(OR19-06-24) Apiaceous Vegetables Improved Gut Dysbiosis Induced by Dextran Sodium Sulfate in Mice Consuming Total Western Diet

Objectives: A Western dietary pattern is associated with alterations in gut microbiota and colon cancer development. We investigated whether apiaceous vegetables (API; celery, parsnip) supplemented to Total Western Diet (TWD) improved gut microbiome dysbiosis in mice with dextran sulfate sodium (DSS)-induced colitis.<

Methods: TWD reflects the 50^th percentile of NHANES data for American macro- and micronutrient intake. TWD ingredients were mixed with 21% (wet wt:wt; equivalent to ~1 c/d in the human diet using allometric scaling based on kcals) of fresh organically grown celery and parsnips or 42% (wet wt:wt). C57BL/6J mice (n=7/group) were assigned to 1 of 6 groups: G1) TWD; G2) TWD+21%API (10.5% celery and 10.5% parsnip); G3) TWD+42%API (21% celery and 21% parsnip); G4) TWD+DSS; G5) TWD+21%API+DSS; and G6) TWD+42%API+DSS. Mice received diets for 19 days, and mice in G4-G6 received 2% DSS in drinking water from D12 to D17. Fecal samples were collected on D0, D12 (before DSS treatment), and D17 (last day of DSS treatment). 16s rRNA sequencing was performed and data processed using QIIME2, Deblur, and SILVA database. Differences in α-diversity were assessed by Kruskal-Wallis test, β-diversity by ANOSIM, and composition by LDA score.

Results: Alpha diversity (Shannon index and number of observed features) decreased over time in all groups; API supplementation (G2, G3, G5, G6) mitigated the alteration. At D17, DSS treatment (G4) decreased number of observed features when compared to G1 (p < 0.01), but both indices were higher in G5 and G6 compared to G4 (each p< 0.05). Beta diversity (Bray-Curtis and Jaccard) showed significantly separated microbial composition structure in all groups over time. On D17, G4 showed distinct separation from G1, however G5 and G6 attenuated the separation. Most abundant features were: G4, phyla Verrucomicrobiota, and genera Akkermansia, and Peptostreptococcaceae (LDA score >4.0); G5, Bacteroides genera, , and Oscillospiraceae family (LDA score >4.0); and in G6, Lachnoclostridium, Dorea sps. and Lachnospiraceae FCS020 group (LDA score >3.0).

Conclusions: TWD and DSS each led to loss of diversity and altered gut microbiome composition while API intake attenuated the alterations. These results suggest API vegetable intake may be protective against gut dysbiosis mediated by Western style diet and colitis.

Funding Sources: None