation Day 1 and Clinical Investigation Day 2
Gamma-glutamyl transferase
Gamma-glutamyl transferase levels of participants in fasting condition will be analyzed by biochemical autoanalyzer and reported in mg/dL.
Measured: Clinical Investigation Day 1 and Clinical Investigation Day 2
Leptine
Blood leptine concentration will be analyzed after an overnight fast by ELISA kit.
Measured: Clinical Investigation Day 1 and Clinical Investigation Day 2
Adiponectin
Blood adiponectin concentration will be analyzed after an overnight fast by ELISA kit.
Measured: Clinical Investigation Day 1 and Clinical Investigation Day 2
Monocyte Chemoattractant Protein-1 (MCP1)
Blood MCP1 concentration will be analyzed after an overnight fast by ELISA kit.
Measured: 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.
Measured: 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.
Measured: 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.
Measured: 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.
Measured: Clinical Investigation Day 1 and Clinical Investigation Day 2
Life quality
Life quality of participants will be evaluated by SF-36 questionnaire.
Measured: 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.
Measured: 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
Measured: Clinical Investigation Day 1 and Clinical Investigation Day 2
Dietary intake
Dietary intake (energy, macronutrients and micronutrients) will be analysed by food frequency questionnaire.
Measured: Clinical Investigation Day 1 and Clinical Investigation Day 2
Chronotype
Morningness-Eveningness Questionnaire (MEQ)
Measured: Clinical Investigation Day 1 and Clinical Investigation Day 2
Depression
Depression will be evaluated by Beck questionnaire.
Measured: Clinical Investigation Day 1 and Clinical Investigation Day 2
Anxiety
Anxiety will be evaluated by Stai questionnaire.
Measured: Clinical Investigation Day 1 and Clinical Investigation Day 2
Lipidomic
Lipidomic will be analyzed in plasma and serum.
Measured: Clinical Investigation Day 1 and Clinical Investigation Day 2
Urine untargeted metabolomics
Untargeted metabolomics will be analyzed in urine.
Measured: Clinical Investigation Day 1 and Clinical Investigation Day 2
Blood untargeted metabolomics
Untargeted metabolomics will be analyzed in plasma and serum.
Measured: Clinical Investigation Day 1 and Clinical Investigation Day 2
Fecal microbiota
Fecal microbiota of participants will be analyzed by bacterial 16S or Shotgun gene sequencing technology.
Measured: Clinical Investigation Day 1 and Clinical Investigation Day 2
Adherence to supplement consumption
Adherence will be assessed using the supplement consumption record form.
Measured: Clinical Investigation Day 1 and Clinical Investigation Day 2
Blood lipopolysaccharide (LPS) levels
Blood LPS concentration will be analyzed by ELISA kit.
Measured: Clinical Investigation Day 1 and Clinical Investigation Day 2
Blood zonulin levels
Zonulin concentration will be analyzed by ELISA kit.
Measured: Clinical Investigation Day 1 and Clinical Investigation Day 2
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted10 Sep 2025
- Study start1 Dec 2025
- Primary completion30 May 2026 (estimated)
- Study completion30 Jun 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Nutrition, HealthyStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Parallel groups, 12-week randomized nutritional intervention
- Masking
- Triple blind
- Who is masked
- Participant, Care provider, Investigator
- Enrolment
- 114 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Clinica Universidad de Navarra, Universidad de Navarra
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Paula Aranaz, PhD, Principal investigator, Center for Nutrition ResearchFermín Milagro, PhD, Study chair, Center for Nutrition ResearchIdoia Ibero, PhD, Study chair, Center for Nutrition ResearchBlanca Martínez, Study chair, Center for Nutrition ResearchMaría Goñi, Study chair, Center for Nutrition ResearchSalomé Pérez, Study chair, Center for Nutrition ResearchVerónica Ciaurriz, Study chair, Center for Nutrition ResearchAna Lorente, Study chair, Center for Nutrition Research
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07165431
- Sponsor's protocol ID
- PARABIOTICS-2 (2025.113 Mod1)
- Acronym
- PARABIOTICS-2
- Status last verified
- Feb 2026
- First submitted
- 2 Sep 2025
- Last updated
- 19 Feb 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No