蒟蒻補充劑對腸道菌叢及體內抗氧化狀態之影響

The effects of konjac supplement on intestinal microflora and antioxidative status in human

鄭翰鍾(Han-Chung Cheng)

指導教授 ： 陳曉鈴

中山醫學大學/健康管理學院/營養學研究所/碩士(2005年)

摘要

我國成年人每日膳食纖維攝取量大幅低於衛生署建所建議之攝取量( 20-30公克)。膳食纖維雖非維持人體生命所必須之營養素，但是對於心血管疾病、便秘以及結直腸癌等文明病，具有一定程度之預防功效。
蒟蒻主成分葡甘聚糖(glucomannan)是由D－葡萄糖(D-Glucose)和D－甘露糖(D-Mannose) 以β－1,4糖苷鍵鍵合而成的一種水溶性膳食纖維。本實驗主要目的在探討蒟蒻葡甘聚糖精粉(glucomannan)對於健康與便秘者腸道菌相以及血中抗氧化力之影響。參試者依排便情形分為兩組(一)健康組：16位無習慣性便秘及其他腸胃疾病之健康成人；(二)便秘組：14位有習慣性排便困難或便秘之便秘成人，各組再分為服用安慰劑及蒟蒻者，各佔半數。實驗為期四週：介入適應期一週及蒟蒻期三週(服用蒟蒻精粉4.5 克/天)。實驗期間研究單位提供午、晚餐7天循環之高脂低纖飲食，參試者全期接受飲食控制。實驗開始和結束前最後一週收集參試者排出之糞便以螢光原位雜交技術( Fluorescence In Situ Hybridization；FISH)進行菌相分析；實驗前和結束後一天抽空腹血，進行維生素E、C、GSH、TBARs以及及總抗氧化力(Oxygen Radical Absorbance Capacity；ORAC)測定。
結果顯示，糞便菌相部分，相較於控制組：(1)健康參試者：蒟蒻組糞便中(count/g wet feces)Lactobacillus acidophilus與總菌數顯著增加；(2)便秘參試者：蒟蒻組Lactobacillus acidophilus菌數顯著增加。Bifidobacterium spp.、Bacteroides spp.與Clostridium perfringens則無顯著差異。每天糞便中菌數(counts/d feces)變化：(1)健康參試者：蒟蒻組Bifidobacterium spp.、Lactobacillus acidophilus與總菌數顯著增加；(2)便秘參試者亦然。而Bacteroides spp.與Clostridium perfringens則無顯著差異。各腸道菌佔總厭氧菌菌數比例部分：(1)健康參試者：蒟蒻組Lactobacillus acidophilus比例顯著增加；(2)便秘參試者：蒟蒻組Lactobacillus acidophilus比例顯著增加而Clostridium perfringens比例顯著降低。Bifidobacterium spp.與Bacteroides spp.則無顯著差異。兩組參試者合併後，蒟蒻組糞便中(count/g wet feces) Bifidobacterium spp.、Lactobacillus acidophilus與總菌數顯著增加；此外Bifidobacterium spp.、Lactobacillus acidophilus與Bacteroides spp.糞便中之比例亦顯著增加且Clostridium perfringens糞便中之比例則顯著降低。
血液抗氧化力方面：健康參試者：控制組在食用高脂控制飲食4週後，血中尿酸顯著下降而維生素E濃度有下降趨勢，蒟蒻組沒有顯著變化；而維生素E與尿酸變化量(change %)之比較上，蒟蒻組比控制組顯著增加。便秘參試者：蒟蒻組實驗後相較於實驗前，ORAC值有顯著上升。另外， ORAC與尿酸變化量蒟蒻組比控制組顯著的增加 (p＜0.05)。
綜合以上結果發現，蒟蒻可幫助健康或便秘參試者增加腸道中Bifidobacterium spp.、Lactobacillus acidophilus與總菌數目，且提高腸道益生菌之比例達88.2 %。此外，蒟蒻可以具有緩和血中維生素E消耗以及增加體內抗氧化力之功效。因此，本研究建議健康及輕度便秘成人補充蒟蒻纖維三週後，皆可能藉由促進腸道益生菌之生長而促進腸道健康，並且可能有提升抗氧化之效力。

關鍵字

蒟蒻 ； 葡甘聚糖 ； 螢光原位雜交技術 ； 腸道菌相 ； 抗氧化

並列摘要

Konjac is rich in glucomannan polysaccharide, a soluble dietary fiber, which is composed of D-glucose and D-mannose by β-1,4 glycosidic bond. Our previous study indicated konjac glucomannan (KGM) supplement effectively promote the bowel movement and stool bulk. In addition, dietary fiber is known to prevent coronary heart disease, which is closely associated with oxidative stress. Therefore, dietary fiber could be involved in the reduction in oxidative stress, which further prevents the cardiovascular disease.
The main goals of this study were to investigate effects of KGM supplement on fecal microflora, blood antioxidants and anti-oxidative indices of healthy and constipated subjects. Sixteen healthy and fourteen constipated subjects were recruited and completed this study. The experiment consisted of an adaptation phase (d1-7) and an experimental phase (d8-28) in which subjects were divided to placebo and KGM groups. Experimental material was given as capsules after each meal (1.5 g/meal, 4.5 g/d). All subjects were given a control diet throughout the experiment. Fasting blood was drawn to determine the blood antioxidants and anti-oxidative indices on days 1 and 28 of the study. Feces excreted during the week before the study and during d22-28 were collected for determining the intestinal flora with fluorescence in situ hybridization method.
KGM significantly increased both the fecal Lactobacillus acidophilus and total anaerobes (counts/g wet feces) in healthy subjects while only raised Lactobacillus acidophilus in constipated subjects, as compared with placebo. KGM did not modulate the Bifidobacterium spp.、Bacteroides spp. and Clostridium perfringens in either group of subjects. Furthermore, KGM significantly raised the daily excretion of fecal Bifidobacterium spp. and Lactobacillus acidophilus (counts/d feces) and decreased Clostridium perfringens in healthy and constipated subjects. KGM significantly increased the ratio of Lactobacillus acidophilus in both healthy and constipated subjects, and decreased the ratio of Clostridium perfringens in constipated subjects.
The control diet reduced the plasma vitamin E concentration in healthy subjects, which was reversed by the KGM supplement. KGM supplement significantly increased the plasma uric acid concentration in healthy subjects and raised plasma total antioxidant capacity (ORAC) significantly in constipated subjects. Glutathione concentrations were not modulated by the KGM supplement.
In conclusion, konjac glucomannan improved intestinal flora and blood anti-oxidative status in healthy and constipated subjects. KGM could be an adjunct to maintain human bowel healthiness and to reduce the oxidative stress in humans.

並列關鍵字

konjac ； glucomannan ； Fluorescence In Situ Hybridization ； FISH ； intestinal microflora ； antioxidation

參考文獻

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