New frontiers in probiotic research

The increasing incidence of antibiotic resistance, coupled with a growing prevalence of cancer and allergic conditions in an aging population, has forced clinical research to explore alternative therapeutic and prophylactic avenues. One such approach involves the use of probiotics: beneficial bacterial cultures, which, when administered as a part of the daily dietary intake, reduce the incidence and severity of acute and chronic infection, facilitate prevention and reduced recurrence of certain cancers and lower the incidence of several atopic conditions. Herein, we review the most recent advances in the emerging area of patho-biotechnology in the context of improving probiotic production, delivery and clinical efficacy, in addition to the emerging area of 'designer probiotics'- strains specifically tailored to target certain pathogens and/or toxins in vivo.     

Optimization of culture conditions of probiotic bifidobacteria for maximal adhesion to hexadecane

Culture growth conditions were optimized for adhesion to hexadecane of the probiotic Bifidobacterium bifidum HI 39 and HI 48. Among three growth media used, MILS lactose broth was the best medium to obtain maximum cell adhesion, followed by MRS and TPY lactose broth for B. bifidum HI 39 and HI 48. Increasing the incubation time from 6 to 18 h resulted in a gradual increase in percentage adhesion at 37 °C of both organisms in MILS, MRS and TPY media. Thereafter, incubation up to 48 h showed a marked reduction in adhesion of B. bifidum HI 39 and B. bifidum HI 48. When the test cultures were grown at pH values from 5.0 to 8.0 in MILS lactose broth at 37 °C for 18 h, there was a gradual enhancement in cell adhesion up to pH 7.0; but higher pH values retarded the bacterial adhesion. The study showed that the optimum conditions for adhesion to hexadecane of the selected bifidobacterial strains were pH 7.0 and incubation at 37 °C for 18 h in MILS broth.     

Characterization of the genus Bifidobacterium by automated ribotyping and 16S rRNA gene sequences

In order to characterize the genus Bifidobacterium, ribopatterns and approximately 500 bp (Escherichia coli positions 27 to 520) of 16S rRNA gene sequences of 28 type strains and 64 reference strains of the genus Bifidobacterium were determined. Ribopatterns obtained from Bifidobacterium strains were divided into nine clusters (clusters I-IX) with a similarity of 60%. Cluster V, containing 17 species, was further subdivided into 22 subclusters with a similarity of 90%. In the genus Bifidobacterium, four groups were shown according to Miyake et al.: (i) the Bifidobacterium longum infantis-longum-suis type group, (ii) the B. catenulatum-pseudocatenulatum group, (iii) the B. gallinarum-saeculare-pullorum group, and (iv) the B. coryneforme-indicum group, which showed higher than 97% similarity of the 16S rRNA gene sequences in each group. Using ribotyping analysis, unique ribopatterns were obtained from these species, and they could be separated by cluster analysis. Ribopatterns of six B. adolescentis strains were separated into different clusters, and also showed diversity in 16S rRNA gene sequences. B. adolescentis consisted of heterogeneous strains. The nine strains of B. pseudolongum subsp. pseudolongum were divided into five subclusters. Each type strain of B. pseudolongum subsp. pseudolongum and B. pseudolongum subsp. globosum and two intermediate groups, which were suggested by Yaeshima et al., consisted of individual clusters. B. animalis subsp. animalis and B. animalis subsp. lactis could not be separated by ribotyping using Eco RI. We conclude that ribotyping is able to provide another characteristic of Bifidobacterium strains in addition to 16S rRNA gene sequence phylogenetic analysis, and this information suggests that ribotyping analysis is a useful tool for the characterization of Bifidobacterium species in combination with other techniques for taxonomic characterization.     

早期益生菌干预联合肠内营养对重型颅脑外伤患者术后胃肠功能和认知功能的改善作用

目的探讨早期益生菌干预联合肠内营养对重型颅脑外伤患者术后胃肠功能和认知功能的改善作用。方法选择80例重型颅脑外伤患者作为研究对象,所有患者均接受手术治疗。回顾性分析患者临床资料,按照是否给予早期益生菌干预分为对照组和观察组,每组各40例。对照组患者术后给予早期肠内营养支持,观察组患者在对照组基础上联合早期益生菌(双歧杆菌乳杆菌三联活菌片)干预。应用简易智力状态检查量表(MMSE)和蒙特利尔认知评估量表(MoCA)评价患者认知功能。比较两组患者营养状况、胃肠道不良反应、胃肠黏膜屏障功能及认知功能。结果与对照组相比,干预后观察组患者白蛋白(g/L)、前白蛋白(g/L)、血红蛋白(g/L)水平升高(34.63±4.79 vs 32.05±3.64,215.56±30.13 vs 201.57±29.47,121.51±13.08 vs 114.90±12.36),胃肠道不良反应发生率升高(37.5%vs 15.0%),D-乳酸(mmol/L)、降钙素原(μg/L)水平降低(1.31±0.38 vs 2.15±0.43,4.20±1.03 vs 6.45±1.16),MMSE评分和MoCA评分升高(24.65±2.08 vs 22.16±1.95,26.61±2.17 vs 24.35±1.83),差异有统计学意义(均P0.05)。结论早期益生菌干预联合肠内营养能够一定程度上改善重型颅脑外伤患者术后的营养状况、胃肠功能和认知功能,值得应用。     

双歧杆菌丝状体生长形态初探

研究双歧杆菌在特定培养条件下生长及增殖模式的变化.采用不同浓度维生素B6和维生素E烟酸酯药敏纸片联合影响双歧杆菌生长,通过革兰染色和原子力显微镜扫描观察双歧杆菌的生长、增殖情况.在维生素B6和维生素E联合作用下,双岐杆菌出现丝状体群集生长的现象,且二分裂增殖方式受到抑制.第1次转种于普通培养基中可保持此种生长增殖方式,但连续转种3次后会恢复常规生长增殖方式.不同浓度维生素B6和维生素E烟酸酯药敏纸片联合可诱生双歧杆菌丝状体.     

口服双歧杆菌活菌散剂治疗急慢性腹泻的随机对照双盲双模拟多中心临床研究

目的 评价口服双歧杆菌活菌散剂治疗肠道菌群失调所致的急慢性腹泻的疗效和安全性.方法 采用阳性药物平行对照、分层区组随机、双盲双模拟、多中心临床试验设计方法.其中急性腹泻136例,慢性腹泻125例;每次口服双歧杆菌活菌散剂1包(1.0 g,含双歧杆菌活菌1.0亿个)或丽珠肠乐胶囊2粒,每日2次;急性腹泻疗程3 d,慢性腹泻疗程14 d,观察治疗后临床症状和大便常规的恢复情况,慢性腹泻中39例进行肠道菌群分析.结果 疗程结束时急性腹泻总有效率:口服双歧杆菌活菌散剂组为89.6%,丽珠肠乐胶囊组为91.2%,2组疗效相似,差异无显著性(P＞0.05);慢性腹泻总有效率:口服双歧杆菌活菌散剂组为88.1%,丽珠肠乐胶囊组为79.0%,2组疗效相似,差异无显著性(P＞0.05);慢性腹泻组中39例治疗前后进行的肠道菌群分析表明,2组双歧杆菌、拟杆菌和真杆菌治疗后比治疗前均有显著增加(P=0.00～0.02),但治疗前后增加值2组间比较差异无显著性(P＞0.05).安全性研究未发现不良反应.结论 口服双歧杆菌活菌散剂能有效治疗急慢性腹泻,疗效和安全性与丽珠肠乐胶囊相当.     

Adhesion of Bifidobacterium spp. to human intestinal mucus

Twenty-four Bifidobacterium strains were examined for their ability to bind to immobilized human and bovine intestinal mucus glycoproteins. Each of the tested bacteria exhibited its characteristic adhesion to human and bovine fecal mucus. No significant differences were found among the taxonomic species. Among the tested bacteria, B. adolescentis, B. angulatum, B. bifidum, B. breve, B. catenulatum, B. infantis, B. longum and B. pseudocatenulatum adhered to human fecal mucus better than bovine fecal mucus, while the binding of B. animalis and B. lactis was not preferential. These results suggest that the mucosal adhesive properties of bifidobacteria may be a strain dependent feature, and the mucosal binding of the human bifidobacteria may be more host specific.     

In vitro Th1 cytokine-independent Th2 suppressive effects of bifidobacteria

A comparison between 17 strains of lactic acid bacteria and 15 strains of bifidobacteria indicated that bifidobacteria induced significantly lower levels of interleukin-12 (IL-12) in murine splenic cells. The present study aims to evaluate the effect and mechanism of Bifidobacterium longum BB536, a probiotic strain, in suppressing antigen-induced Th2 immune response in vitro. BB536 suppressed immunoglobulin (Ig) E and IL-4 production by ovalbumin-sensitized splenic cells, but induction of Th1-inducing cytokine production, such as IL-12 and gamma interferon (IFN-gamma) tended to be lower compared with lactic acid bacteria. Neutralization with antibodies to IL-12, IFN-gamma, IL-10 and transforming growth factor beta indicated negative involvement of Th1-inducing cytokines and regulatory cytokines in the suppression of Th2 immune response by BB536, especially when treated at higher doses of BB536 (>10 microg cells/ml). Furthermore, BB536 induced the maturation of immature bone marrow-derived dendritic cells (BM-DCs), and suppressed antigen-induced IL-4 production mediated by BM-DCs. These results suggested that BB536 suppressed Th2 immune responses, partially independent of Th1-inducing cytokines and independent of regulatory cytokines, mediated by antigen-presenting cells such as dendritic cells.     

冷热两种方法提取的褐藻硫酸多糖促双歧杆菌增殖效果的比较

目的 比较褐灌硫酸多糖（冷提取物ＳＰＣ和热提取物ＳＰＨ）对青春双歧杆菌和婴儿双歧杆菌性外促增殖效果。方法 选用ＢＳ培养基,采取度管法。结果 在实验深度下。ＳＰＣ和ＳＰＨ对两种双歧杆菌增殖均有明显的促进作用。其活菌数,实验组与对照组比,有显著性和非常显著性差异（Ｐ〈０．０５,Ｐ〈０．０５,Ｐ〈０．００１）,且呈量效关系。ＳＰＨ促菌增殖效果优于ＳＰＣ,当浓度为０．５％和１．０％时,具有显著性差异（Ｐ〉