丁酸梭菌替代金霉素对肉鸡腿肌肉品质和抗氧化功能的影响

丁酸梭菌（Clostridium butyricum）是一种产丁酸等短链脂肪酸的有益菌,添加到饲料中可改善动物的生产性能、提高饲料利用率和机体的抗氧化功能。【目的】本文研究了丁酸梭菌替代金霉素添加到肉鸡日粮中,对肉鸡腿肌肉品质和抗氧化功能的影响。【方法】随机选取1日龄健康艾拔益加（AA）肉仔鸡360只,分为3组,每组8个重复,阴性对照组（CON）饲喂基础日粮;抗生素组（ANT）饲喂添加75 mg/kg金霉素的基础日粮;丁酸梭菌组（CB）饲喂添加500 mg/kg丁酸梭菌（活菌数10⁹ CFU/g）的基础日粮,试验为期42 d。【结果】与CON组相比,CB组肉鸡腿肌重、腿肌肉24 h红度（a^*）、pH_{45 min}、pH_{24 h}、粗蛋白质和粗脂肪的含量显著提高,腿肌肉总抗氧化能力（total-antioxidant capacity,T-AOC）、过氧化氢酶（catalase,CAT）、总超氧化物歧化酶（total superoxide dismutase,T-SOD）和谷胱甘肽过氧化物酶（glutat...     

解淀粉芽孢杆菌3-2发酵羽毛产氨基酸

【目的】建立废弃羽毛液体发酵工艺,优化发酵条件,提高羽毛降解率及氨基酸产量,研发新型、高效复合氨基酸肥料。【方法】利用解淀粉芽孢杆菌3-2发酵羽毛,探究温度、发酵时间、羽毛含量、单一碳源、复合碳氮源、金属离子等对废弃羽毛降解效果以及发酵液中氨基酸种类和含量的影响。【结果】废弃羽毛降解率与氨基酸总产量呈负相关。随着发酵时间延长,羽毛降解率增加,当发酵温度为37°C、羽毛添加量为1%、以乳糖为外加碳源、添加Mg2+时,羽毛降解率最高,达到81.92%。随着羽毛添加量增加,氨基酸总含量也增加(在20%范围以内),当发酵温度为37°C、降解时间为108 h、羽毛添加量为10%、乳糖添加量为0.5%、不添加复合碳氮源、不添加金属离子时,氨基酸的种类最全(富含17种氨基酸),总含量最高,达到20.861 g/kg。【结论】利用解淀粉芽孢杆菌3-2发酵废弃羽毛生产氨基酸复合肥料是一种可靠、环保、经济的方法,获得的氨基酸肥料营养齐全。研究结果为新型复合氨基酸肥料的研发提供技术支撑。     

基于盲肠菌群和回肠粘膜基因表达探讨解淀粉芽孢杆菌提高蛋鸡生产性能的潜在机制

【背景】我们的前期工作表明,在蛋鸡饲料中添加解淀粉芽孢杆菌BLCC1-0238可显著提高产蛋性能和蛋品质,但其益生机制还不清楚。【目的】从基因组学和转录组学的视角去揭示益生菌提高蛋鸡生产性能的潜在机制。【方法】利用高通量测序技术比较分析基础日粮组(C组)和解淀粉芽孢杆菌BLCC1-0238添加组(0.06%,2.0×1010 CFU/g,T组)盲肠微生物菌群和回肠粘膜基因表达的差异。【结果】基因组学分析发现,与对照组相比,益生菌添加组的盲肠菌群Chao1和Shannon指数升高;在门水平上,厚壁菌门/拟杆菌门(Firmicutes/Bacteroidetes)的比例显著增加,梭杆菌门(Fusobacteria)和变形菌门(Proteobacteria)的相对丰度降低;在属水平上,厚壁菌门中的考拉杆菌属(Phascolarctobacterium)、乳酸杆菌属(Lactobacillus)、瘤胃球菌科UCG-014属(Ruminococcaceae UCG-014)、厌氧棍状菌属(Anaerotruncus)、瘤胃梭菌属(Ruminiclostridium9)、克里斯滕森氏菌(Christensenellaceae_R-7_group)相对丰度明显增加。转录组学结果表明,回肠粘膜组织中共有356个差异表达基因,其中,上调基因199个,下调基因157个。生物信息学分析提示,上调基因参与了淀粉和蔗糖代谢、半乳糖代谢以及甘氨酸、丝氨酸和苏氨酸代谢等促进物质代谢和营养吸收的过程。【结论】日粮中添加解淀粉芽孢杆菌BLCC1-0238,可通过改善盲肠菌群多样性和肠道营养吸收能力提高蛋鸡的饲料利用率和产蛋性能,具有潜在的实用价值。     

载锌凹凸棒石黏土对瘤胃体外发酵细菌多样性的影响

【目的】研究载锌凹凸棒石黏土对瘤胃体外发酵细菌多样性的影响。【方法】本试验采用离子交换法制备载锌凹凸棒石黏土,利用16S rDNA测序技术分析了载锌凹凸棒石黏土对奶牛瘤胃体外发酵细菌菌群和多样性的影响。【结果】研究共获得1490959个有效序列和87662个OTUs。测序结果表明,与对照组相比,试验Ⅳ组中的细菌多样性在体外发酵24 h时提高,试验Ⅳ组中的细菌丰度在体外发酵48 h时提高。细菌菌群组成分析表明,60个样本中的优势菌门主要是厚壁菌门、拟杆菌门、变形菌门和黏胶球形菌门。与对照组相比,各试验组的厚壁菌门在体外发酵24 h和48 h时均显著增加(P0.05),试验Ⅳ组中拟杆菌门在发酵48 h时显著降低(P0.05);60个样本中共获得124个细菌菌属,其中对照组与试验组中普氏菌属含量均没有显著变化(P0.05)。在体外发酵48 h时,试验Ⅳ组中密螺旋体属含量与对照组相比显著增加(P0.05),而食物谷菌属和假丁酸弧菌属含量与对照组相比均显著降低(P0.05)。【结论】载锌凹凸棒石黏土对奶牛瘤胃体外发酵中细菌多样性产生一定影响,其影响随发酵时间和添加剂量而不同。     

地衣芽孢杆菌对南美白对虾零水交换养殖系统细菌群落的影响

【目的】地衣芽孢杆菌（Bacillus licheniformis）对南美白对虾（Penaeus vannamei）免疫反应、抗病性和营养的影响已被广泛研究，但零水交换养殖系统下地衣芽孢杆菌对对虾肠道和养殖水环境微生物群落的影响尚不清楚。【方法】通过收集添加地衣芽孢杆菌在饲料或水中后，对虾肠道、池水和池低沉积物样品，通过16S rRNA基因测序和线性判别分析（linear discriminant analysis effect size，LEfSe）进行微生物分析。【结果】结果表明，添加地衣芽孢杆菌对对虾的生长影响较小。此外，添加方式的不同对对虾肠道菌群的影响较小。但添加地衣芽孢杆菌可以有效地改变对虾肠道微生物群落，并改善对虾免疫力。【结论】这些结果有助于全面了解在零水交换养殖系统中，通过饲料和水添加地衣芽孢杆菌后对虾肠道和环境的变化，从而为选择正确的益生菌以及如何添加益生菌维持对虾健康提供基础信息。     

蜡状芽孢杆菌S458-1对水产养殖系统中水质调节的作用

【目的】水产养殖过程中蜡状芽孢杆菌(Bacillus cereus)作为益生菌被广泛应用。本研究旨在深入了解分离于养殖水体中的一株蜡状芽孢杆菌S458-1对养殖水体以及养殖对象的影响,以期为菌株S458-1在水产养殖生产上的应用提供理论依据。【方法】根据控制变量法,各试验组鲫鱼养殖模式设置相同温度、盐度、溶氧和pH,利用分光光度法测定水体的水化学指标;利用试剂盒法测定鲫鱼的血清生理生化指标。【结果】添加菌株S458-1处理组(终浓度分别为10~6、10~7、10~8CFU/mL)与对照组(未加S458-1菌)相比:水体活性磷浓度显著性增加(P0.05);同时具有把NH_4~+-N和NO_2~–-N转化为NO_3~–-N的趋势,但无显著性差异(P0.05);养殖鲫鱼血清检测结果显示谷草转氨酶(GOT)、超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)以及丙二醛(MDA)含量均显著降低(P0.05)。【结论】蜡状芽孢杆菌S458-1具有脱氮解磷、调节水质的作用,并可增强养殖对象的生理健康状态,可作为益生菌应用于水产养殖中,具有较高的应用价值。     

河南省白龟山水库下游水体氨化细菌分离鉴定及其降解有机氮条件

【目的】从河南省白龟山水库下游水体中分离筛选氨化细菌,并研究其降解有机氮的条件。【方法】利用选择性培养基从微污染水源水中筛选氨化细菌,进一步比较了不同氨化细菌降解有机氮的效果;采用单因子法研究菌株N24降解有机氮的条件;通过形态、生理生化特征及16S rRNA基因序列分析对菌株N24进行鉴定。【结果】从微污染水源水中分离筛选到4株氨化细菌,其中菌株N24培养48 h后氨氮浓度较高,达到138.926 mg/L。菌株N24降解有机氮最适温度为30-35°C,最适初始pH值为6.0,500 mL摇瓶最适装液量75 mL。菌株N24被鉴定为弯曲芽孢杆菌(Bacillus flexus,GenBank登录号:JX291240.1),其16S rRNA基因序列与基因库中芽孢杆菌属菌株的16S rRNA基因序列有99%-100%的相似性,与弯曲芽孢杆菌(Bacillus flexus IFO15717T,GenBank登录号:NR024691.1)的遗传距离最近。【结论】菌株N24是一株高效降解有机氮的弯曲芽孢杆菌;本研究丰富了降解有机氮菌种资源,可为该菌在环境工程领域的实际应用提供理论基础。     

浓缩营养液对肉鸡增重效果的研究

通过在肉鸡饮水中添加浓缩营养液,观察其对肉鸡增重效果。结果表明,实验肉鸡比未空白对照组多增重0.075kg,每只鸡多收益0.6元;扣除浓缩液成本后,万羽肉鸡净增效益4100元;与添加多维对照组相比,肉鸡多增重0.056kg,表明浓缩营养液的效果显著超过多维。     

副猪嗜血杆菌外膜囊泡激活caspase-11和NLRP3炎性体诱导炎性细胞因子IL-1β和IL-18分泌

【背景】副猪嗜血杆菌可引起多种炎性反应和较高死亡率,其致炎机制目前尚不清楚。【目的】探究副猪嗜血杆菌外膜囊泡(outer membrane vesicles,OMVs)诱导RAW264.7细胞caspase-11及NLRP3炎性体活化的功能,以及caspase-11在OMVs活化炎性体诱导炎性因子表达过程中的关键作用。【方法】副猪嗜血杆菌OMVs感染RAW264.7细胞,收集6、12和24h细胞,RT-PCR检测caspase-11、NLRP3、ASC和caspase-1 mRNA的表达;收集感染后48 h细胞,Western blotting检测caspase-11、NLRP3、ASC和caspase-1蛋白表达。收集感染后6、12、24、48和72h细胞上清,ELISA检测interleukin(IL)-1β和IL-18表达水平;不同浓度OMVs(0、2.5、10、25、50和100μg/mL)感染RAW264.7细胞24h,ELISA检测上清中IL-1β和IL-18水平。构建caspase-11沉默RAW264.7细胞株,收集OMVs感染后12、24和48h细胞培养上清检测IL-1β和IL-18水平。【结果】Caspase-11 mRNA转录水平在OMVs感染6、12和24h均极显著高于对照组(P<0.01);NLRP3 mRNA转录水平在感染后6、24h极显著高于对照组(P<0.01);ASC mRNA转录水平在感染后12、24h显著低于对照组(P<0.05);caspase-1 mRNA转录水平在感染后6、12和24h显著高于对照组(P<0.05)。Western blotting结果显示,与空白对照组相比,OMVs组caspase-11、NLRP3、ASC和caspase-1蛋白表达均明显升高。OMVs感染RAW264.7细胞后12、24、48和72h,IL-1β表达量极显著高于对照组(P<0.01),而且呈现时间依赖性升高,IL-18表达水平在感染后6、12、24、48和72h显著高于对照组(P<0.05);不同浓度OMVs感染细胞时,OMVs对细胞的致炎作用呈现剂量依赖性增强。Caspase-11沉默后,IL-1β水平在感染后12、24和48h显著低于未沉默组;Caspase-11沉默组IL-18表达量在感染后24、48h均显著低于未沉默组(P<0.05)。【结论】副猪嗜血杆菌OMVs在副猪嗜血杆菌诱导的炎症反应中发挥重要作用,OMVs可诱导RAW264.7细胞caspase-11介导的非经典NLRP3炎性体信号通路活化。     

循环水养殖系统中凡纳滨对虾肠道微生物对三种复合益生菌制剂的响应

【目的】在循环养殖系统中应用不同的复合益生菌制剂,探讨凡纳滨对虾肠道菌群结构特征及免疫水平发生的变化。【方法】30 d养殖周期结束后,通过平板计数法分析肠道细菌总数和弧菌总数;基于高通量测序技术分析肠道样品V3+V4区菌群特征;采用实时荧光定量PCR技术分析免疫相关因子TLR1和Dorsal基因表达水平,阐述益生菌制剂应用的意义。【结果】益生菌制剂的应用降低了凡纳滨对虾肠道中细菌总数,抑制弧菌的生长,间接预防疾病的发生。不同益生菌制剂从不同程度上优化了凡纳滨对虾肠道菌群结构,提高高质量序列和有效OTU数量,Chao1、Simpson、Shannon指数显示了丰富度和多样性变化,复合益生菌制剂3效果较好。同时,菌群结构得到优化,其中益生菌制剂1组对拟杆菌门含量百分比产生显著影响。Toll受体TLR1和Toll通路中的Dorsal基因m RNA表达受到益生菌制剂的影响,1、3组促进了TLR 1表达,1、2、3组都促进了Dorsal基因表达。【结论】在循环水养殖系统中添加益生菌制剂可优化凡纳滨对虾肠道菌群特征,提高免疫水平,为病害防控和健康养殖提供理论依据。     

百里酚和香芹酚改变肠道微生物组成抑制羔羊腹泻的作用研究

【目的】本试验研究百里酚和香芹酚对滩羊羔羊腹泻、肠道短链脂肪酸和微生物组成的影响,旨在为利用植物提取物手段治疗羔羊腹泻提供可用的添加剂和理论基础。【方法】本研究选择腹泻发病时间为2-3 d的10只腹泻羔羊,随机分为2组,分为腹泻羔羊组(CON组)和百里酚和香芹酚处理组(SCAT组),试验期间SCAT组羔羊补充200 mg/只/d的百里酚和香芹酚1:1混合品,处理时间为7 d。【结果】百里酚和香芹酚处理能够显著提高腹泻羔羊日增重,降低羔羊腹泻指数和腹泻率(P<0.05),降低血清促炎因子表达水平(P<0.05),提高肠道短链脂肪酸(short-chain fatty acids,SCFA)丁酸浓度(P<0.05);同时百里酚和香芹酚能够改变腹泻羔羊肠道微生物组成,提高肠道中双歧杆菌(Bifidobacteriaceae)和阿克曼氏菌(Akkermansiaceae)的相对丰度,降低肠杆菌科(Enterobacteriaceae)相关菌的相对丰度。【结论】百里酚和香芹酚能够提高肠道有益菌相对丰度和有益代谢物丁酸的浓度,降低致病菌相对丰度,从而有效抑制羔羊腹泻,可作为新型替...     

Effects of Clinoptilolite on Growth Performance and Antioxidant Status in Broilers

The objective of this study was to compare the effects of natural clinoptilolite and modified clinoptilolite on growth performance and antioxidant capacity in broiler chicks. Two hundred forty 1-day-old commercial Arbor Acres broilers were randomly distributed into three treatments, each of which had eight replicates. Each replicate contains 10 chicks. Control (CON) group fed with the basal diets, natural clinoptilolite (NCLI) group fed basal diets with 2 % natural clinoptilolite, and modified clinoptilolite (MCLI) group fed basal diets with 2 % modified clinoptilolite for 42 days. The results showed that the 2 % supplementation of natural clinoptilolite and modified clinoptilolite had no adverse effect on growth performance of broilers at 42 days of age. Relative weights of organs were not influenced by dietary treatments at 21 and 42 days. The activity of total nitric oxide synthase was significantly (P?<?0.05) decreased in MCLI group than CON group at 21 days of age. At 21 and 42 days, the activities of glutathione peroxidase, catalase, total superoxide dismutase, total antioxidant capacity (T-AOC) were significantly (P?<?0.05) increased in NCLI and MCLI groups than the CON group while there was no difference in T-AOC between CON and NCLI groups. The malondialdehyde content was significantly (P?<?0.05) decreased in NCLI and MCLI groups than the CON group. It was concluded that the addition of 2 % natural clinoptilolite and modified clinoptilolite to diet can improve antioxidant capacity in broilers, although their effects on growth performance was negligible.     

Effect of glycerol supplementation during early lactation on milk yield,milk composition,nutrient digestibility and blood metabolites of dairy buffaloes

This study was conducted to evaluate the effect of increasing levels of glycerol in the diet on milk yield and composition, diet digestibility and some blood metabolites of dairy buffaloes in early lactation. A total of 24 buffaloes were blocked by average milk yield, parity and BW and then randomly assigned to three treatments: control without glycerol (CON); low glycerol (LG): control plus glycerol at 150 ml/day per buffalo; and high glycerol (HG): control plus glycerol at 300 ml/day per buffalo. The experimental period lasted for 60 days. Feeding LG and HG decreased (P<0.0001) dry matter intake compared with the CON. Buffaloes supplemented with LG and HG produced more milk (P<0.01) and had a greater (P<0.0001) yield of fat-corrected milk (3.5%) than those buffaloes fed control treatment. Glycerol-supplemented buffaloes showed a positive energy status indicated by reduced concentrations of non-esterified fatty acids and β-hydroxybutyrate. Feeding LG and HG tended to increase (P⩽0.10) concentrations of milk fat, and serum total protein and globulin and significantly decreased (P⩽0.05) milk urea nitrogen and somatic cells counts (SCCs) compared to the CON group. Inclusion of LG and HG had no effect on organic matter and non-fiber carbohydrate digestion, but improved dry matter (P=0.02), CP (P=0.09), ether extract (P=0.03), NDF (P=0.07) and ADF (P=0.03) digestion.     

凝结芽孢杆菌-乳果糖合生元对DSS诱导的溃疡性结肠炎小鼠肠道健康的影响

[目的]旨在探究凝结芽孢杆菌-乳果糖合生元对葡聚糖硫酸钠(dextran sodium sulfate,DSS)诱导的溃疡性结肠炎小鼠临床体征、肠道形态和肠道菌群结构的影响.[方法]选取24只初始体重为(22.96±1.87)g的7周龄雄性C57/BL6小鼠,随机分为4组,每组6只,即CON组、DSS组(连续5 d饮用...     

不同配方益生菌在高脂饮食诱导小鼠肥胖发生中的差异化作用

【目的】基于肠道微生物与宿主代谢的相互关系,研究不同配方的益生菌对小鼠肥胖的影响。【方法】50只C57BL/6J雄性小鼠随机平均分成10组,分别给予正常饲料、高脂饲料以及高脂饲料加8种不同配方的益生菌产品(50亿CFU/只),所有动物连续喂养9周,每周测量小鼠体重1次。最后一周测定空腹血糖、葡萄糖耐量试验(glucose tolerance test,GTT)、血脂相关指标,称取内脏重量,并留取小鼠盲肠内容物,提取小鼠肠道菌群总DNA,利用16S rDNA测序检测相关细菌含量。【结果】部分益生菌可引起小鼠体重增速加快,而部分益生菌可减缓小鼠肥胖和降低内脏脂肪重量,同时缓解高血脂症。丹尼斯克品牌益生菌配方组小鼠肠道中厚壁菌/拟杆菌比例(F/B)是正常饮食组的22.8倍,Akkermansia muciniphila(Akkermansia)细菌含量几乎为0;而菌拉丁品牌益生菌配方组小鼠F/B比例与正常饲料饮食组类似,Akkermansia含量为0.5%,为正常饮食对照组小鼠的一半左右。【结论】益生菌可影响小鼠体重和代谢,但不同配方的益生菌效果截然相反。特定的益生菌配方对肥胖和高血脂的改善可能是由于其选用的菌株本身的特性以及菌株之间的相互配比能够降低小鼠肠道中F/B比例以及升高Akkermansia的含量所带来的。此研究为进一步开发可改善代谢的益生菌产品提供了参考。     

Response of animals to dietary gramine. II. effects of feeding high‐gramine yellow lupin seeds on reproductive performance of rats and on selected hematological and biochemical parameters in offspring

Two groups of 26 male and 26 female rats at the initial age 30 ± 2 days were fed during 31 weeks on diets containing 20 percent of yellow lupin seeds having low (LG) or high (HG) gramine content. The animals were mated twice within nutritional groups, 1 male: 1 female, and their main reproductive parameters were recorded. In both reproductive cycles body weight of females at mating, after parturition and after 21‐days lactation was lower in HG than in LG group. Fertility rate and body weight of neonates were not affected by the diet while number of neonates per litter tended to be lower by 0.7 and 0.8 pups in HG than in LG group. Body weight of weaners was also substantially smaller in dams fed on HG than LG diet. Relative weight of spleen but not of liver, kidney and heart was significantly greater in HG females. Four weeks old males and females issued from the first litters born to LG and HG animals (ten males and ten females per treatment) were fed individually on respective diets during 3 weeks. Feed intake and growth rate did not differ between the treatments. In males relative weight of liver and testicles was greater, while hematocrit and red blood count were lower in HG than in LG group. In females organ weights did not differ. Activity of liver enzymes determined in males was not affected by the diet. It may be concluded that high‐gramine lupin affects negatively lactational performance, probably via lower feed intake, but it does not induce apparent teratogenic effects in the progeny.     

The effects of the dietary glycemic load on type 2 diabetes risk factors during weight loss

Objective: To compare the effects of two calorie-restricted diets that differ in glycemic load (GL) on glucose tolerance and inflammation. Research Methods and Procedures: Thirty-four healthy overweight adults, ages 24 to 42 years, were randomized to 30% provided calorie-restricted diets with high (HG) or low (LG) glycemic load for 6 months. Outcomes were changes in glucose-insulin dynamics and C-reactive protein (CRP) levels. Results: Compared with baseline, levels of fasting insulin, homeostasis model assessment of insulin resistance, post-load insulin at 30 minutes, and incremental area-under-the-curve-insulin during the oral glucose tolerance test were significantly lower in both groups at 6 months (p range, 0.01 to 0.05), but after adjustment for baseline values and weight change, there were no differences between the two groups with regard to changes over time in any parameter. The mean percentage change in insulin sensitivity by a frequently sampled intravenous glucose tolerance test was +26% in the HG group and +24% in the LG group (p = 0.83); first-phase acute insulin release was −20% in the HG group and −21% in the LG group (p = 0.77). More participants on the LG diet (14 of 16 subjects) had a decline in serum CRP, compared with those on the HG diet (7 of 16 subjects) (p < 0.05). Discussion: In healthy overweight adults provided with food for 6 months, the dietary GL did not seem to influence chronic adaptations in glucose-insulin dynamics above that associated with weight loss. This finding highlights the importance of absolute weight loss over the dietary macronutrient composition used to achieve weight loss. The finding of greater declines in CRP concentration after consumption of a low-GL diet warrants further investigation.     

探讨不同浓度的清郁和降汤对反流性食管炎大鼠肠道菌群的影响

【目的】观察不同浓度的清郁和降汤对反流性食管炎（reflux esophagitis，RE）的治疗效果，并探讨其对肠道菌群的影响。【方法】将36只健康雄性SD大鼠随机分为6组，其中1组为假手术组，剩余5组大鼠采用“前胃结扎+外置幽门部分结扎术”手术造模方法建立反流性食管炎模型。造模2周后将术后全部存活的30只大鼠随机分成对照组、中药高剂量组（予高剂量清郁和降汤）、中药中剂量组（予中剂量清郁和降汤）、中药低剂量组（予低剂量清郁和降汤）、西药组（予泮托拉唑钠肠溶胶囊+枸橼酸莫沙比利分散片+复方嗜酸乳杆菌片），每组6只。于术后第15天开始灌胃，其中假手术组及对照组予蒸馏水灌胃，其他组分别给予相应的药物灌胃，持续灌胃14 d后将所有大鼠处死后进行取材。以苏木精-伊红（hematoxylin-eosin，HE）染色观察大鼠食管组织的病理学改变；采用16S rRNA基因高通量测序检测其肠道黏膜的菌群构成。【结果】反流性食管炎大鼠存在着较为明显的肠道菌群结构变化及肠道菌群多样性较低的情况，B组（对照组）中厚壁菌门和拟杆菌门占比减少，变形菌门占比增多，且假单胞菌属、青枯菌属等细菌增多。低、中、高3种浓度的清郁和降汤均能够提升RE大鼠的肠道菌群多样性，增加拟杆菌门及厚壁菌门，降低变形菌门的占比，从属水平上看，清郁和降汤能够提升大鼠肠道中拟杆菌属、乳杆菌属、瘤胃球菌属、颤螺旋菌属、双歧杆菌属和狄氏副拟杆菌属等益生菌占比。以D组（中剂量组）对大鼠肠道菌群多样性提升最为明显，其效果最接近假手术组。特征微生物方面，B组以变形菌门为特征性微生物，D、E两组出现了放线菌门及拟杆菌门下属细菌为特征微生物的情况，在门水平与F组相同。【结论】清郁和降汤能够有效地治疗反流性食管炎，其机制可能与改变RE大鼠的肠道菌群结构、减少有害菌、提升益生菌的占比和改善肠道菌群多样性有关。     

猪源乳酸菌的分离、鉴定及其生物学特性

【目的】将分离自猪肠道粘膜、食糜和粪便的乳酸菌,通过产乳酸能力、生长性能、耐酸和耐胆盐性能及抑菌能力评价,筛选适应养猪生产的潜在益生特性的菌株。【方法】共分离获得155株乳酸菌纯菌株,从中筛选出4株产酸能力较强的乳酸菌,结合生理生化试验及细菌16S rRNA测序鉴定其种属,评价候选乳酸菌的生长情况、耐酸、耐胆盐及抑菌特性。【结果】综合变色时间(8 h)、pH值(3.9)和乳酸含量(100 mmol/L),筛选出4株(L45、L47、L63和L79)候选菌株,经鉴定依次为罗伊氏乳杆菌、植物乳杆菌、约氏乳杆菌和粪肠球菌。该4株乳酸菌均可在体外快速生长;L47和L79能够耐受pH 2.5的酸性环境,L47能够耐受0.5%胆盐环境;各乳酸菌上清液与指示菌共培养,发现对E coli K88和沙门氏菌均产生了抑制作用,其中L47上清液对指示菌的抑制作用较强。【结论】L47具有较好的产酸性能与生长性能、可耐受猪胃酸和肠道胆盐环境,对E.coli K88和沙门氏菌具有较好的抑制作用,说明该乳酸菌具有潜在的益生特性。