Effects of difructose anhydride III (DFA III) administration on bile acids and growth of DFA III-assimilating bacterium Ruminococcus productus on rat intestine

The growth of DFA III-assimilating bacteria in the intestines of rats fed 3% DFA III for 2 weeks was examined. Sixty-four percent of the DFA III intake had been assimilated on day 3 of ingestion, and almost all of the DFA III was assimilated at the end of the experiment. The DFA III-assimilating bacterium, Ruminococcus productus, in DFA III-fed rats was in the stationary state of 10(8)-10(9) cells/g dry feces within a week from 10(6) cells/g dry feces on day 1 of DFA III ingestion. The number of R. productus cells was associated with the amount of DFA III excreted in the feces. The acetic acid produced from DFA III by R. productus lowered the cecal pH to 5.8. In control-fed rats and DFA III-fed rats, 94% of secondary bile acids and 94% of primary bile acids, respectively, were accounted for in the total bile acids analyzed. DFA III ingestion increased the ratio of primary bile acids and changed the composition of fecal bile acids. In conclusion, R. productus assimilated DFA III, produced short chain fatty acids, and the cecal pH was lowered. The acidification of rat intestine perhaps inhibited secondary bile acid formation and decreased the ratio of secondary bile acids. Therefore, it is expected that DFA III may prevent colorectal cancer and be a new prebiotic candidate.     

Effects of long-term ingestion of difructose anhydride III (DFA III) on intestinal bacteria and bile acid metabolism in humans

Changes in the intestinal microbiota of 10 human subjects with long-term ingestion of 3 g/d difructose anhydride III (DFA III; 4 persons, 2 months; 3 persons, 6 months; and 3 persons, 12 months) were examined by denaturing gradient gel electrophoresis (DGGE). According to the answers to questionnaires, the subjects were divided into two groups (constipated and normal). The DGGE profile was different for every individual and each subject had unique profiles of intestinal microbiota. In the DGGE profiles of constipated subjects, the intensities of bands related to Bacteroides spp. increased. Moreover, the DFA III-assimilating bacteria, Ruminococcus sp. were isolated from subjects who ingested DFA III for 12 months. These strains showed 95% similarity of their 16S rDNA sequences with that of Ruminococcus obeum ATCC 29174(T) (X85101) and produced large amounts of acetic acid. DFA III ingestion for 2 months tended to increase total organic acids in feces, and tended to decrease fecal pH and the secondary bile acid (SBA) ratio in total bile acids. The SBA ratio in total bile acids corresponded to fecal pH. The production of SBA was decreased by low pH in vitro. These results indicated that DFA III ingestion in humans tended to lower intestinal pH, inhibited bile acid 7alpha-dehydroxylation activities and also tended to decrease the SBA ratios in total bile acids. Moreover, as another cause for the decrease in the SBA ratio in total bile acids, it was suggested that the number of bile acid 7alpha-dehydroxylating bacteria were decreased by DFA III ingestion.     

The effects of di-D-fructofuranose-1,2':2,3'-dianhydride (DFA III) administration on human intestinal microbiota

Di-D-fructofuranose-1,2':2,3'-dianhydride (DFA III) was shown to enhance Ca absorption in rat and human intestine. The effects of DFA III administration (9 g per day for 4 weeks that corresponded to 3-fold the optimal dosage of DFA III) on human intestinal microbiota were studied using denaturing gradient gel electrophoresis (DGGE). The major groups of human intestinal microbiota reported previously: the Bacteroides, the Clostridium coccoides group (Clostridium cluster XIVa), the Clostridium leptum group (Clostridium cluster IV), and the Bifidobacterium group were detected. The similarity of 30 DGGE profiles based on the V3 region (before and after administration to the 15 subjects) of the 16S rDNA were calculated using Pearson's correlation based on numbers, positions and intensity of bands, and then a dendrogram of DGGE profiles was constructed by the unweighted pair group method using arithmetic average (UPGMA) clustering method. By these analyses, no difference in DGGE profiles after DFA III administration was observed in healthy subjects, while two subjects with chronic constipation showed different profiles, namely on numbers, positions and the intensity of some bands. Their stools were softer and stool frequencies increased and they obtained relief from constipation.     

Short communication: Effect of difructose anhydride III on serum immunoglobulin G concentration in newborn calves

Difructose anhydride (DFA) III is an indigestible disaccharide that promotes paracellular absorption of calcium, magnesium, and other minerals in the intestine by acting on epithelial tight junctions. This study aimed to elucidate the effect of DFA III on serum IgG concentration. One hundred and twenty Holstein and Holstein/Japanese Black crossbred calves were randomly divided into 4 groups of 30 to receive untreated colostrum (DFA0) or colostrum containing 3, 6, or 18 g of DFA III (DFA3, DFA6, or DFA18, respectively). At 24h after birth, both serum IgG (ranging from 16.4 to 21.2mg/mL) and apparent efficiency of absorption (26.0 to 37.2%) showed increases with the amount of DFA III intake. By multiple regression analysis, the standardized partial regression coefficient for DFA III was 0.25, the second highest following that for the colostrum IgG concentration (0.80), indicating a positive effect of DFA III on serum IgG. A positive linear regression was found between colostrum IgG and serum IgG concentrations at 24h of age. These results indicate that IgG absorption occurred as a nonsaturable process, which might be characteristic of gradient-dependent paracellular transport. Thus, it was concluded that DFA III improves not only minerals but IgG absorption in calves.     

双果糖酐Ⅲ的生理功能及制备方法

双果糖酐Ⅲ是近年来发现的一种新型天然功能性甜味剂,具有能量值较低,在消化系统不被消化,防止龋齿,促进人体吸收矿物质,增进有益菌群生长繁殖,降低胆固醇,防治糖尿病、高血压等多种生理功能,可以应用到焙烤食品、饮料、糖果中,还可用于低能量食品及糖尿病人食品中。目前制备方法主要采用生物催化法,该方法具有原料来源广泛且价格低廉,转化率高,适于工业化生产的优点。日本甜菜制药株式会社和日本Fancl公司已经实现双果糖酐Ⅲ的工业化生产,国内还处于研究阶段。目前市面上销售的双果糖酐Ⅲ产品主要是日本Fancl公司的促进矿物质吸收的保健食品。本文主要介绍了双果糖酐Ⅲ的理化性质、生理功能、制备方法以及国内外的发展动向。     

Efficient induction of inulin fructotransferase by inulin and by difructose anhydride III in Arthrobacter aurescens SK 8.001

Inulin fructotransferase (IFTase; EC 4.2.2.18) has received great attention mainly due to its application in producing difructose anhydride III (DFA III), which is a novel functional sweetener. The object of this study was to investigate the induction of IFTase in Arthrobacter aurescens SK 8.001 with various carbon sources, especially inulin and DFA III. IFTase production could be significantly promoted by the supplement of inulin (5–50 g/L) and DFA III (5–20 g/L). Inulin at high initial concentrations gave no indication of catabolite repression, whereas 30 and 40 g/L DFA III intensely inhibited cell growth and IFTase activity. No fructose was detected in broth throughout the cultivation with inulin, and inulin was converted into DFA III and minor fructooligosaccharides. And when DFA III was the carbon source, DFA III was the only sugar detected in the broth. In conclusion, both DFA III and inulin are effective for IFTase induction, and inulin with higher IFTase activity proved to be a more potent inducer.     

叔丁基对苯二酚对小鼠肠道菌群的影响

目的 研究食品添加剂叔丁基对苯二酚(tert-butylhydroquinone, TBHQ)对小鼠肠道菌群的影响。方法 BALB/c小鼠随机分为空白对照组和TBHQ处理组, 分别饮用纯水和TBHQ溶液(200 mg/L)。干预5周后, 利用酶联免疫吸附试验(enzyme linked immunosorbent assay, ELISA)测定小鼠血液样本炎症因子水平; 收集两组小鼠的粪便, 利用16S rDNA扩增子高通量测序分析肠道微生物群落结构和组成变化, 判断TBHQ对肠道菌群的影响。结果 与对照组相比, TBHQ处理显著降低了小鼠肠道疣微菌门(Verrucomicrobia)、拟杆菌门(Bacteroidetes)、阿克曼氏菌(Akkermansia)、瘤胃球菌属(Ruminococcus)等菌的相对丰度, 提高了厚壁菌门(Firmicutes)、变形菌门(Proteobacteria)、毛罗菌属(Lachnospira)、螺杆菌属(Helicobacter)等微生物的相对丰度。结论 本研究剂量TBHQ显著影响了小鼠的肠道菌群组成, 该变化对机体健康的影响有待进一步研究。     

Xanthohumol does not affect the composition of rat intestinal microbiota

Xanthohumol (XN), a prenylated chalcone, has been proposed to have beneficial effects on human health, including antimicrobial activity. To clarify whether the exposure to XN has an impact on the composition of the intestinal microbiota, 100 mg XN/kg body weight was given daily to rats for 4 wk. Diversity of the fecal microbial community was analyzed using PCR-DGGE. Although intact XN was detected in the feces of the rats at a concentration of up to 2.3 mg/g fecal dry weight, major shifts in the PCR-DGGE patterns in response to this flavonoid were not observed. The similarity index decreased slightly from 70 to 62% for the XN-treated rats and from 71 to 63% for the untreated animals. Thus, changes in the rat fecal microbiota observed in the course of the XN application are most likely due to intraindividual variability. However, the water content of the feces increased significantly during the XN treatment period.     

Effects on intestinal microbiota of probiotic fermented milk used for prevention of antibiotic-associated diarrhoea

Probiotic administration could prevent antibiotic-associated diarrhoea due to the restoration of an intestinal microbiota imbalance caused by antibiotics. The effect of the probiotics Lactobacillus acidophilus LA-5, Lactobacillus casei subsp. casei LC-01 and Bifidobacterium animalis subsp. lactis BB-12 on the composition and metabolic activities of the intestinal microbiota in human subjects during antibiotic treatment has been analyzed. Subjects that were placed on antibiotic therapy (amoxiciline/clavulanic or levofloxacin) were randomly assigned to receive a multispecies probiotic fermented milk (n = 122) or a placebo fermented milk (n = 125). Stool samples were collected at different intervals during the intervention study and analysed for faecal microbiota enumeration, probiotic species detection, enzyme activities and short chain fatty acid (SCFA) concentrations. The most predominant microbiota groups were total anaerobes, bacteroides and total aerobes. Probiotic species in fecal samples were analyzed by real-time PCR and results indicated that prevalence of the probiotic species within the probiotic group was below 50 % during the intervention study. Enzyme activities and SCFA concentrations showed a large inter-individual variability over the time in the placebo and probiotic groups, except to β-galactosidase activity, which was the most abundant in both groups over the time. In conclusion, the combination of L. acidophilus LA-5, L. casei subsp. casei LC-01 and B. animalis subsp. lactis Bb-12 taken in daily doses of 10⁹–10¹⁰ colony-forming units (CFU) does not significantly influence (P > 0.05) either the fecal microbiota or its metabolic activity in elderly hospitalized patients taking amoxicillin/clavulanate or levofloxacin. In addition, this combination of probiotic strains did not reduce the rate of occurrence of diarrohea in these patients.     

Effects of Fe(III) chemical speciation on dissimilatory Fe(III) reduction by Shewanella putrefaciens

Shewanella putrefaciens, a heterotrophic member of the gamma-proteobacteria is capable of respiring anaerobically on Fe(III) as the sole terminal electron acceptor (TEA). Recent genetic and biochemical studies have indicated that anaerobic Fe(III) respiration by S. putrefaciens requires outer-membrane targeted secretion of respiration-linked Fe(III) reductases. Thus, the availability of Fe(III) to S. putrefaciens may be governed by equilibrium chemical speciation both in the solution phase and at the bacterial cell-aqueous or cell-mineral interface. In the present study, effects of Fe(III) speciation on rates of bacterial Fe(III) reduction have been systematically examined by cultivating S. putrefaciens anaerobically on a suite of Fe(III)-organic complexes as the sole TEA. The suite of Fe(III)-organic complexes spans the range of stability constants normally encountered in natural water systems and includes Fe(III) complexed to citrate, 5-sulfosalicylate, NTA, salicylate, tiron, and EDTA. Rates of bacterial Fe(III) reduction in the presence of dissolved chelating agents correlate with the thermodynamic stability constants of the Fe(III)-organic complexes, implying that chemical speciation governs Fe(III) bioavailability. Equilibrium Fe(III) sorption experiments measured the reversible coordination of Fe(III) with S. putrefaciens as a function of cell/Fe(III) concentration, time, and activity of competing chelating agents. Results show that S. putrefaciens readily sorbs dissolved Fe(III) but that adsorption is restricted by the presence of strong Fe(III)-chelating agents. Our results indicate that dissimilatory Fe(III) reduction by S. putrefaciens is controlled by equilibrium competition for Fe(III) between dissolved organic ligands and strongly sorbing functional groups on the cell surface.     

Effects of probiotic yoghurt on symptoms and intestinal microbiota in patients with irritable bowel syndrome

The aim of the present study was to investigate the efficacy of probiotic yoghurt Lactobacillus rhamnosus GG (LGG) in the treatment of Irritable bowel syndrome (IBS). Eighty‐three IBS patients yielded data to be analysed from this 9‐week, placebo‐controlled, double‐blind and randomized trial. The patients consumed either a LGG‐containing probiotic yoghurt (treatment group; n = 44) or a placebo (n = 39) twice daily for 6 weeks. The results indicate that this probiotic yoghurt was effective in alleviating some IBS symptoms and resulted in slight changes in certain gut microbiota. Probiotic yoghurt may represent a treatment for some gastrointestinal disorders.     

木糖醇靶向调控菌群代谢流机制研究

本研究采用体内动物模型及体外模拟消化实验,通过对腹泻率统计、16S rRNA测序、短链脂肪酸检测、肠道微生物PICRUSt预测及宏转录组测序结果分析,探究木糖醇在肠道菌群中代谢机制.结果表明,木糖醇脱氢酶(EC 1.1.1.14)、木酮糖激酶(EC 2.7.1.17)和木糖磷酸异构酶(EC 5.1.3.1)是木糖醇代谢...     

Effects of extracts from bean (Phaseolus vulgaris) and field bean (Vicia faba) varieties on intestinal D-glucose transport in rat in vivo

Saline extract solutions from seeds of both Phaseolus vulgaris and Vicia faba varieties were prepared and tested for their total polyphenolic content and effect on intestinal D -Glucose transport across rat ileum in vivo. Intestinal D -glucose transport was significantly reduced (P < 0.001) by the presence of seed-extracts in the intestinal loop, regardless of the source of the extract. The order of potency (Phaseolus vulgaris, var. artropurpurea > Vicia faba, var. caballar > Vicia faba, var. minor > Phaseolus vulgaris, var. albus) is closely related to the polyphenolic content. Clear differences in the mode of action of the extracts were also observed. Extracts with appreciable polyphenolic content caused both a reversible and a lasting inhibitory effect on glucose transport, whilst extracts with negligible polyphenolic content only induced a reversible inhibition. Polyamide treatment of the extracts decreased their ability to inhibit glucose transport, but their inhibitory effect was not completely abolished by the treatment, further suggesting the presence of some other anti-absorptive factor(s) in the seeds.     

黄酒对小鼠肝脏功能及肠道菌群的影响

该实验探究黄酒对小鼠肝脏功能及其肠道菌群构成的影响。将24只4周龄雄性昆明种小鼠随机等分为3组,分别灌胃生理盐水、酒精、黄酒,连续灌胃30 d后,检测血液生化指标,二代测序检测粪便细菌的种群构成。结果表明,对照组小鼠血清中的谷丙转氨酶（ALT）浓度显著高于酒精组和黄酒组（P＜0.05）。黄酒组受试小鼠粪便细菌的Ace、Chao1、PD_whole_tree指数均显著低于对照组和酒精组（P＜0.05）。三个组肠道菌群组成具有一定差异。门水平上,对照组变形菌门（Proteobacteria）相对丰度显著高于酒精组和黄酒组（P＜0.05）;属水平上,对照组瘤胃球菌属（Ruminococcus）相对丰度显著低于酒精组和黄酒组（P＜0.05）,而单胞菌属（Stenotrophomonas）相对丰度显著高于酒精组和黄酒组（P＜0.05）,对照组颤螺旋菌属（Oscillospira）相对丰度显著低于酒精组（P＜0.05）。低度酒精以及同样酒精度下的黄酒短期投用未对小鼠肝脏功能造成明显影响,并可通过抑制部分肠道致病菌的生长,增加有益菌,从而起到一定的调节肠道菌群的作用。     

Effects of exogenous porcine somatotropin (pST) administration on pork meat quality

Two experiments were conducted on Large White pigs in order to assess the effect of porcine somatotropin (pST) administration upon meat quality criteria. No clear trend was observed concerning pH1 or pH2 measurements in Longissimus dorsi (LD), Adductor femoris (AF) and Semi spinalis (SS) muscles or drip loss in LD. Cooking loss in LD was not affected by pST treatment. Intramuscular lipid content was decreased by pST in LD and AF. Only non-polar lipids were affected by pST, whereas polar lipid content was similar in control and pST treated pigs. Percentage polyunsaturated fatty acids was significantly increased by pST in backfat and LD lipids, whereas no clear trend was observed concerning fatty acid composition of AF lipids.     

One-pot conversion of levan prepared from Serratia levanicum NN to difructose anhydride IV by Arthrobacter nicotinovorans levan fructotransferase

The newly established difructose anhydride IV (DFA IV) production system is comprised of the effective production of levan from sucrose by Serratia levanicum NN, the conversion of the levan into DFA IV by levan fructotransferase from Arthrobacter nicotinovorans GS-9, which is highly expressed in an Escherichiacoli transformant, and a practical purification step. The chemical properties of DFA IV were also investigated.