Hylla S, Gostner A, Dusel G, Anger H, Bartram H P, Christl S U, Kasper H, Scheppach W
Department of Medicine, University of Würzburg, Germany.
Am J Clin Nutr. 1998 Jan;67(1):136-42. doi: 10.1093/ajcn/67.1.136.
Recent evidence suggests that resistant starch (RS) is the single most important substrate for bacterial carbohydrate fermentation in the human colon. During two 4-wk periods. 12 healthy volunteers consumed a controlled basal diet enriched with either amylomaize starch (55.2 +/- 3.5 g RS/d; high-RS diet) or available cornstarch (7.7 +/- 0.3 g RS/d; low-RS diet). Approximately 90% of the RS consumed disappeared during intestinal passage; increased fermentation was verified by elevated breath-hydrogen excretion. During the high-RS diet, fecal wet and dry weight increased 49% and 56%, respectively (P < or = 0.005), whereas stool water content did not change significantly. Fecal concentrations and daily excretion of short-chain fatty acids were not different in the two study periods. During the high-RS diet, bacterial beta-glucosidase activity decreased by 26% (P < or = 0.05). Fecal concentrations of total and secondary bile acids were significantly lower during the high-RS than during the low-RS period [a decrease of 30% (P < or = 0.05) and 32% (P < or = 0.01), respectively, in total and secondary bile acids] whereas concentrations of primary bile acids were unaffected by RS consumption. During the high-RS diet, fecal concentrations of total neutral sterols decreased by 30% (P < or = 0.005) and fecal concentrations of 4-cholesten-3-one decreased by 36% (P < or = 0.05). These data suggest that RS has potentially important effects on bacterial metabolism in the human colon that may be relevant for cancer prevention.
近期证据表明，抗性淀粉（RS）是人类结肠中细菌碳水化合物发酵的最重要单一底物。在两个为期4周的时间段内，12名健康志愿者食用了添加了直链玉米淀粉（55.2±3.5克RS/天；高RS饮食）或可利用玉米淀粉（7.7±0.3克RS/天；低RS饮食）的对照基础饮食。摄入的RS约90%在肠道通过过程中消失；呼出氢气排泄增加证实了发酵增强。在高RS饮食期间，粪便湿重和干重分别增加了49%和56%（P≤0.005），而粪便含水量没有显著变化。两个研究时间段内短链脂肪酸的粪便浓度和每日排泄量没有差异。在高RS饮食期间，细菌β-葡萄糖苷酶活性下降了26%（P≤0.05）。高RS饮食期间总胆汁酸和次级胆汁酸的粪便浓度显著低于低RS饮食期间[总胆汁酸和次级胆汁酸分别下降30%（P≤0.05）和32%（P≤0.01）]，而初级胆汁酸的浓度不受RS摄入的影响。在高RS饮食期间，总中性固醇的粪便浓度下降了30%（P≤0.005），4-胆甾烯-3-酮的粪便浓度下降了36%（P≤0.05）。这些数据表明，RS对人类结肠中的细菌代谢具有潜在的重要影响，这可能与癌症预防相关。
