Biodiversity metrics on ecological networks: Demonstrated with animal gastrointestinal microbiomes

Biodiversity has become a terminology familiar to virtually every citizen in modern societies.It is said that ecology studies the economy of nature,and economy studies the ecology of humans;then measuring biodiversity should be similar with measuring national wealth.Indeed,there have been many parallels between ecology and economics,actually beyond analogies.For example,arguably the second most widely used biodiversity metric,Simpson(1949)’s diversity index,is a function of familiar Gini-index in economics.One of the biggest challenges has been the high“diversity”of diversity indexes due to their excessive“speciation”-there are so many indexes,similar to each country’s sovereign currency-leaving confused diversity practitioners in dilemma.In 1973,Hill introduced the concept of“numbers equivalent”,which is based on Renyi entropy and originated in economics,but possibly due to his abstruse interpretation of the concept,his message was not widely received by ecologists until nearly four decades later.What Hill suggested was similar to link the US dollar to gold at the rate of$35 per ounce under the Bretton Woods system.The Hill numbers now are considered most appropriate biodiversity metrics system,unifying Shannon,Simpson and other diversity indexes.Here,we approach to another paradigmatic shift-measuring biodiversity on ecological networks-demonstrated with animal gastrointestinal microbiomes representing four major invertebrate classes and all six vertebrate classes.The network diversity can reveal the diversity of species interactions,which is a necessary step for understanding the spatial and temporal structures and dynamics of biodiversity across environmental gradients.

Alterations of gut microbiota diversity, composition and metabonomics in testosterone-induced benign prostatic hyperplasia rats

Background: Studies had shown many diseases affect the stability of human microbiota, but how this relates to benign prostatic hyperplasia(BPH) has not been well understood. Hence, this study aimed to investigate the regulation of BPH on gut microbiota composition and metabonomics.Methods: We analyzed gut samples from rats with BPH and healthy control rats, the gut microbiota composition and metabonomics were detected by 16S rDNA sequencing and liquid chromatography tandem mass spectrometry(LC–MS/MS).Results: High-throughput sequencing results showed that gut microbiota beta-diversity increased(P<0.01) in the BPH group vs. control group. Muribaculaceae(P<0.01), Turicibacteraceae(P<0.05), Turicibacter(P<0.01) and Coprococcus(P<0.01) were significantly decreased in the BPH group, whereas that of Mollicutes(P<0.05) and Prevotella(P<0.05)were significantly increased compared with the control group. Despite profound interindividual variability, the levels of several predominant genera were different. In addition, there were no statistically significant differences in several bacteria. BPH group vs. control group: Firmicutes(52.30% vs. 57.29%, P>0.05), Bacteroidetes(46.54% vs. 41.64%,P>0.05), Clostridia(50.89% vs. 54.66%, P>0.05), Ruminococcaceae(25.67% vs. 20.56%, P>0.05). LC–MS/MS of intestinal contents revealed that differential metabolites were mainly involved in cellular processes, environmental information processing, metabolism and organismal systems. The most important pathways were global and overview maps, lipid metabolism, amino acid metabolism, digestive system and endocrine system. Through enrichment analysis, we found that the differential metabolites were significantly enriched in metabolic pathways, steroid hormone biosynthesis,ovarian steroidogenesis, biosynthesis of unsaturated fatty acids and bile secretion. Pearson correlation analysis(R=0.94) showed that there was a strong correlation between Prevotellaceae, Corynebacteriaceae, Turicibacteraceae,Bifidobacteriaceae and differential metabolites.Conclusions: Our findings suggested an association between the gut microbiota and BPH, but the causal relationship between the two groups is unclear. Thus, further studies are warranted to elucidate the potential mechanisms and causal relationships between BPH and gut microbiota.

Gut microbial diversity analysis using Illumina sequencing for functional dyspepsia with liver depression-spleen deficiency syndrome and the interventional Xiaoyaosan in a rat model

AIM To investigate gut microbial diversity and the interventional effect of Xiaoyaosan(XYS) in a rat model of functional dyspepsia(FD) with liver depression-spleen deficiency syndrome. METHODS The FD with liver depression-spleen deficiency syndrome rat model was established through classic chronic mild unpredictable stimulation every day. XYS group rats received XYS 1 h before the stimulation. The models were assessed by parameters including state ofthe rat, weight, sucrose test result and open-field test result. After 3 wk, the stools of rats were collected and genomic DNA was extracted. PCR products of the V4 region of 16 S rD NA were sequenced using a barcoded Illumina paired-end sequencing technique. The primary composition of the microbiome in the stool samples was determined and analyzed by cluster analysis.RESULTS Rat models were successfully established, per data from rat state, weight and open-field test. The microbiomes contained 20 phyla from all samples. Firmicutes, Bacteroidetes, Proteobacteria, Cyanobacteria and Tenericutes were the most abundant taxonomic groups. The relative abundance of Firmicutes, Proteobacteria and Cyanobacteria in the model group was higher than that in the normal group. On the contrary, the relative abundance of Bacteroidetes in the model group was lower than that in the normal group. Upon XYS treatment, the relative abundance of all dysregulated phyla was restored to levels similar to those observed in the normal group. Abundance clustering heat map of phyla corroborated the taxonomic distribution. CONCLUSION The microbiome relative abundance of FD rats with liver depression-spleen deficiency syndrome was significantly different from the normal cohort. XYS intervention may effectively adjust the gut dysbacteriosis in FD.

Association between childhood obesity and gut microbiota:16S rRNA gene sequencing-based cohort study

BACKGROUND This study aimed to identify characteristic gut genera in obese and normal-weight children(8-12 years old)using 16S rDNA sequencing.The research aimed to provide insights for mechanistic studies and prevention strategies for childhood obesity.Thirty normal-weight and thirty age-and sex-matched obese children were included.Questionnaires and body measurements were collected,and fecal samples underwent 16S rDNA sequencing.Significant differences in body mass index(BMI)and body-fat percentage were observed between the groups.Analysis of gut microbiota diversity revealed lowerα-diversity in obese children.Differences in gut microbiota composition were found between the two groups.Prevotella and Firmicutes were more abundant in the obese group,while Bacteroides and Sanguibacteroides were more prevalent in the control group.AIM To identify the characteristic gut genera in obese and normal-weight children(8-12-year-old)using 16S rDNA sequencing,and provide a basis for subsequent mechanistic studies and prevention strategies for childhood obesity.METHODS Thirty each normal-weight,1:1 matched for age and sex,and obese children,with an obese status from 2020 to 2022,were included in the control and obese groups,respectively.Basic information was collected through questionnaires and body measurements were obtained from both obese and normal-weight children.Fecal samples were collected from both groups and subjected to 16S rDNA sequencing using an Illumina MiSeq sequencing platform for gut microbiota diversity analysis.RESULTS Significant differences in BMI and body-fat percentage were observed between the two groups.The Ace and Chao1 indices were significantly lower in the obese group than those in the control group,whereas differences were not significant in the Shannon and Simpson indices.Kruskal-Wallis tests indicated significant differences in unweighted and weighted UniFrac distances between the gut microbiota of normal-weight and obese children(P<0.01),suggesting substantial disparities in both the species and quantity of gut microbiota between the two groups.Prevotella,Firmicutes,Bacteroides,and Sanguibacteroides were more abundant in the obese and control groups,respectively.Heatmap results demonstrated significant differences in the gut microbiota composition between obese and normal-weight children.CONCLUSION Obese children exhibited lowerα-diversity in their gut microbiota than did the normal-weight children.Significant differences were observed in the composition of gut microbiota between obese and normal-weight children.

Lycium barbarum polysaccharide ameliorates radiation-induced brain injury by regulating gut microbiota

Objective: To determine the extent to which Lycium barbarum polysaccharide(LBP) improves60Co γ-ray radiation-induced brain injury(RIBI) by regulating the gut microbiota.Methods: The RIBI model of mice was established with the appropriate dose of60Co γ-ray to identify the changes in the body weight, behaviors, gut microbiota, and inflammatory reactions of mice. Mice were randomly divided into healthy, RIBI model, and LBP groups. The related inflammatory cytokines were determined using an enzyme linked immunosorbent assay kit. Then, 16S rRNA sequencings of feces were carried out to evaluate the differences in intestinal flora.Results: Compared with the spontaneous activity and exploratory spirit of the healthy group, those traits in the RIBI model mice in the open field significantly decreased, the freezing time in the elevated plus maze(EPM) significantly increased, and the number of times the mice discriminated the novel object was significantly lower. Hematoxylin-eosin slides showed that the main histopathological changes of RIBI occurred in the hippocampus. In addition, the diversity and relative abundances ratio of the gut bacterial phylum, order, family, and genus in the model group varied widely. Changes in Bacteroidetes,Firmicutes, and Proteobacteria were the most obvious after head radiation exposure. In comparison, LBP could accelerate the recovery of weight loss in RIBI mice. The frequency that mice entered the center of the open field, facing the open arm in the EPM, and the number of times they discriminated the novel object were significantly increased with LBP administration. LBP could also reduce the levels of inflammatory factor caused by RIBI. LBP increased the diversity and abundance of gut microbiota in RIBI model mice. In addition, LBP increased the relative abundance of Bacteroidetes but decreased the levels of Firmicutes and Proteobacteria for irradiated mice.Conclusion: LBP can improve depression and tension by regulating the composition of gut microbiota,including lowering the relative abundance of Clostridia and Burkholderiales and raising that of Lactobacillales. Thus, LBP provides a new strategy for improving the protective effects of RIBI.

Maintenance of gut microbiome stability for optimum intestinal health in pigs——a review

Pigs are exposed to various challenges such as weaning,environmental stressors,unhealthy diet,diseases and infections during their lifetime which adversely affects the gut microbiome.The inability of the pig microbiome to return to the pre-challenge baseline may lead to dysbiosis resulting in the outbreak of diseases.Therefore,the maintenance of gut microbiome diversity,robustness and stability has been influential for optimum intestinal health after perturbations.Nowadays human and animal researches have focused on more holistic approaches to obtain a robust gut microbiota that provides protection against pathogens and improves the digestive physiology and the immune system.In this review,we present an overview of the swine gut microbiota,factors affecting the gut microbiome and the importance of microbial stability in promoting optimal intestinal health.Additionally,we discussed the current understanding of nutritional interventions using fibers and pre/probiotics supplementation as non-antibiotic alternatives to maintain microbiota resilience to replace diminished species.

SMRT sequencing and ddPCR reveal the complexity of developmental trajectories and temporal dynamics of gut bifidobacterial communities in infants

Infant intestinal microbiome is closely linked with health and risk of disease. Bifidobacterium are important components of the infant gut and are known to confer various health effects on the host. However, few studies have described the precise composition and dynamics of early infant gut bifidobacterial communities. Thus, this was a pilot study aiming to describe the developmental trajectories and temporal dynamics of bifidobacterial communities in infants before 6 months of age. A total of 28 fecal samples from 4 infants(GF, ZZ, QM, TN, respectively)were collected and analyzed after 5, 15, 30, 60, 90, 120, 150, and 180 days of birth by a bifidobacteria-target method(based on single-molecule real-time sequencing of partial bifidobacterial rpsK genes)in conjunction with droplet digital polymerase chain reaction(ddPCR). The infant fecal microbiota comprised a total of 11 bifidobacterial species, including 4 major species, i.e., B. dentium(37.35%), B. catenulatum(32.04%), B. breve(22.24%), and B. animalis(8.02%). The infant microbiota showed highly individualized developmental trajectories. The leading species for GF was B. catenulatum, with a relatively stable developmental trajectory. In ZZ, B. breve was enriched, and the developmental trajectory was rather fluctuating. The most abundant species for QM and TN was B. dentium. The developmental trajectory of B. dentium in QM showed a trend of gradual decrease, whereas an opposite trend was seen in samples of TN. The results of ddPCR confirmed large variations in quantities of bifidobacteria between infants and suggested discordances in temporal dynamics of bifidobacterial communities during the first half year of infancy. In conclusion, our results suggested that the early infant gut bifidobacterial microbiota was highly complex and temporal dynamics, with individualized developmental trajectories, which should be considered in future research of infant gut microbiota.

肠道菌群情况与发声和多种运动联合抽动障碍患儿神经递质、神经功能及T细胞亚群的相关性分析

目的探讨发声和多种运动联合抽动障碍(又称抽动症)患儿肠道菌群分布情况与其神经递质、神经功能及T细胞亚群的相关性。方法以2020年5月—2023年5月南京中医药大学附属南京市中西医结合医院收治的97例抽动症患儿作为研究对象,通过耶鲁抽动症整体严重度量表(YGTSS)将所有患儿分为轻度组23例、中度组42例和重度组32例。采集所有患儿粪便样本,采用16S rRNA测序技术和Qiime软件进行肠道菌群α多样性分析[Chao1指数、observed species(Sobs)指数、Shannon指数、Simpson指数];测定T淋巴细胞亚群(CD4^(+)、CD8^(+)、CD4^(+)/CD8^(+))和神经递质[5-羟色胺(5-HT)、多巴胺(DA)、γ-氨基丁酸(GABA)、去甲肾上腺素(NE)]水平;评估两组儿童神经功能;采用Pearson相关性分析探讨患儿肠道菌群与神经递质、神经功能及T细胞亚群的关系。结果与轻度组相比,中度组和重度组的YGTSS评分的运动性抽动、发声性抽动、总分更高(P<0.05);轻度组、中度组和重度组患儿的Chao1、Sobs、Shannon和Simpson指数比较,经方差分析,差异均有统计学意义(P<0.05);与轻度组相比,中度组和重度组的α多样性更低(P<0.05);轻度组、中度组和重度组患儿的CD4^(+)、CD8^(+)和CD4^(+)/CD8^(+)比较,经方差分析,差异均有统计学意义(P<0.05);与轻度组相比,中度组和重度组的CD4^(+)和CD4^(+)/CD8^(+)更低,CD8^(+)更高(P<0.05);与轻度组相比,中度组和重度组的5-HT和DA更高,GABA、NE、神经功能评分更低(P<0.05)。根据Pearson相关性分析结果,患儿Chao1、Sobs、Shannon和Simpson指数与5-HT、DA呈负相关(P<0.05),与CD4^(+)、GABA、NE和神经功能评分呈正相关(P<0.05)。结论肠道菌群与抽动症患儿的神经递质、神经功能和T细胞亚群密切相关。

辽宁省东南部地区冬季獐肠道菌群组成及多样性差异

肠道菌群与动物营养代谢、机体健康、免疫等方面紧密相关,同时也可以间接反映物种的环境适应能力。2017年獐(Hydropotes inermis)的足迹在东北地区重新出现,初步探究其种群扩散、恢复的原因,并进一步为有效扩大獐在我国的分布,于2021年冬季通过无损伤取样法在辽宁省东南部四个地区采集獐新鲜粪便样本,采用高通量测序技术对粪便DNA中细菌16Sr RNA的V3—V4高变区进行扩增,对獐肠道菌群的组成及多样性进行分析。结果显示:厚壁菌门(Firmicute)和拟杆菌门(Bacteroidete)是獐肠道中的优势菌门,变形菌门(Proteobacteria,30.40%)和大肠杆菌志贺菌属(Escherichia_Shigella,28.48%)仅在沙尖子(SJZ)地区的相对丰度较大,而在其它三个地区中丰度分别不到2%和0.1%。四个地区獐的肠道微生物在丰富度上没有差异(ACE和Chao1,P>0.05),而獐肠道菌群多样性比较中,沙尖子地区与其它三个地区存在显著差异(Shannon和Simpson,P<0.05)。NMDS分析和ANOSIM分析结果显示,沙尖子地区獐肠道菌群与其它三地区在组内结构相似,但组间存在着一定差异(R>0,P<0)。LDA直方图表明四个地区的獐肠道中存在显著差异的细菌菌属有18种,Anaerobutyricum菌属在下露河地区獐的肠道中被显著富集,沙尖子地区中对组间差异影响最大的是近芽孢杆菌属(Peribacillus)。通过对东北地区分布的獐肠道菌群的分析,初步了解獐在寒冷地区生存的肠道菌群的适应机制,揭示獐体内的潜在致病菌和通过消化粗纤维来获取能量的方式,为进一步探究东北地区獐肠道微生物生理生态适应提供基础资料。建议通过一定措施保护或恢复辽宁省东南部地区獐的食物来源,提升獐适宜生境内的生物多样性水平,从而在一定程度上有效保护该种群。

基于16S rRNA测序分析阻塞性睡眠呼吸暂停患者肠道靶标菌群的变化

目的分析阻塞性睡眠呼吸暂停(OSA)患者和健康人群肠道菌群的差异,探讨肠道菌群在OSA发病中的作用及意义。方法随机纳入2022年1月~12月就诊于本院诊断为OSA的患者39例作为OSA组,健康志愿者20例作为对照组。收集两组人群的粪便标本,通过16SrRNA高通量测序分析其微生物组成,分析两组人群肠道菌群之间的Alpha多样性、Beta多样性、物种差异与标志物种和差异生物功能代谢通路功能预测分析。结果Alpha多样性分析显示,OSA组的物种多样性指数Shannon和Simpson、物种丰度指数Observedspecies及菌群均匀度指数Pielou均低于对照组(P<0.05);Beta多样性分析显示,两组间群落结构存在差异(P<0.05)。OSA组肠道菌群群落结构上与对照组存在差异,潜在致病菌属如假单胞菌属、巨单胞菌属等菌群丰度增加(P<0.05)。LEfSe分析结果显示,与对照组相比,OSA组假单胞菌属、巨单胞菌属、梭杆菌属丰度升高(P<0.05)。关联网络分析结果显示,影响宿主稳态的为差异标志菌群;随机森林分析和ROC曲线结果显示,假单胞菌属是具有重要鉴别意义的生物标志菌属。差异代谢通路预测功能显示,维持肠道菌群稳态起主要作用功能的是生物合成功能,假单胞菌属参与了芳香族生物胺降解和酮葡萄糖酸代谢。结论OSA患者存在肠道菌群紊乱,肠菌中假单胞菌属可能通过参与物质代谢影响OSA发生发展,可望作为防治OSA的潜在肠菌靶标。

叉角厉蝽不同发育阶段肠道细菌群落组成、多样性及功能预测

【目的】分析天敌昆虫叉角厉蝽[Eocanthecona furcellata(Wolff)]不同发育阶段肠道细菌群落组成及多样性,并预测其功能,为深入了解肠道细菌对叉角厉蝽生长发育和营养获取方式的影响及开发新的害虫生物防治策略提供理论依据。【方法】选取叉角厉蝽1龄、2龄、5龄若虫和7日龄雌、雄成虫,分别提取其肠道细菌基因组DNA。利用单分子实时测序技术对肠道细菌16S rRNA序列全长进行测序,统计操作分类单元(OTU)数量,分析肠道细菌群落组成结构与多样性,并采用PICRUSt预测肠道细菌功能。【结果】从叉角厉蝽15个肠道样品中共得到202401条有效序列,聚类为222个OTUs,其中共有OTUs为5个。共注释到19门32纲62目103科154属188种细菌,优势门、纲、目、科、属、种分别为变形菌门(Proteobacteria,72.22%)、γ-变形菌纲(Gammaproteobacteria,72.21%)、肠杆菌目(Enterobacterales,72.11%)、肠杆菌科(Enterobacteriaceae,49.39%)、西地西菌属(Cedecea,49.24%)和奈氏西地西菌(C.neteri,49.24%)。多样性和差异分析结果显示,肠道细菌菌群组成在叉角厉蝽不同发育阶段存在显著差异(P<0.05,下同)。线性判别分析结果显示,1龄、2龄若虫和7日龄雌、雄成虫肠道具有显著优势的菌群,而5龄若虫肠道不存在显著优势菌群(P>0.05),且不同发育阶段肠道的优势菌群在科、属、种3级分类阶元水平上亦不同。KEGG代谢途径分析发现,叉角厉蝽不同发育阶段肠道菌群的功能相似,主要涉及新陈代谢(74.17%~75.59%)和环境信息处理(10.53%~11.03%),二级代谢功能通路主要为全局和概述图谱、糖类代谢和氨基酸代谢等。【结论】叉角厉蝽不同发育阶段肠道细菌群落组成和多样性存在显著差异,优势菌分布呈动态变化。

鄱阳湖周边农田生境中越冬白鹤和鸿雁肠道微生物多样性研究

为了掌握鄱阳湖周边农田生境中越冬白鹤(Leucogeranus leucogeranus)和鸿雁(Anser cygnoides)的肠道微生物多样性,利用高通量测序技术,对来自五星垦殖场和康山垦殖场的200份白鹤、鸿雁粪便样品进行检测。结果表明:厚壁菌门(Firmicutes)是白鹤肠道菌群的绝对优势菌门,厚壁菌门和变形菌门(Proteobacteria)是鸿雁肠道菌群的绝对优势菌门,白鹤肠道菌群多样性低于鸿雁,且二者肠道菌群结构存在显著差异。白鹤和鸿雁共携带184种病原菌,包括动物病原菌、人兽共患病病原菌和植物病原菌。白鹤携带的病原菌种类和数量均少于鸿雁,其中解没食子酸链球菌巴氏亚种(Streptococcus gallolyticus subsp.pasteurianus)、粪肠球菌(Enterococcus faecium)和铅黄肠球菌(E.casseliflavus)是白鹤和鸿雁携带的主要病原菌。研究结果为了解鄱阳湖越冬候鸟肠道微生物结构提供了依据,并对制定越冬候鸟保护管理策略具有一定的参考价值和现实意义。

心力衰竭患者肠道微生物群特征的系统评价

目的:系统评价心力衰竭患者肠道微生物群的特征。方法:计算机检索PubMed、Embase、Cochrane Library、Web of Science、CNKI、VIP、Wangfang Data和CBM数据库,检索时限设置为自建库至2023年6月,对纳入的研究进行系统评价。结果:最终纳入21项病例对照研究,包括心衰患者869例,对照人群925例。系统评价结果显示,与健康人群相比,心衰患者肠道微生物群α多样性降低,β多样性分离明显。门水平上,丰度升高的有Actinobacteria、Proteobacteria,丰度降低的有Firmicutes、Bacteroidetes;科水平上,丰度升高的有Enterococcaceae;属水平上,丰度升高的有Escherichia-Shigella、Enterococcus、Escherichia coli、Yeast like Fungi、Klebsiella和Streptococcus,丰度降低的有Bifidobacterium、Bacteroides和Lactobacillus。结论:心力衰竭患者肠道微生物群多样性降低,有益菌群的丰度降低,有害菌群的丰度升高。考虑到相关研究存在的局限性,上述结论需要仍需要更多大样本、高质量研究予以进一步验证。

不同中医证型三阴性乳腺癌患者肠道菌群多样性及差异性研究

目的研究不同中医证型三阴性乳腺癌(TNBC)患者肠道菌群的多样性与差异性。方法纳入2022年1月1日至2022年11月30日浙江省肿瘤医院乳腺外科收治的TNBC患者共21例作为TNBC患者组,其中脾胃虚弱证5例、肝肾阴虚证8例、肝郁气滞证8例,并纳入健康志愿者10名作为健康对照组,分别收集粪便标本,利用16S rDNA基因测序技术检测各组间肠道菌群的丰度和分布情况,并进行组间差异分析获得各组间的差异菌属。结果TNBC患者组与健康对照组以及TNBC不同证型组之间的菌群多样性比较,差异均无统计学意义(P>0.05)。TNBC患者组较健康对照组显著减少(P<0.05)的菌群包括毛螺菌属(Lachnospira)、光冈菌属(Mitsuokella)、粪球菌属(Coprococcus)、臭气杆菌属(Odoribacter)、肠球菌属(Enterococcus)等。与健康对照组比较,脾胃虚弱组显著富集(P<0.05)的菌属包括肠杆菌科(Enterobacteriaceae)、普雷沃氏菌属(Prevotella)、乳杆菌属(Lactobacillus)、Tyzzerella、成对杆菌属(Dyadobacter)、奇异球菌属(Deinococcus)、放线杆菌属(Actinobacillus)等,肝肾阴虚组显著富集(P<0.05)的菌属包括Tyzzerella、戈登氏杆菌属(Gordonibacter)、亨盖特氏菌属(Hungatella)等,肝郁气滞组显著富集(P<0.05)的菌属包括解黄酮菌属(Flavonifractor)、变形菌属(Proteus)、水栖菌属(Enhydrobacter)、柠檬酸杆菌属(Citrobacter)、厌氧球形菌属(Anaeroglobus)、醋杆菌属(Acetobacter)等。结论TNBC患者与健康人群的肠道菌群存在显著差异,且不同证型TNBC患者的肠道菌群组成也显著不同。TNBC的发生可能与肠道内Coprococcus等有益菌的减少和Hungatella等有害菌的增加有关,不同中医证型的证候差异与其肠道内环境的菌群变化也存在一定的联系。

基于16sRNA测序分析亚油酸对小鼠肠道菌群的影响

目的探究亚油酸(LA)对小鼠肠道菌群多样性和结构的影响。方法将7周12只SPF级雄性C57BL/6J小鼠随机分为对照组(CTRL组)和亚油酸组(LA组)。在补充LA饮食前1 d,对LA组撤去正常粮食,禁食一晚,以便LA组小鼠更易接受LA饮食,且于实验记录当天给予LA,随时保持饲料更新,保证小鼠能自由饮食到造模结束。于造模12周后收集小鼠粪便,每2只小鼠粪便进行混合采样,后续进行16sRNA高通量测序分析肠道菌群结构、Alpha多样性、Beta多样性等分析。结果通过16sRNA高通量测序发现,LA干预后肠道菌群的丰富度及多样性受损;主成分分析结果表明,CTRL组与LA组菌群组成相差较多。在门水平中,LA组放线菌门相对丰富度增加(P<0.01);在属水平中,LA组杜氏乳杆菌属相对丰富度下降(P<0.05),双歧杆菌、粪杆菌属和丹毒丝菌属相对丰富度升高(均P<0.01)。结论LA干预后降低小鼠肠道菌群的丰富度与多样性,且调整肠道菌群的结构。LA干预后的肠道菌群中有益菌及致病菌存在差异,为LA的生物活性化合物的疗法和以肠道微生物为靶点的治疗调整提供一定的依据。

牛奶蛋白过敏婴儿肠道菌群特异性变化及短链脂肪酸水平分析

目的探索牛奶蛋白过敏(cow's milk protein allergy,CMPA)患儿肠道菌群及短链脂肪酸水平的变化,明确其在CMPA中的作用。方法纳入2019年8月—2020年8月在郑州大学附属儿童医院就诊的25例CMPA婴儿作为CMPA组,同时选取25例正常婴儿作为对照组。收集两组婴儿粪便200mg,采用16SrDNA高通量检测技术和液相色谱质谱联用技术分别检测肠道微生物组成及其代谢产物的变化,并将微生物多样性与代谢产物进行联合分析。结果与对照组相比,CMPA组患儿肠道菌群结构发生变化,且α-多样性显著增加(P<0.001)。与对照组相比,CMPA组患儿肠道内厚壁菌门、梭状芽孢杆菌目、拟杆菌丰度显著降低,而梭菌科、支原体科、鞘脂单胞菌科丰度显著增加(P<0.001)。代谢组学检测发现,与对照组相比,CMPA组菌群代谢产物乙酸、丁酸和异戊酸水平显著下降,并与短链脂肪酸产生菌粪杆菌属、罗氏菌属等丰度呈正相关(P<0.05)。结论CMPA患儿肠道内菌群结构发生改变,微生物多样性增加,短链脂肪酸水平降低,可能导致肠道炎症反应增加。

基于16sRNA测序技术探讨不同体质腹型肥胖者肠道菌群特征

目的:探讨痰湿体质与非痰湿体质腹型肥胖人群肠道菌群的丰度及物种差异。方法:共纳入91例不同体质腹型肥胖受试者,收集了91例大便样本,其中痰湿体质受试者44例,非痰湿体质受试者47例。使用NovaSeq6000基因测序仪,对痰湿体质与非痰湿体质受试者肠道菌群相对丰度、物种多样性进行分析。结果:痰湿体质与非痰湿体质腹型肥胖受试者的肠道菌群门纲目科属五个层级菌群相对丰度的差异显著。痰湿体质与非痰湿体质相比门纲目科属五个层级菌群相对丰度以及差别较大,其中拟杆菌、类杆菌、毛螺菌、肠杆菌相对丰度差异有统计学意义(P<0.05)。结论:痰湿体质与非痰湿体质腹型肥胖受试者肠道菌群存在差异,二者间菌群差异可能是形成体质差异的内在因素。

重症肌无力患者肠道菌群及其代谢产物的变化

目的探讨重症肌无力(myasthenia gravis,MG)患者肠道菌群及其代谢产物的变化。方法收集MG患者及健康对照者的新鲜粪便标本,使用16S rRNA基因测序测定两组肠道菌群的丰度,并使用气相色谱质谱技术测定代谢产物的水平。收集受试者的临床特征,包括MG定量评分(quantitative MG score,QMGS)、MG日常生活活动能力量表(MG-activities of daily living,MG-ADL)评分、15项MG生活质量量表(MG-specific quality-of-life 15,MGQOL-15)评分、徒手肌力评定量表(manual muscle testing,MMT)评分及乙酰胆碱受体抗体滴度水平,对差异菌群与临床特征的相关性进行分析。结果研究共收集50例MG患者及15名健康对照者。MG组Simpson指数(0.936±0.041)高于对照组(0.888±0.123),即MG组Alpha多样性降低,差异有统计学意义(t=2.349,P=0.022),且两组的微生物表型即Beta多样性存在差异(R=0.966,P=0.001,Adonis)。LEfSe结果提示MG组中志贺氏杆菌、琥珀酸弧菌属、梭杆菌属、瘤胃球菌属富集,而丰度降低的有毛螺菌属、罗氏菌属、脱硫弧菌属、粪球菌属。两组菌群的代谢产物不同,其中MG组有28种上调及71种下调代谢产物。京都基因与基因组百科全书功能聚类分析显示差异代谢产物主要参与代谢途径为氨基酸代谢、核苷酸代谢途径。MG患者肠道微生物61.2%(30/49)的扩增子序列(amplicon sequence variant,ASV)与多种代谢产物相关(P<0.001)。毛螺菌科与患者QMGS(r=-0.496,P<0.001)、MG-ADL评分(r=-0.542,P<0.001)、MG-QOL15评分(r=-0.464,P=0.007)、乙酰胆碱受体抗体滴度(r=-0.315,P=0.026)呈负相关,与MMT评分(r=0.374,P=0.008)呈正相关。结论MG患者肠道菌群存在有益菌丰度下调,有害菌丰度上调的情况,亦存在代谢产物紊乱,且差异ASV与MG肌无力严重程度具有负相关。

枯草芽孢杆菌对肥育猪生长性能、养分表观消化率、肠道菌群、屠宰性能、肉品质和免疫功能的影响

为了研究枯草芽孢杆菌对肥育猪生长性能、养分表观消化率、肠道菌群、屠宰性能、肉品质和免疫功能的影响,将80头育肥猪随机分为4组,即A、B、C、D组,分别在基础日粮中添加0、0.01%、0.05%、0.10%的枯草芽孢杆菌,测定生长性能、养分表观消化率、肠道菌群、屠宰性能、肉品质、免疫功能等指标。结果表明:B、C、D组的末重、CP消化率、乳酸杆菌数、芽孢杆菌数、屠体重、IgG含量均高于A组,其中C、D组显著高于A组(P<0.05),B、C、D组大肠杆菌数、滴水损失率均显著低于A组(P<0.05)。C、D组的平均日增重、粗脂肪消化率、粗纤维消化率、屠宰率、瘦肉率、pH_(24 h)、脾脏指数、IgA含量均较A组显著提高(P<0.05),料重比、沙门氏菌数、背膘厚、剪切力均较A组显著降低(P<0.05)。说明随着枯草芽孢杆菌添加剂量的增加,育肥猪的生长性能、养分表观消化率、肠道菌群、屠宰性能、肉品质、免疫功能逐步得到改善;适宜添加剂量为0.10%。

家蚕肠道菌的多样性及研究方法进展

家蚕作为重要的经济昆虫和鳞翅目模式昆虫,近年对家蚕肠道菌结构和功能多样性的研究成为热点。研究发现家蚕的品种、性别、龄期及不同的环境和饲养条件下家蚕肠道菌群数量和种类差异较大,且优势菌群也不尽相同。该文介绍了家蚕肠道菌群结构、功能及研究方法的多样性研究进展,分析了肠道菌群的影响因素,对理解肠道菌与家蚕相互作用机制,以及对家蚕的生长发育、免疫及抗病力等方面具有重大意义,为后续推动蚕业可持续发展和肠道菌在其他领域的研究提供科研价值和实际应用推广价值。