丁酸菌与老年肠道功能的相关性

丁酸菌是一种专性厌氧芽胞杆菌,是以丁酸为主要代谢产物的益生菌,可定植于人体肠道,在某种程度上与乳酸菌有协同作用,可抑制人肠道内有害菌的生长、促进营养物质的吸收、改善肠道功能等。本研究主要对丁酸菌在临床中的应用研究进展进行综述,尤其是对丁酸菌与老年人肠道功能的相关性进行阐述,并展望丁酸菌对老年慢性疾病如糖尿病、心血管疾病、老年痴呆、风湿性疾病及骨质疏松症防治的研究未来。     

两种微生态调节剂对网箱鲤鱼生产效果的影响

两种微生态调节剂（ＭｉｃｒｏｂｅＦＡ９１０２和一种芽胞杆菌制剂）添加到基础饵料中用于网箱鲤鱼的饲养试验。ＭｉｃｒｏｂｅＦＡ９１０２试验组和对照组鲤鱼在增重及饲料利用率方面无显著差异,但ＭｉｃｒｏｂｅＦＡ９１０２可取代部分蛋白饲料和降低生产成本,而芽胞杆菌制剂似乎不宜用于鲤鱼生产。因而进一步筛选适用于红鱼生长的理想的微生态制剂仍是必要的。     

Probiotic potential of lactic acid bacteria isolated from chicken gastrointestinal digestive tract

This study was conducted in order to evaluate the probiotic properties of lactic acid bacteria (LAB) isolated from intestinal tract of broilers and Thai indigenous chickens. The major properties, including the gastric juice and bile salts tolerance, starch, protein and lipid digesting capabilities, and the inhibition on certain pathogenic bacteria were investigated. Three-hundred and twenty-two and 226 LAB strains were isolated from ten broilers and eight Thai indigenous chickens, respectively. The gastrointestinal transit tolerance of these 548 isolates was determined by exposing washed cell suspension at 41°C to simulated gastric juice (pH 2.5) containing pepsin (3 mg ml⁻¹), and to simulated small intestinal juice (pH 8.0) in the presence of pancreatin (1 mg ml⁻¹) and 7% fresh chicken bile, mimicking the gastrointestinal environment. The survival of 20 isolates was found after passing through the gastrointestinal conditions. The survival rates of six strains; KT3L20, KT2CR5, KT10L22, KT5S19, KT4S13 and PM1L12 from the sequential study were 43.68, 37.56, 33.84, 32.89, 31.37 and 27.19%, respectively. Twelve isolates exhibited protein digestion on agar plate but no isolates showed the ability to digest starch and lipid. All 20 LAB showed the antimicrobial activity against Salmonella sp., Staphylococcus aureus and Escherichia coli except one strain which did not show the inhibitory activity toward E. coli. Accordingly, five isolates of selected LAB (KT2L24, KT3L20, KT4S13, KT3CE27 and KT8S16) can be classified as the best probiotics and were identified as Enterococcus faecalis, Enterococcus durans, Enterococcus faecium, Pediococcus pentosaceus, and Enterococcus faecium, respectively. The survival rate of microencapsulation of E. durans KT3L20 under simulated small intestine juice after sequential of simulated gastric juice was also investigated. An extrusion technique exhibited a higher survival rate than emulsion technique and free cell, respectively.     

Mode of action of acidocin D20079, a bacteriocin produced by the potential probiotic strain, <Emphasis Type="Italic">Lactobacillus acidophilus</Emphasis> DSM 20079

Lactobacillus acidophilus DSM 20079 is the producer of a novel bacteriocin termed acidocin D20079. In this paper, mode of action using three various concentrations of acidocin D20079 (2,048, 128 and 11.3 AU/ml) was determined against an indicator strain L. delbrueckii subsp. lactis DSM 20076. These concentrations all led to marked decreases in both the number of viable cells and in optical density, indicating that the activity of the acidocin D20079 was bactericidal with concomitant cell lysis. Moreover, the probiotic potential of L. acidophilus DSM 20079 was analyzed for its ability to survive and retain viability at conditions (acid and bile concentrations) mimicking the gastrointestinal (GI) tract, under which it survived exposure to pH 2.0 with a 1.2 log cycle reduction in viability and where 45% of the original population survived in a medium containing 0.3% bile for 3 h.     

产酶益生素对肉鸭生长性能及肠道菌群的影响

目的产酶益生素对肉鸭生产性能及肠道菌群的影响,为开发利用产酶益生素提供理论依据。方法选用1日龄120只樱桃谷肉鸭,随机分为4组,每组30只,设2个重复,每重复15只,对照组I饲喂基础日粮,实验II、III和IV组分别在基础日粮中添加0.1%、0.2%和0.3%产酶益生素,测定肉鸭的生长性能及肠道菌群数量。结果与对照组相比,实验II、III和IV组平均日增重分别提高了5.82%、11.50%和12.60%,日均采食量分别提高了0.85%、1.71%和3.78%,料重比分别降低了4.85%、8.81%和7.93%;盲肠内双歧杆菌的数量分别提高了3.29%、9.86%和9.48%,乳酸杆菌分别提高了5.49%、10.98%和12.56%,大肠埃希菌分别降低了11.88%、16.35%和22.48%。结论产酶益生素能提高肉鸭的生产性能,促进肠道双歧杆菌及乳酸杆菌的增殖,降低大肠埃希菌的数量。     

Physiological characterization of non-<Emphasis Type="Italic">Saccharomyces</Emphasis> yeasts from agro-industrial and environmental origins with possible probiotic function

Probiotics are defined as live microorganisms, which when administered in adequate amount confer a health benefit to the host. Most of studied or commercialized probiotics contain bacteria and very few of them present yeast in its composition. In this last case, the microorganisms almost always belong to Saccharomyces genus. In the present study, it was of interest to screen among 103 non-Saccharomyces yeasts a candidate for probiotic by using in vitro and in vivo criteria. In vitro assays included growth at 37°C and production of antagonistic compounds against enteropathogenic indicators, and the in vivo assays evaluated the colonization ability of mouse gastrointestinal tract without pathologic consequences and the protective ability in mice experimentally challenged with Clostridium difficile. In conclusion, Pichia kluyveri strain 898 showed to be a potential candidate for probiotic use, based on the criteria cited above, particularly as demonstrated by its protective effect against experimental infection in mice. Interestingly, an in vivo inhibition against C. difficile observed in the animal models did not correlate with the results obtained with the in vitro assays.     

益生菌微胶囊化技术研究概述

本文介绍了益生菌的生理功能及其微胶囊化的不同方法,并探讨了其发展前景。     

光合细菌2c菌株益生特性的实验研究

目的研究沼泽红假单胞菌2c菌株益生特性。方法利用耐酸、耐胆盐、体外黏附、平板抑菌试验及大鼠摄入2c菌株后在其体内的存活和持续时间实验研究其益生特性。结果pH2.5条件下处理30min及0.5%或0.9%牛胆盐处理对2c菌株活菌数无显著影响(P0.05);2c菌株体外对4株临床致病菌无抑制作用,体外黏附性能一般。2c菌株在大鼠体内存活和持续时间与摄入剂量有关,停止摄入3d后便不能富集出。结论2c菌株具有较好益生特性。     

Influence of probiotic supplementation on blood parameters and growth performance in broiler chickens

Effects of commercial probiotic (Bactocell®) on growth performance and blood parameters were evaluated. A total of 800 one day-old Ross broiler chicks were raised over 42 days. Chicks were wing-banded, weighed individually and randomly allocated into four equally major groups each having two replicates. Chicks of group 1 (control group) were fed the starter and finisher diets that did not supplemented with probiotic. The chicks of groups 2, 3, and 4 were fed the control starter and finisher diets supplemented with 1.6 g, 1 g and 0.8 g of probiotic per kg feed, respectively. Weekly body weight, feed consumption and feed conversion were measured. Blood parameters at 1, 4 and 6 weeks of age including packed cell volume (PCV), haemoglobin (Hb), total protein, albumin, total lipid and cholesterol were determined. All birds were kept under similar environmental, managerial and hygienic conditions. The results of the current study revealed that there was no significant change for Hb and PCV concentrations among different groups at all studied times. Also, total protein, lipids and albumin concentrations were not affected by probiotic supplementation. Chicken fed a diet containing various levels of probiotic showed a significant decrease (p ⩽ 0.05) in cholesterol concentration compared to control group. Probiotic supplementation significantly increased the body weight and daily weight gain of broiler chicks at late ages (3–6 weeks). Also, the birds fed on probiotic levels 1 and 0.8 g/kg diet exhibited higher body weight among chicken groups at 6 weeks of age. Improved feed conversion was noticed in birds fed a diet supplemented with probiotic. There was no significant difference in mortality rate among groups. We concluded that use of selected commercial probiotic resulted in improved performance parameters and reduced serum cholesterol in broiler chickens. Moreover, supplementation of the probiotic to broilers in the levels of 1 and 0.8 g/kg diet was found to be better than control and 1.6 g/kg level indicating that increasing dietary probiotic level does not has the best performance.     

Modulation of humoral immune response through probiotic intake

Thirty healthy volunteers were randomised into three different treatment groups and consumed Lactobacillus GG, Lactococcus lactis or placebo (ethyl cellulose) for 7 days. On days 1, 3 and 5, an attenuated Salmonella typhi Ty21a oral vaccine was given to all subjects to mimic an enteropathogenic infection. All subjects responded well to the vaccine, but no significant differences were observed in numbers of IgA-, IgG- and IgM-secreting cells among the different groups. There was a trend towards a greater increase in specific IgA among the subjects receiving the vaccine in combination with Lactobacillus GG. Those receiving L. lactis with their vaccine evinced significantly higher CR3 receptor expression on neutrophils than those receiving either the placebo or Lactobacillus GG. These results indicate that probiotics may influence differently the immune response to oral S. typhi vaccine and that the immunomodulatory effect of probiotics is strain-dependent.