The effect of 14-strain probiotic in healthy volunteers

Study objective

While probiotics are widely used and known to benefit host health, few studies have explored their effects on the gut microbiome of healthy adults. This study aimed to evaluate both compositional and functional changes in the faecal microbiome following 8 weeks of supplementation with a 14-strain probiotic blend.

How does it address a real-world gut health problem?

Understanding how probiotics interact with a healthy gut microbiome is essential for guiding their use beyond clinical populations. Most research focuses on compositional changes (e.g., diversity and abundance), but this study also assessed functional gene-level changes, offering deeper insight into how probiotics may influence metabolic and immune pathways in healthy individuals.

Study design

Type of trial: Single-arm, open-label clinical trial

Sample size and population: 41 healthy volunteers

Duration and intervention:

  • 8-week daily intake of a 14-strain probiotic blend (8 billion CFU/day via 4 capsules)

Endpoints

Primary outcome:

  • Compositional changes in gut microbiota (alpha/beta diversity, taxonomic abundance)

  • Functional changes in microbial gene expression (KEGG pathways via shotgun metagenomics)

Secondary outcomes:

  • Stool frequency and consistency

  • Fasting breath hydrogen and methane levels

  • Fecal biomarkers of inflammation (calprotectin, lactoferrin, zonulin)

  • Safety assessments

Results

Microbiome composition:

  • No significant changes in overall alpha or beta diversity

  • Significant decrease in Odoribacteraceae and Bacteroidaceae families

  • Significant increase in Megamonas genus

Functional gene changes:

  • Alterations in pathways related to phenylalanine metabolism, O-antigen biosynthesis, bacterial chemotaxis, and flagellar assembly

Commercial relevance

How the findings support product claims:

The study provides evidence that even in healthy individuals, multi-strain probiotics can induce modest but measurable changes in gut microbiota composition and function. These findings support the use of probiotics not only for symptom relief but also for maintaining microbial balance and functional diversity in healthy populations.

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