Phenolamide Extract of Apricot Bee Pollen Alleviates DSS-Induced Ulcerative Colitis in Mice by Reducing Oxidative Stress, Modulating Inflammation, and Regulating Gut Microbiota

Phenolamides in bee pollen exhibit notable bioactivities, such as antioxidant, anti-inflammatory, and antimicrobial effects. Ulcerative colitis (UC) is a prevalent intestinal disorder, while the potential effects of phenolamides on UC remain unclear. This study aims to investigate the effects and mechanisms of phenolamide extract (PAE) from apricot bee pollen on dextran sulfate sodium (DSS)-induced UC in mice. Firstly, we analyzed the main compounds of PAE. Mice were treated with PAE (100, 200, and 400 mg/kg bw) both during the 7 days preceding 2.5% DSS induction and throughout the induction period (7 days). The results show that the primary compounds of PAE were isomers of tri-<i>p</i>-coumaroyl spermidine (97.78 ± 2.76%). A biochemical analysis showed that PAE decreased the levels of pro-inflammatory cytokines and increased the activities of antioxidant enzymes. Regarding the gut microbiota, PAE reduced the Bacillota/Bacteroidota ratio. Additionally, PAE elevated beneficial bacteria, including <i>norank_f</i>_<i>Muribaculaceae</i>, <i>norank_o</i>_<i>Clostridia</i>_<i>UCG-014</i>, and <i>Lachnospiraceae</i>_<i>NK4A136</i>_<i>group</i>, while reducing harmful bacteria, including <i>Escherichia-Shigella</i>, <i>Clostridium</i>, and <i>Romboutsia.</i> A quantitative analysis of short-chain fatty acids (SCFAs) demonstrated that PAE intervention promotes the biosynthesis of SCFAs in UC mice. This study first demonstrates that PAE attenuates DSS-induced colitis by modulating gut microbiota and SCFAs, suggesting its potential as a functional dietary supplement for colitis.