使用FISH-FC测定益生菌对肠道菌群失衡的调节作用

目的：使用荧光原位杂交-流式细胞计数法(FISH-FC)测定灌胃自筛菌株嗜酸乳杆菌KLDS1.8701与植物乳杆菌KLDS1.0355混合液对抗生素性肠道菌群失衡小鼠的影响,并初步研究其发挥作用的机制。方法：在体外实验中,测定上述两株菌对肠道病原菌的抑制作用,并探讨其作用机理。在体内实验中,采用随机饮用盐酸克林霉素水溶液(2.8mg/mL)的方法建立抗生素性肠道菌群失衡小鼠模型,并使用FISH-FC方法测定小鼠粪便中总厌氧菌、球形梭菌属(Clostridium coccoides-Eubacterium rectale)、肠杆菌(Enterobacteria)、拟杆菌属(Bacteroides-Prevotella)的数量变化,以此判断模型是否建立成功。之后,灌胃嗜酸乳杆菌KLDS1.8701和植物乳杆菌KLDS1.0355的混合液(活菌数分别为107、108、109CFU/mL),以生理盐水为对照,采用上述方法评价混合菌液对小鼠模型的影响。结果：与对照组相比,灌胃混合菌液组可迅速恢复肠道菌群平衡(P＜0.01),产生作用的效应剂量为107CFU/mL。结论：直接的抗微生物效应可能是该混合菌液调节肠道菌群平衡的机制之一。     

益生菌制剂对抗生素诱导腹泻模型小鼠肠道菌群的调节作用

研究了益生菌制剂对腹泻模型（Antibiotic-Associated Diarrhea,AAD）小鼠肠道菌群的调节作用。BALB/c小鼠随机分为6组,每组8只,灌胃给予氨苄青霉素（22.4 g/kg）,建立小鼠腹泻模型,空白组给予等体积生理盐水。模型建立后,阳性组灌胃给予培菲康（8 g/kg）、益生菌制剂低、中、高剂量组（2.5×106、5×106、1×107 CFU）给予复合益生菌制剂,模型组和空白组给予等体积生理盐水,连续14 d。观察益生菌制剂对小鼠体质量、稀便率、稀便级和腹泻指数的影响,测定小鼠IgA、IgG水平,肠道屏障功能相关基因表达水平以及肠道菌群组成。结果表明,与模型组相比三个剂量组在给予益生菌第14天时小鼠稀便率、稀便级和腹泻指数显著降低,IgA水平分别提高13.30%、20.25%、25.83%,IgG水平分别提高6.84%、19.81%、29.64%,TLR4基因表达水平下调16.88%、20.78%、40.91%,NF-κB基因表达水平下调24.91%、37.19%、55.79%,肠道双歧杆菌、乳杆菌数量明显增加,产气荚膜梭菌、肠球菌、肠杆菌数量明显减少。综上所述,益生菌制剂通过调节肠道菌群,调节免疫球蛋白水平,发挥改善AAD作用。     

益生菌Lactobacillus paracasei LC01对小鼠肠道菌群的调节作用

探讨益生菌Lactobacillus paracasei LC01对小鼠肠道菌群的调节作用。将32 只Balb/c小鼠随机分成4 组,分别作为对照组、灌胃LC01灭活菌组、灌胃LC01活菌组和活菌定殖组。干预2 周后,通过MiSeq高通量测序手段,分析不同处理条件下小鼠肠道菌群变化。结果表明：相对于对照组和灌胃灭活菌组,灌胃LC01活菌可以显著提高小鼠肠道内Lactobacillus属、Ruminococcaceae_UCG014属、Alistpes属的相对含量。进一步通过荧光定量聚合酶链式反应和群落聚类分析发现,灌胃LC01活菌不但可以显著提高小鼠肠道内乳酸菌LC01的相对含量,同时可以促进小鼠肠道中格氏乳杆菌、罗伊氏乳杆菌和唾液乳杆菌的增殖。在活菌定殖组中,停止灌胃2 周后,小鼠粪便中不能检测到菌株LC01,说明菌株LC01不能在小鼠肠道内长期定殖。以上结果表明菌株LC01对肠道小鼠菌群结构具有一定的调节作用,具有潜在的益生作用和应用价值。     

免疫乳对肠道菌群的调节作用

以24种人肠道病原茵作为抗原对乳牛进行免疫，制得的免疫乳中乳抗体的凝集价为非免疫乳的64倍。以免疫乳作为原料制备的免疫乳粉具有调节肠道茵群的作用。结果表明免疫乳粉较普通乳粉可显著增加小鼠肠道中双歧杆茵和乳杆茵的数量以及肠道中乳酸和已酸的含量，同时可显著降低小鼠肠道中肠球茵、大肠杆茵及产气荚膜梭茵的数量。     

不同剂量植物乳杆菌对小鼠肠道菌群的影响

植物乳杆菌是人体肠道中的益生菌,可自发酵乳肉制品中分离。本实验将处于正常生理状态下的小鼠分为4组,通过灌喂不同剂量的植物乳杆菌X3-2B来探讨其对小鼠肠道各类微生物菌群的影响。结果表明,灌喂植物乳杆菌X3-2B时,小鼠对饲料的利用率优于对照组,且小鼠粪便p H低于对照组（高剂量组最低）。灌喂乳酸菌的小鼠其肠道内乳酸菌与双歧杆菌数显著（p<0.05）高于对照组。高剂量组与中剂量组小鼠在灌喂14d时小鼠肠道内大肠杆菌数无显著差异,但总肠杆菌和肠球菌数显著低于灌喂第1d（p<0.05）,即植物乳杆菌X3-2B对肠道内致病菌有一定的抑制作用,对肠道微生物区系有一定的调节作用。      

植物乳杆菌ST-Ⅲ对小鼠肠道菌群的调节

以小鼠粪便中的双歧杆菌、乳杆菌、肠杆菌、肠球菌、产气荚膜梭菌数量为检测指标,比较了灌胃含有植物乳杆菌ST-Ⅲ活菌量6×107,6×108,6×109mL-1的脱脂奶液对小鼠肠道菌群的影响。结果表明,植物乳杆菌ST-Ⅲ对小鼠肠道菌群具有一定的调节效果,有效剂量为6×108mL-1。灌胃108mL-1活菌15d,停止灌胃3～5d后仍具有显著效果,5～7d后各项指标菌的量回复到灌胃前水平。     

大豆低聚糖对肠道菌群的调节作用

通过动物实验及人体实验研究大豆低聚糖对肠道菌群的影响.实验小鼠灌胃不同剂量的大豆低聚糖,观察其肠道内肠杆菌、肠球菌、产气荚膜梭菌、拟杆菌、乳酸杆菌、双歧杆菌的变化.受试人群每日服用10mL大豆低聚糖,同样观察以上菌群变化 . 结果表明,大豆低聚糖具有调节肠道菌群的作用.     

益生菌发酵番茄汁对小鼠抗疲劳和肠道菌群的调节作用

为研究益生菌发酵番茄汁（probiotic fermented tomato juice,PFTJ）的抗疲劳和肠道菌群调节作用,将40 只雄性ICR 小鼠随机分成4 组,分别为空白对照组、阳性对照组（0.06 g/kg）、PFTJ 低剂量组（5 mg/kg）和PFTJ 高剂量组（15 mg/kg）。通过测定各组小鼠负重力竭游泳时间、生化指标及与能量代谢相关基因的表达,评价PFTJ 抗疲劳作用,并分析其对肠道菌群的影响。结果表明,与空白对照组相比,高剂量PFTJ 能明显延长小鼠负重力竭游泳时间,降低尿素氮、乳酸和丙二醛含量,提高肌糖原的含量、超氧化物歧化酶活性和谷胱甘肽还原酶活性,并能显著提高小鼠骨骼肌中AMPK 和PGC-1α 的mRNA 表达水平。PFTJ 可以增加肠道菌群多样性,上调乳酸杆菌属、norɑnk_f_Muribɑculɑceɑes 属相对丰度,下调丹毒丝菌科菌群的相对丰度。PFTJ 具有潜在的抗疲劳能力,这与减少代谢物质积累、抑制糖原消耗、抗氧化、激活AMPK/PGC-1α 通路直接相关,并可能通过调节小鼠肠道菌群群落结构间接实现其抗疲劳效果。     

干酪乳杆菌LC01对小鼠肠道菌群和肠道转运调节作用的剂量效应

为研究干酪乳杆菌LC01对肠道的益生功能,本实验探讨了不同剂量干酪乳杆菌LC01小鼠肠道菌群及转运的影响。基于MiSeq高通量平台进行扩增子测序,比较LC01菌对正常小鼠、青霉素诱导的菌群失调小鼠的肠道菌群调节作用;并利用墨汁推进率评价LC01菌对便秘小鼠肠道转运的影响。结果表明,LC01菌可明显提高正常小鼠肠道中Lactobacillus属和Bacteroides属的相对丰度,降低条件性致病菌Prevotella属、Helicobacter属的相对丰度,对小鼠肠道菌群具有显著的调节作用。相对于模型组,菌群失调小鼠灌胃LC01菌两周后,能够显著增加拟杆菌属、梭菌属和乳杆菌属的丰度,并可改善肠道转运速率,且600亿活菌效果均优于300亿活菌。综上表明,干酪乳杆菌LC01对小鼠肠道菌群具有一定的调节作用,并且对肠道转运有着良好的促进作用,说明LC01菌具有潜在的益生作用和应用价值。     

魔芋低聚糖对小鼠肠道菌群的调节作用

该实验研究了魔芋低聚糖（KOGM）对小鼠肠道菌群的调节作用。以不同剂量魔芋低聚糖连续灌胃小鼠35 d,测定血清生化指标,无菌条件下取小鼠粪便培养肠道菌群。结果表明,与对照组比较,魔芋低聚糖高剂量组（2.00 g/kg体质量）小鼠粪便中双歧杆菌和乳杆菌数量（对数值分别为3.65、3.81）显著增加（P＜0.05）,肠杆菌和产气杆菌数量无显著性变化（P＞0.05）;结肠内容物中乙酸、丙酸以及丁酸的含量（6.51 mmol/100 g、1.69 mmol/100 g、3.83 mmol/100 g）显著增加（P＜0.05）。说明魔芋低聚糖对小鼠肠道菌群有较好调节作用。     

Probiotic administration effect on fecal mutagenicity and microflora in the goat's gut

The application of potentially beneficial microorganisms to increase host defense is a new trend to increase health benefits. In this paper the first specific host probiotics for goats from a mixture isolated from healthy animals (Lactobacillus reuteri DDL 19, Lactobacillus alimentarius DDL 48, Enterococcus faecium DDE 39 and Bifidobacterium bifidum DDBA) was assayed. The effect of probiotic oral administration on goats' weight, gut microbiota, as well as on the production of mutagen compounds and their indicator (putrescine), were evaluated. The probiotic supplement was able to modify microflora balance by reducing Enterobacteria like Salmonella/Shigella (1.09 and 1.21 log CFU/g feces, respectively) and increasing lactic acid bacteria and Bifidobacteria (1.67 and 2.34 log CFU/g feces, respectively). The probiotics administration was correlated with a ten time diminution of fecal putrescine (cancer and bacterial disease marker) and a decrease of 60% mutagen fecal concentration, indicating the protective effect of the treatment. Additionally, a significant increase in ruminant weight was observed after probiotic administration. These results are encouraging towards the use of probiotic mixtures as functional food for goats.     

Importance of stable gastrointestinal microflora in growing animals

A zysbiosis can be caused by food constituents. Food portions with 40% rye for chickens release a destabilisation of the gut flora. This can be prevented by effective stabilizers. Early weaned piglets harbour high numbers of E. coli in their ileum and jejunum content. These become decreased by about three tens powers by affective gut flora stabilizers. Simultaneously the body mass rises considerably without an increase of the food consumption with reference to the living mass. Partially, the ergotropic effect of the gut flora stabilizers is attributed to the smaller expense for the immune defence. Therefore, a new hypothesis for the growth stimulating effect of ergotropics for early weaned piglets is created.     

Significance of gastrointestinal microflora for the metabolism of foreign compounds

Microbiological biotransformation as a part of metabolism of foreign compounds in general, has great toxicological consequences. An overview on the most important types of reactions is given. In detail, comparative investigations of the metabolism of gamma-HCH, azobenzene and progoitrin in germfree and conventionalized rats are described and results from the literature are presented.     

Probiotic lactobacilli in a semi-soft cheese survive in the simulated human gastrointestinal tract

In this study, probiotics Lactobacillus acidophilus NCFM and Lactobacillus rhamnosus HN001 in cheese were studied using models simulating the human gastrointestinal tract with the aim of investigating whether the cheese matrix affected the survival and metabolic properties of these probiotic strains. Probiotics in cheese survived in the simulated upper gastrointestinal tract model, and numbers of L. acidophilus, L. rhamnosus and total lactobacilli were increased in the colonic fermentation simulations of the probiotic cheese when compared with the non-probiotic cheese used as a control. The cheese matrix also beneficially affected cyclooxygenase-gene expression of colonocytes in a cell culture model. Freeze-dried probiotics, which were also analysed in the colonic simulator, showed similar changes in Lactobacillus numbers, although gave a stronger increase and also affected other microbial groups. These results indicate that the probiotic microbes in cheese survive in the gastrointestinal tract and that the cheese matrix does not seem to affect the probiotic survival.     

Microorganisms associated with epithelial surfaces and stability of the indigenous gastrointestinal microflora

Indigenous microorganisms of many genera and species associate with mucosal epithelia in the gastrointestinal tracts of animals and humans. These mechanisms may involve a high degree of specificity for host and surface habitat. They may include a capacity of the microorganisms to adhere to the membranes of substratum epithelial cells, to colonize and utilize as a source of nutrients the mucus overlying epithelial cells, and to be motile and attracted into the mucous layer by chemotaxis. The microbes must be able as well to thrive in the nutritional and environmental conditions prevailing on the epithelial surfaces. Microbial communities associated with epithelial surfaces are critical for maintaining a microflora in areas of the tract (i.e., stomach, small intestine) where the lumenal content moves at a rate exceeding the maximum rates at which indigenous microorganisms can multiply. Such communities even may be important in areas (i.e., the cecum and colon) where the content moves at rates below those at which the microbes can multiply. In such areas, microorganisms colonizing mucus on the epithelium and in the crypts of Lieberkuhn may provide a stable inoculum for the lumenal content which may be altered in composition in times of dietary change. Microorganisms associated with gastric and intestinal surfaces undoubtedly serve in a major way to stabilize the composition of the indigenous gastrointestinal microflora. At the molecular level, however, little is known about the mechanisms stabilizing the composition or the biochemical and genetic activities of the microflora. Such mechanisms are important subjects for research in the future.     

补充益生菌对肥胖机体免疫调节作用的研究进展

肥胖不仅会诱发慢性代谢性疾病,还会导致免疫功能的损伤,降低生活质量。益生菌是对宿主健康起促进作用的活菌,具有免疫调节作用。本文综述了补充益生菌对肥胖机体适应性免疫与固有免疫的作用,讨论了菌株特异性、益生菌补充剂量、补充方式、宿主状态等对免疫调节效果的影响,旨在进一步加深补充益生菌对肥胖机体免疫调节作用的认识,为合理应用益生菌提供参考。     

Effect of fructo-oligosaccharides on intestinal microflora

Fructo-oligosaccharides are widely distributed in plants such as onions, asparagus, wheat etc., and obtained from sucrose by the action of fructosyltransferase. They are not hydrolyzed by human digestive enzymes, but are utilized by intestinal bacteria such as bifidobacteria. Bacteroides fragilis group, peptostreptococci and klebsiellae. In the experiment with 23 patients (73 +/- 9 years old), improvement of fecal microflora was observed by oral administration of fructo-oligosaccharides 8 g per day for two weeks: the population of bifidobacteria in feces increased about 10 times compared before the administration; average pH of stool showed 0.3 lower than that before administration.     

Effect of Various Encapsulating Materials on the Stability of Probiotic Bacteria

ABSTRACT:  Ten probiotic bacteria, including Lactobacillus rhamnosus , Bifidobacterium longum , L. salivarius , L. plantarum , L. acidophilus , L. paracasei , B. lactis type Bl-04, B. lactis type Bi-07, HOWARU L. rhamnosus , and HOWARU B. bifidum , were encapsulated in various coating materials, namely alginate, guar gum, xanthan gum, locust bean gum, and carrageenan gum. The various encapsulated probiotic bacteria were studied for their acid and bile tolerance. Free probiotic organisms were used as a control. The acid tolerance of probiotic organisms was tested at pH 2 over a 2-h incubation period. Bile tolerance was tested with taurocholic acid over an 8-h incubation period. The permeability of the capsules was also examined using a water-soluble dye, 6-carboxyflourescin (6-CF). The permeability was monitored by measuring the amount of 6-CF released from the capsules during a 2-w storage period. Results indicated that probiotic bacteria encapsulated in alginate, xanthan gum, and carrageenan gum survived better ( P < 0.05) than free probiotic bacteria, under acidic conditions. When free probiotic bacteria were exposed to taurocholic acid, viability was reduced by 6.36 log CFU/mL, whereas only 3.63, 3.27, and 4.12 log CFU/mL was lost in probiotic organisms encapsulated in alginate, xanthan gum, and carrageenan gum, respectively. All encapsulating materials tested released small amounts of 6-CF; however, alginate and xanthan gum retained 22.1% and 18.6% more fluorescent dye than guar gum. In general, microcapsules made of alginate, xanthan gum, and carrageenan gum greatly improved the survival of probiotic bacteria when exposed to acidic conditions and bile salts.     

辣椒素对肠道菌体外发酵的影响

食用辣椒会带来肠道不适反应,对肠道环境存在潜在影响.实验拟通过体外发酵验证辣椒素对肠道发酵环境的影响.向大鼠盲肠内容物发酵液中添加0.05％、0.10％、0.15％三种浓度辣椒素,培养10h后检测发酵液中pH、游离氨、短链脂肪酸(SCFA)及双歧杆菌、乳酸杆菌、大肠杆菌3种微生物的变化趋势,探讨辣椒素对肠道发酵环境的影响.结果表明,与空白组相比,添加辣椒素使盲肠内容物发酵液pH、游离氨浓度升高,短链脂肪酸含量降低,双歧杆菌、乳酸杆菌数量下降,而大肠杆菌数量上升.所有变化均与辣椒素添加剂量存在相关性.研究结果表明,辣椒素对肠道发酵环境有潜在危害.     

辣椒素对肠道菌体外发酵的影响

食用辣椒会带来肠道不适反应,对肠道环境存在潜在影响。实验拟通过体外发酵验证辣椒素对肠道发酵环境的影响。向大鼠盲肠内容物发酵液中添加0.05%、0.10%、0.15%三种浓度辣椒素,培养10h后检测发酵液中pH、游离氨、短链脂肪酸(SCFA)及双歧杆菌、乳酸杆菌、大肠杆菌3种微生物的变化趋势,探讨辣椒素对肠道发酵环境的影响。结果表明,与空白组相比,添加辣椒素使盲肠内容物发酵液pH、游离氨浓度升高,短链脂肪酸含量降低,双歧杆菌、乳酸杆菌数量下降,而大肠杆菌数量上升。所有变化均与辣椒素添加剂量存在相关性。研究结果表明,辣椒素对肠道发酵环境有潜在危害。