Amelioration of colitis by donor microbiota modulated with tea active ingredients: A fecal microbiota transplantation study

Fecal microbiota transplantation (FMT) using donor microbiota modulated by tea represents an emerging approach to ameliorate ulcerative colitis (UC). This study aims to demonstrate the amelioration of dextran sulfate sodium (DSS)-induced colitis by donor microbiota modulated with tea-derived bioactive ingredients-tea polyphenols (TPP), tea polysaccharides (TPS), or theabrownin (TB). Following transplantation of fecal microbiota modulated by TPP, TPS, or TB from donors into colitis mice, significant reductions in Disease Activity Index (DAI) were observed, alongside attenuated intestinal histopathological damage. Additionally, gut barrier integrity was enhanced, as indicated by upregulated expression of occludin and Muc2. Fecal microbiota modulated by TPP and TPS showed superior efficacy in alleviating colitis compared with TB-modulated microbiota. The mechanism involved that marked enrichment of beneficial genera, including Akkermansia (TPP-enriched) and Allobaculum/Lactobacillus (TPS-enriched), which promoted the biosynthesis of short-chain fatty acids (SCFAs) and secondary bile acids, while reducing primary bile acids levels. These metabolic changes enhanced intestinal barrier function and suppressed suppressing pro-inflammatory cytokines through the modulation of TLR4/NF-κB p65 and Nrf2/ARE signaling pathways. This study not only elucidates the mechanism of tea bioactive ingredients-modulated donor microbiota alleviates colitis through regulation of the gut-microbiota-metabolite axis, but also provides a foundation for FMT-based strategies in colitis intervention.