Search bioRxiv⌕ Search

bioRxiv · 10.1101/2025.05.29.656766

Gut3Gel as an in vitro model to investigate dietary modulation of the intestinal microbiota: An inulin supplementation case study

Abstract

The intestinal microbiota plays a key role in human health, influencing digestion, immunity, and metabolism. While factors such as genetics and medications shape its composition, diet remains a primary driver of microbial modulation. Despite growing interest in using dietary interventions to beneficially alter the intestinal microbiota, assessing their effects in humans is challenging due to individual variability and the complexity of in vivo systems. This study explores Gut3Gel gradient colonic (G3GG) preclinical model as a tool to assess its representativeness on studying the effect of inulin supplementation on the intestinal microbiota of five healthy individuals compared to clinical evaluation studies. Significant inter-individual variability in baseline microbiota composition was observed, which strongly influenced microbiota response to inulin. While inulin supplementation led to a general decrease in alpha diversity, it significantly increased the abundance of health-associated genera such as Bifidobacterium and Lacticaseibacillus, along with enhanced microbial metabolic activity. Despite the intrinsic selectivity of G3GG for beneficial microbes, the model successfully captured inulins prebiotic effects and inter-individual differences, underscoring its relevance as a physiologically relevant high throughput tool for evaluating microbiota-targeting compounds and supporting personalized nutrition strategies.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Antunes, M., Jongen, L., Mateen, A., Sobral, J., van Uden, S., Suarez, N., Pacheco, D.. 2025-05-29. Gut3Gel as an in vitro model to investigate dietary modulation of the intestinal microbiota: An inulin supplementation case study. https://doi.org/10.1101/2025.05.29.656766

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

Extreme temperature exposure has negative demographic consequences for Sulfolobus acidocaldarius

Microorganisms inhabiting geothermal springs and volcanic systems experience fluctuating temperatures that can periodically exceed their upper thermal limits, but the demographic consequences of such exposure remain poorly understood. Here, we investigated demographic responses of the thermophilic archaeon Sulfolobus acidocaldarius to an extreme temperature (94.1{degrees}C) under two regimes: sustained exposure varying in duration, and episodic exposure interspersed with recovery at a permissive temperature (75{degrees}C). Under sustained exposure, populations showed no detectable loss of viability after 15 min but declined thereafter, decreasing by approximately five orders of magnitude after 120 min. Under episodic exposure, populations remained viable across nine exposure-recovery cycles but declined in density with successive cycles. Similar responses were observed for three strains, including a DNA mismatch repair knockout ({Delta}nucS), indicating that mismatch repair deficiency did not affect viability or recovery. Together, these results demonstrate that S. acidocaldarius can withstand brief and repeated exposure to near-boiling temperatures, with mortality determined primarily by cumulative exposure duration rather than a fixed thermal threshold.

microbiology↗

Bacteriophage and Antibiotic Resistance Are Positively Associated across a Phylogenetically Diverse Set of Clinical Pseudomonas aeruginosa Isolates

Co-administration of phages and antibiotics has been proposed as a therapeutic approach against antibiotic-resistant bacteria. The relationship, however, between antibiotic resistance and phage resistance in clinical isolates is unclear. Here, we examine associations between phage and antibiotic resistance profiles across a panel of Pseudomonas aeruginosa clinical isolates from the Centers for Disease Control (CDC) and Food and Drug Administration (FDA) Antimicrobial Resistance Isolate (ARI) Bank comprising 55 clinical strains with full genome sequences and antibiotic susceptibility testing (AST) data for 11 clinically relevant antibiotics. As phages in this study, we use three well-characterized, morphologically distinct phages, OMKO1, Luz19, and PAML31-1. We screen for phage resistance using a growth suppression assay, then conduct statistical analysis against antibiotic MIC (Minimum Inhibitory Concentration) data provided by the CDC to define association patterns across this dataset. We find multiple significant susceptibility correlations between pairs of antibiotics and phages, and a positive overall association between average phage resistance and antibiotic resistance across the 55 strains, even controlling for phylogenetic associations (=0.358, p<0.005). We conclude that phage and antibiotic resistance are positively associated across this clinical isolate collection, suggesting that the two resistance phenotypes are not independent in P. aeruginosa. These findings have implications for the development of phage-antibiotic cocktails.

microbiology↗

The Estuary Effect: Variations in Temperature and Salinity Alter msh Promoter Activity in Vibrio cholerae

Vibrio cholerae, the facultative pathogen underlying cholera, naturally inhabits warm aquatic estuaries. Environmental persistence is enhanced by the ability of V. cholerae to colonize host reservoirs and form multicellular biofilms, causing seasonally endemic outbreaks in many tropical regions. Most toxigenic strains utilize the type IVa mannose-sensitive hemagglutinin (MSHA) pilus for host reservoir colonization and biofilm formation. Temperature and salinity can alter V. cholerae biofilm formation, yet their impact on MSHA production specifically remains largely unknown. Here, we utilized transcriptional reporters of predicted msh promoters (msh-P1/msh-P2/msh-P3) and functional assays, to determine temperature and salinity impacts on msh expression and pilus biogenesis. Under standard laboratory conditions (30{degrees}C, 1% NaCl) only msh-P1/P2 are active and inversely-coordinated with one another. Both msh-P1/P2 activity were elevated by high temperature (37{degrees}C) and low salinity (0.25%/0.5% NaCl), and reduced by low temperature (20{degrees}C/25{degrees}C) and high salinity (2%/3% NaCl). Temperature-mediated alterations in promoter activity were not immediately reflected in changes to cell-surface MSHA levels, whereas high salinity led to decreased MSHA production. Combining high temperature (37{degrees}C) and high salinity (2%/3% NaCl), attenuated the salinity-mediated reduction of msh-P1/P2 activity. Biofilm biomass levels were only substantially heightened at 25{degrees}C and 20{degrees}C, likely a result of no temperature-dependent changes in cell-surface MSHA, and additional temperature-controlled biofilm regulation previously described. We also found msh-P1/P2 promoter activity and MSHA production varies widely across toxigenic O1 and O139 serogroups despite complete sequence homology. These results shed new light on how key signals regulate MSHA pilus production to support V. cholerae persistence in aquatic environments.

microbiology↗