Effect of a Postbiotic Supplementation in Overweight and Obese Subjects: A Randomized Controlled Trial (PARABIOTICS-2).

NCT07165431 | Recruiting

• 1 other identifier: PARABIOTICS-2 (2025.113 Mod1)
• Study Type: interventional
• Target: 114
• Locations: 1 country
• Sites: 1

Brief 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 associated with these outcomes. Specific objectives are focus on evaluate the effect of the intervention on the following parameters:

• 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.

Conditions

Nutrition, Healthy; Weight Loss; Overweight and Obesity

Keywords

Postbiotic; Obesity; Nutritional advice; Microbiota; Glucose tolerance

Outcome Measures

Primary Outcomes (1)

• Body fat mass 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

Secondary Outcomes (44)

• Body weight

  Clinical Investigation Day 1 and Clinical Investigation Day 2

• Height

  Clinical Investigation Day 1

• Body mass index

  Clinical Investigation Day 1 and Clinical Investigation Day 2

• Body lean mass

  Clinical Investigation Day 1 and Clinical Investigation Day 2

• Body water mass

  Clinical Investigation Day 1 and Clinical Investigation Day 2

Study Arms (2)

Postbiotic group

EXPERIMENTAL

Gummy containing postbiotic formula.

Dietary Supplement: Postbiotic + nutritional recommendations

Placebo group

PLACEBO COMPARATOR

Gummy containing placebo formula.

Dietary Supplement: Placebo + nutritional recommendations

Interventions

Postbiotic + nutritional recommendations DIETARY_SUPPLEMENT

Study participants will consume daily one gummy containing a postbiotic formulation, along with adherence to healthy nutritional recommendations for 12 weeks.

Postbiotic group

Placebo + nutritional recommendations DIETARY_SUPPLEMENT

Study participants will consume daily one gummy containing a placebo formulation, along with adherence to healthy nutritional recommendations for 12 weeks.

Placebo group

Eligibility Criteria

• Age: 18 Years - 70 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• 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).

You may not qualify if:

• 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.
• 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.

Sponsors & Collaborators

• Clinica Universidad de Navarra, Universidad de Navarra: lead

Study Sites (1)

Center for Nutrition Research

Pamplona, Navarre, Spain

RECRUITING

MeSH Terms

Conditions

Weight Loss; Overweight; Obesity

Condition Hierarchy (Ancestors)

Body Weight Changes; Body Weight; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Overnutrition; Nutrition Disorders; Nutritional and Metabolic Diseases

Study Officials

• Paula Aranaz, PhD

  Center for Nutrition Research

  PRINCIPAL INVESTIGATOR

• Fermín Milagro, PhD

  Center for Nutrition Research

  STUDY CHAIR

• Idoia Ibero, PhD

  Center for Nutrition Research

  STUDY CHAIR

• Blanca Martínez

  Center for Nutrition Research

  STUDY CHAIR

• María Goñi

  Center for Nutrition Research

  STUDY CHAIR

• Salomé Pérez

  Center for Nutrition Research

  STUDY CHAIR

• Verónica Ciaurriz

  Center for Nutrition Research

  STUDY CHAIR

• Ana Lorente

  Center for Nutrition Research

  STUDY CHAIR

Central Study Contacts

Paula Aranaz, PhD

CONTACT

+34948425600; paranaz@unav.es

Fermín Milagro, PhD

CONTACT

+34948425600; fmilagro@unav.es

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: Parallel groups, 12-week randomized nutritional intervention

Study Record Dates

• First Submitted: September 2, 2025
• First Posted: September 10, 2025
• Study Start: December 1, 2025
• Primary Completion (Estimated): May 30, 2026
• Study Completion (Estimated): June 30, 2026
• Last Updated: February 19, 2026

Record last verified: 2026-02

Data Sharing

• IPD Sharing: Will not share

Locations

ES (1)