Graduate School of Agriculture, Hokkaido University, Sapporo, Japan.
PLoS One. 2012;7(11):e50658. doi: 10.1371/journal.pone.0050658. Epub 2012 Nov 29.
Isomaltosyloligosaccharides (IMO) and dextran (Dex) are hardly digestible in the small intestine and thus influence the luminal environment and affect the maintenance of health. There is wide variation in the degree of polymerization (DP) in Dex and IMO (short-sized IMO, S-IMO; long-sized IMO, L-IMO), and the physiological influence of these compounds may be dependent on their DP.
METHODOLOGY/PRINCIPAL FINDINGS: Five-week-old male Wistar rats were given a semi-purified diet with or without 30 g/kg diet of the S-IMO (DP = 3.3), L-IMO (DP = 8.4), or Dex (DP = 1230) for two weeks. Dextran sulfate sodium (DSS) was administered to the rats for one week to induce experimental colitis. We evaluated the clinical symptoms during the DSS treatment period by scoring the body weight loss, stool consistency, and rectal bleeding. The development of colitis induced by DSS was delayed in the rats fed S-IMO and Dex diets. The DSS treatment promoted an accumulation of neutrophils in the colonic mucosa in the rats fed the control, S-IMO, and L-IMO diets, as assessed by a measurement of myeloperoxidase (MPO) activity. In contrast, no increase in MPO activity was observed in the Dex-diet-fed rats even with DSS treatment. Immune cell populations in peripheral blood were also modified by the DP of ingested saccharides. Dietary S-IMO increased the concentration of n-butyric acid in the cecal contents and the levels of glucagon-like peptide-2 in the colonic mucosa.
CONCLUSION/SIGNIFICANCE: Our study provided evidence that the physiological effects of α-glucosaccharides on colitis depend on their DP, linkage type, and digestibility.
异麦芽低聚糖（IMO）和葡聚糖（Dex）在小肠中几乎难以消化，因此会影响腔环境并影响健康的维持。Dex 和 IMO 的聚合度（DP）差异很大（短链 IMO，S-IMO；长链 IMO，L-IMO），这些化合物的生理影响可能取决于它们的 DP。
方法/主要发现：5 周龄雄性 Wistar 大鼠给予含有或不含有 30 g/kg 饮食 S-IMO（DP=3.3）、L-IMO（DP=8.4）或 Dex（DP=1230）的半纯化饮食两周。给大鼠施用葡聚糖硫酸钠（DSS）一周以诱导实验性结肠炎。我们通过评分体重减轻、粪便稠度和直肠出血来评估 DSS 治疗期间的临床症状。用 S-IMO 和 Dex 饮食喂养的大鼠的结肠炎发展被延迟。DSS 处理促进了在对照、S-IMO 和 L-IMO 饮食喂养的大鼠的结肠黏膜中中性粒细胞的积累，如髓过氧化物酶（MPO）活性的测量所评估的。相比之下，即使在 DSS 处理下，用 Dex 饮食喂养的大鼠中也没有观察到 MPO 活性的增加。摄入的糖的 DP 还改变了外周血中的免疫细胞群体。饮食 S-IMO 增加了盲肠内容物中的正丁酸浓度和结肠黏膜中的胰高血糖素样肽-2 水平。
结论/意义：我们的研究提供了证据，表明 α-葡萄糖对结肠炎的生理影响取决于它们的 DP、连接类型和消化率。
