Plasma concentrations and effects of glucagon-like peptide-1 (7-36) amide in calves before and after weaning

Glucagon-like peptide-1 (7-36) amide (GLP-1), secreted by the small intestine, has insulinotropic and glucose-lowering action. Basal plasma GLP-1 concentrations were measured in calves around the weaning period, the effect of short-chain fatty acids (SCFA) on plasma GLP-1 concentrations was examined, and the effects of GLP-1 administration on plasma insulin, glucagon, and glucose concentrations were measured. Thirteen Holstein bull calves were fed whole milk and solid feed and weaned at 7 wk of age. Preprandial plasma samples were obtained from 5 calves once a week from week 0 to 13 to measure basal concentrations of plasma GLP-1 and insulin (experiment 1). Four calves were intravenously administered with a mixed solution of SCFA (2.4 mmol/kg body weight [BW]) in week 2 and 11 to measure plasma GLP-1 concentrations (experiment 2). Another 4 calves were intravenously injected with GLP-1 (1.0 μg/kg BW) to elucidate the response of plasma insulin, glucagon, and glucose concentrations in week 1, 2, 4, 6, 7, 9, 11, and 13 (experiment 3). In experiment 1, age and weaning did not affect preprandial basal concentrations of plasma GLP-1 throughout the experimental period. Preprandial insulin concentrations increased after weaning (P < 0.05), and GLP-1 and insulin were more strongly correlated postweaning than preweaning. In experiment 2, intravenous treatment with SCFA increased plasma GLP-1 concentrations in both week 2 and 11 (P < 0.05.) In experiment 3, intravenous GLP-1 treatment decreased plasma glucose concentrations throughout the experiment (P < 0.05), but increased plasma insulin concentrations only after weaning (P < 0.05). Treatment with GLP-1 did not affect plasma glucagon concentrations, regardless of age. These results indicate that preprandial basal concentrations of plasma GLP-1 in calves are not changed by weaning, but SCFA stimulate GLP-1 secretion. The insulinotropic action of GLP-1 is detected only after weaning, but the glucose-lowering action of GLP-1 is not affected by weaning.     

Trace metals and animal health: Interplay of the gut microbiota with iron,manganese, zinc,and copper

Metals such as iron, manganese, copper, and zinc are recognized as essential trace elements. These trace metals play critical roles in development, growth, and metabolism, participating in various metabolic processes by acting as cofactors of enzymes or providing structural support to proteins. Deficiency or toxicity of these metals can impact human and animal health, giving rise to a number of metabolic and neurological disorders. Proper breakdown, absorption, and elimination of these trace metals is a tightly regulated process that requires crosstalk between the host and these micronutrients. The gut is a complex system that serves as the interface between these components, but other factors that contribute to this delicate interaction are not well understood. The gut is home to trillions of microorganisms and microbial genes (the gut microbiome) that can regulate the metabolism and transport of micronutrients and contribute to the bioavailability of trace metals through their assimilation from food sources or by competing with the host. Furthermore, deficiency or toxicity of these metals can modulate the gut microenvironment, including microbiota, nutrient availability, stress, and immunity. Thus, understanding the role of the gut microbiota in the metabolism of manganese, iron, copper, and zinc, as well as in heavy metal deficiencies and toxicities, and vice versa, may provide insight into developing improved or alternative therapeutic strategies to address emerging health concerns. This review describes the current understanding of how the gut microbiome and trace metals interact and affect host health, particularly in pigs.     

旱区土壤微生物组与土壤健康评价

土壤健康在维持粮食生产、动植物和人类健康方面具有重要作用,是实现农业可持续发展的根本。土壤微生物作为土壤中最具丰富性和多样性的有机生物体,包含细菌、真菌、原生生物和病毒。它们驱动着碳、氮、磷、硫等元素循环过程,并与植物初级生产力和土壤健康息息相关。旱区约占全球陆地表面积的41%,维系了全球约38%以上的人口。西北干旱半干旱区是我国的重要粮食生产后备区,由于其土壤生态系统的复杂性、脆弱性和敏感性导致该地区土壤健康状况相关研究仍缺乏。本文围绕微生物在土壤健康相关生态系统服务如调控作物生长、消减连作障碍、改善水体质量、维持人类健康、缓解气候变化影响和促进碳固存中的贡献,揭示了土壤微生物在维持土壤健康中的关键作用,归纳了土壤微生物作为土壤健康评价指标的发展历程和研究进展。同时介绍了旱区土壤微生物自身特征并总结其对于水分胁迫的响应,归纳了旱区土壤健康研究进展。最后对土壤微生物组与旱区土壤健康研究进行了展望,以期为利用土壤微生物资源维持和改善旱区土壤健康状况提供科学指导。     

冬夏季长白猪精液中细菌多样性与精子质量特性关联分析

为探究冬夏季长白猪精液中细菌多样性变化和精子质量特性之间的相关性,利用16S rRNA基因高通量测序技术得到冬夏季长白猪精液中微生物的特征序列(ASV),计算机辅助精子分析系统(CASA)分析冬夏季精子活力参数指标的变化.结果 显示:长白猪精液中细菌多样性在冬夏季之间差异显著(P＜0.05),门水平冬季优势菌群为厚壁菌...     

The intestinal microbiome in dogs and cats with diarrhoea as detected by a faecal polymerase chain reaction‐based panel in Perth,Western Australia

This study reports the prevalence of potential faecal pathogens in the microbiome detected in a cohort of cats and dogs with diarrhoea in Perth, Western Australia. Records from a commercial diagnostic laboratory using faecal PCR testing between July 2014 and August 2015 were reviewed.Of 289 feline faecal samples reviewed, Salmonella spp. (1.7%), Campylobacter spp. (47.6%), Clostridium perfringens (81.3%), Giardia spp. (11.1%), Toxoplasma gondii (1.2%), Tritrichomonas foetus (4.8%), panleukopenia virus (6.5%) and coronavirus (39.5%) were detected. In dogs, Salmonella spp. (5.4%), Campylobacter spp. (36.3%), C. perfringens (85.4%), Giardia spp. (6.2%), parvovirus (9.4%), coronavirus (4.7%) and distemper virus (1.5%) were detected.     

The aetiopathogenesis of equine periodontal disease – a fresh perspective

Periodontal disease is a painful and highly prevalent disorder of horses that causes a significant welfare problem. Despite its importance, few scientific studies on its aetiopathogenesis have been performed. Equine periodontitis differs from the plaque‐induced periodontitis found in brachydont species where bacteria accumulating in dental plaque induce a destructive inflammatory response in the periodontium. In contrast, equine periodontitis is usually initiated by entrapment of feed between cheek teeth, which causes inflammation of periodontal tissue that likely allows bacterial infection of the periodontal tissues that is later exacerbated by the host's response. Equine oral microbiology is a neglected field of research and identification of the bacteria involved in this disorder by use of molecular bacteriology and examination of the interaction between these bacteria and the equine oral immune response should reveal important information about the pathogenesis of this disease.     

Dietary fiber and microbiota interaction regulates sow metabolism and reproductive performance

Dietary fiber is a critical nutrient in sow diet and has attracted interest of animal nutritionists for many years. In addition to increase sows’ satiety, dietary fiber has been found to involve in the regulation of multiple biological functions in the sow production. The interaction of dietary fiber and gut microbes can produce bioactive metabolites, which are of great significance to sows'' metabolism and reproductive performance. This article reviewed the interaction between dietary fiber and gut microbes in regulating sows'' gut microbial diversity, intestinal immune system, lactation, and production performance, with the aim to provide a new strategy for the use of dietary fiber in sow diets.     

肠道微生物对流感病毒感染小鼠肺损伤调节作用的研究

流感病毒作为一种常见的呼吸道病毒,是人类健康和世界经济的巨大威胁。目前流感治疗遇到病毒高度突变的问题,不断完善已有的控制流感感染方法的同时,也需要开阔视野从宿主反应的角度探索控制流感的新措施,本研究从肠道微生物的角度探索流感造成肺损伤的机制。提前3周将组合抗生素和益生元添加到小鼠饮水中构建不同的肠道微生物环境,小鼠感染流感病毒后运用16S rDNA技术测定结肠微生物组成,蛋白免疫印迹法测定肺部Th17和Treg细胞转录因子RORγT和Foxp3的表达情况,苏木精-伊红染色、荧光定量PCR测定肺损伤状况。结果表明,提前使用组合抗生素和益生元能够改变肠道菌群组成,通过降低肠道菌群数目和增加肠道拟杆菌相对丰度保护肠道,从而反作用于肺部诱导肺Treg细胞分化,抑制Th17细胞分化,改善流感造成的肺损伤。     

生物钟对哺乳动物生理代谢、繁殖和肠道菌群影响的研究进展

进化过程中生物钟通过将合成代谢和分解代谢两种代谢过程进行时间上的分离,优化代谢效率;同时使动物机体的代谢循环与睡眠/活动循环同步,维持基本的代谢节律。哺乳动物的繁殖性能主要受到下丘脑-垂体-性腺轴的调控。下丘脑视交叉神经上核的主生物钟能够产生自发性振荡并且感受光周期的变化,引发褪黑素分泌的变化。褪黑素(MT)作为一种重要的节律调节因子和生殖激素,介导下丘脑-垂体-性腺轴各部分激素的节律性变化,进而调控哺乳动物繁殖性能。同时肠道菌群的变化作为一种繁殖障碍的反映逐渐引起人们的关注。本文将重点阐述昼夜节律对宿主能量代谢、繁殖性能以及肠道菌群之间的相互作用,主要包括中枢生物钟视交叉神经上核(SCN)通过褪黑素介导的下丘脑-垂体-性腺轴各部分激素的节律性变化,进而调控哺乳动物的繁殖节律。