Protective Effect of Apiaceous Vegetables against Total Western Diet- and Dextran Sulfate Sodium-Induced Colitis in Mice

Background: Western-style dietary patterns are associated with colitis and colon cancer. Existing data indicate that intake of apiaceous (API) vegetables (e.g., celery, parsnip) may prevent inflammation-associated diseases. Objectives: We investigated in mice the effect of API supplementation to the total Western diet (TWD) against dextran sulfate sodium-induced colitis. Methods: Male C57BL/6J mice (8-wk-old; 15 per group) were fed TWD supplemented with 21% or 42% fresh API (wt/wt) and given 2% dextran sulfate sodium to induce colitis. Diet intake, body weight, and disease activity index were monitored. Serum was collected for cytokine/chemokine analysis and colonic tissues for histology and Western blot. Fecal samples were analyzed by 16S ribosomal ribonucleic acid gene sequencing and targeted/untargeted metabolomics. Phenotypic data were analyzed by analysis of variance with Tukey’s test. Microbiome data were centered log-ratio (CLR) transformed and analyzed using linear mixed models with adjusted pairwise comparisons. Results: API supplementation attenuated colitis phenotypes including weight loss (44% recovery; P < 0.001), colon shortening (57% recovery; P < 0.01), disease activity (59% lower; P < 0.001), cytokine/chemokine release (35%‒73% reductions; P < 0.05), and mucosal F4/80+ cells infiltration (80% reduction; P < 0.001). API also improved gut microbiota diversity and composition, increasing α diversity metrics (4.4%‒13.8%; P < 0.05), suppressing pathogenic bacteria (Paraclostridium, Enterococcus, Eubacterium; estimated CLR difference: –1.8 to –6.7; P < 0.001), and enriching beneficial bacteria (Lachnospiraceae and Blautia; estimated CLR difference: +1.6 to +3.0; P < 0.05). Furthermore, metabolomics indicated TWD consumption increased arachidonic acid and aliphatic aldehydes (by 109%‒510%; P < 0.001), and decreased short-chain and unsaturated fatty acids (by 30%‒91%; P < 0.001). API supplementation also mitigated TWD-derived functional metabolites (including bile acids; P < 0.05). Conclusions: These data indicate that API intake is beneficial for risk reduction of diseases associated with Western diets. However, further investigations are warranted to determine the mechanism behind these beneficial effects.