P0075 Evaluation of the modulatory potential of polyphenolic compounds on intestinal inflammation at the transcriptomic level
Authors: Inčiūraitė R , Kūlokienė U , Tilindė D , Kiudelis V , Jonaitis L V , Kiudelis G , Kupčinskas J , Skiecevičienė J 
Published: January 2025

Abstract

Background
Inflammatory bowel disease (IBD) is a chronic multifactorial gastrointestinal condition influenced by genetic, environmental, and immune system factors. Gut microbiota disruption plays a key role in disease onset and progression, leading to inflammation, impaired healing, and increased intestinal permeability1,2. Diet, particularly polyphenols from fruits, vegetables, and tea, can impact microbiota composition and offer anti-inflammatory benefits. This study explores the effects of these compounds on inflammation of the intestinal epithelium at the transcriptomic level.

Methods
A panel of polyphenolic compounds (n=8) was tested on Caco-2 cells, which were pre-treated with the metabolites before inflammation was induced for 24 h using TNF-α and IFN-γ. The effects were evaluated through targeted gene expression analysis using RT-qPCR. Prioritized compounds – Urolithin A (UroA) and Gallic Acid (GA) – were further tested on inflamed 3D colonic epithelial organoids derived from ulcerative colitis patient (UC) (n=1) and non-IBD individual (n=1), with mRNA sequencing performed on the NextSeq 550 (Illumina).

Results
Initial metabolite screening in Caco-2 cells was performed by analyzing the expression changes of pro-inflammatory cytokines-coding genes TNF-α, MCP-1, IL-8. Results demonstrated significant induction of cellular inflammation (p &lt; 0.05) after exogenous stimullation with TNF-α and IFN-γ, which was most efficiently and consistenly reduced by GA and UroA. Therefore, GA and UroA were further selected for deeper evaluation on inflamed colonic epithelial organoids. RNA-seq revealed more pronounced cell reactivity to all treatments in UC-organoids compared to non-IBD-organoids and clear sample clustering based on treatment condition. DEA and GSEA of significantly dysregulated genes revealed interesting functional insights into potential mechanisms of action of UroA and GA. Importanly, in inflammed UC-organoids, pre-treatment with GA showed significant (FDR &lt; 0.05) upregulation of pathways involved in cell junction assembly, and significant (FDR &lt; 0.05) downregulation of pathways involved in metabolic processes. Together, these results suggest that GA may lead to colonic epithelial cell metabolic reprogramming in UC from energy-intensive and nucleotide-demanding processess and contribute to the resolution of inflammation and restoration of gut epithelial integrity.

Conclusion
In conclusion, during colonic inflammation, dietary polyphenol metabolites regulate inflammatory responses, epithelial barrier function, and energy production pathways at the transcriptomic level.
Study was funded by the European Union and the State Secretariat for Education, Research and Innovation (SERI) (project: miGut-Health, grant no. 101095470).

References
1 Jostins, L., et al. (2012). Host–microbe interactions have shaped the genetic architecture of inflammatory bowel disease. Nature, 491(7422), 119-124. https://doi.org/10.1038/nature11582
2 Cleynen, I., et al. (2016). Inherited determinants of Crohn’s disease and ulcerative colitis phenotypes: a genetic association study. The Lancet, 387(10014), 156-167. https://doi.org/10.1016/S0140-6736(15)00465-1