Dongowski Gerhard, Huth Mario, Gebhardt Erich, Flamme Wilhelm
Department of Food Chemistry and Preventive Nutrition, German Institute of Human Nutrition Potsdam-Rehbrücke, Bergholz-Rehbrücke, Germany.
J Nutr. 2002 Dec;132(12):3704-14. doi: 10.1093/jn/132.12.3704.
The objective of this study was to investigate the effects of barley-rich diets in the intestinal tract of rats. Four test groups (A-D) of 10 young male Wistar rats were fed diets containing 50 g/100 g barley extrudates (A, B and D) or mixtures (C) for 6 wk; the control diet contained no barley. The barley-containing supplements in the test diets were: A = cultivar "HiAmi"; B = "HiAmi" and "Prowashonupana" (50:50); C = "Prowashonupana" and Novelose (50:50); D = "Prowashonupana" and amylose from maize (60:40). These supplements contained 7-12 g/100 g beta-glucan and 7-24 g/100 g resistant starch. Additionally, 5 g microcrystalline cellulose/100 g was present in all diets. Carbohydrate utilization (indirect calorimetry) was lower (P < 0.05) in rats fed the barley-containing diets C or D than in the controls. In the test groups, the following differences from the controls were found: greater food intake in the last 2 wk (P < 0.05); increased weight gain in wk 6 (P < 0.05); greater mass of the ceca (groups B-D; P < 0.05) and colons (P < 0.001) as well as masses of cecal (groups C and D; P < 0.01) and colon contents (P < 0.001); greater concentrations of resistant starch in cecal and most of the colon contents (P < 0.05); and more beta-glucan in the small intestine, cecum and colon (P < 0.05). The numbers of coliforms and Bacteroides were lower than in the controls in groups B-D and those of Lactobacillus were greater in all test groups (P < 0.05). Short-chain fatty acids (SCFA) were higher in the cecal contents of the test groups (> or = 800 micro mol/g DM; P < 0.001) compared with the controls ( approximately 200 micro mol/g DM). Similarly, SCFA were higher in colon and feces of the test groups. The concentrations of excreted bile acids increased up to 30% during the feeding period. The proportions of secondary bile acids were lower and the amounts of neutral sterols (P < 0.001) were greater in feces of rats fed the barley-containing diets for 6 wk than in the controls. Diets containing more soluble macromolecular dietary fibers such as beta-glucans affected the excretion of bile acids and neutral sterols the most, whereas the fermentation of dietary fiber, including resistant starch, influenced the steroids in feces. These results suggest that dietary fiber-rich barley-containing diets have beneficial physiologic effects.
本研究的目的是调查富含大麦的日粮对大鼠肠道的影响。将4组各10只年轻雄性Wistar大鼠分为试验组（A - D），分别喂食含50 g/100 g大麦挤压物（A、B和D）或混合物（C）的日粮，持续6周；对照日粮不含大麦。试验日粮中的含大麦补充剂分别为：A = “HiAmi”品种；B = “HiAmi”和“Prowashonupana”（50:50）；C = “Prowashonupana”和新型糊精（50:50）；D = “Prowashonupana”和玉米直链淀粉（60:40）。这些补充剂含有7 - 12 g/100 gβ-葡聚糖和7 - 24 g/100 g抗性淀粉。此外，所有日粮中均含有5 g/100 g微晶纤维素。与对照组相比，喂食含大麦日粮C或D的大鼠碳水化合物利用率（间接测热法）较低（P < 0.05）。在试验组中，发现与对照组有以下差异：最后2周食物摄入量增加（P < 0.05）；第6周体重增加（P < 0.05）；盲肠（B - D组；P < 0.05）和结肠（P < 0.001）质量增加，以及盲肠（C和D组；P < 0.01）和结肠内容物质量增加（P < 0.001）；盲肠和大部分结肠内容物中抗性淀粉浓度更高（P < 0.05）；小肠、盲肠和结肠中β-葡聚糖含量更多（P < 0.05）。B - D组中大肠菌群和拟杆菌数量低于对照组，所有试验组中乳酸杆菌数量均更多（P < 0.05）。与对照组（约200 μmol/g DM）相比，试验组盲肠内容物中短链脂肪酸（SCFA）含量更高（≥800 μmol/g DM；P < 0.001）。同样，试验组结肠和粪便中SCFA含量也更高。在喂食期间，排泄胆汁酸浓度增加高达30%。与对照组相比，喂食含大麦日粮6周的大鼠粪便中次级胆汁酸比例更低，中性固醇含量更高（P < 0.001）。含有更多可溶性大分子膳食纤维如β-葡聚糖的日粮对胆汁酸和中性固醇排泄影响最大，而包括抗性淀粉在内的膳食纤维发酵影响粪便中的类固醇。这些结果表明，富含膳食纤维的含大麦日粮具有有益的生理作用。
