Department of Food Science and Technology, Tokyo University of Marine Science and Technology, 4-5-7 Konan, Minato-ku, Tokyo, 108-8477, Japan.
Mol Biol Rep. 2024 Nov 1;51(1):1112. doi: 10.1007/s11033-024-10045-2.
Water-soluble arabinoxylan exerts anti-colitic effect and exhibits ameliorative activity in an inflammatory bowel disease (IBD) mouse model. Water soluble fibre from wheat bran (WB) also exhibits anti-colitic effect. However, arabinoxylan is a primary compound of insoluble polysaccharide (hemicellulose) in WB. This study aimed to clarify the anti-IBD effects of the WB water-soluble (WBS) and water-insoluble (WBI) fractions.
WB suspension was autoclaved and fractionated to WBS and WBI. C57BL/6 mice were divided into control (CT), dextran sodium sulphate (DSS), WBI, and WBS groups. They were fed as follows from day 1: CT, standard diet and distilled water; DSS and WBI, 3% (w/v) DSS in drinking water; WBI, 8% (w/w) WBI diet; and WBS, 50% (v/v) WBS and 3% (w/v) DSS in water. DSS group mice showed diarrhoea, body weight reduction, and blood in faeces by day 5 and colon tissue damage by day 6. These inflammatory indices were significantly inhibited by treatment with WBI. Amplicon sequencing of the 16S rDNA (V4) gene of the caecal contents of the CT, DSS, and WBI groups showed that the abundances of Escherichia, Allobaculum, and Bacteroidaceae increased and that of Faecalibaculum decreased in the DSS group. KEGG pathway prediction showed that amino acid metabolism and lipopolysaccharide biosynthesis decreased and increased, respectively, in the DSS group. However, WBI treatment tended to suppress these effects.
WBI, rather than WBS, reduces inflammation and maintains the gut microbiota. However, further studies are warranted to elucidate the properties of the WBI active components and efficacy of WBI metabolites on gut microbiota, particularly on Faecalibaculum.
水溶性阿拉伯木聚糖具有抗结肠炎症作用，并在炎症性肠病（IBD）小鼠模型中表现出改善活性。来自麦麸的水溶性纤维（WB）也具有抗结肠炎症作用。然而，阿拉伯木聚糖是 WB 不溶性多糖（半纤维素）的主要化合物。本研究旨在阐明 WB 水溶性（WBS）和水不溶性（WBI）部分的抗 IBD 作用。
WB 悬浮液经高压灭菌并分馏为 WBS 和 WBI。C57BL/6 小鼠分为对照组（CT）、葡聚糖硫酸钠（DSS）、WBI 和 WBS 组。从第 1 天开始，它们分别喂食以下食物：CT，标准饮食和蒸馏水；DSS 和 WBI，饮用水中 3%（w/v）DSS；WBI，8%（w/w）WBI 饮食；WBS，50%（v/v）WBS 和 3%（w/v）DSS 水。DSS 组小鼠在第 5 天出现腹泻、体重减轻和粪便带血，第 6 天出现结肠组织损伤。WBI 处理显著抑制了这些炎症指标。CT、DSS 和 WBI 组盲肠内容物 16S rDNA（V4）基因的扩增子测序显示，DSS 组大肠杆菌、Allobaculum 和拟杆菌科的丰度增加，而 Faecalibaculum 的丰度降低。KEGG 途径预测显示，DSS 组的氨基酸代谢和脂多糖生物合成减少和增加，而 WBI 处理则倾向于抑制这些效应。
WBI 而非 WBS 可减轻炎症并维持肠道微生物群。然而，需要进一步研究阐明 WBI 活性成分的性质及其代谢产物对肠道微生物群的功效，特别是对 Faecalibaculum 的功效。
