植物乳杆菌PUM1785抑菌作用及耐胆盐和耐盐性能

目的 通过分析植物乳杆菌PUM1785体外抑菌活性和部分耐受能力,为进一步研发乳杆菌微生态制剂提供理论和数据支持。 方法 以模式菌株WCSF1为对照株,采用双层琼脂点种法进行体外抑菌试验,并开展高胆盐、高盐环境耐受试验。 结果 植物乳杆菌PUM1785体外抑菌活性与模式菌株相近,对6种常见致病菌均有较强的抑制作用,对革兰阴性菌的抑菌效果优于革兰阳性菌。在不同浓度胆盐溶液中培养24 h后,2株乳杆菌生长均受抑制,当胆盐浓度从0 g/100 mL持续增至0.5 g/100 mL后,2株乳杆菌活菌数量呈下降趋势,但始终维持在105 CFU/mL数量级以上,并且PUM1785与WCSF1活菌数量比呈上升趋势;在不同浓度的NaCl溶液中培养24 h后,2株乳杆菌均生长良好,当NaCl浓度从0 g/100 mL升高到8 g/100 mL时,2株乳杆菌活菌数始终维持在108 CFU/mL数量级以上,并且PUM1785与WCSF1活菌数量比呈明显上升趋势。 结论 植物乳杆菌PUM1785具有与模式菌株相近的抑菌活性,对胆盐和高盐环境耐受力均强于模式菌株,表明PUM1785具有良好的生物学特性,可以作为微生态制剂研发的候选菌株。     

鼠李糖乳酪杆菌RH0121冻干工艺优化及降血糖作用的研究

优化鼠李糖乳酪杆菌（Lacticaseibacillus rhamnosus）RH0121的冻干工艺,探究其辅助降血糖作用。

通过单因素试验和响应面试验,优化鼠李糖乳酪杆菌RH0121冻干粉的生产工艺;同时利用小鼠实验,探究服用冻干粉后小鼠的体质量、口服葡萄糖耐量和血清生化指标水平的变化。

优化后的工艺为发酵时间9 h,发酵温度37 ℃,接种量4%,冻干时间50 h。经验证,冻干粉活菌数为5.5×10¹¹ CFU/g。灌胃冻干粉样品后的小鼠体质量缓慢回升,小鼠灌胃后120 min血糖水平低于灌胃前（P＜0.05）。灌胃后,样品组小鼠血清TC、TG、LDL和TNF-α水平均低于模型组,INS水平高于模型组（均P＜0.05）。

鼠李糖乳酪杆菌RH0121具有辅助降血糖作用,可为开发其他降血糖产品提供原料。

     

具有分解嘌呤核苷能力的益生菌菌株筛选

在不同的肠道菌群及奶制品样品中筛选益生菌菌株,对其耐酸和耐胆盐能力、分解嘌呤核苷能力进行评价,为后续研发治疗高尿酸血症益生菌制剂提供依据。

采集内蒙古地区及巴马长寿村的健康婴儿肠道菌群或奶豆腐、奶疙瘩制品,通过选择性培养基划线培养、镜检及16S rDNA测序的方式筛选益生菌菌株。通过耐酸、耐胆盐试验,模拟胃液和模拟肠液筛选出对胃肠道环境耐受能力强的菌株并通过电镜观察其形态。再进一步通过分解嘌呤核苷能力检测确定分解能力最优的菌株。

在8个样本中筛选出23株益生菌,对其胃肠耐受能力进行检测后发现筛选出了8株耐受能力较强的益生菌菌株,分别为鼠李糖乳酪杆菌RH01103,罗伊氏粘液乳杆菌HCS02-001,植物乳植杆菌RH03010,动物双歧杆菌乳亚种RH04020,发酵粘液乳杆菌RH08050,副干酪乳酪杆菌HCS17-040,乳酸片球菌RH27102和戊糖片球菌RH34011。通过对分解嘌呤核苷能力检测,发现与未接种益生菌的空白对照组相比,罗伊氏粘液乳杆菌HCS02-001和副干酪乳酪杆菌HCS17-040对肌苷和鸟苷的分解能力最显著（P = 0.0002, P＜0.0001）。

8个样本筛选出的23株益生菌中罗伊氏乳杆菌HCS02-001和副干酪乳杆菌HCS17-040的胃肠耐受能力最强,分解嘌呤核苷效率最高。

     

不同方案阴道乳杆菌活菌胶囊结合抗菌药物治疗混合性阴道炎的临床研究

研究两种阴道乳杆菌活菌胶囊结合抗菌药物对混合性阴道炎的疗效。

选取2015年4月至2020年12月北京大学第一医院收治的混合性阴道炎患者50例。同时符合以下两项即确诊为混合性阴道炎：（1）阴道分泌物真菌检测阳性;（2）阴道分泌物革兰染色积分法评分（Nugent评分）≥7分;（3）阴道分泌物滴虫镜检阳性。入选患者根据乳杆菌胶囊使用方法分为联合组（25例）及序贯组（25例）,联合组在使用抗菌药物的同时使用阴道乳杆菌活菌胶囊,序贯组在使用抗菌药物结束后序贯使用阴道乳杆菌活菌胶囊。评估两组患者病原体转阴率、症状改善及乳杆菌恢复情况。

序贯组患者综合治愈率高于联合组（56.0% vs 28.0%,P＜0.05）。经过治疗后,联合组有12.0%的患者阴道菌群恢复为形态类似乳杆菌的革兰阳性大杆菌,序贯组有32.0%恢复为形态类似乳杆菌的革兰阳性大杆菌,两组差异无统计学意义（P＞0.05）,但序贯组在趋势上高于联合组。

对于混合性阴道炎的治疗来说,抗菌药物治疗后序贯使用阴道乳杆菌活菌胶囊优于抗菌药物治疗同时联合使用阴道乳杆菌活菌胶囊。

     

两种乳杆菌联用在食蟹猴阴道的定植效率及其毒性分析

研究乳杆菌鼠李糖乳杆菌-格氏乳杆菌联用制剂(LACT)的定植效率, 评估其有效剂量在动物体内的急性和长期毒性。

在食蟹猴中进行2轮阴道定植试验, 通过检测阴道分泌物pH值和清洁度, 并分离鉴定分泌物中的乳杆菌, 确定乳杆菌联用制剂的定植率和定植剂量; 通过单次和多次阴道给药, 检测联用制剂对食蟹猴体质量、食量、生殖器官及生化指标等的影响, 检测联用制剂在体内的急性和长期毒性。

联用制剂在食蟹猴中连续阴道给药5 d后能成功定植, 改善阴道的微生态; 甲硝唑预处理能够提高定植效率和定植时间; 联用制剂对食蟹猴不具有急性和长期的毒性作用。

在动物模型中, 2种乳杆菌联用制剂对细菌性阴道病具有良好的治疗潜质。

     

双歧杆菌乳杆菌三联活菌片对幽门螺杆菌根治后消化道不良反应的改善作用

探讨加用双歧杆菌乳杆菌三联活菌片对临床四联疗法根除幽门螺杆菌(H.pylori)过程中患者消化道不良反应的改善作用。

选择2019年1月至2020年1月在昆明医科大学第二附属医院门诊就诊的100例H.pylori感染患者, 分为益生菌组和正常组, 各50例。全部患者通过四联疗法根除H.pylori后, 益生菌组患者继续加用双歧杆菌乳杆菌三联活菌片治疗, 对结果进行分析。

2组患者使用含有铋剂的四联疗法根除H.pylori后效果满意。益生菌组患者不良反应发生率低于正常组(25.5% vs 47.5%;χ²=11.023, P=0.001)。

益生菌可减轻四联疗法根除H.pylori后消化道不良反应, 根除H.pylori过程中加用益生菌的时机尚待进一步探讨。

     

双歧杆菌三联活菌散/胶囊治疗儿童功能性消化不良的Meta分析

系统评价双歧杆菌三联活菌散/胶囊对儿童功能性消化不良（FD）的治疗作用。

检索中国知网、万方、维普、PubMed、Embase、Web of Science数据库中关于双歧杆菌三联活菌散/胶囊治疗儿童FD的随机对照试验或前瞻性非随机对照试验,检索时间为建库至2022年6月。由两个评价者依据纳入和排除标准分别单独筛选并获得文献和临床资料,采用RevMan 5.3软件进行Meta分析。

纳入9篇文献,共944例患者。Meta分析结果显示,双歧杆菌三联活菌散/胶囊（试验组）治疗儿童功能性消化不良的总有效率显著高于常规治疗（对照组）[OR=4.89,95%CI（3.15～7.59）,P＜0.00001]。试验组患儿治疗后的症状评分、腹痛、腹胀、恶心的消退时间均明显低于对照组（P＜0.05）,而血清胃动素水平显著高于对照组（P＜0.05）。

双歧杆菌三联活菌散/胶囊治疗儿童功能性消化不良效果显著。

     

便秘型肠易激综合征患者肠道菌群变化特点及双歧杆菌四联活菌片的疗效观察

研究便秘型肠易激综合征（IBS-C）患者肠道菌群变化特点,并进一步分析双歧杆菌四联活菌片对其的干预效果。

选取2020年2月至2021年11月于我院消化内科就诊的162例IBS-C患者为研究组;选择同期113例健康体检者作为对照组。采用16S rDNA高通量测序法检测受试者肠道菌群的构成,分析菌群多样性,比较双歧杆菌四联活菌片干预前后IBS-C患者肠道菌群变化特点及便秘症状相关指标变化情况。

研究组患者肠道菌群Ace指数（P=0.001）、Chao指数（P＜0.001）、Shannon指数（P=0.020）、Sobs指数（P＜0.001）均显著低于对照组。在门水平上,研究组患者肠道厚壁菌门和变形菌门的丰度均显著高于对照组,而拟杆菌门丰度均显著低于对照组。双歧杆菌四联活菌片干预后,患者肠道厚壁菌门和变形菌门丰度均显著下降,拟杆菌门丰度显著提高。在属水平上,研究组患者肠道乳杆菌属和双歧杆菌属丰度均显著低于对照组。双歧杆菌四联活菌片干预后,患者肠道乳杆菌属、双歧杆菌属、粪杆菌属丰度均显著上升。干预后IBS-C患者的便秘症状积分（P＜0.001）、GIQLI评分（P＜0.001）、WC评分（P＜0.001）、PAC-QOL评分（P=0.005）均较干预前差异显著,排便次数也显著增加（P＜0.001）。

IBS-C患者肠道菌群显著紊乱,双歧杆菌四联活菌片能在一定程度上调节患者肠道菌群失衡,同时能够改善胃肠道功能,缓解便秘。

     

糖尿病药物那格列奈促进嗜酸乳杆菌生长的作用

系统评价糖尿病药物对乳杆菌属微生物生长的影响,并进一步探讨糖尿病药物促进乳杆菌属微生物生长的作用机制。

利用体外纯培养法评估糖尿病药物对乳杆菌属微生物生长的影响,筛选出具有促进作用的“药菌组合”,并进一步采用非靶向代谢组学技术检测“药菌组合”培养液上清中的代谢物组;采用结晶紫染色法和RT-qPCR法分别检测特定乳杆菌生物膜形成和细菌素生物合成基因的表达。

10种常见糖尿病药物对乳杆菌的生长主要表现为抑制作用,仅那格列奈可在低浓度下刺激嗜酸乳杆菌的生长,促进率达48.30%。“那格列奈―嗜酸乳杆菌组合”培养液上清中共注释到584种已知代谢物,其中差异代谢物有42个,主要富集在氨基酸代谢和生物合成、氨酰t-RNA生物合成和次生代谢产物生物合成等代谢通路上;同时,那格列奈还促进了嗜酸乳杆菌生物膜的形成以及增加了生物膜的黏附性,并上调细菌素合成结构基因的表达（t = 2.373,P = 0.033）。

糖尿病药物对乳杆菌生长普遍具有抑制作用,但那格列奈可通过调节氨基酸代谢和生物合成、促进生物膜的分泌和细菌素的生物合成来刺激嗜酸乳杆菌的生长。

     

模拟人体胃肠道环境筛选益生乳杆菌

【目的】筛选具有益生特性的乳杆菌作为保健型酸奶的候选菌株。【方法】从健康人肠道和奶豆腐中分离筛选出耐受人工胃液的乳杆菌,对其进行体外益生特性(人工胃肠液耐受性、胆盐耐受性、抑菌活性及胆固醇降解能力)研究。【结果】从在乳杆菌分离培养基上有溶钙圈的41株菌株中筛选出5株耐酸、耐人工胃液较强的菌株,经16S rR NA基因测序鉴定,其中3株为乳杆菌,分别命名为植物乳杆菌Lp MT-3、植物乳杆菌Lp MT-5和唾液乳杆菌LsA F-7。在人工胃液中3株菌的耐受力均强于商品化的对照菌株LGG(鼠李糖乳杆菌GG);转入肠液4 h后直至26 h,Lp MT-5存活率基本稳定在45%左右,仅次于LGG。胆盐浓度为0.10%时,3株乳杆菌的耐胆盐能力均强于LGG;胆盐浓度为0.20%时,Lp MT-3和LsA F-7仍能存活。3株乳杆菌均具有抑菌活性,对粪肠球菌的抑制最明显,其次是金黄色葡萄球菌,对大肠杆菌、沙门氏菌的抑制作用较差。3株乳杆菌对胆固醇的清除效力依次为Lp MT-3LpM T-5Ls AF-7;清除率依次为Ls AF-7Lp MT-3LpM T-5。【结论】筛选出3株适应人体胃肠液环境、耐胆盐、抑菌及降胆固醇活力强的乳杆菌,可作为进一步开发新的益生菌产品和保健型酸奶的菌株。     

Single bioreactor gastrointestinal tract simulator for study of survival of probiotic bacteria

The aim of the present study was to design an in vitro model system to evaluate the probiotic potential of food. A single bioreactor system-gastrointestinal tract simulator (GITS) was chosen for process simulation on account of its considerable simplicity compared to multi-vessel systems used in previous studies. The bioreactor was evaluated by studying the viability of four known probiotic bacteria (Lactobacillus acidophilus La-5, Lactobacillus johnsonii NCC 533, Lactobacillus casei strain Shirota, and Lactobacillus rhamnosus GG) as a function of their physiological state. L. acidophilus and L. johnsonii survived in GITS better when introduced at an early stationary or exponential phase compared to being previously stored for 2 weeks at 4 degrees C. These two species were more resistant to bile salts and survived better than L. casei and L. rhamnosus GG. The latter two species gave large losses (up to 6 log) in plate counts independent of growth state due to the bile. However, experiments with some commercial probiotic products containing Lb. GG bacteria showed much better survival compared with model food (modified deMan-Rogosa-Sharpe growth medium), thus demonstrating the influence of the food matrix on the viability of bacteria. The study demonstrated that GITS can be successfully used for evaluation of viability of probiotic bacteria and functionality of probiotic food.     

Bile salt and acid tolerance of Lactobacillus rhamnosus strains isolated from Parmigiano Reggiano cheese

This study aimed to compare phenotypic and genetic characteristics of Lactobacillus rhamnosus strains isolated at the end of the ripening of Parmigiano Reggiano cheese and to investigate an important prerequisite of probiotic interest, such as the capability to survive at low pH and in presence of bile salts. The use of API 50 CH, RAPD-PCR analysis and species-specific PCR allowed to ascertain the identity of 63 L. rhamnosus strains. Three L. rhamnosus strains isolated from Parmigiano Reggiano cheese, L. rhamnosus ATCC 7469T and the commercial strain L. GG were assayed to estimate the resistance to various stress factors reproducing in vitro some conditions of the gastro-intestinal environment such as low pH and different amounts of bile salts and acids. The behaviour of almost all the tested strains isolated from Parmigiano Reggiano cheese resulted analogous to that showed by L. GG.     

Probiotic properties of Lactobacillus strains isolated from the feces of breast-fed infants and Taiwanese pickled cabbage

This study assessed potential probiotic Lactobacillus strains isolated from the feces of breast-fed infants and from Taiwanese pickled cabbage for their possible use in probiotic fermented foods by evaluating their (i) in vitro adhesive ability, resistance to biotic stress, resistance to pathogenic bacteria, and production of β-galactosidase; (ii) milk technological properties; and (iii) in vivo adhesive ability, intestinal survival and microbial changes during and after treatment. Five Lactobacillus isolates identified as Lactobacillus reuteri F03, Lactobacillus paracasei F08, Lactobacillus rhamnosus F14, Lactobacillus plantarum C06, and Lactobacillus acidophilus C11 that showed resistance to gastric juice and bile salts were selected for further evaluation of their probiotic properties. All the strains demonstrated the ability to adhere to Caco-2 cells, particularly, strain L. plantarum C06 and L. reuteri F03 showed satisfactory abilities, which were similar to that of the reference strain L. rhamnosus GG. The strains L. paracasei F08 and L. acidophilus C11 had the highest β-galactosidase activity. Most of the strains were resistant to aminoglycosides and vancomycin but sensitive to ampicillin, erythromycin, and penicillin. All the 5 strains elicited antibacterial activity against both Gram-positive (Bacillus cereus, Listeria monocytogenes and Staphylococcus aureus) and -negative (Escherichia coli and Salmonella enterica) pathogens. Moreover, the strains L. reuteri F03, L. paracasei F08, and L. plantarum C06 could grow rapidly in milk without nutrient supplementation and reached 10? cfu/mL after 24 h of fermentation at 37 °C. The viable cell counts of the 3 strains remained above 10? cfu/mL after 21 d of storage at 4 °C. In the animal feeding trial, the number of intestinal lactobacilli increased significantly after administration of milk fermented with the 3 strains, and the counts of fecal coliforms and Clostridium perfringens were markedly reduced. Lactobacillus strains could also survive in the ileal intestinal tissue of the treated rats. Technologically interesting Lactobacillus isolates may be used in the future as probiotic starter cultures for manufacturing novel fermented foods.     

Taxonomic and strain-specific identification of the probiotic strain Lactobacillus rhamnosus 35 within the Lactobacillus casei group

Lactobacilli are lactic acid bacteria that are widespread in the environment, including the human diet and gastrointestinal tract. Some Lactobacillus strains are regarded as probiotics because they exhibit beneficial health effects on their host. In this study, the long-used probiotic strain Lactobacillus rhamnosus 35 was characterized at a molecular level and compared with seven reference strains from the Lactobacillus casei group. Analysis of rrn operon sequences confirmed that L. rhamnosus 35 indeed belongs to the L. rhamnosus species, and both temporal temperature gradient gel electrophoresis and ribotyping showed that it is closer to the probiotic strain L. rhamnosus ATCC 53103 (also known as L. rhamnosus GG) than to the species type strain. In addition, L. casei ATCC 334 gathered in a coherent cluster with L. paracasei type strains, unlike L. casei ATCC 393, which was closer to L. zeae; this is evidence of the lack of relatedness between the two L. casei strains. Further characterization of the eight strains by pulsed-field gel electrophoresis repetitive DNA element-based PCR identified distinct patterns for each strain, whereas two isolates of L. rhamnosus 35 sampled 40 years apart could not be distinguished. By subtractive hybridization using the L. rhamnosus GG genome as a driver, we were able to isolate five L. rhamnosus 35-specific sequences, including two phage-related ones. The primer pairs designed to amplify these five regions allowed us to develop rapid and highly specific PCR-based identification methods for the probiotic strain L. rhamnosus 35.     

新疆传统发酵乳品中乳酸菌与酵母菌的益生特性

目的 观察新疆传统发酵乳品中分离的14种菌株的生长特点及产酸能力,筛选出具有较强耐胆盐能力,并能在人工胃肠液中存活的菌株。方法 对10株乳酸菌和4株酵母菌进行生长曲线、pH、耐胆盐能力和耐人工胃肠液检测。结果 10株乳酸菌和4株酵母菌具有良好的生长曲线和产酸能力;马乳酒样乳杆菌具有较强的耐胆盐能力;希氏乳杆菌、马乳酒样乳杆菌、乙醇假丝酵母和东方伊萨酵母具有较强的耐人工胃液能力;乳酸乳球菌、哈尔滨乳杆菌、瑞士乳杆菌、马乳酒样乳杆菌、乙醇假丝酵母和东方伊萨酵母具有较强的耐人工肠液能力。结论 10株乳酸菌和4株酵母菌具有优良的益生特性,有望成为益生菌制剂的备用菌株。     

Screening of probiotic activities of forty-seven strains of Lactobacillus spp. by in vitro techniques and evaluation of the colonization ability of five selected strains in humans.

The probiotic potential of 47 selected strains of Lactobacillus spp. was investigated. The strains were examined for resistance to pH 2.5 and 0.3% oxgall, adhesion to Caco-2 cells, and antimicrobial activities against enteric pathogenic bacteria in model systems. From the results obtained in vitro, five strains, Lactobacillus rhamnosus 19070-2, L. reuteri DSM 12246, L. rhamnosus LGG, L. delbrueckii subsp. lactis CHCC 2329, and L. casei subsp. alactus CHCC 3137, were selected for in vivo studies. The daily consumption by 12 healthy volunteers of two doses of 10(10) freeze-dried bacteria of the selected strains for 18 days was followed by a washout period of 17 days. Fecal samples were taken at days 0 and 18 and during the washout period at days 5 and 11. Lactobacillus isolates were initially identified by API 50CHL and internal transcribed spacer PCR, and their identities were confirmed by restriction enzyme analysis in combination with pulsed-field gel electrophoresis. Among the tested strains, L. rhamnosus 19070-2, L. reuteri DSM 12246, and L. rhamnosus LGG were identified most frequently in fecal samples; they were found in 10, 8, and 7 of the 12 samples tested during the intervention period, respectively, whereas reisolations were less frequent in the washout period. The bacteria were reisolated in concentrations from 10(5) to 10(8) cells/g of feces. Survival and reisolation of the bacteria in vivo appeared to be linked to pH tolerance, adhesion, and antimicrobial properties in vitro.     

Impact of environmental and genetic factors on biofilm formation by the probiotic strain Lactobacillus rhamnosus GG

Lactobacillus rhamnosus GG (ATCC 53103) is one of the clinically best-studied probiotic organisms. Moreover, L. rhamnosus GG displays very good in vitro adherence to epithelial cells and mucus. Here, we report that L. rhamnosus GG is able to form biofilms on abiotic surfaces, in contrast to other strains of the Lactobacillus casei group tested under the same conditions. Microtiter plate biofilm assays indicated that in vitro biofilm formation by L. rhamnosus GG is strongly modulated by culture medium factors and conditions related to the gastrointestinal environment, including low pH; high osmolarity; and the presence of bile, mucins, and nondigestible polysaccharides. Additionally, phenotypic analysis of mutants affected in exopolysaccharides (wzb), lipoteichoic acid (dltD), and central metabolism (luxS) showed their relative importance in biofilm formation by L. rhamnosus GG.     

Removal of microcystin-LR by strains of metabolically active probiotic bacteria

The ability of specific strains of probiotic bacteria to remove the cyanobacterial peptide toxin microcystin-LR from aqueous solutions was assessed. Lactobacillus rhamnosus strains GG and LC-705, Bifidobacterium longum 46, Bifidobacterium lactis 420 and Bifidobacterium lactis Bb12 were shown to be the most effective in toxin removal among 11 tested strains. The highest removal percentage of microcystin-LR was 58.1%, observed with B. lactis Bb12 (toxin concentration 100 microg L(-1), 10(10) CFU mL(-1), 37 degrees C, 24 h). Freshly cultured bacteria were shown to be more efficient in microcystin removal than lyophilized or nonviable bacteria. Removal of microcystin-LR was shown to be dependent on both temperature and bacterial concentration. It is concluded that some of the tested strains have good potential in removing microcystins from aqueous solutions.