本研究藉由酸耐受性、膽鹽耐受性、膽鹽水解酶活性、去結合膽鹽能力，篩選159株植生型乳酸菌分離株。結果顯示19株乳酸菌分離株可以在pH 2.5酸的環境下三小時。接續在膽鹽環境下培養24小時，結果顯示19株植生型乳酸菌分離株同樣具有於膽鹽環境下存活之能力。19株耐酸、耐膽鹽之植生型乳酸菌分離株進行降低膽固醇試驗，其結果顯示可吸附膽固醇。將膽固醇吸附能力高之12株植生型乳酸菌分離株進行生長中、停滯生長及熱死滅乳酸菌吸附膽固醇能力之檢測，結果顯示生長中植生型乳酸菌吸附膽固醇能力較停滯生長及熱死滅乳酸菌佳。此外，由於具膽鹽水解酶活性之標準菌株其吸附膽固醇能力並不佳，因此初步認定膽鹽水解酶活性與吸附膽固醇能力無相關性，故接續將159株植生型乳酸菌分離株再進行膽鹽水解酶活性、去結合膽鹽能力的篩選。其結果顯示，大部分植生型乳酸菌分離株顯示具有膽鹽水解酶活性，其中12株植生型乳酸菌分離株，具有較高膽鹽水解酶活性，並且藉由此數據進一步證明膽鹽水解酶活性與吸附膽固醇能力無相關性。而去結合膽鹽能力也進一步證明12株植生型乳酸菌分離株具有水解膽鹽之活性。再者，由上述結果篩選出18株具降低膽固醇能力之乳酸菌分離株進行16S rDNA序列分析，結果顯示18株具降低膽固醇能力之分離株皆為乳酸菌株。將上述18株乳酸菌進行對腸腺癌細胞Caco-2、HT-29之吸附能力分析，結果顯示，5株具有高度吸附能力。 Totally 159 strains of lactic acid bacteria (LAB) were screened for their acid tolerance, bile tolerance, bile salt hydroxylase (BSH) activity and bile salt deconjuation ability. Among them 19 strains showed tolerance to pH 2.5 for 3 hrs. The 19 strains showed similar growth in the tolerance against bile salts and without bile salt. Cholesterol assimilation as determined by the difference in cholesterol content before and after incubation period showed that all 19 strains of LAB were able to assimilate cholesterol. Cholesterol removal was associated with growth of culture than resting and heat-killed cells. All 159 strains of LAB showed varying degree of bile salt hydrolase activity (BSH) and bile salt deconjuagation ability. BSH activity was quantified by determining the amount of glycine liberated from Na-glycocholate. The 12 strains showed higher BSH activity. All 12 strains were able to deconjugate sodim glycocholate and liberate cholic acid. From above results, B0007, B0010, B0011 showed highest cholesterol assimilation, BSH activity and deconjugation ability. Adhesion of LAB to Caco-2 cell line, they showed varying degree of adhesion ability. B0007、B0008、B0009、B0012、B0022、B0023、B0032 were found to adhere to this cell line.
