An interventional study of Probiotic and Postbiotic in Microbiome, sponsored by The Archer-Daniels-Midland Company. Not yet recruiting at 1 site in Greece. Open to participants aged 18 Years to 65 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-05-19.
Sponsored by The Archer-Daniels-Midland Company · Not applicable, Interventional, and Prevention
This study assesses the effects of a probiotic or postbiotic on gut microbiome during antibiotic treatment.
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.
186 studies on the registry are indexed under Dysbiosis; 59 are open to participants now.
This study's planned enrollment of 126 is above the median of 60 across 134 interventional studies indexed under Dysbiosis.
Browse Dysbiosis studies →The Archer-Daniels-Midland Company is the lead sponsor of 19 studies on the registry; 6 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Participants meeting ALL of the following criteria will be recruited for the study:
Exclusion Criteria:
Participants meeting ANY of the following criteria will be excluded from the study:
Participants with substance abuse problems (within two years) defined as:
Participants in this arm will receive a daily dose of a daily dose of of a probiotic (live bacterium), in a form of 2 capsules once daily, for 28 days.
Dietary Supplement: Probiotic
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 Supplement: Postbiotic
Participants in this arm will receive an equivalent placebo for the duration of the study (28 days).
Dietary Supplement: Placebo
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.
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.
Participants in this arm will receive an equivalent placebo for the duration of the study (28 days).
Changes in gut microbiome composition between baseline and day 14 as compared to placebo.
To 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.
Time frame: Day 0 and Day 14
Changes in gut microbiome composition throughout the study as compared to placebo and baseline.
Changes 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.
Time frame: Day 0, Day 3, Day 7, Day 28, and Day 56
Changes in abundance of beneficial versus opportunistic/ pathogenic bacterial species throughout the study as compared to baseline and to placebo
Effects 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.
Time frame: Day 0, Day 3, Day 7, Day 14, Day 28, and Day 56
Changes in the abundances of microbial genes contained in specific functional modules through the study as compared to baseline and placebo.
Effects 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.
Time frame: Day 0, Day 7, Day 14, Day 28, and Day 56
Study the associations of specific microbe abundances with the development of gastrointestinal (GI) symptoms
Association 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.
Time frame: Day 0, Day 3, Day 7, and Day 14
.Changes in the abundances of microbial virulence factors and antibiotic resistant genes through the study as compared to baseline and placebo.
Effects 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.
Time frame: Day 0, Day 7, Day 14, Day 28, and Day 56
Safety profile throughout the study as compared to placebo.
The number of adverse events (AE)/serious adverse events (SAE) related to the study investigational product occurring during the study compared to placebo.
Time frame: 56 days
Tolerability of a probiotic or postbiotic as measured by a validated questionnaire and compared to placebo.
Assess 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.
Time frame: Day 0, Day 7, Day 14, Day 28, and Day 56
Effects on development of antibiotic-associated diarrhea (AAD) as compared to placebo.
Efficacy of probiotic or postbiotic on incidence of diarrhea or AAD during and after antibiotic therapy as assessed by frequency and form of daily bowel movements measured with Bristol Stool Form Scale (BSFS). BSFS scale ranges from 1 to 7 with scores 1-2 indicating hard and lumpy bowel motions and 6-7 indicating runny, watery stools.
Time frame: 56 days
Effects on duration of diarrhea or AAD if presented during the study as compared to placebo.
Efficacy of probiotic or postbiotic on the duration of diarrhea or AAD, if present, as assessed by Bristol Stool Form Scale (BSFS). BSFS scale ranges from 1 to 7 with scores 1-2 indicating hard and lumpy bowel motions and 6-7 indicating runny, watery stools.
Time frame: 56 days
Plan to share: No
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This study is not yet recruiting, as verified in May 2026. You cannot join it, but the record below documents what was studied.
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