猪肠道微生物及其代谢产物与肠道屏障研究进展

肠道微生物参与营养物质代谢，影响猪的健康和发育，当肠道微生物发生紊乱，会造成猪腹泻并引起炎症反应，因此肠道微生物对猪的健康起着至关重要的作用。本文从肠道微生物在仔猪不同发育阶段的分布、肠道微生物的代谢产物对肠道健康的影响机制和肠道微生物与肠道屏障之间的关系进行阐述，并探讨了目前肠道健康研究的进展以及今后的研究方向，旨在为猪肠道健康调控提供理论参考。     

饲料糖脂比对吉富罗非鱼生长、生理生化指标、肠道菌群组成及抗病力的影响

为研究不同糖脂比饲料对罗非鱼幼鱼生长、生理生化指标、肠道菌群组成和抗病力的影响。实验选取平均体重为27g的罗非鱼幼鱼为研究对象，分别用等氮等能的五种不同糖脂比饲料: 44.2/4(D1)、39.6/6(D2)、35/8(D3)、30.4/10(D4)、25.6/12(D5)，饲喂10周，采用营养学、生化分析结合高通量测序技术开展了相关测定研究。结果显示，糖脂比饲喂前期对罗非鱼生长具有显著影响，高糖或高脂饲料均生长较差，但饲喂到10周后，所有组间生长无显著差异 (P > 0.05)。相比之下，10周糖脂比在脏体比、肠系膜脂肪指数、肝体比、全鱼粗蛋白、肝脏甘油三酯、血清低密度脂蛋白胆固醇（LDL）和尿素、抗病力、菌群组成等方面存在显著效应。低糖脂比D4在脏体比上显著高于高糖脂比D1 (P < 0.05)，而在血清尿素和抗病力上显著低于D1 (P < 0.05)，在肠系膜指数上显著高于高糖脂比D1和D2 (P < 0.05)，但在全鱼粗蛋白上显著低于D1和D2 (P < 0.05)。另外，D1不仅在肝体比上高于低糖脂比D5 (P < 0.05)，而且在LDL和糖耐受能力上均高于其它各组 (P < 0.05)。与之相比，糖脂比虽在肠道微生物物种丰度和均一度上没有显著性差异 (P < 0.05)，但在物种组成和热图显示低糖脂比D4与其它组肠道菌群组成不同。D4在聚类关系上单独一支，其门水平上衣原体门、绿弯菌门、放线菌门高于其它各组，特别是D2和D1，但厚壁菌门低于其它各组，特别是D2; 属水平上，D4组幽门螺杆菌属明显多于其它组，而乳杆菌、双歧杆菌属明显少于除D3外的其它组。综上所述，罗非鱼对不同糖脂比饲料有很强的适应和利用能力，但高糖比饲料利用上强于低糖脂比。本实验条件下，高糖组中39.6/6(D2)饲料组虽然在生长上与其它各组无显著差异，但其鱼体粗蛋白含量在各组中最高，肠道菌群组成上也优于其它各组，是罗非鱼适宜的糖脂比水平。     

Germinated brown rice relieves hyperlipidemia by alleviating gut microbiota dysbiosis

Hyperlipidemia is a frequent metabolic disorder that is closely associated with diet.  It is believed that brown rice, containing the outer bran layer and germ, is beneficial for the remission of hyperlipidemia.  This study established a rat model of hyperlipidemia by feeding a high-fat diet.  The hypolipidemic potential of germinated brown rice (Gbrown) and germinated black rice (a germinated black-pigmented brown rice, Gblack) were explored in the model rats, mainly in the aspects of blood lipids, lipases, apolipoproteins, and inflammation.  The gut microbiota in hyperlipidemic rats receiving diverse dietary interventions was determined by 16S rDNA sequencing.  The results showed that the intervention of Gbrown/Gblack alleviated the hyperlipidemia in rats, evidenced by decreased TC, TG, LDL-C, and apolipoprotein B, and increased HDL-C, HL, LPL, LCAT, and apolipoprotein A1.  Gbrown/Gblack also weakened the inflammation in hyperlipidemia rats, evidenced by decreased TNF-α, IL-6, and ET-1.  In addition, 16S rDNA sequencing revealed that the diet of Gbrown/Gblack elevated the abundance and diversity of gut microbiota in hyperlipidemia rats.  At the phylum level, Gbrown/Gblack decreased Firmicutes, increased Bacteroidetes, and decreased the F/B ratio in hyperlipidemia rats.  At the genus level, Gbrown/Gblack decreased Streptococcus and increased Ruminococcus and Allobaculum in hyperlipidemia rats.  Some differential microbial genera relating to lipid metabolism were also determined, such as the Lachnospira and Ruminococcus in the Gblack group, and the Phascolarctobacterium, Dorea, Turicibacter, and Escherichia-Shigella in the Gbrown group.  Notably, the beneficial effect of Gblack was stronger than Gbrown.  To sum up, the dietary interventions of Gbrown/Gblack contributed to the remission of hyperlipidemia by alleviating the dysbiosis of gut microbiota.     

姜黄素调控肠道菌群及抗病毒作用研究进展

姜黄素作为一种天然的多酚类植物提取物，具有抗炎、抗氧化、抗应激和改善动物肠道健康等多种生物学功能，已成为一种绿色安全高效的饲料添加剂。近年研究表明，姜黄素与肠道菌群存在紧密的相互作用。姜黄素能调控肠道菌群的组成和多样性，肠道菌群则影响姜黄素的转化。这种双向调控作用或许是姜黄素发挥生理功能的关键。此外，姜黄素被证实通过不同的机制抵抗多种病毒的感染，提示其具有成为新型抗病毒药物的潜力。因此，本文主要综述了姜黄素与肠道菌群之间的相互作用及姜黄素抵抗不同病毒感染的相关机制，以期为深入了解姜黄素对改善动物健康的作用机制和开发新型绿色饲料添加剂提供理论依据。     

Feeding ecology and coexistence dynamics in a community of fishes in a temperate temporary water body

Temporary water bodies are temporally variable ecosystems supported primarily by rainwater. The biota supported by such water bodies present a range of capacities to remain in this environment for all or part of their life cycles. During floods, temporary pools can connect with permanent streams, promoting changes in trophic networks in the aquatic food webs. The aim of this research was to analyse the feeding ecology of a fish community in a temporary pool near of Tlacotalpan, in the Mexican southeast, in order to understand the dynamics of the feeding habits. First, we identified feeding habits that can be interpreted as guilds of the fishes in the temporary pool: the annual killifish Millerichthys robustus (the only autochthonous species) is planktophagous; Cynodonichthys tenuis and Astyanax aeneus are insectivores; Dormitator maculatus and larvae of amphibians (Lithobates sp.) are mainly detritivorous; and Poecilia mexicana is planktophagous and insectivorous. We then estimated the effect of coexistence on niche breadth and overlap. The niches of M. robustus and P. mexicana evidenced overlap, but the breadth was adjusted inversely, suggesting feeding specialisation in M. robustus in response to competition. We documented the existence of two cohorts of M. robustus; the niche breadth of the first and second cohorts suggesting different strategies probably related to competition under variable conditions. The niche of C. tenuis and A. aeneus, and D. maculatus and tadpoles overlapped, following a pattern of feeding generalisation in response to competition.     

黄粉虫（Tenebrio molitor）肠道中聚乳酸塑料降解菌的筛选及其降解特性

聚乳酸（polylactic acid,PLA）材料是一种环境友好型的可降解塑料,在堆肥或高温条件下可以快速生物降解,但在自然条件下降解缓慢,产生大量的微塑料。本研究拟从黄粉虫肠道中筛选具有降解聚乳酸能力的微生物,鉴定降解菌的种类及测定降解菌的降解特性。采用PLA粉末为唯一食物喂养黄粉虫60 d,将其肠道提取液接种在以PLA为唯一碳源的固体培养基上进行富集、筛选及纯化降解菌。结合菌种形态观察、扫描电镜分析的方法和ITS序列序列信息构建系统进化树确定降解菌的分类;将筛选菌接入添加不同营养条件下的PLA液体发酵培养基,测定其降解效能。结果筛选出11株具有降解PLA塑料潜力的菌株,其中一株鉴定为真菌毛栓孔菌（Trametes hirsuta）FJ001菌株,接种在含有1.0%葡萄糖的PLA薄膜无机盐液体培养基中连续培养30 d,降解率可达20.1%。研究表明,黄粉虫肠道存在对PLA塑料有一定降解性的真菌,为降解聚乳酸材料微生物资源的开发提供了理论依据。     

捕食扶桑绵粉蚧的异色瓢虫肠道菌群分析

迄今,对捕食性天敌昆虫肠道菌系与入侵物猎物之间的关系,知之甚少。本研究旨在查明广谱捕食性异色瓢虫Harmonia axyridis (Pallas)肠道菌群与外来入侵猎物扶桑绵粉蚧Phenacoccus solenopsis (Tinsley)之间的关系。从异色瓢虫幼虫刚孵化开始饲喂扶桑绵粉蚧(食粉蚧组)或本土常见猎物豌豆修尾蚜Megoura japonica (Matsumura)(食蚜虫组对照),直至成虫羽化后20 d;然后,应用高通量测序技术测定异色瓢虫20 d龄成虫肠道的16S rDNA V3-V4区片段,以鉴定微生物群落组成。分析结果发现,食粉蚧组异色瓢虫肠道菌系的基本分类单元(OUT)数量是食蚜组瓢虫的(297个)近2.3倍;在两组瓢虫共有的16个门级阶元中,食粉蚧组瓢虫有7个特有门,而食蚜虫组瓢虫没有特有的门;在两组瓢虫共有的169个属中,食粉蚧组瓢虫有210个特有属,食蚜虫组瓢虫只有35个属,而且两组瓢虫之间在14个属的物种丰度上存在统计学差异。虽然两组瓢虫的肠道代谢通路有一定的相似性,但在功能丰度上具有明显的差异。研究结果说明,取食非本土粉蚧的异色瓢虫成虫的肠道菌群物种丰富度和多样性均高于取食本土蚜虫的同类。     

应用SHIME模型研究肠道微生物对13种农产品中 腐霉利生物可给性的影响

应用模拟人体胃肠消化的SHIME（simulator of the human intestinal microbial ecosystem）体外方法评价肠道菌群对不同农产品中腐霉利生物可给性的作用规律，为正确评价农产品中农药残留健康风险提供理论依据。结果表明：肠道菌群可使葡萄等13种农产品中腐霉利生物可给性降低30.3% ~ 97.2%，其中以葡萄和大豆中供试农药残留生物可给性的影响较为显著；膳食成分可增强肠道菌群对腐霉利生物可给性的影响，菊粉作用下可使肠道菌群对葡萄中腐霉利生物可给性降低39.6%。大肠杆菌是影响腐霉利生物可给性的主要优势菌，36 h时可使葡萄中腐霉利生物可给性显著降低33.9%。     

亚成体胡兀鹫肠道菌群分离及生物特性分析

为探究胡兀鹫肠道菌群多样性，本研究利用5种培养基进行胡兀鹫肠道菌分离、培养、鉴定、耐药性试验及抑菌测定。结果表明：共分离到27株肠道菌，隶属于2门8属12种；这些菌株对3～22种抗生素及抗菌药物具有耐药性；屎肠球菌对5种常见肠道致病菌具有一定的抑制作用，粪肠球菌仅对大肠杆菌有抑制效果。