(PTFS07-02-26) A Nutrient-Dense Diet With Optimal Protein Level Restores Gut Barrier Functions and Microbial Dysbiosis in a Mouse Model of Colitis

Objectives: Intestinal epithelial cell–specific hnRNPI knockout (KO) mice spontaneously develop colitis accompanied by goblet cell depletion and intestinal barrier dysfunction. This study investigated whether an optimized dietary protein level restores goblet cell function and alters immune responses and gut microbiota in this model.

Methods: Male wild-type (WT) and hnRNPI KO mice were fed either a control diet (CON; 14.4% kcal protein) or a nutrient-dense modified diet (MOD; 28.8% kcal protein) from 5 to 32 weeks of age. Goblet cells and mucin content were quantified using Alcian blue/periodic acid–Schiff staining. CD4⁺ T-cell subsets were analyzed by flow cytometry. Gut microbial composition was assessed using 16S rRNA gene sequencing. Statistical analysis was performed using two-way ANOVA.

Results: KO mice fed the CON diet exhibited reduced goblet cell numbers and mucin content compared with WT mice. The MOD diet significantly increased goblet cell numbers and restored mucin levels in KO mice. Flow cytometry revealed alterations in CD4⁺ T-cell populations, including reduced IL17⁺IFNγ⁺ CD4⁺ T cells following the MOD diet. Microbiota analysis showed dietary-dependent shifts in microbial composition, including increased abundance of Dubosiella and decreased Lachnospiraceae NK4A136 in KO mice.

Conclusions: An optimized protein diet restores goblet cell abundance and modulates immune responses and gut microbiota in hnRNPI KO mice, suggesting dietary protein may improve intestinal barrier function during chronic inflammation.

Funding Sources: This project was supported by the USDA Cooperative State Research, Education, and Extension Service (Hatch project numbers # ILLU-698989 and ILLU-698992), the Division of Nutritional Sciences-Vision 20/20, and the Office of the Vice-Chancellor for Research at the University of Illinois Urbana-Champaign.