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.     

Effect of oligofructose supplementation on gut microflora and well-being in young children attending a day care centre

The effect of daily administration of oligofructose (OF) on 7-19 months old healthy children intestinal microflora, intestinal tolerance and well-being was assessed in a double blind placebo controlled study. The study comprised 8 days of observation, 21 days of supplementation, and 15 days of post-supplementation. Exclusion criteria included antibiotic use and intake of other prebiotic and probiotic at any time following enrolment. Faecal flora was analysed by culture methods, and health information was recorded daily. Bifidobacteria, tended to slightly increase with OF supplementation, but not with placebo (p=0.095). Simultaneously, a decrease in potential pathogens, significant for clostridia (p=0.05) but not for staphylococci (p=0.09) was observed in the OF group. These modifications did not persist during the post-supplementation period. OF supplementation were accompanied by less flatulence, diarrhoea, vomiting (p<0.001), and fever (p<0.05) events.     

Effect of rapid cooling and acidic pH on cellular homeostasis of Pectinatus frisingensis, a strictly anaerobic beer-spoilage bacterium.

Pectinatus frisingensis is a strictly anaerobic mesophilic bacterium involved in bottled beer spoilage. Cellular volume, adenylate energy charge, intracellular pH and intracellular potassium concentration measurements were performed in late exponential-phase cell suspensions placed in different physiological conditions, to evaluate the capability of this bacterium to maintain cellular homeostasis. The intracellular pH was calculated from the intracellular accumulation of a [carboxyl-14C]benzoic acid. Optimum physiological conditions were the presence of a carbon source and pH of 6.2, hostile conditions were a pH 4.5, absence of a carbon source, and rapid cooling treatment. The cell was able to maintain a higher intracellular pH than the external pH under all conditions. Intracellular volume was lower at pH 4.5 than at pH 6.2. A low net potassium efflux rate was routinely measured in starving cells, while glucose addition promoted immediate net potassium uptake from the medium. Cooling treatment resulted in sudden net potassium efflux from the cell, a decrease of the intracellular pH, and low modifications of the adenylate energy charge in metabolizing-glucose cell suspensions. Thus, cold treatment perturbs the P. frisingensis homeostasis but the bacteria were able to restore their homeostasis in the presence of a carbon source, and under warm conditions.     

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 anolyte on background microflora, Salmonella, and Listeria monocytogenes on catfish fillets

Near-neutral electrolyzed water (anolyte), having a pH of 6.0 to 6.5 ± 0.02, oxidation reduction potential of greater than 700 mV, and a residual chlorine level of 10 to 200 ppm, was reported to have a potential use to decontaminate food surfaces. An electrolyzing cell was developed that is capable of producing neutral electrolyzed water containing a chlorine level of greater than 700 ppm in the form of hypochlorous acid (anolyte). Anolyte with a chlorine level of 300 ppm was used to determine its effect on Salmonella and Listeria monocytogenes cells after a 3-min contact. Transmission electron micrograph results showed disruption of the outer cellular membrane for both bacteria. The anolyte (300 ppm) was used as a washing solution to decontaminate catfish fillets inoculated with either Salmonella or L. monocytogenes. After a 3-min contact time with the anolyte, there was a 1-log reduction for Salmonella, and after 8 days of refrigerated storage (4°C), this bacterial reduction was maintained. There was no reduction of L. monocytogenes on the catfish fillet surfaces. The anolyte was an effective wash solution for Salmonella reduction on the catfish fillet surfaces.     

Exercise training of late-pregnant and nonpregnant dairy cows affects physical fitness and acid-base homeostasis

The objective was to determine if exercise training improves physical fitness of nonlactating, late-pregnant and nonpregnant multiparous Holstein cows and alters acid-base homeostasis during an exercise test on a treadmill. Twenty-six pairs (each pair having 1 late-pregnant and 1 nonpregnant) of cows were assigned to treatments of exercise training or no exercise. Exercise training was walking (1.25 to 1.5 h at 3.25 km/h) every other day in an outdoor mechanical walker for 70 d. Cows completed treadmill exercise tests on d 0, 30, and 60 of the experiment or about d 70, 40, and 10 before expected parturition of the pregnant cow of each pair. On d 0, physical fitness was similar among all cows based on durations of treadmill tests, heart rates, and acid-base measurements at given workloads (21.1 ± 0.6 min; 144 ± 2.2 beats per min; plasma lactate 3.1 ± 1.9 mmol/L; and venous blood pH 7.44 ± 0.0035, respectively). After 60 d of training, exercised cows walked longer during treadmill exercise tests compared with nonexercised cows (23.7 vs. 18.3 ± 0.85 min, respectively), indicating greater physical fitness (pooled across pregnancy status). Heart rates and plasma lactate concentrations at given workloads were less (144 vs. 156 ± 2.7 beats per min; and 1.4 vs. 3.2 ± 0.24 mmol/L for exercised compared with nonexercised cows, respectively). Additionally, exercised cows more effectively maintained acid-base homeostasis during treadmill tests compared with nonexercised cows. Metabolic, endocrine, and nutritional demands associated with late pregnancy did not affect responses differently to exercise training for late-pregnant compared with nonpregnant cows. Overall, exercise training of late-pregnant and nonpregnant cows for 60 d improved physical fitness.     

婴幼儿配方食品和乳粉中维生素C的测定

目的建立一种前处理简单、仪器条件稳定、准确高效的婴幼儿配方食品和乳粉中维生素C的检测方法。方法用含有三(2-羧乙基)膦(TCEP)的三氯乙酸(TCA)对样品中的维生素C进行提取,C18柱色谱分离,流动相为含TCEP与癸胺作为离子对试剂和pH 5.4的醋酸钠的混合水溶液,然后在紫外检测器265 nm处进行检测。结果本方法的相对标准偏差(n=6)在0.36%~3.2%之间,平均回收率为88.5%~97.9%,线性相关系数r~2大于0.9999。结论本方法实验前处理简单,干扰因素少;仪器条件稳定,灵敏度高,重复性好;适合婴幼儿配方食品和乳粉复杂基质样品的测定。     

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.     

臭氧水对牡蛎细菌菌相及货架期的影响

分析了臭氧水对牡蛎细菌菌相及5℃条件下冷贮货架期的影响。结果表明,在臭氧水的作用下,牡蛎体内的初始细菌总数由3.2×103降至1.75×102,货架期由235h延长至283h。采用SHEWAN等提出的海产鱼贝类细菌测定图示对臭氧水处理前后牡蛎体内的菌相变化情况进行了分析,发现臭氧水对牡蛎体内各属细菌的杀灭作用是不同的。通过分析货架期终点时的菌相,发现对照组与臭氧组在腐败初期时的优势菌都是假单胞菌Ⅰ/Ⅱ群(PseudomonasⅠ/Ⅱsp)。     

Comparative evaluation of intestinal microflora in infants on artificial feeding with various milk formulas

The intestinal microflora was studied in 58 normal full-term infants kept on different types of feeding. The data obtained indicate that the transfer of infants from natural to artificial feeding was attended by changes in the intestinal biocenosis, with these changes being most demonstrable as a result of the use in the feeding of unadapted milk formulas. The feeding with adapted milk formulas (the acidophilic formula Malyutka, Malyutka with a new fatty composition, Detolact) compares very favourably with the feeding with unadapted formulas as regards its effect on the intestinal biocenosis. However, artificial feeding is inferior to natural feeding that exerts a more favourable action on the development of intestinal microflora, both anaerobic and aerobic. This attests to the necessity of further improvement of the biological properties of bady food.     

Periparturient effects of feeding a low dietary cation-anion difference diet on acid-base, calcium, and phosphorus homeostasis and on intravenous glucose tolerance test in high-producing dairy cows

Feeding rations with low dietary cation-anion difference (DCAD) to dairy cows during late gestation is a common strategy to prevent periparturient hypocalcemia. Although the efficacy of low-DCAD rations in reducing the incidence of clinical hypocalcemia is well documented, potentially deleterious effects have not been explored in detail. The objective of the study presented here was to determine the effect of fully compensated metabolic acidosis on calcium and phosphorus homeostasis, insulin responsiveness, and insulin sensitivity as well as on protein metabolism. Twenty multiparous Holstein-Friesian dairy cows were assigned to 1 of 2 treatment groups and fed a low-DCAD ration (DCAD = −9 mEq/100 g, group L) or a control ration (DCAD = +11 mEq/100 g, group C) for the last 3 wk before the expected calving date. Blood and urine samples were obtained periodically between 14 d before to 14 d after calving. Intravenous glucose tolerance tests and 24-h volumetric urine collection were conducted before calving as well as 7 and 14 d postpartum. Cows fed the low-DCAD ration had lower urine pH and higher net acid excretion, but unchanged blood pH and bicarbonate concentration before calving. Protein-corrected plasma Ca concentration 1 d postpartum was higher in cows on the low-DCAD diet when compared with control animals. Urinary Ca and P excretion was positively associated with urine net acid excretion and negatively associated with urine pH. Whereas metabolic acidosis resulted in a 6-fold increase in urinary Ca excretion, the effect on renal P excretion was negligible. A more pronounced decline of plasma protein and globulin concentration in the periparturient period was observed in cows on the low-DCAD diets resulting in significantly lower total protein and globulin concentrations after calving in cows on low-DCAD diets. Intravenous glucose tolerance tests conducted before and after calving did not reveal group differences in insulin response or insulin sensitivity. Our results indicate that fully compensated metabolic acidosis increased the Ca flux resulting in increased urinary calcium excretion before calving and increased plasma Ca concentration on the day after calving, whereas the effect on P homeostasis was unlikely to be clinically relevant. The clinical relevance of the effect of metabolic acidosis on the plasma protein and globulin concentration is unclear but warrants further investigation.     

北京地区不同喂养方式婴幼儿肠道菌群多样性分析

目的 探讨不同喂养方式对0~3岁婴幼儿肠道微生物的影响,以及喂养方式引起的肠道菌群变化与婴幼儿的年龄和分娩方式之间的相关性。方法 选取221例0~3岁北京地区健康婴幼儿肠道粪便样品,按照哺乳方式,将这些样品分为4组：纯母乳组（B）、纯奶粉组（F）、以母乳为主,奶粉和辅食为辅组（BP）、以奶粉为主,辅食为辅（NB）。其中B组44例、F组29例、BP组108例、NB组40例。利用16s微生物多样性测序技术分析了不同喂养方式对婴幼儿肠道微生物的丰度影响。结果 在物种组成上,没有摄入母乳的NB组,门水平上优势菌的含量变化明显。厚壁菌门、变形菌门、放线菌门和拟杆菌门四大优势菌的总含量明显低于B组、BP组和F组。在属水平上B组、BP组和F组相互比较,F组双歧杆菌属和拟杆菌属的含量显著下降,但粪杆菌属、罕见小球菌属等厌氧菌的含量升高。主成分分析的结果表明,NB组和B组的距离最远,F组与BP组的距离最近。F组与B组的差异要大于BP组与B组的差异,说明,与纯母乳喂养的婴幼儿相比,奶粉喂养的婴幼儿其肠道微生物的变化要大于辅以母乳摄入的婴幼儿。同时,关联性分析表明,分娩方式与喂养方式和婴幼儿年龄在影响肠道菌群的丰富度上密切相关。结论 出生前3年的饮食组成和模式会显著影响肠道微生物群的多样性,这种多样性变化与婴幼儿的年龄和分娩方式均具有密切的相关性。     

甘露寡糖对罗非鱼肠道菌群的影响

考察饲料中添加自制酵母甘露寡糖、外购甘露寡糖和黄霉素对奥尼罗非鱼肠道菌群的影响。实验以平均初重20.04±0.13g的奥尼罗非鱼为实验对象,在基础饲料中分别添加0.00%(对照组)、0.5%的自制酵母甘露寡糖、0.5%的外购甘露寡糖和8mg/kg黄霉素。传统菌落计数结果表明,各添加剂都能明显改变幼鱼肠道中的乳酸杆菌和大肠杆菌的数量及比例,饵料中添加0.5%的自制酵母甘露寡糖更能优化罗非鱼肠道微生物的微生态环境。DGGE图谱分析表明,自制酵母甘露寡糖、外购甘露寡糖、黄霉素的加入都改变了罗非鱼原有的肠道微生物的微生态环境,其中自制酵母甘露寡糖对罗非鱼肠道微生物的微生态影响更大。      

Effect of diet on fecal and urinary estrogenic activity

The United States Environmental Protection Agency has identified estrogens from animal feeding operations as a major environmental concern, but few data are available to quantify the excretion of estrogenic compounds by dairy cattle. The objectives of this study were to quantify variation in estrogenic activity in feces and urine due to increased dietary inclusion of phytoestrogens. Ten Holstein heifers were assigned to 2 groups balanced for age and days pregnant; groups were randomly assigned to treatment sequence in a 2-period crossover design. Dietary treatments consisted of grass hay or red clover hay, and necessary supplements. Total collection allowed for sampling of feed refusals, feces, and urine during the last 4 d of each period. Feces and urine samples were pooled by heifer and period, and base extracts were analyzed for estrogenic activity (estrogen equivalents) using the yeast estrogen screen bioassay. Feces and urine samples collected from 5 heifers were extracted and analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS) to quantify excretion of 7 phytoestrogenic compounds. Excretion of 17-β estradiol equivalents in urine was higher and tended to be higher in feces for heifers fed red clover hay (84.4 and 120.2 mg/d for feces and urine, respectively) compared with those fed grass hay (57.4 and 35.6 mg/d). Analysis by LC-MS/MS indicated greater fecal excretion of equol, genistein, daidzein, coumestrol, and formononetin by heifers fed red clover hay (1634, 29.9, 96.3, 27.8, and 163 mg/d, respectively) than heifers fed grass hay (340, 3.0, 46.2, 8.8, and 18.3 mg/d, respectively). Diet had no effect on fecal biochanin A or 2-carbethoxy-5, 7-dihydroxy-4’-methoxyisoflavone. Four phytoestrogens were detected in urine (2-carbethoxy-5, 7-dihydroxy-4’-methoxyisoflavone, daidzein, equol, and formononetin) and their excretion was not affected by diet. Identifying sources of variation in estrogenic activity of manure will aid in the development of practices to reduce environmental estrogen accumulation.     

Effect of a metabolically created systemic acidosis on calcium homeostasis and the diurnal variation in urine pH in the non-lactating pregnant dairy cow

Reducing the dietary cation-anion difference (DCAD) has been shown to be an effective means of preventing parturient paresis in confinement systems where cows are offered a total mixed ration containing DCAD-reducing mineral compounds (anionic salts). Such a supplementation strategy is not possible in cows being group fed forages precalving, and little is known about the effect of supplementing these cows with large amounts of anionic salts twice daily.Eight non-lactating, pregnant Holstein-Friesian cows were allocated to two levels of DCAD (-20 and +18 meq/100 g DM) for 24 d, with an intensive Ca balance undertaken in metabolism stalls following a 2-week acclimatization to diet. The basal diet was 3 kg DM of crushed barley and 7 kg DM of pasture-hay. Urine and faeces were collected separately, weighed daily for 5 d and analysed for Ca content. Urinary Ca, creatinine and hydroxyproline concentration and plasma Ca concentration were determined during the period of the balance study. The diurnal pattern in urine and rumen pH was determined over 2 d. Decreasing DCAD reduced (P<0.001) the pH of urine, and increased (P<0.05) Ca absorption. Plasma Ca concentration was not affected by DCAD, and DCAD did not affect the output of urinary hydroxyproline, a marker of bone resorption. Twice-daily supplementation of anionic salts was sufficient to reduce the pH of blood and increase gastrointestinal Ca absorption. There was no diurnal variation in the pH of urine, suggesting that time of sampling to determine efficacy of DCAD in reducing systemic pH was not important.     

Breast hormones--regulators of energy homeostasis: growth of infants

Studied the possible relationship between the growth rate of children who are breastfed, and the level of protein, fat, insulin-like growth factor- 1 (IGF-1), ghrelin, leptin, adiponectin in breast milk. Examined 71 pair--a mother and a healthy child, who is breastfed. All infants were divided into 3 groups: low, normal and high weight gain. Daily breast milk intake, the level of fat, protein and hormones proteins regulators of energy homeostasis (adiponectin, grelin, IGF-1 and leptin) in breast milk were measured at 1, 2 and 3 months of lactation. It was found that daily breast milk consumption was higher in the group of infants with high weight gain and the content of protein and fat in it did not differ in three groups. Total daily consumption of protein and fat with breast milk was higher in groups of infants with high weight gain. There was significantly higher IGF-1 level and the tendency to higher grelin level in breast milk of mothers of infants with higher weight gain. The possible link of breast milk hormones with growth velocity of breast-fed infants is discussed.     

低聚异麦芽糖对肠道菌群的调节作用

低聚异麦芽糖是功能性低聚糖之一,也称作益生元.本文主要综述了低聚异麦芽糖对肠道菌群调节作用的研究进展,阐述了其作用机理和主要影响因素,并对该作用在食品中的应用及相关新品开发方向提出一定的建议.