Effects of bovine lactoferrin on the immune system and the intestinal microflora of adult dogs

Eighteen Beagle dogs were used to evaluate the effects of bovine lactoferrin (bLF) on immune function and faecal microbial populations. The study comprised three feeding periods, each lasting four weeks. After an initial control Period 1, six dogs per group were supplemented with 0, 120 and 1800 mg bLF/kg dry diet, respectively (Period 2). In Period 3 dogs received again control diets. Peripheral blood mononuclear cell subsets, lymphocyte proliferative response to concanavalin A, phytohaemagglutinin and pokeweed mitogen and plasma IgA and IgG concentrations were analysed. The faecal concentrations of aerobic and anaerobic bacteria, Escherichia coli, Clostridium perfringens, Lactobacillus spp. and Bifidobacterium spp. were determined by cultural methods. Supplementation of bLF increased the number of monocytes, T cells and cytotoxic T cells in the blood and the proliferative response of peripheral blood mononuclear cells. The leukocyte counts were not affected, except monocytes that increased after the supplementation with bLF. Plasma immunoglobulin concentrations were unchanged by treatment. Dogs supplemented with bLF tended to have lower faecal concentrations of E. coli and Clostridium perfringens. In conclusion, bLF seems to alter indices of the cellular immune response and faecal microbial populations of healthy adult dogs.     

Effects of bovine lactoferrin on the immune system and the intestinal microflora of adult dogs

Eighteen Beagle dogs were used to evaluate the effects of bovine lactoferrin (bLF) on immune function and faecal microbial populations. The study comprised three feeding periods, each lasting four weeks. After an initial control Period 1, six dogs per group were supplemented with 0, 120 and 1800 mg bLF/kg dry diet, respectively (Period 2). In Period 3 dogs received again control diets. Peripheral blood mononuclear cell subsets, lymphocyte proliferative response to concanavalin A, phytohaemagglutinin and pokeweed mitogen and plasma IgA and IgG concentrations were analysed. The faecal concentrations of aerobic and anaerobic bacteria, Escherichia coli, Clostridium perfringens, Lactobacillus spp. and Bifidobacterium spp. were determined by cultural methods. Supplementation of bLF increased the number of monocytes, T cells and cytotoxic T cells in the blood and the proliferative response of peripheral blood mononuclear cells. The leukocyte counts were not affected, except monocytes that increased after the supplementation with bLF. Plasma immunoglobulin concentrations were unchanged by treatment. Dogs supplemented with bLF tended to have lower faecal concentrations of E. coli and Clostridium perfringens. In conclusion, bLF seems to alter indices of the cellular immune response and faecal microbial populations of healthy adult dogs.     

喘息样支气管炎患儿肠道微生态变化与免疫耐受关系的研究

目的 观察喘息样支气管炎患儿肠道菌群变化,探讨肠菌群变化与免疫耐受间关系.方法 采用16S rDNA荧光定量PCR法、流式细胞术和ELISA方法对47例喘息样支气管炎患儿、40例急性支气管炎患儿和30例健康儿童进行粪便双歧杆菌与大肠埃希菌的定量检测,外周血单个核细胞CD4+ CD25+T细胞(Treg)和血浆细胞因子TGF-β1的测定.结果 喘息样支气管炎、急性支气管炎患儿粪便中双歧杆菌数量和双歧杆菌/大肠埃希菌比值(B/E值)较健康对照组减少(P＜0.05),且喘息样支气管炎患儿粪便双歧杆菌数量和B/E值均低于急性支气管炎患儿(P＜0.05).喘息样支气管炎患儿的外周血Treg百分数、血浆TGF-β1浓度均低于急性支气管炎患儿和健康对照组(P均＜0.05);且外周血Treg百分数和血浆TGF-β1水平与肠道B/E值呈直线正相关关系.结论 喘息样支气管患儿发病初期即发生肠道菌群紊乱,肠道有益菌数量下降,且诱导免疫耐受失败.肠道菌群紊乱与免疫功能失衡间存在相互影响与制约关系,免疫耐受被打破贯穿疾病的整个病理过程.     

健康儿童与发育不佳儿童肠道菌群结构的比较研究

目的对健康儿童与发育不佳(FTT)儿童肠道中微生物区系的ERIC-PCR指纹图谱异同进行研究。方法根据美国疾病预防控制中心(CDC)对儿童生长发育的评价指标对某幼儿园200例4～6岁儿童进行评价,筛选出16例健康儿童和13例FTT儿童,每周1次连续3周跟踪取样,提取粪便样品中细菌总DNA,获得其ERIC-PCR指纹图谱,再将其中一个样品的ERIC-PCR产物作为混合探针通过杂交对指纹图谱上DNA条带序列的异同进一步比较。结果同一个体的肠道菌群结构在取样期间稳定性较好;虽然健康儿童间的肠道菌群结构也有一定差异,但它们却有着共同的结构特征;而健康儿童与FTT儿童的肠道菌群结构差异较大。结论儿童发育状况与肠道菌群结构有一定的关系。     

Qualitative and quantitative composition of intestinal microflora in healthy young children

The results of the qualitative and quantitative analysis of the microflora of the large intestine in 45 healthy children aged 6, 8, 10 months and 1 year, living in Moscow, are presented. During the first year of life high concentrations and detection rate of not only bifidobacteria, enterococci, nonpathogenic Escherichia, but also bacteria, commonly regarded as opportunistic were typical. The latter include lecithinase positive Clostridium, citrate assimilating enterobacteria, as well as Escherichia with low biochemical activity and capacity for hemolysin production. In addition, this group also includes coagulase-positive staphylococci. Later on, as these children become older, opportunistic bacteria are partially or completely eliminated under normal conditions. Suggestion is made that the composition of intestinal microflora depends on protective and other systems of the host at different periods of life, as well as on the character of nutrition and the microbial contamination of the environment.     

Immunology and probiotic impact of the newborn and young children intestinal microflora

Human body has developed a holistic defence system, which mission is either to recognize and destroy the aggressive invaders or to evolve mechanisms permitting to minimize or restore the consequences of harmful actions. The host immune system keeps the capital role to preserve the microbial intestinal balance via the barrier effect. Specifically, pathogenic invaders such as, bacteria, parasites, viruses and other xenobiotic invaders are rejected out of the body via barriers formed by the skin, mucosa and intestinal flora. In case physical barriers are breached, the immune system with its many components comes into action in order to fence infection. The intestine itself is considered as an “active organ” due to its abundant bacterial flora and to its large metabolic activity. The variation among different species or even among different strains within a species reflects the complexity of the genetic polymorphism which regulates the immune system functions. Additionally factors such as, gender, particular habits, smoking, alcohol consumption, diet, religion, age, gender, precedent infections and vaccinations must be involved. Hormonal profile and stress seems to be associated to the integrity microbiota and inducing immune system alterations. Which bacterial species are needed for inducing a proper barrier effect is not known, but it is generally accepted that this barrier function can be strongly supported by providing benefic alimentary supplements called functional foods. In this vein it is stressed the fact that early intestinal colonization with organisms such as Lactobacilli and Bifidobacteria and possibly subsequent protection from many different types of diseases. Moreover, this benefic microflora dominated but Bifidobacteria and Lactobacilli support the concept of their ability to modify the gut microbiota by reducing the risk of cancer following their capacity to decrease β-glucoronidase and carcinogen levels. Because of their beneficial roles in the human gastrointestinal tract, LAB are referred to as “probiotics”, and efforts are underway to employ them in modern nutrition habits with so-called functional foods. Members of Lactobacillus and Bifidobacterium genera are normal residents of the microbiota in the human gastrointestinal tract, in which they developed soon after birth. But, whether such probiotic strains derived from the human gut should be commercially employed in the so-called functional foods is a matter of debate between scientists and the industrial world. Within a few hours from birth the newborn develops its normal bacterial flora. Indeed human milk frequently contains low amounts of non-pathogenic bacteria like Streptococcus, Micrococcus, Lactobacillus, Staphylococcus, Corynebacterium and Bifidobacterium. In general, bacteria start to appear in feces within a few hours after birth. Colonization by Bifidobacterium occurs generally within 4 days of life. Claims have been made for positive effects of Bifidobacterium on infant growth and health. The effect of certain bacteria having a benefic action on the intestinal ecosystem is largely discussed during the last years by many authors. Bifidobacterium is reported to be a probiotic bacterium, exercising a beneficial effect on the intestinal flora. An antagonism has been reported between B. bifidum and C. perfringens in the intestine of newborns delivered by cesarian section. The aim of the probiotic approach is to repair the deficiencies in the gut flora and restore the protective effect. However, the possible ways in which the gut microbiota is being influenced by probiotics is yet unknown.     

Formation of intestinal microflora in children during the first year of their life

In 525 young children the state of intestinal microbiocenosis was studied every month of the first year their life. The study revealed that the process of the microflora formation lasted throughout the first year of their life and was characterized by dysbiotic disturbances. During this period the aggravation of dysbiotic changes in the intestine of these children on months 3, 6-7 and 11-12 was of particular importance. The formation of stable dysbacteriosis led to a decrease in the immunological status of the child, which was manifested by the increased content of such microorganisms as hemolytic cocci, Proteus and a decrease in the quantitative level of bifidobacteria in the total intestinal microbiocenosis by the end of the first year of child's life.     

State of normal intestinal microflora in preschool children living in the ecologically adverse region

In children living in an ecologically unfavorable area the quantitative content of bifidobacteria and enterococci appeared to be considerably decreased while the level of sulfate-reducing clostridia, on the contrary, elevated. The suppression of bifidoflora leads to decreased immune responsiveness that promotes different somatic diseases. Bronchitis, pneumonia, tonsillitis, pharyngitis, otitis, allergic diseases, diseases of digestive organs, acute respiratory virus infections are more often registered in children living in ecologically unfavorable Central district than in children living in the ecologically favorable Lenin district.     

Effect of normal and immune IgG, IgM and IgA on the intestinal microflora of mice with experimental dysbacteriosis

Human IgG, IgM and IgA produce a pronounced protective effect, preventing enterobacteria from penetration into the mucous membrane of the proximal section of the small intestine of mice in antibiotic-induced dysbacteriosis. Normal mouse IgG and IgM, in contrast to IgA, are effective against mucosal enterobacteria of the small intestine. Immune mouse IgG, IgM and IgA show greater activity in protecting the mucous membrane than normal immunoglobulins of these classes.     

肝移植与肠道微生态

肠道黏膜与肠道内共生的微生物形成了肠道黏膜屏障,可有效防止内源性及外源性微生物及毒素的侵害;肝脏与肠道关系密切,作为终末期肝病的有效治疗手段,肝移植术打破了原有的平衡,造成了肠道微生态的改变。     

Orthogonal array design in optimizing ERIC-PCR system for fingerprinting rat's intestinal microflora

AIMS: The aim of the present study was to rapidly optimize enterobacterial repetitive intergenic consensus (ERIC)-PCR amplification systems for fingerprinting rat's intestinal microflora. METHODS AND RESULTS: Orthogonal array design and statistic analysis methods were attempted to rapidly optimize ERIC-PCR reaction system for fingerprinting intestinal microflora. The results showed that variations of the four factors (Mg(2+), dNTP, primer and HotstarTaq polymerase concentrations) changed the fingerprinting patterns significantly. The order of effects of those factors on fingerprinting patterns was primers (F = 274.000, P = 0.000), Hotstar Taq polymerase (F = 197.000, P = 0.001), Mg(2+) (F = 181.000, P = 0.001) and dNTP (F = 27.000, P = 0.011). The optimal ERIC-PCR condition was containing 200 micromol l(-1) dNTP, 2.5 mmol l(-1) Mg(2+), 0.4 micromol l(-1) primer, 1 U HotstarTaq DNA polymerase namely 25 microl reaction system, which is proved to be a simple, fast and reliable method suitable for fingerprinting rat's intestinal microflora. CONCLUSIONS: The results suggest that Mg(2+), dNTP, primer and HotstarTaq polymerase concentrations play important roles on ERIC-PCR fingerprinting patterns. Orthogonal array design is a considerable method to optimize ERIC-PCR reaction system for its rapidness, simplicity, potential to investigate mutual effects of parameters. SIGNIFICANCE AND IMPACT OF THE STUDY: It is the first report on optimization of ERIC-PCR amplification systems for fingerprinting intestinal microflora using orthogonal array design or statistic analysis methods and systematically observing the effects of variables of reaction conditions.     

Antibiotic resistance in commensal intestinal microflora

The susceptibility toward antibiotics was determined by disc and MIC methods in Lactobacillus and, for comparison, in Escherichia coli strains isolated from cloacal swabs of broiler chickens derived from various farms in Slovakia. The occurrence of acquired tetracycline resistance in E. coli and lactobacilli isolated from the same sample was similar. The presence of tet(M), tet(S), tet(L) and ermB genes was demonstrated in lactobacilli while the tet(M) gene was not detected in E. coli.     

Comparison of intestinal microflora in healthy infants and infants with allergic colitis

Twenty-eight exclusively breast-fed healthy infants and 16 infants also exclusively breast-fed with allergic colitis (aged 85 +/- 60 and 98 +/- 58 d, respectively) were screened for differences in fecal flora. Bifidobacteria were detected in 23 healthy infants and only in 4 fecal samples of infants with allergic colitis. All bifidobacteria-free infants possessed Gram-positive regular rods as a major group of their fecal flora. These bacteria were identified as clostridia using genus-specific FISH probe. Infants with allergy colitis possessed significantly lower counts of bifidobacteria and total anaerobes and significantly higher counts of clostridia in their feces. In healthy infants, Bifidobacterium longum was the most frequently found species (54.5% of the samples), followed by B. adolescentis (20.0), B. breve (18.2), B. bifidum (16.4), B. dentium (10.9) and B. pseudocatenulatum (1.80). Bifidobacterial isolates from two babies with allergic colitis were identified as B. longum, one child from patients group contained species B. dentium and one baby B. adolescentis. Our results suggest that there are significantly lower counts of bifidobacteria in infants with allergic colitis than in healthy infants.     

黄连素对肠道黏膜免疫功能的调节作用

黄连素(berberine)是在中国传统医药中广泛应用的广谱抗菌药物,临床上主要用于治疗肠道细菌感染性疾病。肠道黏膜免疫是机体防止感染的第一道防线,并在宿主与外环境间黏膜稳态的建立和维持上发挥着重要作用。近年来,中医药对肠道黏膜免疫的研究已成为国内外学者的研究热点,现就黄连素在肠道黏膜免疫中的调控作用作一综述。     

NAG infection in Rana temporaria with suppressed normal intestinal microflora]

Frogs of the Rana temporaria species with disturbed biocenosis induced by combined effects of hypothermia (+4 degrees C) and tetracycline were used as an experimental model. The animals were inoculated orally with cultured NAD-vibrios and subjected to clinical, bacteriological, immunomorphological and electron microscopical examinations. The lymph-blood system was shown to be a possible pathway for generalization of the infection. Several causes of long-term persistence of the vibrios in Rana temporaria are discussed.