Investigating the impact of colonic bacteroides intestinalis-mediated wheat arabinoxylan degradation on lipid metabolism and inflammation modulation

Inflammatory bowel diseases (IBD), including Crohn’s disease and ulcerative colitis, are chronic gastrointestinal inflammation driven by genetic factors, immune dysregulation, environmental influences, and gut microbiota. Arabinoxylan, which is one type of dietary fiber commonly present in cereals, consists primarily of xylose chains substituted with arabinofuranose and ferulic acid residues. Bacteroides intestinalis (BI) is a strain of colonic bacteria plays a crucial role in metabolizing arabinoxylan through specialized gene clusters termed polysaccharide utilization loci (PULs). These PULs enable BI to efficiently degrade arabinoxylan, releasing bioactive metabolites including ferulic acid, which is known for its antioxidant and anti-inflammatory properties. This research investigated the combined effects of dietary insoluble wheat arabinoxylan (INWAX) supplementation and Bacteroides intestinalis colonization in germ-free mouse models of colitis. Results indicate that this combination significantly increased systemic ferulic acid levels, enhanced bile acid production, and reduced oxidative stress levels. In a DSS-induced colitis model, mice receiving both INWAX and BI exhibited reduced inflammation, mitigated spleen enlargement and preserved intestinal morphologies. RNA sequencing analyses revealed INWAX diet induced upregulation in genes associated with circadian rhythm regulation, lipid and carbohydrate metabolism, and antioxidant responses. Additionally, RNA sequencing and immune cell fraction analysis of DSS-treated spleen indicated increased adaptive immune responses coupled with reduced spleen size with INWAX diet, suggesting more efficient inflammation control. Overall, these findings highlight the therapeutic potential of integrating dietary insoluble wheat arabinoxylan with Bacteroides intestinalis colonization to manage intestinal inflammation. Future research could explore deeper mechanisms, including examining microbial metabolites, their broader implications in gut health and inflammatory regulation, and their possible interactions with differential gene expressions.

Name thesis:degree_name

M.A.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

VMS - Comparative Biosciences

Grantor

University of Illinois Urbana-Champaign

Year dc:date

2025

Author dc:creator

• Zhou, Ziyu

Contributors dc:contributor

• Mei, Wenyan

• Inflammatory Bowel Disease
• Dietary Fiber
• Wheat Arabinoxylan
• Bacteroides Intestinalis
• Ferulic Acid

Statement dc:rights

• Copyright 2025 Ziyu Zhou

Language dc:language

en, eng

Handle dc:identifier

https://hdl.handle.net/2142/130116

OAI record oai:identifier

https://www.ideals.illinois.edu/oai-pmh?verb=GetRecord&metadataPrefix=etdms&identifier=oai%3Awww.ideals.illinois.edu%3A2142%2F130116