几种益生元制剂对肠道菌群作用效果的研究

目的探讨几种益生元制剂对肠道菌群作用效果。方法通过体外实验和体内试验。结果低聚果糖、水苏糖、低聚木糖、低聚异麦芽糖均能促进双歧杆菌和乳杆菌的增殖,并能够酸化肠道的pH;能够显著提高肠道的B／E值（肠道内双歧杆菌和肠杆菌数量log值的比值）,增加肠道中有益菌的比例,有益于稳定肠道的微生态平衡。结论这几种益生元制剂对肠道菌群有较好的调节作用。     

大豆多糖对双歧杆菌及人肠道菌群生长的影响

目的研究大豆多糖对双歧杆菌及肠道菌群生长的影响。方法替换Bs培养基中的碳源,分为不加糖、加葡萄糖2％、加大豆多糖2％、加大豆多糖5％、加低聚果糖2％五组,加3种双歧杆菌（长双歧、青春双歧、两歧双歧）菌液1％,测其24h后的活菌数,比较大豆多糖对双歧杆菌生长的影响;替换Bs培养基中的碳源,分为不加糖、加葡萄糖2％、加大豆多糖2％,加低聚果糖2％四组,加人体粪便菌液1％,模拟人体肠道环境厌氧培养24h后,用选择性培养基测其肠杆菌、肠球菌、双歧杆菌、乳酸杆菌的活菌数,观察大豆多糖对人体肠道菌群的影响。结果大豆多糖添加量为5％时对长双歧的促进作用明显优于不加糖组（P〈0．05）;大豆多糖对人体肠道各菌群的生长促进作用与低聚果糖差异无显著性（P〉0．05）。结论大豆多糖对长双歧杆菌的体外促进作用较明显;以粪菌群发酵糖试验表明,大豆多糖对乳杆菌和双歧杆菌均有促进作用,和低聚果糖作用效果相比差异无显著性（P〉0．05）,具有益生元的特性。     

三联益生菌对便秘小鼠肠道推进功能改善及其对小鼠肠道菌群调节作用的研究

目的 研究新型嗜酸乳杆菌NCFM‒乳双歧杆菌Bi-07‒鼠李糖乳杆菌NH001三联益生菌制剂对便秘小鼠小肠蠕动的促进作用,以及其对小鼠肠道菌群构成比例的调节作用。方法 小肠推进率实验：将50只KM小鼠适应性饲养后随机分为空白对照组、模型对照组和低中高三个剂量组。空白对照组和模型对照组给予蒸馏水,低中高剂量组每天分别给予0.165、0.330、0.990 g/（kg•bw）益生菌制剂,灌胃14 d后使用复方地芬诺酯建立小鼠便秘模型观察小肠墨汁推进率;肠道菌群调节作用实验：将42只BALB/c小鼠中随机抽取10只作为自身对比空白组,适应性饲养后将所有小鼠随机分为空白对照组和低中高三个剂量组,空白对照组给予蒸馏水,各剂量组以相同剂量给予益生菌制剂灌胃。自身对比空白组于灌胃前无菌采集小鼠直肠粪便,所有小鼠灌胃30 d后无菌采集直肠粪便,使用16S rDNA基因测序对粪便中菌群DNA进行多样性及各水平菌群物种测定。结果 高剂量组便秘小鼠小肠推进率显著高于模型对照组（P<0.05）;各剂量组肠道菌群多样性、双歧杆菌属、乳杆菌属数量较灌胃前显著增加（P<0.05）,大肠埃希菌属、梭菌属、肠球菌属较灌胃前显著降低（P<0.05）。结论 三联益生菌能够有效促进便秘小鼠肠道蠕动能力,改善便秘症状;同时对小鼠肠道菌群结构有调节作用。     

功能性低聚糖生产工艺的研究现状

功能性低聚糖（functional oligosaccharides）是由2—10个单糖通过糖苷键连接形成直链或支链的一类寡糖,具有低热量、抗龋齿、抗肿瘤、防治糖尿病、防止腹泻和便秘等生理作用。因具有糖类某些共同特性,可作为甜食配料,但人体肠道内不具备分解消化功能性低聚糖的酶系统,所以不被人体胃酸、胃酶降解,不在小肠吸收,直接进入大肠内为双歧杆菌所利用,是一类优良的双歧杆菌增殖因子,故又名双歧因子。功能性低聚糖包括水苏糖、棉子糖、低聚果糖、低聚木糖、低聚半乳糖、大豆低聚糖和低聚异麦芽糖等。近年来,国外上市品种有10多种,生产批量较大,我国自1996年开始才有批量生产,主要以低聚异麦芽糖、低聚果糖和大豆低聚糖为主。本文综述了不同种类的功能性低聚糖及生产工艺的现状。     

低聚木糖对模拟失重大鼠肠道微生态的影响

目的 研究低聚木糖对模拟失重大鼠肠道微生态的影响。方法 采用大鼠尾部悬吊法模拟失重。32只雄性SD大鼠随机分为4组,每组8只：FC组（地面对照组,饲喂基础饲料）,FS组（地面处理组,饲喂添加低聚木糖的饲料）,SC组（尾吊对照组,饲喂基础饲料）。SS组（尾吊处理组,饲喂添加低聚木糖的饲料）,实验21d,SC和SS组解除尾吊继续观察。实验21d。采用选择性培养基对大鼠粪便肠杆菌、肠球菌、类杆菌、双歧杆菌以及乳杆菌进行定量测定。结果 SC组与FC组相比,双歧杆菌数量减少,肠杆菌和肠球菌数量增加;FS组比FC组双歧杆菌数量增加显著,肠杆菌和肠球菌有不同程度的减少,SS组比SC组双歧杆菌数量增加显著,肠杆菌和肠球菌也有不同程度的减少。类杆菌和乳杆菌变化不明显。尾吊解除期,SS组双歧杆菌数量比SC组更快恢复到正常水平。结论 低聚木糖可促进尾吊大鼠肠道益生菌主要是双歧杆菌的增殖,一定程度上促进由于模拟失重造成肠道微生态失调的平衡,并对条件致病菌具有一定的抑制作用。     

益生菌体外增殖因子的初步研究

目的研究单糖、pH、温度及时间对青春双歧杆菌、长双歧杆菌和类干酪乳杆菌体外增殖的影响。方法用甘露糖、半乳糖、山梨醇及果糖代替MRS中的葡萄糖,筛选出每种细菌的最适碳源。以此为基础,选择其最佳初始pH、培养温度、碳源添加量及培养时间。结果青春双歧杆菌、长双歧杆菌和类干酪乳杆菌的最适碳源分别为葡萄糖、甘露糖和半乳糖;最佳初始pH为6.0、7.0和6.0;培养温度为42、30和30℃;碳源添加量为20、15和25 g/L;培养时间都为28-48 h。结论益生菌具有不同的最适增殖条件,本文研究结果为优化益生菌的生长条件提供了基础数据。     

低聚半乳糖对肠道益生菌产胞外多糖作用的研究

旨在研究低聚半乳糖对肠道益生菌产胞外多糖的作用。以低聚半乳糖、葡萄糖、半乳糖和乳糖4种碳源作比较,分别从碳源的利用、胞外多糖的产量和种类及其对有害菌的黏附作用进行研究。结果显示,低聚半乳糖不仅能促进长双歧杆菌和植物乳杆菌的增殖,而且有利于胞外多糖的产生,其含量分别为208.78μg/m L和192.78μg/m L,产生的胞外多糖种类较其他3种碳源更多,对肠道有害菌大肠杆菌具有明显黏附作用。结果证明,与其他3种碳源相比,低聚半乳糖能促进植物乳杆菌和两歧双歧杆菌生成更多的胞外多糖。     

摄入含嗜酸乳杆菌NCFM和乳双歧杆菌Bi-07的益生菌补充剂增强免疫功能的动物实验研究

目的测定与验证摄入含特定乳酸菌株组合（嗜酸乳杆菌NCFM和乳双歧杆菌Bi-07）一定剂量的益生菌补充剂对动物（小鼠）免疫功能的影响。方法SPF昆明种小白鼠经口连续分别给予0．25、0．50、1．50g／kgBW的益生菌补充剂4周,进行迟发型变态反应试验、溶血素滴度测定、NK细胞活性测定等。结果在小白鼠迟发型变态反应试验中,中、高剂量组足跖增厚值均高于对照组,差异有显著性（P〈0．05）;对受试动物血清溶血素抗体滴度水平的影响的实验中,中、高剂量组的抗体积数高于对照组,差异均有显著性（P〈0．05）。NK细胞活性测定中,高剂量组脾NK细胞活性增强,差异有非常显著性（P〈0．01）。结论含该两种特定乳酸菌株的益生菌补充剂被小自鼠摄入一定剂量后,起到了增强小白鼠细胞免疫、体液免疫功能及NK细胞活性的作用。     

低聚异麦芽糖对模拟失重大鼠肠道益生菌以及钙代谢和骨矿盐密度影响的初步研究

目的：研究低聚异麦芽糖对模拟失重大鼠肠道益生菌的影响以及与骨钙代谢变化的关系。方法：30只雄性SD大鼠随机分为3组（每组10只）FC组;普通对照组（饲喂普通饲料）;SC组,模拟失重对照组（饲喂普通饲料）;SS组,模拟失重低聚异麦芽糖组（饲喂普通饲料 低聚异麦芽糖）,实验期21d。结果：SC组大鼠肠道益生菌（主要是双歧杆菌和乳杆菌）数量、饲料钙的表观吸收率、股骨骨密度（BMD）,骨钙含量以及骨钙素（BGP）的水平显著低于FC组,而血钙水平明显高于FC组;SS组大鼠肠道益生菌数量,饲料钙的表观吸收率,骨密度,骨钙含量以及骨钙素水平较SC组高,血钙水平显著低于SC组。结论：低聚异麦芽糖可以促进模拟失重大鼠肠道益生菌的增殖,减少股骨骨质的丢失,提高股骨BMD,增加骨形成,对骨代谢产生一定的有益影响。     

多酶级联反应合成能够促进肠道益生菌生长的纤维寡糖

聚合度2–6的可溶性纤维寡糖是一种具有多种生物功能的低聚糖,它能够促进双歧杆菌(Bifidobacteria)、副干酪乳杆菌(Lactobacillus paracei)等肠道益生菌的增殖,因此对人体肠道微生态具有调节作用。本研究通过在大肠杆菌中表达纤维寡糖磷酸化酶(cellodextrin phosphorylase,CDP),构建Cc 01菌株,并与之前构建的COS 01菌株联合使用,建立了基于COS 01、Cc 01的三酶级联反应催化底物葡萄糖和蔗糖合成纤维寡糖反应体系。经过优化后,最终可溶性纤维寡糖的产量达到97g/L,纯度约为97%,其中含有纤维二糖(16.8wt%)、纤维三糖(49.8wt%)、纤维四糖(16.4 wt%)、纤维五糖(11.5 wt%)和纤维六糖(5.5 wt%)。在纤维寡糖对益生菌株生长促进作用的测试中,以菊粉、低聚木糖、低聚果糖为基准,干酪乳杆菌(WSH004)、副干酪乳杆菌(WSH005)以及嗜酸乳杆菌(WSH 006)利用纤维寡糖(聚合度2–6)为碳源进行生长后,益生菌的生物量(OD600)相比对照增加约2倍。该研究证明了三酶级联反应能够高效合成纤维寡糖,并表明聚合度2–6的纤维寡糖是一类具有促进肠道微生物增殖的功能性碳水化合物。     

Predominant genera of fecal microbiota in children with atopic dermatitis are not altered by intake of probiotic bacteria Lactobacillus acidophilus NCFM and Bifidobacterium animalis subsp. lactis Bi-07

The effect of probiotic bacteria Lactobacillus acidophilus NCFM and Bifidobacterium lactis Bi-07 on the composition of the Lactobacillus group, Bifidobacterium and the total bacterial population in feces from young children with atopic dermatitis was investigated. The study included 50 children randomized to intake of one of the probiotic strain or placebo. Microbial composition was characterized by denaturing gradient gel electrophoresis, quantitative PCR and, in a subset of subjects, by pyrosequencing of the 16S rRNA gene. The core population of the Lactobacillus group was identified as Lactobacillus gasseri, Lactobacillus fermentum, Lactobacillus oris, Leuconostoc mesenteroides, while the bifidobacterial community included Bifidobacterium adolescentis, Bifidobacterium bifidum, Bifidobacterium longum and Bifidobacterium catenulatum. The fecal numbers of L. acidophilus and B. lactis increased significantly after intervention, indicating survival of the ingested bacteria. The levels of Bifidobacterium correlated positively (P=0.03), while the levels of the Lactobacillus group negatively (P=0.01) with improvement of atopic eczema evaluated by the Severity Scoring of Atopic Dermatitis index. This correlation was observed across the whole study cohort and not attributed to the probiotic intake. The main conclusion of the study is that administration of L. acidophilus NCFM and B. lactis Bi-07 does not affect the composition and diversity of the main bacterial populations in feces.     

Prebiotics enhance survival and prolong the retention period of specific probiotic inocula in an in vivo murine model

AIM: To identify novel prebiotics that could be used to maintain persistence of three representative probiotic strains in vivo. METHODS AND RESULTS: Test mice were treated with prebiotics soybean oligosaccharide (SOS), fructooligosaccharide (FOS) or inulin, followed by probiotics Lactobacillus acidophilus LAFTI L10 (L10), Bifidobacterium lactis LAFTI B94 (B94) or Lactobacillus casei L26 LAFTI (L26). Faecal samples were then collected and analysed using selective medium and PCR analysis to determine the presence of the probiotic strains. In contrast to the control groups, in mice fed prebiotics, the survival and retention time of the test probiotics was increased extensively. SOS and FOS prolonged the retention period of L10 from 24 to 30 h. Of the three prebiotics, FOS gave the best result with B94, prolonging the retention period from 3 to > or =10 days. Of the three prebiotics, inulin gave the best result for L26, prolonging the retention period from 2 to > or =6 days. CONCLUSIONS: The prebiotics SOS, FOS and inulin significantly enhance survival and prolong the retention period of L10, B94 and L26 in vivo. SIGNIFICANCE AND IMPACT OF THE STUDY: Our results demonstrate the potential use of FOS, inulin and SOS as prebiotics in conjunction with the probiotic strains L10, B94 and L26 for new synbiotic products.     

Selected prebiotics support the growth of probiotic mono-cultures in vitro

The aim of the present study was to identify suitable prebiotics for synergistic combinations with representative probiotics from the lactobacilli and bifidobacterium genera. Eleven different types of commercially available carbohydrates and compounds were screened in basal media for their effects on the growth of the probiotic cultures Lactobacillus acidophilus LAFTI L10 (L10), Bifidobacterium animalis lactis LAFTI B94 (B94) and Lactobacillus casei LAFTI L26 (L26). Growth of these probiotics was investigated by measuring optical density (OD) levels over a period of 48 h. The results of this study showed that all three probiotic strains were able to utilize a range of carbohydrates. Maximal growth of L10 was observed in basal medium supplemented with soybean oligosaccharide (SOS), followed by fructooligosaccharide (FOS) and inulin, while maximal growth of B94 was observed in basal medium supplemented with SOS, followed by raffinose, FOS, beta-glucan hydrolysate, inulin and Fibregum TAN. L26 was shown to exhibit maximal growth in basal medium supplemented with FOS followed by inulin, SOS, beta-glucan hydrolysate and beta-glucan concentrate. The results of this study indicate that several carbohydrates/compounds can enhance the growth of these representative probiotic strains in vitro.     

Utilization of different types of dietary fibres by potential probiotics

A better understanding of the functionality of probiotics and dietary fibres with prebiotic activity is required for the development of improved synbiotic preparations. In this study, utilization of β(2-1) fructans, galactooligosaccharides, and plant polysaccharides as prebiotics by lactobacilli, bifidobacteria, and pediococci was investigated. Our results demonstrate that prebiotics with linear chains consisting of galactose units are better utilized by probiotics than are those consisting of glucose and fructose units, and the ability of probiotic bacteria to utilize prebiotics is strain-specific. In addition, rye fructooligosaccharides represent a prebiotic fibre that supports the growth of a wide range of probiotic cultures and as such has a potential to improve the successfulness of probiotic treatments. This study also demonstrates dietary fibre utilization by pediococci and provides data supporting the possible use of pediococci as a probiotic in synbiotic combinations.     

Functional petit-suisse cheese: measure of the prebiotic effect

Prebiotics and probiotics are increasingly being used to produce potentially synbiotic foods, particularly through dairy products as vehicles. It is well known that both ingredients may offer benefits to improve the host health. This research aimed to evaluate the prebiotic potential of novel petit-suisse cheeses using an in vitro fermentation model. Five petit-suisse cheese formulations combining candidate prebiotics (inulin, oligofructose, honey) and probiotics (Lactobacillus acidophilus, Bifidobacterium lactis) were tested in vitro using sterile, stirred, batch culture fermentations with human faecal slurry. Measurement of prebiotic effect (MPE) values were generated comparing bacterial changes through determination of maximum growth rates of groups, rate of substrate assimilation and production of lactate and short chain fatty acids. Fastest fermentation and high lactic acid production, promoting increased growth rates of bifidobacteria and lactobacilli, were achieved with addition of prebiotics to a probiotic cheese (made using starter+probiotics). Addition of probiotic strains to control cheese (made using just a starter culture) also resulted in high lactic acid production. Highest MPE values were obtained with addition of prebiotics to a probiotic cheese, followed by addition of prebiotics and/or probiotics to a control cheese. Under the in vitro conditions used, cheese made with the combination of different prebiotics and probiotics resulted in the most promising functional petit-suisse cheese. The study allowed comparison of potentially functional petit-suisse cheeses and screening of preferred synbiotic potential for future market use.     

In vitro effects of selected synbiotics on the human faecal microbiota composition

Synbiotics are recognized means of modulating gut microbiota composition and activities. However, whether synbiotics are superior to prebiotics and probiotics alone in moderating the gut microbiota towards a purportedly healthy composition has not been determined. Eight selected synbiotics (short-chain fructooligosaccharides or fructooligosaccharides, each combined with one of four probiotics, Lactobacillus fermentum ME-3, Lactobacillus plantarum WCFS1, Lactobacillus paracasei 8700:2 or Bifidobacterium longum 46) were added to 24-h pH-controlled anaerobic faecal batch cultures. The prebiotic and probiotic components were also tested alone to determine their respective role within the synbiotic for modulation of the faecal microbiota. Effects upon major groups of the microbiota were evaluated using FISH. Rifampicin variant probiotic strains were used to assess probiotic levels. Synbiotic and prebiotics increased bifidobacteria and the Eubacterium rectale-Clostridium coccoides group. Lower levels of Escherichia coli were retrieved with these combinations after 5 and 10 h of fermentation. Probiotics alone had little effect upon the groups, however. Multivariate analysis revealed that the effect of synbiotics differed from the prebiotics as higher levels of Lactobacillus-Enterococcus were observed when the probiotic was stimulated by the prebiotic component. Here, the synbiotic approach was more effective than prebiotic or probiotic alone to modulate the gut microbiota.     

Cell viability of microencapsulated Bifidobacterium animalis subsp. lactis under freeze-drying, storage and gastrointestinal tract simulation conditions

The purpose of this study was to improve the survival of Bifidobacterium animalis subsp. lactis 10140 during freeze-drying process by microencapsulation, using a special pediatric prebiotics mixture (galactooligosaccharides and fructooligosaccharides). Probiotic microorganisms were encapsulated with a coat combination of prebiotics–calcium-alginate prior to freeze-drying. Both encapsulated and free cells were then freeze-dried in their optimized combinations of skim milk and prebiotics. Response surface methodology (RSM) was used to produce a coating combination as well as drying medium with the highest cell viability during freeze-drying. The optimum encapsulation composition was found to be 2.1 % Na-alginate, 2.9 % prebiotic, and 21.7 % glycerol. Maximum survival predicted by the model was 81.2 %. No significant (p?>?0.05) difference between the predicted and experimental values verified the adequacy of final reduced models. The protection ability of encapsulation was then examined over 120 days of storage at 4 and 25 °C and exposure to a sequential model of infantile GIT conditions including both gastric conditions (pH 3.0 and 4.0, 90 min, 37 °C) and intestinal conditions (pH 7.5, 5 h, 37 °C). Significantly improved cell viability showed that microencapsulation of B. lactis 10140 with the prebiotics was successful in producing a stable symbiotic powdery nutraceutical.     

Antigenotoxicity of probiotics and prebiotics on faecal water-induced DNA damage in human colon adenocarcinoma cells

Six strains of lactic acid producing bacteria (LAB) were incubated (1 x 10(8)cfu/ml) with genotoxic faecal water from a human subject. HT29 human adenocarcinoma cells were then challenged with the resultant samples and DNA damage measured using the single cell gel electrophoresis (comet) assay. The LAB strains investigated were Bifidobacterium sp. 420, Bifidobacterium Bb12, Lactobacillus plantarum, Streptococcus thermophilus, Lactobacillus bulgaricus and Enterococcus faecium. DNA damage was significantly decreased by all bacteria used with the exception of Strep. thermophilus. Bif. Bb12 and Lact. plantarum showed the greatest protective effect against DNA damage. Incubation of faecal water with different concentrations of Bif. Bb12 and Lact. plantarum revealed that the decrease in genotoxicity was related to cell density. Non-viable (heat treated) probiotic cells had no effect on faecal water genotoxicity. In a second study, HT29 cells were cultured in the presence of supernatants of incubations of probiotics with various carbohydrates including known prebiotics; the HT29 cells were then exposed to faecal water. Overall, incubations involving Lact. plantarum with the fructooligosaccharide (FOS)-based prebiotics Inulin, Raftiline, Raftilose and Actilight were the most effective in increasing the cellular resistance to faecal water genotoxicity, whereas fermentations with Elixor (a galactooligosaccharide) and Fibersol (a maltodextrin) were less effective. Substantial reductions in faecal water-induced DNA damage were also seen with supernatants from incubation of prebiotics with Bif. Bb12. The supernatant of fermentations involving Ent. faecium and Bif. sp. 420 generally had less potent effects on genotoxicity although some reductions with Raftiline and Elixor fermentations were apparent.