Intracellular Polysaccharides of Aspergillus cristatus from Fuzhuan Brick Tea Leverage the Gut Microbiota and Repair the Intestinal Barrier to Ameliorate DSS-Induced Colitis in Mice

The intracellular polysaccharides of Aspergilluscristatus (IPSs) from Fuzhuan brick tea have beendemonstrated to improve immune function linked to modulating the gutmicrobiota. Herein, to further investigate the efficacy of IPSs tomaintain gut homeostasis, the protection of the purified fractionof IPSs (IPSs-2) on the mice with colitis induced by dextran sulfatesodium (DSS) and the underlying mechanisms were explored in this study.The results revealed that IPSs-2 alleviated the typical symptoms ofcolitis and suppressed the excessive inflammatory mediators, regulatingthe genes related to inflammatory responses in the colon at the mRNAlevel. Meanwhile, IPSs-2 treatment reinforced the intestinal barrierfunction by ameliorating the DSS-induced histological injury, facilitatingthe differentiation of goblet cells to enhance Mucin-2 generation,and enhancing the expression of tight junction proteins to alleviatecolitis. In addition, IPSs protected against colitis by promotingthe production of short-chain fatty acids (SCFAs), the activationof SCFAs receptors, and the leverage of the gut microbiota via the enrichment of Bacteroides, Parabacteroides, Faecalibacterium, Flavonifractor_plautii, and Butyricicoccus, linking with reducing inflammation and repairing intestinal barrierfunction. Overall, our research revealed the therapeutic potentialof IPSs-2 as a prebiotic for attenuating inflammatory bowel diseaseand provided a rationale for future investigation.