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Effect of a Probiotic or Postbiotic on Gut Microbiome During Antibiotic Treatment

Assessment Of Gut Microbiome Changes During Antibiotic Treatment With Probiotic, Postbiotic Or Placebo: A Randomized, Triple-blind, Placebo-controlled Pilot Study.

Status
Not yet recruiting
Phases
Unknown
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT07594860
Acronym
POTATO-2
Enrollment
126
Registered
2026-05-19
Start date
2026-06-01
Completion date
2027-05-31
Last updated
2026-05-19

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Microbiome

Keywords

Antibiotic, Dysbiosis, Microbiome composition, Antibiotic Resistance Genes, Microbiome Recovery, Antibiotic Scarring, Probiotic, Postbiotic

Brief summary

This study assesses the effects of a probiotic or postbiotic on gut microbiome during antibiotic treatment.

Detailed description

The current study aims to assess the changes in microbiome composition in healthy adults receiving antibiotic treatment, and concomitantly a probiotic or postbiotic. The trial will be run in Greece, and will recruit healthy adults from the general population.

Interventions

DIETARY_SUPPLEMENTProbiotic

Participants in this arm will receive a daily dose of of a probiotic (live bacterium), in a form of 2 capsules once daily, for 28 days.

DIETARY_SUPPLEMENTPostbiotic

Participants in this arm will receive a daily dose of a postbiotic (heat-inactivated bacterium), in a form of 2 capsules once daily, for 28 days.

DIETARY_SUPPLEMENTPlacebo

Participants in this arm will receive an equivalent placebo for the duration of the study (28 days).

Sponsors

The Archer-Daniels-Midland Company
Lead SponsorINDUSTRY
NEXT CRO
CollaboratorUNKNOWN

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
TRIPLE (Subject, Investigator, Outcomes Assessor)

Eligibility

Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
Yes

Inclusion criteria

Participants meeting ALL of the following criteria will be recruited for the study: * Males and females aged ≥18 to ≤ 65 years; if female, either not of childbearing potential or using a medically approved method of birth control and willing to take a pregnancy test at screening. * Body mass index (BMI) 18.5-29.9 kg/m². * Healthy as determined by medical history and physical examination. * Agreed not to change current dietary habits during the course of the study. * Able to attend study visits, comply with study requirements (consumption of study medications, especially biological sample collection procedures, and study visit schedule) and provide reliable and complete data regarding AEs/SAEs and PROs. * Have been informed and have given written consent for the use of their data in accordance with local regulations before study inclusion.

Exclusion criteria

Participants meeting ANY of the following criteria will be excluded from the study: * Women who are pregnant, breastfeeding, or planning to become pregnant during the course of the study. * People on vegetarian or vegan diet; People on special diet (e.g. Ducan, Keto, etc.) * BMI ≥ 30 kg/m² or \<18.5 kg/m². * History of intake of antibiotics, other probiotics, postbiotics, prebiotics, synbiotics, proton pump inhibitors, acid sequestrants (cholestyramine, Bile colestipol), within six months prior to the screening day. * Participation in other clinical trials in the last 90 days prior to screening. * Allergy to any penicillin antibiotic or any other beta-lactam agent (e.g. cephalosporin, carbapenem or monobactam). * History of jaundice/hepatic impairment due to amoxicillin/clavulanic acid. * Active smokers or using any form of smokeless tobacco. * Participants with substance abuse problems (within two years) defined as: * Use of recreational drugs (such as cocaine, methamphetamine, marijuana, etc.)/ Nicotine dependence. * High-risk drinking as defined by the consumption of four or more alcohol-containing beverages on any day or eight or more alcohol-containing beverages per week for women and five or more alcohol-containing beverages on any day or 15 or more alcohol-containing beverages per week for men. * Participants having clinically significant illnesses of cardiovascular, endocrine, immune, respiratory, hepato-biliary, kidney and urinary, haematological, musculoskeletal system and/or any inflammatory disorder, tumour, and other gastrointestinal diseases. * Participants with a history of bariatric surgery or surgical resection of the stomach, small intestine, or large intestine. * Participants actively using GLP1 agonist drugs (Wegovy, Semiglutide etc.) or completed treatment with said medication less than 12 weeks before screening. * Any condition that could, in the opinion of the Investigator, preclude the participant's ability to successfully and safely complete the study or that may confound study outcomes.

Design outcomes

Primary

MeasureTime frameDescription
Changes in gut microbiome composition between baseline and day 14 as compared to placebo.Day 0 and Day 14To assess the effects of a probiotic or postbiotic in gut microbiome composition of healthy adults receiving antibiotic therapy, as measured by changes in alpha and beta diversity of the gut microbiome as compared to placebo.

Secondary

MeasureTime frameDescription
Changes in gut microbiome composition throughout the study as compared to placebo and baseline.Day 0, Day 3, Day 7, Day 28, and Day 56Changes in microbiome composition as measured by changes in alpha and beta diversity of the gut microbiome throughout the study as compared to placebo and baseline.
Changes in abundance of beneficial versus opportunistic/ pathogenic bacterial species throughout the study as compared to baseline and to placeboDay 0, Day 3, Day 7, Day 14, Day 28, and Day 56Effects of a probiotic or postbiotic on the abundance of beneficial versus opportunistic/pathogenic bacterial species throughout the study as compared to baseline and to placebo.
Changes in the abundances of microbial genes contained in specific functional modules through the study as compared to baseline and placebo.Day 0, Day 7, Day 14, Day 28, and Day 56Effects of probiotic or postbiotic on the abundances of genes contained in specific functional modules obtained from KEGG database. A Gene Set Enrichment Analysis (GSEA) is performed to obtain which modules are enriched by the biotics effect thought the study. Significant associations will be reported with the Normalized Enrichment score (NES) and adj.p.value.
Study the associations of specific microbe abundances with the development of gastrointestinal (GI) symptomsDay 0, Day 3, Day 7, and Day 14Association between each bacterial abundance and the clinical measures, related to GI symptoms, will be performed using linear models. Significant associations will be reported with the linear model coefficient and adj.p.value.
.Changes in the abundances of microbial virulence factors and antibiotic resistant genes through the study as compared to baseline and placebo.Day 0, Day 7, Day 14, Day 28, and Day 56Effects of probiotic or postbiotic on the abundances of genes annotated as virulence factors or antibiotic resistant genes through the study as compared to baseline and placebo. The results will be tested using the most fitting statistical method, and p.value will be reported.
Safety profile throughout the study as compared to placebo.56 daysThe number of adverse events (AE)/serious adverse events (SAE) related to the study investigational product occurring during the study compared to placebo.
Tolerability of a probiotic or postbiotic as measured by a validated questionnaire and compared to placebo.Day 0, Day 7, Day 14, Day 28, and Day 56Assess tolerability of a probiotic or postbiotic consumption as measured by a validated questionnaire, the Gastrointestinal Symptom Rating Scale (GSRS) throughout the study and compared to baseline and placebo.

Countries

Greece

Contacts

CONTACTADM Medical Team
medical@protexin.com+441460243230

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: May 20, 2026