长双歧杆菌特性及应用研究进展

长双歧杆菌是存在于人和动物肠道内重要的益生菌,它与机体的许多生理、病理现象密切相关,在缓解代谢综合征、脑肠综合征以及免疫相关疾病等方面的益生功能,更成为各领域专家研究的热点。本文综述了长双歧杆菌的亚种分型鉴定、定植方面的生物学特性,在缓解脑肠综合征以及免疫综合征方面的热点益生功能,及其在国内外的研究进展与热点应用发展前景,旨在加深和完善关于长双歧杆菌的生物学特性、益生功能及应用的认识。     

双歧杆菌RH 菌株不同处理物修复肠道菌群平衡失调的研究

为探讨双歧杆菌RH 菌株对肠道菌群平衡失调的修复功能,本研究通过动物实验,考察双歧杆菌活菌(LB)、菌体破碎物(CE)及发酵上清液(FS)3 种处理物灌胃由抗生素造成的菌群失调模型小鼠后对其肠道内双歧杆菌、乳杆菌、产气荚膜梭菌、肠球菌、肠杆菌和拟杆菌6 大类主要菌群的影响。结果显示：3 种处理物均可使小鼠肠道内双歧杆菌和乳杆菌数量极显著增加(P ＜ 0.01),产气荚膜梭菌和肠球菌数量显著降低(P ＜ 0.05 和P ＜ 0.01),并能使肠杆菌和拟杆菌数量恢复至正常水平,说明该双歧杆菌LB、CE 和FS 均可起到修复、调节小鼠肠道微生态平衡的作用。     

双歧杆菌生理生化特性及调控大鼠肠道菌群、脂质代谢功能的研究进展

肠道微生态是人和动物体内最为复杂、最为主要的微生态系统。双歧杆菌是肠道微生态存在的一种益生菌，在防治肥胖、代谢综合征等多个疾病领域呈现出潜在应用前景，成为食品补充剂、保健食品等多个领域研究的热点。双歧杆菌能够通过调节饮食结构与能量摄入，肠道菌群微环境、微生物-肠-脑轴及肠道免疫等途径调控大鼠肠道菌群，保护肠道黏膜屏障，并能通过对碳水化合物利用途径、抵抗炎症应激途径、调节脂肪分解途径、基因途径、胆汁酸盐共沉淀与菌体同化胆固醇途径等调控脂质代谢，同时肠道菌群与脂质代谢之间具有双向调节作用。但双歧杆菌对肠道菌群、脂质代谢的效果，因应用领域、配方、添加数量而异，仍需要更深度控制研究和临床验证来确立配方、添加数量等。且应用于食品领域时，可能通过与宿主自身肠道菌群交流遗传物质途径，导致肠道耐药基因转移或耐药病原菌传播。本文就双歧杆菌调控大鼠肠道菌群及脂质代谢多种途径和机制进行综述，并对相关问题进行展望，以期为双歧杆菌相关领域研究提供思路。     

木糖调节小鼠肠道菌群作用的研究

本实验研究木糖对小鼠肠道菌群的影响。实验小鼠灌胃不同剂量的木糖,观察双歧杆菌、乳杆菌、肠杆菌和肠球菌等4 种肠道菌群的变化。结果表明,木糖具有调节小鼠肠道菌群及促进双歧杆菌增殖功能。     

纳豆菌的米糠发酵物对小鼠肠道菌群的调节

通过动物试验来考察纳豆芽孢杆菌发酵米糠的提取物(RBF)对小鼠肠道正常茵群生长的影响.结果表明:灌胃RBF能够显著促进以乳酸杆茵、双歧杆菌等厌氧菌为优势茵群的小鼠肠道正常菌群的生长,抑制肠杆菌、肠球菌等好氧茵的增殖,作用效果与微生态制剂培菲康相当.纳豆芽孢杆菌的米糠发酵物中,纳豆芽孢杆菌及其米糠发酵成分均对小鼠的肠道正常茵群具有调节作用,两者复合能发挥更强的功能.     

益生菌缓解肥胖形成相关机制及研究进展

肥胖及相关代谢综合征已成为世界范围内的公共健康问题。研究表明,肠道菌群与肥胖的形成密切相关,肠道菌群失调导致脂代谢紊乱、肠道通透性及氧化应激等改变。益生菌(主要包括乳酸菌和双歧杆菌)是一类能对宿主生理功能产生有益作用的微生物,能在肠道中存活并定殖,改善肠道菌群紊乱,进一步缓解肥胖的形成。本文主要围绕益生菌对肥胖的干预作用及相关机制进行综述,以为肥胖相关的研究提供参考。     

海南地区健康青年肠道中乳酸菌和双歧杆菌多样性研究

目的：在种的水平揭示海南地区健康青年肠道中乳酸菌和双歧杆菌的丰度和生物多样性，探讨性别、年龄和BMI对上述两者可能的影响。方法：以海南地区27名健康志愿者为研究对象，将乳酸菌特异性引物和双歧杆菌特异性引物扩增与PacBio SMRT测序技术相结合，采用相关生物信息学与统计学方法分析。结果：志愿者肠道中乳酸菌主要由链球菌属、乳杆菌属、魏斯氏菌属、瘤胃球菌属等组成。按照乳酸菌在种水平的组成，所有人群可以分为两个肠型，两个肠型人群唾液链球菌的比例存在显著差异（P<0.05）。此外，男性志愿者肠道中乳酸菌丰度和多样性显著高于女性。依据肠道双歧杆菌多样性特征，可将志愿者分为以链状双歧杆菌、长双歧杆菌、粪双歧杆菌为优势菌的3个类群，性别和BMI均是对双歧杆菌组成产生影响的因素。结论：青年人群肠道中具有丰富的乳酸菌和双歧杆菌，其构成与个人饮食习惯、性别和BMI有一定相关性，肠道中优势乳酸菌和双歧杆菌对人体健康发挥着重要作用。     

纳豆芽孢杆菌的米糠发酵提取物的整肠作用研究

目的：为深度开发米糠资源,考察纳豆芽孢杆菌发酵的米糠提取物(supernatant of Bacillus natto-fermentedrice bran,SBRB) 的整肠作用。方法：米糠提取物与双歧杆菌的体外共培养试验;灌胃SBRB,检测小鼠肠道正常菌群的生长。结果：体外试验证明纳豆菌在严格厌氧环境不能促进双歧杆菌的生长。加入SBRB 与米糠水提液(aqueous extract of rice bran,ABRB)均能显著促进双歧杆菌的生长,提高比率分别为65.2% 和17.8%;SBRB 经过胃蛋白酶和胰蛋白酶消化后,仍有51.6% 的促生率。作为外源因子的SBRB 与AERB 中含有多种促生成分。动物实验结果表明,灌胃SBRB 能够显著促进以厌氧菌为优势菌群的小鼠肠道菌群的生长,抑制好氧菌的增殖,作用效果与微生态制剂培菲康相当;纳豆菌和发酵成分均对小鼠的肠道菌群具有调节作用,两者复合能发挥更强的功能。结论：SBRB 具有调整肠道菌群的功能,适于制成合生素制剂。     

槲皮素对肠道菌群的调节作用研究

为探究槲皮素对肠道菌群的调节作用,利用光电比浊法动态观察槲皮素在体外对肠道优势菌肠球菌、肠杆菌、乳杆菌和双歧杆菌增殖的影响;利用盐酸林可霉素灌胃构造小鼠肠道菌群失调动物模型,通过小鼠体内实验评价槲皮素调节肠道菌群失调的效果。体外实验结果表明,在一定浓度范围内(0.01、0.05、0.1μmol/mL)槲皮素对乳杆菌增殖有明显扶植作用,超过这一范围时(0.5、1μmol/mL)对乳杆菌增殖强烈抑制,各浓度槲皮素均对肠球菌的体外增殖表现为强烈的抑制作用,对肠杆菌和双歧杆菌无明显的抑制作用但也不表现出扶植作用;体内实验表明,200、400 mg/kg BW槲皮素可增加小鼠肠道双歧杆菌数量。槲皮素可调节肠道菌群。     

双歧杆菌生理功能研究进展

双歧杆菌是存在于人和动物肠道内重要的益生菌,它与机体的许多生理、病理现象密切相关,因此成为人体健康的重要指标之一.它在调节肠道菌群、降低人体胆固醇、抗肿瘤以及在延缓人体衰老等方面的生理功能,更成为各领域专家研究的热点.本文综述了双歧杆菌热点生理功能在国内外的研究进展及应用发展前景.     

全谷物在疾病调控中的作用和分子机制研究进展

全谷物食品的摄入对人体益处颇丰，诸多有益效果主要归因于全谷物食品中的各种功能性物质。全谷物摄入后，经胃肠消化及肠道微生物菌群发酵等作用，促使谷物中的有效成分转化为对人体健康具有调节作用的重要代谢物，对人体某些疾病产生有益的调控作用。诸多研究表明，糖尿病、肥胖症、炎症性肠病及肠道癌变等多种疾病的发生与饮食和肠道微生物菌群有关。虽然上述病症与全谷物及肠道微生物菌群之间的关系尚未研究透彻，但近年来肠道微生物菌群与全谷物食品之间的互作及对相关调控基因表达的影响研究越来越深入，且越来越多的研究成果证实了全谷物在调节人体疾病方面的作用。本文主要综述了全谷物在调控上述疾病中的作用和分子机制相关研究成果，为日后全谷物食品的深入研究及相关应用提供生物学理论依据及参考。     

Lessons from probiotic-host interaction studies in murine models of experimental colitis

In inflammatory bowel diseases (IBD), it is known that besides genetic and environmental factors (e.g. diet, drugs, stress), the microbiota play an important role in the pathogenesis. Patients with IBD have an altered microbiota (dysbiosis) and therefore, probiotics, defined as 'live micro-organisms that when administered in adequate amounts can confer a health benefit on the host', have been suggested as nutritional supplements to restore these imbalances. The best response on probiotics among the different types of IBD appears to be in the case of ulcerative colitis. Although probiotics show promise in IBD in both clinical and animal studies, further mechanistic studies are necessary to optimize the use of probiotics as supporting therapy in IBD. Murine models of experimental colitis have been used for decades to study this pathology, and these models have been proven useful to search for new therapeutic approaches. The purpose of this review is to summarize probiotic-host interaction studies in murine models of experimental colitis and to evaluate how these models can further help in understanding these complex interactions. Unraveling the molecular mechanisms behind the beneficial effects will assist in better and possibly more efficient probiotic formulations.     

乳铁蛋白对炎症性肠炎大鼠肠道微生态的正向调节作用

本研究采用葡聚糖硫酸钠（dextran sulphate sodium,DSS）刺激以构建SD大鼠炎症性肠炎（inflammatory bowel disease,IBD）模型,通过高通量测序分析乳铁蛋白（lactoferrin,LF）对大鼠结肠粪便肠道菌群α-多样性、物种差异性分布、KEGG信号通路相关操作分类单元（operational taxonomic unit,OTU）丰度的影响。结果表明,LF有助于缓解DSS刺激所引起的α-多样性降低和优势菌群——厚壁菌门（Firmicutes）与拟杆菌门（Bacteroidetes）的比例失调;与DSS组相比,高剂量LF提高了患IBD大鼠乳杆菌科（Lactobacillaceae）（12% vs. 40%）、瘤胃菌科（Ruminococcaceae）（17% vs. 27%）等菌群的相对丰度,降低了拟杆菌科（Bacteroides）（28% vs. 8%）、普雷沃氏菌科（Prevotellaceae）（13% vs. 6%）等菌群的相对丰度。KEGG信号通路OTU丰度分析表明,LF的摄入降低了患IBD大鼠菌群中与癌症、感染性疾病等人类疾病、免疫系统和细胞及遗传相关信号通路的OTU丰度,并降低了这些疾病的发生风险。综上,LF的摄入对患IBD大鼠结肠微生态具有正向调节作用,可使其肠道菌群的组成更接近于健康大鼠,且有降低其他伴随性疾病风险的可能。     

蛋源性活性组分对炎症性肠病的缓解作用研究进展

炎症性肠病是发生在肠道的慢性且反复发作的炎性疾病。传统的药物治疗虽能缓解临床症状但却存在一 定的副作用。蛋源性活性组分是近期食品科学领域研究的热点之一,禽蛋组分的抗菌、抗病毒、降血压、抗氧 化、抗炎以及免疫调节等功能活性已被相继证实。蛋源性活性组分的开发应用有望为炎症性肠病提供新的治疗策 略。本文综述了氨基酸、多肽、蛋白质和脂质这些蛋源性活性组分的抗炎活性以及其对炎症性肠病缓解作用的分 子作用机制的研究进展,并对其研究进行了展望,以期为蛋源性抗肠炎活性组分的进一步深入研究和应用开发提 供参考。     

Probiotics: The scientific evidence in the context of inflammatory bowel disease

Inflammatory bowel disease (IBD) generally comprises Crohn's disease (CD) and ulcerative colitis (UC), and their main characteristic is the intestinal mucosa inflammation. Although its origin is not yet fully known, there is growing evidence related to genetics, intestinal microbiota composition, and the immune system factors such as precursors for the initiation and progression of intestinal conditions. The use of certain probiotic microorganisms has been touted as a possible and promising therapeutic approach in reducing the risk of inflammatory bowel disease, specifically ulcerative colitis. Several mechanisms have been proposed to explain the benefits of probiotics, indicating that some bacterial strains are able to positively modulate the intestinal microbiota and the immune system, and to produce metabolites with anti-inflammatory properties. The aim of this paper is to bring together the various results and information, based on scientific evidence, that are related to probiotics and inflammatory bowel disease, emphasizing the possible mechanisms involved in this action.     

Effects of dietary fiber on inflammatory bowel disease

The chronic idiopathic inflammatory bowel diseases (IBDs), namely Crohn's disease and ulcerative colitis, appear to be derived from an inappropriate reaction towards a luminal agent, most probably driven by the intestinal microflora, which upregulates the synthesis and release of different pro-inflammatory mediators, thus contributing to tissue damage that characterizes these intestinal conditions. Several studies have reported that IBD is associated with impairment in short-chain fatty acid (SCFA) production, mainly acetate, propionate, and butyrate. They are produced in the large bowel by anaerobic bacterial fermentation of undigested dietary carbohydrates and fiber polysaccharides, with butyrate being considered as the major fuel source for colonocytes. These SCFAs have been proposed to play a key role in the maintenance of colonic homeostasis. Therefore, it is reasonable to consider therapeutic approaches that increase colonic SCFA production, as it can be achieved by administration of dietary fiber to IBD patients. Unfortunately, there is quite limited documentation of efficacy of dietary fiber in properly designed trials. This review discusses the rationale, available evidence for the use of dietary fiber and its mechanisms of action in the treatment and prevention of IBDs.     

膳食多酚改善炎症性肠病的作用机制研究进展

文章概述了膳食多酚通过调节氧化应激、保护肠黏膜屏障、调节肠道菌群及代谢物改善炎症性肠病的作用机制,重点阐述了膳食多酚对炎症性肠病炎症信号通路的调节作用,并展望了膳食多酚在炎症性肠病等疾病营养干预领域的研究方向。     

Dietary roles of non-starch polysachharides in human nutrition: a review

Nonstarch polysaccharides (NSPs) occur naturally in many foods. The physiochemical and biological properties of these compounds correspond to dietary fiber. Nonstarch polysaccharides show various physiological effects in the small and large intestine and therefore have important health implications for humans. The remarkable properties of dietary NSPs are water dispersibility, viscosity effect, bulk, and fermentibility into short chain fatty acids (SCFAs). These features may lead to diminished risk of serious diet related diseases which are major problems in Western countries and are emerging in developing countries with greater affluence. These conditions include coronary heart disease, colo-rectal cancer, inflammatory bowel disease, breast cancer, tumor formation, mineral related abnormalities, and disordered laxation. Insoluble NSPs (cellulose and hemicellulose) are effective laxatives whereas soluble NSPs (especially mixed-link β-glucans) lower plasma cholesterol levels and help to normalize blood glucose and insulin levels, making these kinds of polysaccharides a part of dietary plans to treat cardiovascular diseases and Type 2 diabetes. Moreover, a major proportion of dietary NSPs escapes the small intestine nearly intact, and is fermented into SCFAs by commensal microflora present in the colon and cecum and promotes normal laxation. Short chain fatty acids have a number of health promoting effects and are particularly effective in promoting large bowel function. Certain NSPs through their fermented products may promote the growth of specific beneficial colonic bacteria which offer a prebiotic effect. Various modes of action of NSPs as therapeutic agent have been proposed in the present review. In addition, NSPs based films and coatings for packaging and wrapping are of commercial interest because they are compatible with several types of food products. However, much of the physiological and nutritional impact of NSPs and the mechanism involved is not fully understood and even the recommendation on the dose of different dietary NSPs intake among different age groups needs to be studied.     

In vitro screening of probiotics and synbiotics according to anti-inflammatory and anti-proliferative effects

There is emerging evidence of the efficiency of probiotic, prebiotic and synbiotic treatments in inflammatory bowel diseases (IBDs) and one of their long-term complications, colorectal cancer (CRC). In this study, various strains of probiotic lactic acid bacteria, prebiotic glucooligosaccharides (GOS) or a synbiotic combination of the two were screened for anti-inflammatory and anti-proliferative effects in different in vitro models in the context of such diseases. To mimic IBD response to Gram negative bacteria, HT-29 cells were sensitised to inflammatory response to lipopolysaccharide (LPS) by IFNγ which increased expression of TLR4, the LPS biosensor, and were then treated by probiotics, prebiotics and synbiotics. Secreted IL-8 and activated NF-κB were monitored as inflammation biomarkers. A selection of active strains were then subjected to a second inflammatory cell culture model consisting of inflammatory activated transgenic Caco-2 cells transfected by a reporter gene under the control of NF-κB inducible promoter. Quantification of reporter gene expression allowed us to demonstrate some probiotic inhibitory properties or to confirm such characteristics in two different models. Proliferation of cancerous HT-29 cells was monitored by XTT assay. Only three probiotic strains induced a proliferation decrease, but with a lack of reproducibility. Binary or ternary probiotic associations, complemented or not by prebiotic GOS, significantly decreased proliferation, especially with a synbiotic association of Bifidobacterium breve, Lactococcus lactis and oligoalternan, a GOS. This combination was selected for the following experiments. We showed the involvement of both bacterial and carbohydrate compounds of this synbiotic in the observed effect by dose range tests. We demonstrated that this decrease in proliferation may be due to an induction of a differentiated phenotype, as shown by the up-regulation of intestinal alkaline phosphatase, a biomarker of differentiation, monitored by real-time RT-PCR in HT-29 cells treated by the selected synbiotics. Thus, this study demonstrates the ability of probiotics to exert anti-inflammatory effects and shows some anti-proliferative characteristics for a specific synbiotics. These products should be further evaluated in animal models to confirm the in vitro results.     

食源性天然产物中多糖干预炎症性肠病的研究进展

多糖类物质是具有生物活性的大分子物质,广泛存在于多种食源性物质中。炎症性肠病对结肠有广泛的损伤作用,并可能破坏免疫系统的动态平衡。尽管药物能够在一定程度上缓解炎症性肠病,但许多临床实践中的药物都有不良反应。研究表明,多糖类物质能有效预防和改善炎症性肠病引起的结肠损伤和免疫系统紊乱。本文主要对食源性天然产物中多糖类物质干预炎症性肠病的研究进展和发挥保护作用的相关分子机制进行综述,以期为预防炎症性肠病和营养干预机制的进一步研究提供参考。