Christl S U, Katzenmaier U, Hylla S, Kasper H, Scheppach W
Department of Medicine, University of Würzburg, Germany.
JPEN J Parenter Enteral Nutr. 1997 Sep-Oct;21(5):290-5. doi: 10.1177/0148607197021005290.
Malabsorbed starch is probably the most important substrate for bacterial fermentation in the human large intestine. Fermentability of starch may depend on the composition of the colonic flora and its adaptation to the substrate supply.
Ten healthy volunteers were fed a controlled diet containing either 7.0 to 8.3 or 50.7 to 59.7 g/d of resistant starch (Hylon VII) for 4 weeks. At the end of each diet period, fecal starch concentrations were measured. Fecal samples were incubated in 48-hour batch cultures containing 10 g/L Hylon VII or digestible Lintner's starch. Bacterial breakdown of starch and short-chain fatty acid concentrations were measured at 0, 3, 6, 12, 24, and 48 hours.
Fecal starch concentrations were higher during the Hylon VII period (35.7 +/- 16 vs 8.9 +/- 3.3 mg/g). Starch was fermented rapidly and completely in vitro in all but two subjects. Fermentability of resistant starch was comparable to that of digestible starch. No differences were found between the dietary periods. Fermentation of resistant starch produced higher rates of n-butyrate. Two subjects had substantially higher fecal starch concentrations. In vitro starch breakdown in these subjects was slow and incomplete.
Fermentation of resistant starch by the colonic microflora was rapid and complete in 8 of 10 subjects. No adaptation of the fermentation capacity was observed after 4 weeks of dietary resistant starch supplementation. Fermentation of resistant starch increased the proportion of n-butyrate in vitro. In two subjects, fecal starch concentrations were substantially higher than in the other subjects and in vitro starch fermentation was slow and incomplete.
未被吸收的淀粉可能是人类大肠中细菌发酵的最重要底物。淀粉的发酵能力可能取决于结肠菌群的组成及其对底物供应的适应性。
10名健康志愿者食用含有7.0至8.3克/天或50.7至59.7克/天抗性淀粉（Hylon VII）的对照饮食，为期4周。在每个饮食期结束时，测量粪便淀粉浓度。将粪便样本在含有10克/升Hylon VII或可消化的林特纳淀粉的48小时分批培养物中孵育。在0、3、6、12、24和48小时测量淀粉的细菌分解和短链脂肪酸浓度。
在食用Hylon VII期间，粪便淀粉浓度较高（35.7±16对8.9±3.3毫克/克）。除两名受试者外，所有受试者的淀粉在体外均迅速且完全发酵。抗性淀粉的发酵能力与可消化淀粉相当。不同饮食期之间未发现差异。抗性淀粉的发酵产生了更高比例的正丁酸。两名受试者的粪便淀粉浓度显著更高。这些受试者的体外淀粉分解缓慢且不完全。
10名受试者中有8名的结肠微生物群对抗性淀粉的发酵迅速且完全。在补充4周的抗性淀粉饮食后，未观察到发酵能力的适应性变化。抗性淀粉的发酵增加了体外正丁酸的比例。在两名受试者中，粪便淀粉浓度显著高于其他受试者，且体外淀粉发酵缓慢且不完全。
