Korean Red Ginseng Polysaccharides Enhance Intestinal IgA Production and Barrier Function via Peyer’s Patch Activation in Mice

<b>Background</b>: Natural products are gaining attention for their potential benefits in gastrointestinal health. Plant-derived polysaccharides are essential for boosting intestinal immunity and maintaining gut homeostasis. This study investigated the effects of Korean red ginseng polysaccharides (KRG-P) on intestinal homeostasis including IgA and SCFA production and mucosal barrier integrity. <b>Methods</b>: Mice were orally administered KRG-P at doses of 50 mg/kg or 200 mg/kg for 10 days. Fecal IgA levels were measured on days 3, 5, and 11 and IgA from cultured Peyer's patch cells from KRG-P-treated mice were analyzed. Additionally, mRNA and protein expression levels of α-defensin, lysozyme, and E-cadherin in the small intestine were examined. Short-chain fatty acids (SCFAs) content in the cecum was also assessed. <b>Results</b>: KRG-P-treated groups showed a significant increase in fecal IgA levels on days 5 and 11, with no notable change on day 3. Cultured Peyer's patch cells from mice demonstrated heightened IgA production. Additionally, KRG-P administration upregulated α-defensin and lysozyme mRNA expression, along with elevated protein expression of E-cadherin, α-defensin, and lysozyme, in the small intestine. KRG-P treatment also led to increased cecal SCFA levels, including acetate, butyrate, and propionate. <b>Conclusions</b>: KRG-P may promote intestinal homeostasis and host defense mechanisms by activating immune cells in Peyer's patches, stimulating IgA production, enhancing antimicrobial peptide expression, and modulating gut microbiota metabolism through increased SCFA production.