结肠镜下结肠息肉形态和临床病理学特征与肠道菌群变化的关系

探讨结肠镜下结肠息肉形态和临床病理学特征与肠道菌群变化的关系。

选择2017年5月至2019年8月于本院消化内科行结肠镜检查并进行内镜下切除手术的结肠息肉患者224例为有结肠息肉组,均于结肠镜下观察记录结肠息肉形态、数量、大小及发生部位等特征,并经病理组织学检查确定其病理类型,所有患者术前均采集粪便标本检测肠道菌群。另选择同期行结肠镜检查确定无结肠息肉的健康体检者230例为无结肠息肉组,所有受试者均采集粪便标本检测肠道菌群。

与无结肠息肉组相比,有结肠息肉组患者肠道乳杆菌、双歧杆菌数量显著降低,大肠埃希菌数量显著升高（均P＜0.05）。腺瘤性息肉好发于息肉形态为隆起型、数量为多发、大小≥1.5 cm、发生部位位于近端结肠的结肠息肉患者。结肠息肉位于近端结肠、大小≥1.5 cm、数量多发或隆起型形态的患者较其他结肠息肉患者肠道乳杆菌、双歧杆菌数量显著降低,大肠埃希菌数量显著升高（均P＜0.05）。与非腺瘤性息肉患者相比,腺瘤性息肉患者肠道乳杆菌、双歧杆菌数量显著降低,大肠埃希菌数量显著升高（均P＜0.05）。

结肠息肉形态和临床病理学特征与肠道菌群变化之间存在密切联系,检测肠道菌群变化可能有助于预判结肠息肉病理类型,及时开展治疗。

     

原发性干燥综合征患者肠道菌群特征分析

通过比较原发性干燥综合征(pSS)患者和健康人群肠道菌群的差异, 深入探讨pSS患者肠道菌群与pSS发生发展的关系。

招募2019年1月至2021年2月于大连市中心医院风湿免疫科住院的pSS患者60名, 作为本研究的pSS组; 同时招募大连市中心医院体检中心的健康志愿者50名作为本研究的对照组(Control组)。收集两组粪便标本, 各50例, 提取细菌DNA进行16S rDNA高通量测序后进行菌群多样性和LEfSe分析。

pSS组肠道菌群α-多样性较Control组显著降低(P < 0.05)。与Control组相比, pSS组厚壁菌门/拟杆菌门比值降低; 普雷沃菌科、红蝽菌科、消化链球菌科、Eggerthellaceae, unidentified_Clostridiales丰度降低, 而拟杆菌科升高; 罗姆布茨菌属和Dorea等丰度降低, 拟杆菌属、韦荣球菌属等丰度升高。并且在pSS组肠道菌群中发现大肠埃希菌丰度明显升高。

pSS患者存在肠道菌群失调, 提示菌群失调可能与pSS的发生发展有关。

     

圈养食叶猴的肠道菌群特征

充分认识圈养食叶猴的肠道菌群组成特征, 为饲养管理方法的改进提供参考依据。

通过MiSeq高通量测序平台对3个物种的19个个体[黑叶猴(n=5)、川金丝猴(n=9)和西非黑白疣猴(n=5)]的肠道菌群16S rRNA V4-V5区进行测序和分析。

食叶猴肠道菌群以厚壁菌门和拟杆菌门为优势菌门, 瘤胃菌科、普氏菌科、理研菌科和毛螺菌科为优势菌科, 普氏菌属、密螺旋体属和瘤胃球菌属为优势菌属; 食叶猴物种间肠道菌群组成存在显著差异, 肠道菌群按照宿主物种聚类, 而不受环境因素的影响。

宿主物种是决定肠道微生物组成的重要因素, 食叶猴肠道菌群特征反映了宿主对其食性的适应。

     

内毒素血症对新生鼠肠道菌群的影响

利用高通量测序技术分析内毒素血症新生鼠肠道菌群的变化, 探究肠道菌群与内毒素血症的关系, 为临床诊治提供思路。

复制新生大鼠内毒素损伤模型, 注射LPS后第24小时、第3天、第7天分别处死新生大鼠, 留取粪便并将对照组(C1组6只、C3组5只、C7组7只)和LPS组(L1组5只、L3组5只、L7组5只)按处死天数各分为3组。高通量测序分析各组间菌群多样性及相对丰度差异。

(1) Alpha多样性分析提示对照组和LPS组菌群多样性及丰度有显著差异, C3组较L3组Shannon指数均值小(t=-3.386 8, P=0.009 5), Simpson指数均值大(t=3.102 4, P=0.014 6);C7组较L7组Shannon指数均值大(t=2.459 4, P=0.033 7), Simpson指数均值小(t=-2.475 6, P=0.032 8)。(2)物种组成分析表明LPS组的菌群结构发生改变, 在门水平LPS组较对照组变形菌门相对丰度高, 厚壁菌门相对丰度低; 在属水平上LPS组较对照组埃希菌-志贺菌属相对丰度高, 乳杆菌属相对丰度低; 且随着天数的递增LPS组埃希菌-志贺菌属呈递增趋势, 红球菌属呈递减趋势。

内毒素血症可以改变新生鼠肠道菌群的组成, 并与肠道菌群失调有一定的关系。

     

基于高通量测序分析哮喘小鼠呼吸道菌群的变化

通过高通量测序分析哮喘模型小鼠呼吸道菌群的变化情况。

将12只SPF级BALB/c雄性小鼠随机分为对照组和模型组, 每组6只。采用卵清蛋白致敏方法建立哮喘小鼠模型后, 进行支气管组织切片病理学观察, ELISA法检测血清IgE水平, 测定肺指数, 采集咽拭子后提取DNA行高通量测序分析。

与对照组比较, 模型组小鼠血清IgE水平明显升高(P < 0.05), 肺指数明显上升(P < 0.05), 可见支气管上皮粘膜有水肿, 少量淋巴细胞浸润, 平滑肌增生。模型组小鼠呼吸道菌群与对照组比较, 菌种丰度升高, 厚壁菌门较对照组减少(P < 0.05), 放线菌门和变形菌门增多(P < 0.05), 菌群结构有明显差异。

哮喘小鼠存在呼吸道微生态菌群失衡。

     

复合乳酸菌联合蒙脱石散对慢性腹泻患儿肠道菌群和氧化应激及炎性因子的影响

探讨复合乳酸菌联合蒙脱石散对慢性腹泻患儿肠道菌群、氧化应激和炎性因子的影响,为该类患者的治疗提供参考。

选取2020年6月至2022年8月我院门诊收治的400例慢性腹泻患儿作为研究对象,按照随机数表法分为观察组（予以复合乳酸菌联合蒙脱石散治疗）与对照组（仅予以复合乳酸菌治疗）,各200例。对比2组患儿肠道菌群（双歧杆菌、乳杆菌、大肠埃希菌）和应激指标[丙二醛（MDA）、一氧化氮（NO）]、炎性因子[白细胞介素-10（IL-10）、肿瘤坏死因子-α（TNF-α）、干扰素-γ（IFN-γ）]、胃肠道激素[胃泌素（GAS）、胃动素（MOT）、生长抑素（SSTI）]水平的变化。

治疗后,观察组患儿肠道双歧杆菌、乳杆菌数量均高于对照组,而大肠埃希菌数量低于对照组（均P＜0.05）;同时观察组患儿MDA、NO、TNF-α、GAS、MOT水平均低于对照组,而IL-10、IFN-γ、SSTI水平均高于对照组（均P＜0.05）。

复合乳酸菌联合蒙脱石散治疗慢性腹泻的疗效显著,有利于调节患儿肠道菌群以及氧化应激、炎性因子水平。

     

慢性肾衰竭患者肠道菌群改变与肾小球滤过率的关系

探究慢性肾衰竭患者肠道菌群结构改变与肾小球滤过率的关系。

选取2017年3月至2020年3月我院收治的202例慢性肾衰竭患者作为试验组, 并选取198例同期健康体检者作为对照组。收集两组入选者粪便标本并进行检测, 对比两组入选者肠道菌群数量; 同时对比两组入选者体质量、肾小球滤过率、血肌酐、血尿素氮、血胱抑素C水平, 采用Pearson相关性分析肠道菌群改变与肾小球滤过率的相关性。

相比于对照组, 试验组患者肠道双歧杆菌(t=21.915, P < 0.001)、大肠埃希菌数量显著降低(t=18.220, P < 0.001), 肠球菌数量显著增高(t=16.782, P < 0.001)。相比于对照组, 试验组患者肾小球滤过率(t=147.035, P < 0.001)显著降低, 血肌酐(t=43.129, P < 0.001)、血尿素氮(t=170.206, P < 0.001)、血胱抑素C(t=22.432, P < 0.001)水平显著增高。Spearman相关性分析显示, 慢性肾衰竭患者肠道双歧杆菌(r=-0.695, P < 0.001)和大肠埃希菌(r=-0.631, P < 0.001)与肾小球滤过率呈负相关。Logistic回归分析显示, 双歧杆菌、大肠埃希菌、肠球菌、血肌酐、血尿素氮和血胱氨酸均是慢性肾衰竭患者肾小球滤过率降低的独立危险因素。

慢性肾衰竭患者肠道双歧杆菌和大肠埃希菌数量降低、肠球菌数量升高, 且与肾小球滤过率呈显著负相关。

     

夏季老年慢性阻塞性肺疾病患者口咽菌群分析

分析夏季老年慢性阻塞性肺疾病（COPD）患者与健康人群的口咽菌群构成,旨在确定老年COPD患者与健康人群上呼吸道菌群间的差异。

选择2018年6—8月沈阳市沈阳医学院附属第二医院COPD患者29例和健康体检者25例,采集口咽拭子进行细菌16S rRNA高通量测序。通过菌群多样性分析、物种组成和物种差异分析,比较老年COPD患者与健康人群口咽部微生物的异同。

老年COPD患者口咽中菌群丰富度显著高于健康人群,物种多样性低于健康人群。在门水平上,老年COPD患者口咽菌群中拟杆菌门相对丰度降低,放线菌门相对丰度显著增高;在属水平上,老年COPD患者口咽菌群中罗氏菌属、放线菌属和劳特罗普氏菌属丰度均显著高于健康人群,奈瑟菌属和普雷沃菌属相对丰度降低,差异均具有统计学意义（P＜0.05）。

老年COPD患者口咽部正常菌群组成发生变化,机会致病菌如罗氏菌属、劳特罗普氏菌属比例增加,提示夏季老年COPD患者口咽菌群失调。

     

YNS益肤面霜对豚鼠皮肤变态反应及肠道菌群的影响

建立豚鼠皮肤变态反应模型,并使用YNS益肤面霜对皮肤变态反应模型进行干预,探讨这种面霜对改善及修复受损皮肤的作用及其对豚鼠肠道菌群的影响。

豚鼠24只,随机分成4组：对照组、阳性组、化妆品组和治疗组,每组6只。致敏接触后进行激发反应。提取4组豚鼠粪便标本DNA,使用16S rRNA高通量测序检测肠道菌群构成。

治疗组豚鼠皮肤致敏率为16.7%。益肤面霜治疗对肠道菌群alpha多样性影响不大,但有降低厚壁菌门（Firmicutes）与拟杆菌门（Bacteroidetes）比值（F/B）及粪球菌属（Coprococcus）相对丰度的趋势,有利于皮肤变态反应豚鼠肠道菌群组成的恢复。

YNS益肤面霜对皮肤具有改善及修复作用,并对豚鼠肠道菌群具有一定影响。

     

基于16S rRNA高通量测序技术分析福州地区慢传输型便秘患者肠道菌群的变化

运用16S rRNA高通量测序技术分析福州地区慢传输型便秘(STC)患者肠道菌群变化的特征。

纳入60例STC患者和健康志愿者20例, 留取新鲜粪便样本, 冰块运送至实验室并存放于-80度冰箱, 应用16S rRNA高通量测序技术, 分析各组肠道菌群的生物多样性与结构组成。

测序后共得到1 702 004 524条有效序列, 样本序列平均有效长度为414.1 bp, 总样本平均序列条数为2 127 505.7条。与对照组比较, STC患者肠道菌群丰度指数Ace指数、Chao指数和肠道菌群多样性指数Shannon指数下降(P < 0.05), 肠道菌群多样性指数Simpson指数显著升高(P < 0.05)。在门水平上, STC组以拟杆菌门、放线菌门为主, 正常对照组以厚壁菌门为主。在属水平上, STC组以拟杆菌属(Bacteroides)、肠杆菌科(Enterobacteriaceae)、丹毒杆菌属(Erysipelatoclostridium)、巨单胞菌属(Megamonas)为主, 正常对照组以乳酸杆菌属(Lactobacillus)、双歧杆菌属(Bifidobacterium)、布劳特菌属(Blautia)为主。

STC患者肠道菌群发生紊乱, 表现为丰度及多样性下降, 菌群结构发生改变, 可能与慢传输型便秘的发生发展有关。

     

Lentinula edodes-Derived Polysaccharide Alters the Spatial Structure of Gut Microbiota in Mice

Lentinula edodes-derived polysaccharides possess many therapeutic characteristics, including anti-tumor and immuno-modulation. The gut microbes play a critical role in modulation of immune function. However, the impact of Lentinula edodes-derived polysaccharides on the gut microbes have not yet been explored. In this study, high-throughput pyrosequencing technique was employed to investigate the effects of a new heteropolysaccharide L2 from Lentinula edodes on microbiota diversity and composition of small intestine, cecum, colon and distal end of colon (feces) in mice. The results demonstrated that along mouse intestine the microbiota exhibit distinctly different space distribution. L2 treatment reduced the diversity and evenness of gut microbiota along the intestine, especially in the cecum and colon. In the fecal microbial communities, the decrease of Bacteroidetes by significantly increasing Proteobacteria were observed, which were characterized by the increased Helicobacteraceae and reduced S24-7 at family level. Some OTUs, corresponding to Bacteroides acidifaciens, Alistipes and Helicobacter suncus, were found to be significantly increased in L2 treated-mice. In particular, 4 phyla Chloroflexi, Gemmatimonadetes, Nitrospirae and Planctomycetes are exclusively present in L2-treated mice. This is helpful for further demonstrating healthy action mechanism of Lentinula edodes-derived polysaccharide L2.     

普氏蹄蝠胃肠道菌群的多样性

【目的】研究普氏蹄蝠(Hipposideros pratti)胃肠道菌群多样性及致病菌的种类。【方法】采用Mi Seq高通量测序技术,通过对16S r RNA基因V1-V2区基因进行测序,研究普氏蹄蝠胃肠道细菌的群落组成。应用MG-RAST V3.3.6分析和统计样品序列和操作分类单元(OTU)数目,分析胃肠道菌群物种丰度,并进行聚类分析。【结果】从普氏蹄蝠胃和肠道中分别获得144 998条和275 274条原始序列以及48 332条和91 758条有效序列,分属于894个和756个操作分类单元。胃中菌群丰度指数Chao指数(1 490)和ACE指数(2 221)分别低于肠道菌群的Chao指数(2 051)和ACE指数(3 556);Shannon多样性指数(2.405)低于肠道(2.407);Simpson多样性指数(0.168)高于肠道(0.151)。系统进化分析表明胃肠中的细菌主要分布在6个门,均以变形菌门(Proteobacteria)(胃中占56.4%,肠中占46.0%)和厚壁菌门(Firmicutes)(胃中占40.7%,肠中占49.2%)为优势菌门。胃肠道中丰度在0.1%以上的属有24个,胃中优势类群为乳球菌属(Lactococcus)和哈夫尼菌属(Hafnia),分别占整个菌群的26.1%和21.0%;肠道中优势类群为肠球菌属(Enterococcus)和沙门氏菌属(Salmonella),分别占整个菌群的15.2%和12.7%。普氏蹄蝠胃肠道中的优势菌群均为人类的致病菌或者条件致病菌。【结论】普氏蹄蝠携带有大量人类致病菌。因此,应注意防止向人类传播。     

Bacterial Community Mapping of the Mouse Gastrointestinal Tract

Keeping mammalian gastrointestinal (GI) tract communities in balance is crucial for host health maintenance. However, our understanding of microbial communities in the GI tract is still very limited. In this study, samples taken from the GI tracts of C57BL/6 mice were subjected to 16S rRNA gene sequence-based analysis to examine the characteristic bacterial communities along the mouse GI tract, including those present in the stomach, duodenum, jejunum, ileum, cecum, colon and feces. Further analyses of the 283,234 valid sequences obtained from pyrosequencing revealed that the gastric, duodenal, large intestinal and fecal samples had higher phylogenetic diversity than the jejunum and ileum samples did. The microbial communities found in the small intestine and stomach were different from those seen in the large intestine and fecal samples. A greater proportion of Lactobacillaceae were found in the stomach and small intestine, while a larger proportion of anaerobes such as Bacteroidaceae, Prevotellaceae, Rikenellaceae, Lachnospiraceae, and Ruminococcaceae were found in the large intestine and feces. In addition, inter-mouse variations of microbiota were observed between the large intestinal and fecal samples, which were much smaller than those between the gastric and small intestinal samples. As far as we can ascertain, ours is the first study to systematically characterize bacterial communities from the GI tracts of C57BL/6 mice.     

Bacterial diversity in the gastrointestinal tracts of Rhinolophus luctus and Murina leucogaster in Henan Province,China

Previous studies have assessed the diversity of gastrointestinal bacteria in bats and reported that some of the strains are pathogenic to humans; therefore, bats are considered to be potential reservoirs of zoonotic pathogens. However, the bacterial diversity and types of pathogenic bacteria in the gastrointestinal tracts of Rhinolophus luctus and Murina leucogaster have not yet been determined. Humans frequently come into contact with these species; therefore, assessments of their gut microbiota, especially potential pathogens, are essential for public health. In the present study, MiSeq high-throughput sequencing was used to address this research gap, and the results were compared with those reported previously. The V3–V4 regions of the 16S rRNA gene were sequenced using the MiSeq high-throughput sequencing platform to determine the bacterial community of the stomach and the intestines of R. luctus and M. leucogaster. The bacteria in the gastrointestinal tracts of R. luctus and M. leucogaster were classified into three and four main bacterial phyla, respectively. In both R. luctus and M. leucogaster, the dominant phylum was Proteobacteria (stomach 86.07% and 95.79%, intestines 91.87% and 88.78%, respectively), followed by Firmicutes (stomach 13.84% and 4.19%, intestines 8.11% and 11.20%, respectively). In total, 18 and 20 bacterial genera occurred in a relative abundance of 0.01% or more in the gastrointestinal tracts of R. luctus and M. leucogaster, respectively. In R. luctus, the dominant genera were Lactococcus (10.11%) and Paeniclostridium (3.41%) in the stomach, and Undibacterium (28.56%) and Paeniclostridium (4.69%) in the intestines. In M. leucogaster, the dominant genera were Undibacterium (54.41%) and Burkholderia (5.28%) in the stomach, and Undibacterium (29.67%) and Enterococcus (7.19%) in the intestines. Among the detected gastrointestinal tract flora of R. luctus and M. leucogaster, 12 bacterial genera were pathogenic or opportunistic pathogens. A high number of human pathogens were detected in the gastrointestinal tracts of R. luctus and M. leucogaster, which demonstrates the urgency for increased efforts in the prevention and management of bat-to-human disease transmission from these species.     

Changes in the diversity and composition of gut microbiota of weaned piglets after oral administration of <Emphasis Type="Italic">Lactobacillus</Emphasis> or an antibiotic

The gut microbiota plays important roles in the health and well-being of animals, and high-throughput sequencing facilitates exploration of microbial populations in the animal gut. However, previous studies have focused on fecal samples instead of the gastrointestinal tract. In this study, we compared the microbiota diversity and composition of intestinal contents of weaned piglets treated with Lactobacillus reuteri or chlortetracycline (aureomycin) using high-throughput sequencing. Nine weaned piglets were randomly divided into three groups and supplemented with L. reuteri, chlortetracycline, or saline for 10 days, and then the contents of three intestinal segments (jejunum, colon, and cecum) were obtained and used for sequencing of the V3–V4 hypervariable region of the 16S rRNA gene. The microbiota diversity and composition in the jejunum were different from those in the colon and cecum among the three treatments. In the jejunum, treatment with L. reuteri increased the species richness of the microbiota, as indicated by the ACE and Chao1 indexes, compared with the chlortetracycline group, in which several taxa were eliminated. In the colon and cecum, relative abundances of the phylum Firmicutes and the genus Prevotella were higher in the chlortetracycline group than in the other groups. Distances between clustered samples revealed that the L. reuteri group was closer to the chlortetracycline group than the control group for jejunum samples, while colon and cecum samples of the L. reuteri group were clustered with those of the control group. This study provides fundamental knowledge for future studies such as the development of alternatives to antibiotics.     

Antibiotics conspicuously affect community profiles and richness, but not the density of bacterial cells associated with mucosa in the large and small intestines of mice

The influence of three antibiotics (bacitracin, enrofloxacin, and neomycin sulfate) on the mucosa-associated enteric microbiota and the intestines of mice was examined. Antibiotics caused conspicuous enlargement of ceca and an increase in overall length of the intestine. However, there were no pathologic changes associated with increased cecal size or length of the intestine. Conspicuous reductions in the richness of mucosa-associated bacteria and changes to community profiles within the small (duodenum, proximal jejunum, middle jejunum, distal jejunum, and ileum) and large (cecum, ascending colon, and descending colon) intestine occurred in mice administered antibiotics. Communities in antibiotic-treated mice were dominated by a limited number of Clostridium-like (i.e. clostridial cluster XIVa) and Bacteroides species. The richness of mucosa-associated communities within the small and large intestine increased during the 14-day recovery period. However, community profiles within the large intestine did not return to baseline (i.e. relative to the control). Although antibiotic administration greatly reduced bacterial richness, densities of mucosa-associated bacteria were not reduced correspondingly. These data showed that the antibiotics, bacitracin, enrofloxacin, and neomycin sulfate, administered for 21 days to mice did not sterilize the intestine, but did impart a tremendous and prolonged impact on mucosa-associated bacterial communities throughout the small and large intestine.     

Potential rates of fermentation in digesta from the gastrointestinal tract of pigs: effect of feeding fermented liquid feed

Microbial catabolic capacity in digesta from the gastrointestinal tract of pigs fed either dry feed or fermented liquid feed (FLF) was determined with the PhenePlate multisubstrate system. The in vitro technique was modified to analyze the kinetics of substrate catabolism mediated by the standing stock of enzymes (potential rates of fermentation), allowing a quantitative evaluation of the dietary effect on the catabolic capacity of the microbiota. In total, the potential rates of fermentation were significantly reduced in digesta from the large intestine (cecum, P < 0.1; colon, P < 0.01; and rectum, P < 0.0001) of pigs fed FLF compared to pigs fed dry feed. No effect of diet was observed in the stomach (P = 0.71) or the distal part of the small intestine (P = 0.97). The highest rates of fermentation and the most significant effect of diet were observed for readily fermentable carbohydrates like maltose, sucrose, and lactose. Feeding FLF to pigs also led to a reduction in the large intestine of the total counts of anaerobic bacteria in general and lactic acid bacteria specifically, as well as of microbial activity, as determined by the concentration of ATP and short-chain fatty acids. The low-molecular-weight carbohydrates were fermented mainly to lactic acid in the FLF before being fed to the animals. This may have limited microbial nutrient availability in the digesta reaching the large intestine of pigs fed FLF and may have caused the observed reduction in activity and density of the cecal and colonic microbial population. On the other hand, feeding FLF to pigs reduced the viable counts of coliform bacteria (indicator of Escherichia coli and Salmonella spp.) most profoundly in the stomach and the distal part of the small intestine, probably due to the bactericidal effect of lactic acid and low pH. The results presented clearly demonstrate that feeding FLF to pigs had a great impact on the indigenous microbiota, as reflected in bacterial numbers, short-chain fatty acid concentration, and substrate utilization. However, completely different mechanisms may be involved in the proximal and the distal parts of the gastrointestinal tract. The present study illustrates the utility of the PhenePlate system for quantifying the catabolic capacity of the indigenous gastrointestinal tract microbiota.     

Spatial dynamics of the bacterial community structure in the gastrointestinal tract of red kangaroo (<Emphasis Type="Italic">Macropus rufus</Emphasis>)

The quantification and community of bacteria in the gastrointestinal (GI) tract (stomach, jejunum, ileum, cecum, colon and rectum) of red kangaroos (Macropus rufus) were examined by using real-time PCR and paired-end Illumina sequencing. The quantification of bacteria showed that the number of bacteria in jejunum and rectum was significantly lower than that in colon and cecum (P < 0.05). A total of 1,872,590 sequences was remained after quality-filtering and 50,948 OTUs were identified at the 97 % similarity level. The dominant phyla in the GI tract of red kangaroos were identified as Actinobacteria, Bacteroidetes and Firmicutes. At the level of genus, the samples from different parts of GI tract clustered into three groups: stomach, small intestine (jejunum and ileum) and large intestine (cecum and rectum). Prevotella (29.81 %) was the most dominant genus in the stomach and significantly (P < 0.05) higher than that in other parts of GI tract. In the small intestine, Bifidobacterium (33.04, 12.14 %) and Streptococcus (22.90, 19.16 %) were dominant genera. Unclassified Ruminococcaceae was the most dominant family in large intestine and the total relative abundance of unclassified bacteria was above 50 %. In identified genera, Dorea was the most important variable to discriminate large intestine and it was significantly higher in cecum than in stomach, small intestine and colon (P < 0.05). Bifidobacterium (21.89 %) was the only dominant genus in colon. Future work on culture in vitro and genome sequencing of those unidentified bacteria might give us insight into the function of these microorganisms in the GI tract. In addition, the comparison of the bacterial community in the foregut of kangaroos and other herbivores and the rumen might give us insight into the mechanism of fiber degradation and help us exploit approaches to improve the feed efficiency and subsequently, reduce the methane emission from herbivores.     

Gut microflora of vervet and samango monkeys in relation to diet.

The microflora in the gastrointestinal tracts of wild vervet and samango monkeys (Cercopithecus aethiops and C. mitis, respectively) were studied, using fermentation acid analysis, electron microscopy, and culturing methods. The diets of the two species of monkey differ considerably, with that of the samango including a greater proportion of cellulose-rich leaf material, and this is reflected in the microflora. Volatile fatty acid measurements along the gut of both species showed that these end products of bacterial metabolism were concentrated in the cecum and colon. Electron microscopy indicated that morphologically similar bacteria were present in the cecum and colon of both species, but the samango possessed a distinct stomach microflora. Bacteria in the lumina of the four main regions of the gut of the monkeys (stomach, small intestine, cecum, and colon) were plated on a number of anaerobic media (Mann, Rogosa, and Sharp; clostridial basal; and complex media). The cecum and colon were found to contain higher numbers of microbes per gram (wet weight) of gut content than the stomach and small intestine. Microbial isolates were able to catabolize carboxymethyl cellulose and other polymers. This may aid the monkeys, particularly samangos, in the digestion of fibrous dietary components such as leaves.     

Gut microflora of vervet and samango monkeys in relation to diet

The microflora in the gastrointestinal tracts of wild vervet and samango monkeys (Cercopithecus aethiops and C. mitis, respectively) were studied, using fermentation acid analysis, electron microscopy, and culturing methods. The diets of the two species of monkey differ considerably, with that of the samango including a greater proportion of cellulose-rich leaf material, and this is reflected in the microflora. Volatile fatty acid measurements along the gut of both species showed that these end products of bacterial metabolism were concentrated in the cecum and colon. Electron microscopy indicated that morphologically similar bacteria were present in the cecum and colon of both species, but the samango possessed a distinct stomach microflora. Bacteria in the lumina of the four main regions of the gut of the monkeys (stomach, small intestine, cecum, and colon) were plated on a number of anaerobic media (Mann, Rogosa, and Sharp; clostridial basal; and complex media). The cecum and colon were found to contain higher numbers of microbes per gram (wet weight) of gut content than the stomach and small intestine. Microbial isolates were able to catabolize carboxymethyl cellulose and other polymers. This may aid the monkeys, particularly samangos, in the digestion of fibrous dietary components such as leaves.