Polysaccharides from Citrus Fruit with Different Mastication Traits Ameliorate DSS-Induced Ulcerative Colitis by Restoring Intestinal Barrier Function and Microbiota Balance

Mastication trait is an important indicator for evaluating citrus fruit texture and may modulate the biological activity of citrus polysaccharides. This study compared the protective effects of pulp polysaccharides from citrus fruit with different mastication traits, namely Hongmeiren (HMR, superior), Satsuma (WM, moderate), and Nanfeng tangerine (NF, inferior mastication trait) on ulcerative colitis (UC) in mice. All polysaccharides alleviated UC symptoms, with HMR showing the most pronounced effects by more markedly reducing TNF-α levels, while enhancing IL-10, ZO-1, Occludin, and MUC2 expression. NF exhibited a stronger inhibitory effect on IL-6. Microbiota analysis revealed that citrus polysaccharides suppressed Escherichia-Shigella and Helicobacter, enriched <i>Akkermansia</i> and <i>norank_f_Muribaculaceae</i>, and promoted short-chain fatty acid production, particularly of propionate and butyrate. LEfSe analysis further indicated that HMR selectively enriched <i>Dubosiella</i> and <i>norank_o_Clostridia_UCG-014</i>, WM increased the abundance of <i>Lachnospiraceae_NK4A136_group</i>, and NF promoted the growth of <i>Parabacteroides</i>. Overall, HMR with superior mastication trait exhibited the greatest efficacy in attenuating inflammation and maintaining intestinal homeostasis. These findings reveal an intrinsic link between citrus mastication traits and their colitis-alleviating activity, offering a mechanistic basis for dietary intervention in inflammatory bowel disease as well as for functional citrus breeding.