肠道微生物多样性与能量代谢调控及肥胖关系的研究进展

肠道微生物与宿主之间相互选择,构成了一个相对稳定的超有机体。宿主基因型和遗传关系影响肠道微生物的生态学特征,而肠道微生物发酵肠道内多糖,为宿主提供可吸收利用的养分,增强肠道对养分吸收的能力。同时,肠道微生物还影响一些转录因子的活性,调控宿主基因的表达,增强宿主甘油三酯的合成和脂肪沉积,减少脂肪酸氧化分解,调控宿主能量代谢。     

生物发酵稻秸对湖羊消化道上皮形态及微生物区系的影响

【目的】本研究旨在通过显微观察和16SrRNA基因高通量测序技术来探究饲喂生物发酵稻秸对湖羊肠道上皮形态及微生物区系的影响。【方法】试验选择70日龄、体重相近(25.15±0.47)kg的湖羊公羔21只,根据饲粮中粗饲料的组成随机分为3组：稻秸组、生物发酵稻秸组和苜蓿干草组,饲粮精粗比为6:4,试验持续7周,其中适应期3周,正试期4周,结束后屠宰取样,采集瘤胃、空肠和结肠上皮组织进行观察测量,收集对应肠段内容物用于微生物区系和代谢产物测定。【结果】与稻秸组相比,饲喂生物发酵稻秸显著提高湖羊瘤胃中纤维杆菌(Fibrobacteres)的相对丰度和挥发性脂肪酸(volatile fatty acids, VFA)的含量,促进瘤胃上皮的发育;显著提高湖羊空肠中厚壁菌门(Firmicutes)和疣微菌门(Verrucomicrobia)的相对丰度,改变空肠微生物菌群结构,促进空肠上皮组织的发育;改变湖羊结肠微生物菌群结构。【结论】饲喂生物发酵稻秸有利于湖羊肠道上皮的发育,并增加消化道内的微生物多样性。     

口臭患者口腔微生物区系研究

目的研究口臭口腔微生物区系组成,为口臭治疗提供依据。方法采用稀释平板测数法对需氧和厌氧细菌、真菌、放线菌分别进行计数。结果非口臭口腔好氧细菌数量(1180±380)和厌氧细菌数量(680±100)分别低于口臭口腔好氧细菌数量(7200±800)和厌氧细菌数量(12520±120),差异有统计学意义(P0.01),且口臭口腔以革兰阳性菌和杆菌占优势,非口臭口腔真菌数量低于口臭口腔真菌数量,两者差异无统计学意义(P0.05)。口腔中没有检出放线菌。结论口臭患者口腔微生物多样性高于非口臭组,可以通过调整口腔微生态改善口臭。     

大曲酒微生物区系的初步研究

通过对四个酒厂发酵料的分离、培养,共获得霉菌５６种;细菌３４种;酵母菌２１种;放线菌３种。确定了优势菌株。发现在大曲酒发酵过程中,微生物数量在不同发酵期里规律变化。     

肠道微生物菌群与消化道肿瘤关系的研究进展

人体肠道作为一个多元化的微生态系统,其中共生着100多万亿个微生物菌群,约有1 000多种,是人体细胞的10倍。肠道微生物固有的微生物基因有300多万个,是人体基因的100多倍,这些微生物基因帮助人体微生物适应多变的环境,与人类相互作用,对人类健康产生了巨大影响,其中有积极的作用,同时又伴随着潜在的威胁。总结了肠道微生物菌群与消化道肿瘤的关系,从肠道菌群的多样性、影响因素及其作用机制展开综述,以期为开展肠道微生物的研究提供参考。     

母体与外界环境影响新生儿肠道微生物区系建立的研究进展

肠道微生物在宿主营养吸收、器官发育、抵抗病原菌入侵以及调节免疫应答等方面是不可或缺的。新生儿早期建立的微生物区系与成年人的微生物区系有很大的不同,容易受到母体和外界环境因素的影响,经历由少到多,从简单到复杂和从不稳定到稳定的过程。本文对影响新生儿早期肠道微生物区系建立的因素进行综述,系统阐述分娩时间、分娩方式、喂养方式以及抗生素这几种重要因素对微生物区系变化所产生的作用。     

南极长城站微生物区系调查

1992～1993年的夏季,对南极中国长城站的陆地进行了微生物区系的现场调查。先后采集各种类型上样多个。其中对有生态意义的25个样进行了不同类型微生物的分离和计数;中温培养下每克湿土壤菌量为10²～10⁶,用马丁培养基对真菌进行分离培养和计数,每克湿土含菌量为10²～10⁴;0℃下分离计数,发现低温下微生物的数量较中温的多,每克湿土壤含菌为10³～10⁶。对该地区烃氧化菌进行了特别调查,以长城站为中心东西宽0．4Km,南北长1Km的范围内烃氧化菌发育最为活跃,但距长城站距离越远,烃氧化菌数量越少。     

黄土高原不同植被坡地土壤微生物区系特征

应用稀释平板法对黄土高原不同植被覆盖下坡地土壤0～5cm和5～20cm土层的细菌、真菌和放线菌的分布特征进行了研究;结果表明:(1)该区域不同植被下土壤中细菌、真菌和放线菌总体比较丰富,数量差异较大,柠条土壤中微生物数量最多,苜蓿地中的最少.同一植被下各类菌群数量排序为细菌>放线菌>真菌.(2)放线菌和真菌随土层深度的增加而呈明显的减少趋势,而细菌的不明显.(3)天然荒坡的微生物数量高于人工草地的,人工灌木林微生物数量高于人工乔木林的,人工乔草复生果树林的微生物数量高于人工纯生乔木林、纯生草地和纯生果树林的.     

饮食和肠道微生物对肥胖的代谢调控作用与机制

肥胖是人体脂肪过度堆积呈现的一种病理状态,成年人和未成年人均可发病。作为名副其实的健康杀手,肥胖可导致人体多个系统发生病变,发病机制与饮食结构和肠道微生物群落改变导致的代谢失衡关系密切。通过调整饮食结构可在生理生化和肠道微生态水平实现肥胖的有效干预和治疗。本文综述了近年来肥胖发生的代谢机制及其治疗策略,重点阐述了饮食调节与肠道微生物群落变化对肥胖发生的影响,并探讨了二者对肥胖治疗调控的内在机制,以期为肥胖预防与治疗提供参考。     

中草药对消化道微生物的影响

中草药在我国使用的历史悠久,具有防病保键的作用。其绝大多数经口服在消化道内代谢吸收,当中草药进入消化道后势必接触到消化道微生物,影响消化道微生物区系,从而影响动物的生理健康状况。本文简要的概述了中草药进入消化道后对消化道微生物产生的影响。     

Impact of the factors shaping gut microbiota on obesity

Obesity is considered as a risk factor for chronic health diseases such as heart diseases, cancer and diabetes 2. Reduced physical activities, lifestyle, poor nutritional diet and genetics are among the risk factors associated with the development of obesity. In recent years, several studies have explored the link between the gut microbiome and the progression of diseases including obesity, with the shift in microbiome abundance and composition being the main focus. The alteration of gut microbiome composition affects both nutrients metabolism and specific gene expressions, thereby disturbing body physiology. Specifically, the abundance of fibre-metabolizing microbes is associated with weight loss and that of protein and fat-metabolizing bacteria with weight gain. Various internal and external factors such as genetics, maternal obesity, mode of delivery, breastfeeding, nutrition, antibiotic use and the chemical compounds present in the environment are known to interfere with the richness of the gut microbiota (GM), thus influencing weight gain/loss and ultimately the development of obesity. However, the effectiveness of each factor in potentiating the shift in microbes’ abundance to result in significant changes that can lead to obesity is not yet clear. In this review, we will highlight the factors involved in shaping GM, their influence on obesity and possible interventions. Understanding the influence of these factors on the diversity of the GM and how to improve their effectiveness on disease conditions could be keys in the treatment of metabolic diseases.     

肠道微生物对肥胖影响

肠道微生物是哺乳动物最密集的微生物群落,也是最多样化的微生物群落之一。随着宏基因组学的不断发展,肠道微生物成为热门的研究领域。肠道微生物具有保护和代谢等功能,在胰岛素抵抗和肥胖等疾病中发挥重要作用。本文介绍了肠道微生物及其代谢物通过调节食欲、神经递质合成分泌、炎性反应进而调节肥胖,探讨了肠道微生物的影响因素,展望了肠道微生物对治疗人类肥胖的应用前景。     

The intestinal microbiome associated with lipid metabolism and obesity in humans and animals

Intestinal microbiota is considered to play an integral role in maintaining health of host by modulating several physiological functions including nutrition, metabolism and immunity. Accumulated data from human and animal studies indicate that intestinal microbes can affect lipid metabolism in host through various direct and indirect biological mechanisms. These mechanisms include the production of various signalling molecules by the intestinal microbiome, which exert a strong effect on lipid metabolism, bile secretion in the liver, reverse transport of cholesterol and energy expenditure and insulin sensitivity in peripheral tissues. This review discusses the findings of recent studies suggesting an emerging role of intestinal microbiota and its metabolites in regulating lipid metabolism and the association of intestinal microbiota with obesity. Additionally, we discuss the controversies and challenges in this research area. However, intestinal micro-organisms are also affected by some external factors, which in turn influence the regulation of microbial lipid metabolism. Therefore, we also discuss the effects of probiotics, prebiotics, diet structure, exercise and other factors on intestinal microbiological changes and lipid metabolism regulation.     

Orally administered heat-killed Lactobacillus gasseri TMC0356 alters respiratory immune responses and intestinal microbiota of diet-induced obese mice

Aims: To investigate the influence of heat‐killed Lactobacillus gasseri TMC0356 on changes in respiratory immune function and intestinal microbiota in a diet‐induced obese mouse model. Methods and Results: Male C57BL/6J mice were fed a high‐fat diet for 16 weeks. After 8 weeks, the high‐fat‐diet‐induced obese mice (DIO mice) were randomly divided into two 0067roups, the DIO and DIO0356 groups. DIO0356 group mice were orally fed with heat‐killed TMC0356 every day for 8 weeks, while DIO group mice were exposed to 0·85% NaCl over the same time period as controls. After intervention, the pulmonary mRNA expression of cytokines and other immune molecules in DIO0356 mice compared to those in DIO group mice was significantly increased (P < 0·05, P < 0·01). In faecal bacterial profiles, analysed using the terminal restriction fragment length polymorphism (T‐RFLP) method, T‐RFLP patterns in 75% of the DIO0356 group mice were apparently changed compared with those in control group mice. Conclusion: These results suggest that inactive lactobacilli may stimulate the respiratory immune responses of obese host animals to enhance their natural defences against respiratory infection, partially associating with their potent impact on intestinal microbiota. Significance and Impact of the Study: We have demonstrated that oral administration of inactive lactobacilli may protect host animals from the lung immune dysfunction caused by obesity.     

Evidence for host effect on the intestinal microbiota of whitefish (Coregonus sp.) species pairs and their hybrids

Investigating relationships between microbiota and their host is essential toward a full understanding of how animal adapt to their environment. Lake Whitefish offers a powerful system to investigate processes of adaptive divergence where the dwarf, limnetic species evolved repeatedly from the normal, benthic species. We compared the transient intestinal microbiota between both species from the wild and in controlled conditions, including their reciprocal hybrids. We sequenced the 16s rRNA gene V3‐V4 regions to (a) test for parallelism in the transient intestinal microbiota among sympatric pairs, (b) test for transient intestinal microbiota differences among dwarf, normal, and hybrids reared under identical conditions, and (c) compare intestinal microbiota between wild and captive whitefish. A significant host effect on microbiota taxonomic composition was observed when all lakes were analyzed together and in three of the five species pairs. In captive whitefish, host effect was also significant. Microbiota of both reciprocal hybrids fell outside of that observed in the parental forms. Six genera formed a bacterial core which was present in captive and wild whitefish, suggesting a horizontal microbiota transmission. Altogether, our results complex interactions among the host, the microbiota, and the environment, and we propose that these interactions define three distinct evolutionary paths of the intestinal microbiota.     

The role of intestinal microbiota in cardiovascular disease

Accumulating evidence has indicated that intestinal microbiota is involved in the development of various human diseases, including cardiovascular diseases (CVDs). In the recent years, both human and animal experiments have revealed that alterations in the composition and function of intestinal flora, recognized as gut microflora dysbiosis, can accelerate the progression of CVDs. Moreover, intestinal flora metabolizes the diet ingested by the host into a series of metabolites, including trimethylamine N‐oxide, short chain fatty acids, secondary bile acid and indoxyl sulfate, which affects the host physiological processes by activation of numerous signalling pathways. The aim of this review was to summarize the role of gut microbiota in the pathogenesis of CVDs, including coronary artery disease, hypertension and heart failure, which may provide valuable insights into potential therapeutic strategies for CVD that involve interfering with the composition, function and metabolites of the intestinal flora.     

肠道菌群与肥胖关系的研究进展

西方化的高脂饮食方式造成了越来越多的肥胖人群。高脂饮食在一定程度上可以改变肠道菌群的结构组成和功能,促进宿主对食物营养的吸收,从而增加体重形成肥胖。高脂饮食诱导的肥胖者肠道菌群的改变会导致宿主能量吸收增加,肠道通透性和炎症增加,而有减肥功能的短链脂肪酸合成能力下降。最近研究发现肠道菌群也可以通过影响中枢神经系统,尤其是下丘脑相关基因的表达来控制食欲,从而调控肥胖的形成。本文系统介绍了最近几年高脂饮食诱导肥胖的研究,总结了一些与肥胖形成有密切关系的肠道菌群以及其在肥胖形成中的作用机制,为进一步研究肠道菌群与肥胖之间的调控作用奠定了基础。最后总结了肠道菌群可以作为一个预防和治疗肥胖的有效靶点,可以通过在食物中添加有益菌或者通过菌群移植来治疗肥胖。     

Biphasic assembly of the murine intestinal microbiota during early development

The birth canal provides mammals with a primary maternal inoculum, which develops into distinctive body site-specific microbial communities post-natally. We characterized the distal gut microbiota from birth to weaning in mice. One-day-old mice had colonic microbiota that resembled maternal vaginal communities, but at days 3 and 9 of age there was a substantial loss of intestinal bacterial diversity and dominance of Lactobacillus. By weaning (21 days), diverse intestinal bacteria had established, including strict anaerobes. Our results are consistent with vertical transmission of maternal microbiota and demonstrate a nonlinear ecological succession involving an early drop in bacterial diversity and shift in dominance from Streptococcus to Lactobacillus, followed by an increase in diversity of anaerobes, after the introduction of solid food. Mammalian newborns are born highly susceptible to colonization, and lactation may control microbiome assembly during early development.     

肥胖相关的肠道微生物群落结构动力学与功能解析研究

肥胖及相关的慢性代谢性疾病近年来已经成为威胁全球的公共健康问题。越来越多的证据表明,在宿主的营养、免疫和代谢中有不可替代的作用的肠道菌群不仅可以通过调节宿主脂肪吸收存储相关的基因,影响后者的能量平衡,更重要的是其结构失调导致宿主循环系统中内毒素增加,诱发慢性、低水平炎症,导致肥胖和胰岛素抵抗。运用微生物分子生态学、元基因组学和代谢组学的方法,揭示与代谢性疾病相关的菌群结构失调,并鉴定出相关的特定细菌类群及其功能,使得通过以菌群为靶点的营养干预手段防止慢性代谢性疾病成为可能,将带来代谢性疾病预防和控制策略的革命性的变化。