In vitro evaluation of plant-based postbiotics for human gut microbiota modulation

Overview

This research platform evaluates how plant-based postbiotics influence the human gut microbiota using controlled in vitro fermentation models. The work focuses on understanding how different plant-based fermentations, individually and in combination, affect the taxonomic composition and functional output of gut microbial communities. By generating 16S metagenomic data and measuring short-chain fatty acid (SCFA) profiles, the platform provides a rapid, informative screening tool for assessing postbiotic properties before advancing to more complex biological models.

Technical specifications

Core methodology:

• In vitro batch fermentation using 5% fecal slurries inoculated with dietary fibers or plant-based fermented products
• Time-course sampling at 0, 4, 8, 24, 32, and 48 hours to capture dynamic microbial shifts
• Incubation at 37°C to simulate human gut conditions

Analytical capabilities:

• 16S rRNA gene sequencing targeting the V4 region using 515F/926R primers on an Illumina MiSeq platform
• Bacterial taxonomy assignment via QIIME2 with the Silva database (NR 99 138)
• SCFA profiling to quantify metabolic outputs linked to gut health benefits
• Testing of individual fibers (inulin, pectin, dextran) and combinations to evaluate synergistic effects on microbial balance

Future validation pipeline:

• Freeze-dried lyophilized product testing at multiple concentrations and in paired combinations
• Extended fermentation time courses with bacterial growth monitoring
• Caenorhabditis elegans model for evaluating postbiotic effects on lifespan, immunity, obesity, and aging

Technology readiness level

The platform has been validated using three reference dietary fibers (inulin, pectin, and dextran) with demonstrated ability to differentiate fermentability and microbial community modulation based on fiber complexity. Results have shown that more complex fibers promote beneficial bacteria and that fiber combinations yield more balanced microbial communities. The methodology is established and reproducible, with planned extensions to plant-based fermented products and downstream evaluation in C. elegans models for broader health outcome assessment.