- 學位論文
蒟蒻及其水解產物之腸道效應
Effects of konjac glucomannan and its hydrolysates on bowel habits, ecosystem, and lipid metabolism
摘要
蒟蒻(Amorphophallus konjac)是為葡萄糖和甘露糖以β鍵結而成之水溶性膳食纖維，所以不被人體消化吸收。本研究主旨在探討蒟蒻(Konjac; K)及其水解產物(Konjac hydrolysates; KH)對小鼠食物攝取量、體重變化、糞便特性、小腸酵素活性、血脂濃度及盲腸與糞便菌相之影響。由於蒟蒻及其水解產物平均分子量的差異可能影響其生理活性之起始時間和效應程度，因此本研究分別探討時間及劑量效應。 利用熱酸水解法製備蒟蒻水解產物，所得到之平均聚合度(Degree of polymerization; DP)為12。將七週大BALB/c雄性小鼠隨機分派，並餵食含5%纖維素、5%蒟蒻或5%蒟蒻水解產物之AIN-93無纖維半純化飼料各2週和4週，每組8隻小鼠。 在時間實驗發現各組間體重、攝食量以及小腸黏膜酵素活性並無異，在第2週及4週糞便溼重、乾重及排便頻率皆以5%纖維素組> 5%蒟蒻組> 5%蒟蒻水解產物組；糞便濕份以蒟蒻及蒟蒻水解物組高於纖維素組。在第2週時蒟蒻及其水解產物組明顯提高盲腸內容物中總厭氧菌(Total anaerobes)及雙歧桿菌(Bifidobacterium spp.)菌數，並可抑制大腸桿菌(E.coli)菌數，但對產氣莢膜梭菌(Clostridium perfringens)菌數則無顯著變化。在第4週時，蒟蒻及其水解產物組也明顯提高盲腸內容物中Total anaerobes及Bifidobacterium spp.菌數，並可有效抑制Clostridium perfringens之生長，但不影響E.coli菌數。在血脂濃度方面，在第4週時，蒟蒻水解產物對降低血清總膽固醇及低密度膽固醇濃度有顯著效果，並有降低三酸甘油酯和磷脂質的趨勢。 在劑量實驗方面發現，7.5%劑量對改善腸道菌相最具有顯著之效果。 綜上所述，當攝取蒟蒻及其水解產物達四週時，可有效的改善腸道菌相、促進糞便保水能力以及顯著降低血清總膽固醇及低密度膽固醇濃度，並有降低三酸甘油酯和磷脂質的趨勢。在改善腸道菌相以劑量為7.5%最具有顯著效果。且蒟蒻水解產物效應較蒟蒻明顯或持久。
並列摘要
The aim of this study is to investigate the effects of Amorphophallus konjac and its hydrolysates on bowel habits, fecal characteristics, food intake, body weight change, lipid metabolism and intestinal hydrolase activities of BALB/c mice. The time-dependent effects of cellulose (C), konjac (K) and konjac hydrolysates (KH) were first investigated. 7 wk mice were randomly allocated to 5% cellulose diet (2 or 4 wk feeding), 5% konjac diet (2 or 4 wk feeding) and 5% konjac hydrolysates diet (2 or 4 wk feeding). We have found that various diets did not cause differences in the daily food intake, body weight gain and intestinal hydrolase activities at both 2 wk and 4 wk duration. Wet, dry fecal weights and number of fecal pellets in the descending order was cellulose group > konjac group > konjac hydrolysates group. The concentration of Bifodobacterium spp. tended to increase at 2 wk. The concentrations of Clostridium perfringens were decreased by feeding mice with konjac hydrolysates diet at 4 wk. Furthermore, Bifidobacterium spp. became predominant anaerobes after mice were fed on konjac hydrolysates diets for 4 wk. In the lipid metabolism, konjac hydrolysates diets for 4 wk. can decrease serum total and LDL cholesterol, and tend to decrease triacylglycerol and phospholipid. In the dose-response experiments, we have found the effects of 7.5% dose were greater than 2.5 % and 5% konjac or its hydrolysates. In conclusion, konjac and its hydrolysates can improve bowel habits, fecal moisture, and lipid metabolism. The effects of 7.5% dose were greater than that of 2.5 % or 5% konjac or its hydrolysates. And the effects of konjac hydrolysates were better than konjac.