嗜酸乳桿菌在培養基中降低膽固醇之能力   全文下載

Reduction of Cholesterol by Lactobacillus acidophilus in Culture Broth

以六株嗜酸乳桿菌包括ATCC 4356 、B 、E 、Farr 、LA-1 及N-1 探討在試管試驗中降低膽固醇之能力。實驗結果發現，雖然降低膽固醇之程度不同，但所有的測試菌株在液體培養基系統中皆表現出降低膽固醇之能力，在這些測試菌株中，ATCC 4356 表現出最好的膽固醇降低能力，可降低57 ? 71 ％之膽固醇。在對酸及膽鹽的耐受測試中發現，嗜酸乳桿菌可耐受酸及膽鹽之存在。而在酸性的條件下，膽固醇雖會與去結合型膽鹽產生共同沉澱而導致試管試驗中膽固醇之降低，然而由於人體小腸環境為偏微鹼性，此共同沉澱不會發生。而本實驗中發現，以不會與膽固醇發生沉澱的牛磺膽酸作為膽鹽來源時，嗜酸乳桿菌仍可降低膽固醇，因此在其他活體實驗中所發現之嗜酸乳桿菌所具之降低膽固醇能力，推論是由於菌體可同化膽固醇或膽固醇可附著於菌體表面隨著糞便排出之故。

Cholesterol reducing abilities of six strains of Lactobacillus acidophilus including ATCC 4356, B, E, Farr, LA-1 and N-1 were investigated in vitro. All these strains were able to reduce cholesterol at various levels in the broth system used in this study. Among the strains tested, L. acidophilus ATCC 4356 demonstrated the best cholesterol reducing ability at 57 and 71% in the presence of oxgall and cholic acid, respectively, in the broth. Results from the acid tolerance and growth in oxgall studies demonstrated that these L. acidophilus strains would likely survive in the human gastrointestinal tract, where acid and oxgall are present in the stomach and small intestine. Coprecipitation, which was observed in the presence of cholic acid, of cholesterol with deconjugated bile at acidic pH contributed to the reduction of cholesterol in vitro. However, coprecipitation is not likely to take place in vivo since the pH in the small intestine is higher than neutral. Results from this study indicate that the in vivo hypocholesteremic ability is likely due to the assimilation of cholesterol by L. acidophilus cells or/and attachment of cholesterol to the surface of L. acidophilus cells. 以六株嗜酸乳桿菌包括ATCC 4356 、B 、E 、Farr 、LA-1 及N-1 探討在試管試驗中降低膽固醇之能力。實驗結果發現，雖然降低膽固醇之程度不同，但所有的測試菌株在液體培養基系統中皆表現出降低膽固醇之能力，在這些測試菌株中，ATCC 4356 表現出最好的膽固醇降低能力，可降低57 ∼ 71 ％之膽固醇。在對酸及膽鹽的耐受測試中發現，嗜酸乳桿菌可耐受酸及膽鹽之存在。而在酸性的條件下，膽固醇雖會與去結合型膽鹽產生共同沉澱而導致試管試驗中膽固醇之降低，然而由於人體小腸環境為偏微鹼性，此共同沉澱不會發生。而本實驗中發現，以不會與膽固醇發生沉澱的牛磺膽酸作為膽鹽來源時，嗜酸乳桿菌仍可降低膽固醇，因此在其他活體實驗中所發現之嗜酸乳桿菌所具之降低膽固醇能力，推論是由於菌體可同化膽固醇或膽固醇可附著於菌體表面隨著糞便排出之故。