Strain-specific effect of Streptococcus thermophilus consumption on host physiology

Streptococcus thermophilus is one of the most prevalent species in stool samples of westernized populations due to continuous exposure to fermented dairy products.However,few studies have explored the effect on host physiology by multiple S.thermophilus strains and considered the inter-strain differences in regulating host.In the present study,we investigated how four S.thermophilus strains influenced the gut microbiota,mucin changes,and host metabolism after 28 days of intervention in conventional mice.The results indicated that the consumption of S.thermophilus affected the host with strain specificity.Among four S.thermophilus strains,DYNDL13-4 and DQHXNQ38M61,especially DQHXNQ38M61,had more effect on host physiology by modulating gut microbiota and host metabolism than LMD9 and 4M6.Ingestion of strains DYNDL13-4 and DQHXNQ38M61 resulted in more remarkable changes in amino acid metabolism and lipid metabolism than that of strains LMD9 and 4M6,which may be related to the elevation of intestinal Bifidobacterium by DYNDL13-4 and DQHXNQ38M61.The enriched Coriobacteriaceae UCG-002,Rikenellaceae RC9 gut group,and Lactobacillus only in the DQHXNQ38M61 group,had a close relationship with the prominent effect of DQHXNQ38M61 on regulating amino acid and lipid metabolism.In addition,DQHXNQ38M61 had a strong influence on degrading colonic mucin fucose by decreasedα-fucosidase activity in feces,and improving mucin sulfation by upregulated Gal3ST2 expression.Comparative genomic analysis revealed that the four S.thermophilus strains belonged to different branches in the phylogenetic tree,and DYNDL13-4 and DQHXNQ38M61 had more genes involved in carbohydrate metabolism,amino acid metabolism,membrane transport,and signal transduction,which may confer the capacity of nutrient utilization and gastrointestinal adaptation of the strains and be associated with their strong regulation in host.Our study provides valuable information for understanding the regulation of host metabolism after consuming different S.thermophilus strains and could facilitate potential personalized applications of S.thermophilus based on strain varieties.

益生菌Lactobacillus plantarum P8与Streptococcus thermophilus混合发酵对发酵乳品质的影响

将益生菌Lactobacillus plantarum P8以不同接种比例分别与Streptococcus thermophilus ND03、ND05和ND07复配发酵牛乳,并以S.ther-mophilus单菌发酵为对照。于0 h、发酵结束(pH=4.5)及4℃冷藏24 h,分别测定发酵乳样品的发酵时间,及pH值、黏度、脱水收缩率和活菌数并进行感官鉴评。结果表明,L.plantarum P8与S.thermophilus ND03复配,发酵时间显著高于其他组,各组样品黏度和脱水收缩率差异不显著;L.plantarum P8与S.thermophilus ND05分别以5×106mL-1接种1∶1复配时,样品中L.plantarum P8的活菌数为5.26×107mL-1,酸度适宜,无乳清析出,有良好的黏度,产品风味较好,将该组合应用于发酵乳生产,较可行。

基因组分析揭示Streptococcus thermophilus ND-07富产胞外多糖分子机制

Streptococcus thermophilus ND-07分离自青海地区自然发酵酸牦牛奶样品,通过与商业发酵剂菌株进行发酵特性的比较,发现Streptococcus thermophilus ND-07具有优良的发酵特性,特别是具有富产胞外多糖的能力。为了深入分析Streptococcus thermophilus ND-07富产胞外多糖的分子机制,本研究利用Pac Bio RS II三代测序平台完成了Streptococcus thermophilus ND-07全基因组测序。Streptococcus thermophilus ND-07基因组全长为1,869,510-bp,编码2,095个基因。比较基因组分析发现,Streptococcus thermophilus ND-07基因组含有一个20.5-kb的胞外多糖基因簇,其中包括两对决定胞外多糖链长度的eps C-epsD基因,表明Streptococcus thermophilus ND-07可以产生两种胞外多糖:荚膜多糖和黏液多糖。本研究在分子水平上揭示了Streptococcus thermophilus ND-07富产胞外多糖的机制,为Streptococcus thermophilus ND-07的工业化应用奠定了基础。

Lactobacillus delbrueckii subsp. bulgaricus和Streptococcus thermophilus接种比例对Bifidobacterium lactis益生菌发酵乳品质的影响

将Lactobacillus delbrueckii subsp.bulgaricus ND02(LB-ND02)和Streptococcus thermophilus ND03(ST-ND03)按1∶1、1∶10、1∶100、1∶1000接种于脱脂乳中,同时接入益生菌Bifidobacterium lactis V9(B.lactis V9,接种量为2.0×107g-1),于42℃进行发酵。通过对发酵及贮藏过程中发酵乳指标的测定,评价LB-ND02和ST-ND03的接种比例对发酵乳品质的影响。结果表明,随着LB-ND02接种比例减小,凝乳时间显著延长,B.lactis V9活菌数显著提高。4℃贮藏28 d后,随LB-ND02接种比例减小,B.lactis V9存活率差异显著,后酸化也显著减弱。研究发现,LB-ND02和ST-ND03的接种比例,显著影响发酵乳的发酵时间、B.lactis V9活菌数、后酸化及黏度。

抗噬菌体嗜热链球菌突变菌株Streptococcus thermophilus-21UD的选育

以高密度噬菌体培养处理嗜热链球菌菌株,筛选出1株噬菌体抗性菌株S-18,但其产酸、产黏、产香能力不如原菌株。通过照射距离20cm,照射时间60s的紫外线诱变和DES振荡70min的复合诱变,得到SUD-21菌株,其产酸力较敏感菌株提高了0.5%,产黏性提高了0.8%,产乙醛能力提高了0.2%,产丁二酮能力提高了0.1%,且具有遗传稳定性和抗109pfu/mL噬菌体浓度的能力。

Streptococcus thermophilus S10复合Lactobacillus plantarum P-8在发酵豆乳中的应用

以商业豆乳发酵剂A和B为对照组,Streptococcus thermophilus S10和Lactobacillus plantarum P-8(S10+P-8)复合发酵豆乳为实验组,对42℃发酵过程及4℃贮藏期间活菌数、酸度、黏度、持水性、活性大豆异黄酮含量、基本味觉特征和质构特性进行测定,对感官进行品鉴。结果表明:3种样品到达发酵终点的时间、酸度、黏度和持水性差异不显著;发酵结束后,实验组和发酵剂A组样品中活性大豆异黄酮含量变化显著(P <0. 05);发酵完成到贮藏结束实验组样品益生菌Lactobacillus plantarum P-8活菌数高于1. 0×109CFU/g;贮藏结束时,样品pH在4. 30左右,滴定酸度均低于74. 00°T; 6种基本滋味和3种回味的相对强度及差异性分析表明:3种样品的苦味、涩味、咸味和甜味差异显著(P <0. 05);贮藏过程中,实验组感官得分显著高于对照组(P <0. 05),28 d时为93. 7分。豆乳发酵剂S10+P-8在发酵豆乳制品开发中具有良好的应用潜力。

多个Y-STR等位基因缺失及AZF分析

本文探讨多个Y-STR基因座等位基因分型缺失特点及其与AZF(无精子因子)缺失相关性,为法医学应用提供参考。使用Y-STR试剂盒(Yfller Platinum、SureID PathFinder Plus)对23461份男性家系个体血样分析,发现4个及4个以上Y-STR分型缺失样本共14例,使用Y染色体微缺失检测试剂盒检测序列标签位点(sequence-tagged site,STS),根据缺失STS,评价样本Y染色体AZF区缺失情况。结果显示:多个Y-STR分型缺失比例为0.0597%(14/23461),短臂1例,长臂13例,来自不同家系,分型互不相同;13例长臂多个分型缺失样本在AZF区均检出STS缺失,1例短臂多个分型缺失样本未检见异常。本研究提示发生于Y染色体长臂多个STR分型缺失与AZF区微缺失存在对应性,该类分型个体存在不育的生物学基础。

Therapeutic effect of Streptococcus thermophilus CRL 1190-fermented milk on chronic gastritis

AIM: To investigate the potential therapeutic effect of exopolysaccharide (EPS)-producing Streptococcus thermophilus (S. thermophilus) CRL 1190 fermented milk on chronic gastritis in Balb/c mice. METHODS: Balb/c mice were fed with the fermented milk for 7 d after inducing gastritis with acetyl-salicylic acid (ASA, 400 mg/kg body weight per day for 10 d). Omeprazole was included in this study as a positive therapeutic control. The gastric in? ammatory activity was evaluated from gastric histology and in? ammation score, number of interleukin-10 (IL-10), interferon-γ (INFγ) and tumor necrosis factor-α (TNF-α) cytokine-producing cells in the gastric mucosa, and thickness of the mucus layer. RESULTS: Animals receiving treatment with the EPS-producing S. thermophilus CRL 1190 fermented milk showed a conserved gastric mucosa structure similar to that of healthy animals. In? ammation scores of the fermented milk-treated mice were lower than those of mice in the gastritis group (0.2 ± 0.03 vs 2.0 ± 0.6, P < 0.05). A marked decrease in INFγ+ (15 ± 1.0 vs 28 ± 1.2, P < 0.05) and TNF-α+ (16 ± 3.0 vs 33 ± 3.0, P < 0.05) cells and an increase in IL-10+ (28 ± 1.5 vs 14 ± 1.3, P < 0.05) cells compared to the gastritis group, was observed. Also, an increase in the thickness of the mucus gel layer (2.2 ± 0.6 vs 1.0 ± 0.3; 5.1 ± 0.8 vs 1.5 ± 0.4 in the corpus and antrum mucosa, respectively, P < 0.05) compared with the gastritis group was noted. A milk suspension of the purif ied EPS from S. thermophilus CRL1190 was also effective as therapy for gastritis.

多拷贝Y-STR基因座突变分析1例

使用ABI Yfi ler华夏白金、中德美联AGCU Y SUPP Plus、SureID PathFinder Plus三种试剂盒对一四代家系中的五例样本进行检验和复核,获得样本Y-STR分型,发现其中1例样本与其他4例样本在DYF387S1、DYS527、DYF404S1、DYS459共4个基因座分型不同,共计11个步长,其他样本上述基因座均为“两条带”,而该样本均为“一条带”,不符合逐步突变模型。对该样本Y染色体序列标签位点检测发现,样本Y染色体AZFc区部分缺失(gr/gr),结合家系遗传结构图,分析认为系父-子遗传时发生片断缺失。AZFc区的部分缺失突变会导致位于该区域的DYF387S1等多个多拷贝基因座分型与家系样本分型不一致,实际工作中应引起重视,必要时可对样本进行Y染色体STS检测,为Y分型家系排查提供科学依据。

Influence of Ethanol on Probiotic and Culture Bacteria <i>Lactobacillus bulgaricus</i>and <i>Streptococcus thermophilus</i>within a Therapeutic Product

Probiotic bacteria in plain yogurt namely of Lactobacillus ssp. have been reported to treat thrush, diarrhea, athlete’s foot, jock itch and vaginal yeast infections. Lactobacillus delbrueckii ssp. bulgarius (LB-12) and Streptococcus thermophilus (ST-M5) are lactic acid bacteria widely used in the manufacture of yogurt. Alcohol is used in manufacture of some medications such as cough syrups and some products such as eggnog and rum-raisin ice cream. The objectives were to study the effect of food grade ethanol on the growth of yogurt culture bacteria and the physico-chemical characteristics of therapeutic yogurt. The treatments were 0% (control), 2.5%, 5%, and 7.5% v/v ethanol in plain yogurt. The ethanol was incorporated by stirring it into one day old plain yogurt. Product characteristics were studied weekly for a month of refrigerated (4?C) storage. Data were analyzed using Proc Mixed model of Statistical Analysis System. The ethanol amount × storage period interaction effect was significant for Lactobacillus bulgaricus counts while the ethanol amount × storage period effect was not significant for Streptococcus thermophilus counts, viscosity, pH and titratable acidity (TA). Therapeutic yogurts with ethanol, at these concentrations, can successfully be manufactured without adversely influencing counts of its probiotic bacteria over product shelf life.

应用STR荧光标记分析烟台地区草莓种质资源遗传多样性

本研究以烟台地区1份野生草莓种质和6份常规栽培品种为试材,选取已发表具有扩增多态性的11对STR荧光标记引物进行扩增,采用多重荧光毛细管电泳检测,分析了该地区草莓种质的遗传多样性,并构建了其分子身份证.结果表明,用这11对引物从7份草莓种质中共检测到60个STR等位基因位点,平均每对引物5.45个,扩增片段长度在90~270 bp之间,多态信息含量平均为0.676,可用于草莓种质的多态性检测.聚类分析显示7份草莓种质间的遗传相似系数为0.077~0.842,在遗传相似系数为0.257时,7份种质被分为3个类群,W1(野生草莓)与S2(丰香种质)同源性较高.对7份草莓种质进行不同等位基因编码,构建了分子身份证.本研究结果可为烟台地区草莓种质资源鉴定、保护和开发利用提供重要依据.

食管鳞癌组织中STR基因座和Amelogenin基因座的变异分析

目的:探究食管鳞癌组织中21个常染色体STR基因座及Amelogenin基因座变异情况。方法:收集89例食管鳞癌患者的新鲜肿瘤组织及对照组织,采用酚氯仿法提取组织基因组DNA。利用AGCU Expressmarker 22荧光检测试剂盒对提取的基因组DNA进行PCR扩增,AB3500遗传分析仪对PCR扩增产物进行毛细管电泳,通过GeneMapper® ID-X软件进行STR分型。结果:在89例食管鳞癌患者肿瘤样本中,检出26例STR基因型变异(STR_(GA)),占样本总数的29%,新等位基因(A_(new))、增加的等位基因(A_(add))、完全杂合性丢失(cLOH)和部分杂合性丢失(pLOH)4种变异类型均被检出,同时观察到D21S11、D12S391、vWA、FGA和D18S51基因座发生STR基因型变异频次最高,仅在D13S317、D2S441、TH01、D10S1248和Amelogenin等5个基因座未观察到STR基因型变异;本次研究采用的21个常染色体基因座中有17个出现STR基因型变异,且观察到2例肿瘤组织在多个基因座检出STR基因型变异。结论:法医DNA鉴定中常用的17个常染色体STR基因座用于食管鳞癌肿瘤组织的个体识别时,出现和对照组织分型不一致的结果,应慎重下结论。同时,STR遗传标记在食管鳞癌的临床诊疗中有一定应用潜力。

Streptococcus thermophilus IMAU20551胞外多糖基因簇及其表达分析

以1株产胞外多糖(exopolysaccharide,EPS)的嗜热链球菌(Streptococcus thermophilus)IMAU20551为研究对象,提取其DNA后采用Illumina HiSeq技术对DNA进行二代基因组重测序,并利用SOAPdenovo软件对其进行组装,通过与RAST、直系同源集、基因本体论、京都基因与基因组百科全书等数据库进行比对,注释基因组中功能基因。发现S.thermophilus IMAU20551基因组全长1725107 bp,共注释出1884个功能基因,其中包含一个长度为19376 bp的完整eps基因簇,该基因簇中与EPS合成相关的基因共有18个,主要包括epsA、epsB、epsC、epsD、epsE、eps1F、eps2F、epsJ、wzx、epsP和epsX等,这些基因分别对EPS的合成、组装以及转运输出进行调控。另一方面,利用实时聚合酶链式反应对S.thermophilus IMAU20551 eps基因簇表达进行验证,发现所有基因均可表达,且除个别糖基转移酶基因外,其他被测基因均在6 h达到最大表达量。本研究介绍了S.thermophilus IMAU20551的基因组特征、eps基因簇及其表达能力,为今后深入研究S.thermophilus EPS基因簇及其表征结构的互作关系奠定基础。

Microreader^(TM)23HS Plex ID System中23个常染色体STR基因座在中国北方汉族人群中多态性调查

目的评价Microreader^(TM)23HS Plex ID System试剂盒中包含的23个常染色体STR基因座在中国北方汉族人群中等位基因频率分布,获得群体遗传数据,探究其在法医学中的应用价值。方法使用Microreader^(TM)23HS Plex ID System试剂盒对中国北方汉族人群548例无关样本DNA进行检测,收集分型数据,计算各基因座的等位基因频率、样本的杂合度(heterozygosity,H)、这些常染色体STR基因座的多态信息含量(polymorphism information content,PIC)、个体识别力(power of discrimination,DP)和非父排除率(probability of paternity exclusion,PE)并使用统计软件对各基因座是否符合Hardy-Weinberg平衡进行检验;同时对Microreader^(TM)23HS Plex ID System的累积个体识别能力(CDP)和累积非父排除率(CPE)进行计算。结果在548例无关样本中23个STR基因座共计检出260个等位基因,等位基因频率为0.0009~0.5902,H为0.611~0.885,PIC为0.577~0.864,DP为0.815~0.973(平均DP为0.922),PE为0.089~0.406,CDP=1-3.663×10^(-27),CPE=1-2.668×10^(-16),所有基因座等位基因的分布符合Hardy-Weinberg平衡。结论Microreader^(TM)23HS Plex ID System的23个基因座在中国北方汉族人群中具有良好的多态性,在法医学个人识别、群体遗传学研究、亲子鉴定,特别是复杂亲缘关系鉴定中应用价值较高。

应用STR荧光标记分析烟台地区菊花种质资源遗传多样性

【目的】探明烟台地区菊花种质资源的遗传多样性,为烟台地区菊花种质的分类鉴别、资源保护及品种培育提供依据。【方法】应用荧光STR分子标记和毛细管电泳检测技术分析烟台地区非洲菊、秋菊、洋甘菊等12份菊花种质,结合主要表型性状观察进行聚类分析并构建分子身份证。【结果】10对引物共检测到103个STR等位基因位点,平均每对引物的位点数10.3个,扩增片段长度在118~376 bp之间,引物多态性信息(PIC)平均0.795 8。聚类分析依照遗传相似系数将12份菊花种质分为四大类,其中,Ⅰ类群包括秋菊、雏菊、野菊(1)、杭菊(白)、杭菊(黄)、翠菊、野菊(2)共7份种质,占总数的58.3%,含大菊1份、小菊6份,平瓣2份、匙瓣3份、管瓣2份;Ⅱ类群包括非洲菊、洋甘菊2份种质,占总数的16.7%,花瓣类型均为平瓣;Ⅲ类群仅杭菊(紫)1份种质,占总数的8.3%;Ⅳ类群包括一年蓬、野菊(3)2份种质,占总数的16.7%,均为小菊、平瓣花。不同花色、花序大小、花瓣类型的种质存在交叉聚集现象。【结论】烟台地区菊花种质具有较好的遗传多样性,STR荧光标记可有效分析该类种质资源,基于STR分子手段构建了12份菊花种质资源的分子身份证。

Influence of “Mild” Sonication Conditions on the Characteristics of <i>Streptococcus thermophilus</i>ST-M5

Mild sonication intensity is an acoustic energy which involves the conversion of electrical signal into a physical vibration modifying the permeability of the cell plasma membrane. The objective of this study was to determine the effect of mild sonication intensities at different temperatures on growth, bile tolerance and protease activity of Streptococcus thermophilus. The treatments were four mild sonication intensities (8.07, 14.68, 19.83 and 23.55 W/cm2) randomized at three different temperatures (4°C, 22°C and 40°C). The energy input (1500 J) was kept constant in all treatments. Control samples did not receive any sonication treatment. Growth and bile tolerance were determined every two hours for 12 h of incubation. Protease activity was determined at 0, 12 and 24 h. Mild sonication conditions included a) mild sonication intensities, b) temperatures and c) times, all three of which played a role in influencing the desirable attributes of Streptococcus salivarius ssp. thermophilus ST-M5. Of all the mild sonication intensities studied, 14.68 W/cm2 had the best overall influence at certain time points for improving bile tolerance and growth at 4°C, growth at 22°C and bile tolerance and growth at 40°C of Streptococcus salivarius ssp. thermophilus ST-M5. Mild sonication intensity of 23.55 W/cm2 had the overall best influence at certain time points for protease activity of Streptococcus salivarius ssp. thermophilus ST-M5 at 40°C. Streptococcus thermophilus ST-M5 pretreatment with some mild sonication conditions can be recommended for improvement of some of its characteristics.

Influence of Medicinal Spices on the Acid Tolerance of a Health Beneficial Bacterium <i>Streptococcus thermophilus</i>ST-M5

There is a great deal of public interest in the use of herbal remedies. Garlic is said to antiviral and antifungal and along with ginger;they are antibacterial and preventatives for cardiovascular diseases. Ginger is very effective against nausea and has analgesic properties. Onion reduces the risk of developing diabetes and like garlic, has anticancer properties. Streptococcus thermophilus is a lactic acid bacterium that produces lactase, which facilitates the digestion of lactose in milk, decreases the symptoms of malabsorption, and reduces the risk of antibiotic associated diarrhea. Acid tolerance is an important probiotic characteristic and it is an indication of the ability of the microorganism to withstand the acidic pH of the stomach. Freshly thawed culture was inoculated in acidified MRS broth at pH 2 and 1% v/v of freshly ex-tracted spice juice was added. Control was without spice juice. Growth was determined hourly during 2 hours of incu-bation at 37?C. Bacterial culture treated with all three spices individually showed a significant increase in counts at 0 and 1 hours of incubation when compared to control. After 2 hours of incubation, culture exposed to ginger showed no significant difference compared to control, while there were slight yet significantly lower counts for culture exposed to garlic and onion individually. Among the spices, ginger had the best overall effect. These three spices can be used with Streptococcus thermophilus enabling health benefits from both sources.

基于Y-SNP和Y-STR揭示汉族人群父系遗传关系

汉族是中国人口最多的民族,现有研究多集中于汉族人群的起源、迁徙、融合等遗传历史,以及局部地区汉族人群的父系遗传关系,鲜有全局视角下的汉族人群父系遗传结构研究。本研究检测了362份青海、四川和辽宁的汉族无关男性样本,整合已发表文献相关数据,最终获得了国内15个省份16个汉族人群1830人份样本,覆盖89个Y-SNP、16个Y-STR的数据。通过统计Y-SNP单倍群频率、Y-STR单倍型多样性,使用主成分分析(principal component analysis,PCA)、系统发育树、单倍型网络等分析,综合Y-SNP和Y-STR两个反映不同时间尺度的遗传标记,研究不同地区汉族人群之间的遗传分化、汉族人群与其周边少数民族的遗传关系。单倍群频率统计结果显示单倍群O-M175是汉族人群主体单倍群(青海汉族60.53%~广东汉族92.7%),其下游亚单倍群呈现地域差异化分布。单倍群O2-M122高频分布于各地汉族,总体分布趋势北高南低;单倍群O1b-M268分布频率由南向北递减,尤其在岭南地区汉族人群中分布显著;单倍群O1a-M119在中部汉族人群中分布频率较高。汉族人群遗传结构研究表明,其主要分为北部、中部及南部三个聚类簇,其中青海汉族与其他地区汉族存在一定的遗传分化。在合并少数民族的遗传关系研究中,汉族人群彼此之间遗传关系更紧密,但北部汉族与回族遗传关系更近,而南部汉族则与仡佬族、黎族遗传关系更近。总之,本文基于89个Y-SNP和16个Y-STR,系统地研究了中国不同地域的汉族人群的单倍群分布、遗传亚结构及其与周边少数民族的遗传关系,为群体遗传学、法医遗传学补充理论依据,为Y染色体的法医学应用提供数据支撑。Y-SNP单倍群结合Y-STR单倍型对于分析汉族人群遗传亚结构以及法医学应用具有重要作用。

Influence of Different Sterilization Conditions on the Growth and Exopolysaccharide of <i>Streptococcus thermophilus</i>and Co-Cultivation with <i>Lactobacillus delbrueckii</i>subsp. <i>bulgaricus</i>OLL1073R-1

The sterilization conditions between experiment and dairy industrial level are different and concern about influence on product’s qualities. In this study, the fermentation properties of Streptococcus thermophilus, alone and in combination with Lactobacillus delbrueckii subsp. bulgaricus, were evaluated in skim milk that had been subjected to distinct sterilization conditions. Growth, organic acid generation, and EPS production were determined using pasteurized or autoclaved milk. When S. thermophilus was cultivated in pasteurized skim milk, the growth was strain-dependent. On the other hand, growth of S. thermophilus was accelerated in autoclaved milk. Exocellular polysaccharide (EPS) production by L. bulgaricus was not affected by the combination of S. thermophilus strains. Thus, we observed that yogurt fermented by L. bulgaricus was minimally affected by the combination of S. thermophilus strains;growth of L. bulgaricus was maintained under the constant environment. These results should facilitate the development of fermented milk produced from L. bulgaricus in the dairy industry.

Effect of Flaxseed on Bile Tolerances of <i>Lactobacillus acidophilus, Lactobacillus bulgaricus</i>, and <i>Streptococcus thermophilus</i>

Consumption of flaxseed provides health benefits. Bile tolerance allows survival of probiotics in the intestinal tract. The objective was to determine whether or not flaxseed enhances bile tolerance of Lactobacillus acidophilus (L. acidophilus) LA-K, Lactobacillus delbruekii ssp. bulgaricus (L. bulgaricus) LB-12, and Streptococcus salivarius ssp. thermophilus (S. thermophilus) ST-M5. Control and experimental (62 g flaxseed/L) broths containing 0.3% oxgall were prepared for each culture, sterilized, cooled, inoculated, and plated for 8 h. Growth of each microorganism in both the control and experimental broths was evaluated by the slope of the regression line of its log count versus time after inoculation. Flaxseed significantly enhanced growth of L. acidophilus but not L. bulgaricus and S. thermophilus over 8 h compared to its corresponding control. Therefore, flaxseed improved the bile tolerance of L. acidophilus but not of S. thermophilus and L. bulgaricus.