Abstract: Objective: To promote the high-value utilization and industrial development of tartary buckwheat and to develop functional products based on tartary buckwheat bran (TBB), this study analyzed the basic composition and investigated the ameliorative effect of TBB on dextran sodium sulfate (DSS)-induced ulcerative colitis (UC) in mice and its anti-inflammatory mechanism. Methods: The contents of protein, fat, total dietary fiber, ash, and starch in TBB were determined. The ameliorative effect on UC induced by 3% DSS in mice was evaluated by hematoxylin and eosin staining of colon sections, enzyme-linked immunosorbent assay (ELISA), Western blotting, gas chromatography (GC), and 16S rDNA high-throughput sequencing. Results: Compared with the model group, TBB significantly alleviated body mass loss, reduced appetite, shortened colon length, and rectal bleeding in mice suffering from UC, mitigated colon crypt damage and goblet cell reduction, suppressed the secretion of pro-inflammatory cytokines, and reduced inflammation through inhibiting nuclear factor kappa-B (NF-κB) signaling pathway. It also restored the levels of acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, and total short-chain fatty acids in the intestine while modulating the gut microbiota composition, especially enhancing the relative abundance of g__Akkermansia and g__Lactobacillus. Conclusion: TBB contains a high level of dietary fiber, which can significantly alleviate UC. This finding provides a scientific basis for the high-value utilization of TBB as a functional food ingredient.

Key words: tartary buckwheat bran, dietary fiber, ulcerative colitis, high-value utilization