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Human gut microbiome

George Kunnackal John, Lin Wang, Julie Nanavati, Claire Twose, Rajdeep Singh, Gerard Mullin
Dietary alteration of the gut microbiome is an important target in the treatment of obesity. Animal and human studies have shown bidirectional weight modulation based on the probiotic formulation used. In this study, we systematically reviewed the literature and performed a meta-analysis to assess the impact of prebiotics, probiotics and synbiotics on body weight, body mass index (BMI) and fat mass in adult human subjects. We searched Medline (PubMed), Embase, the Cochrane Library and the Web of Science to identify 4721 articles, of which 41 were subjected to full-text screening, yielding 21 included studies with 33 study arms...
March 16, 2018: Genes
Matthias Bochtler, Danuta Mizgalska, Florian Veillard, Magdalena L Nowak, John Houston, Paul Veith, Eric C Reynolds, Jan Potempa
Bacteroidetes feature prominently in the human microbiome, as major colonizers of the gut and clinically relevant pathogens elsewhere. Here, we reveal a new Bacteroidetes specific feature in the otherwise widely conserved Sec/SPI (Sec translocase/signal peptidase I) pathway. In Bacteroidetes , but not the entire FCB group or related phyla, signal peptide cleavage exposes N-terminal glutamine residues in most SPI substrates. Reanalysis of published mass spectrometry data for five Bacteroidetes species shows that the newly exposed glutamines are cyclized to pyroglutamate (also termed 5-oxoproline) residues...
2018: Frontiers in Microbiology
Sandra Infante Villamil, Roger Huerlimann, Christina Morianos, Zoltan Sarnyai, Gregory E Maes
Obesity and other lifestyle diseases in modern society can be related to historical dietary changes from diets balanced in omega-6 and omega-3 to the unbalanced "Western-type" diet. It is recognized that diet influences the murine and human gut microbiome, and most research indicates that microbial diversity and composition are altered by high-fat diets (HFDs). However, good knowledge about the effects of early exposure to HFD on the maturation and structure of the bacterial community is limited. Using mice as model, we hypothesized that an HFD alters the early dynamic of the gut bacterial community toward an unstable/unhealthy state...
February 2018: Nutrition Research
Amy N Jacobson, Biswa P Choudhury, Michael A Fischbach
Lipopolysaccharide (LPS), a cell-associated glycolipid that makes up the outer leaflet of the outer membrane of Gram-negative bacteria, is a canonical mediator of microbe-host interactions. The most prevalent Gram-negative gut bacterial taxon, Bacteroides , makes up around 50% of the cells in a typical Western gut; these cells harbor ~300 mg of LPS, making it one of the highest-abundance molecules in the intestine. As a starting point for understanding the biological function of Bacteroides LPS, we have identified genes in Bacteroides thetaiotaomicron VPI 5482 involved in the biosynthesis of its lipid A core and glycan, generated mutants that elaborate altered forms of LPS, and used matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry to interrogate the molecular features of these variants...
March 13, 2018: MBio
Yi Lyu, Lei Wu, Fang Wang, Xinchun Shen, Dingbo Lin
Dysbiosis, a broad spectrum of imbalance of the gut microbiota, may progress to microbiota dysfunction. Dysbiosis is linked to some human diseases, such as inflammation-related disorders and metabolic syndromes. However, the underlying mechanisms of the pathogenesis of dysbiosis remain elusive. Recent findings suggest that the microbiome and gut immune responses, like immunoglobulin A production, play critical roles in the gut homeostasis and function, and the progression of dysbiosis. In the past two decades, much progress has been made in better understanding of production of immunoglobulin A and its association with commensal microbiota...
January 1, 2018: Experimental Biology and Medicine
Jocelyn Sietsma Penington, Megan A S Penno, Katrina M Ngui, Nadim J Ajami, Alexandra J Roth-Schulze, Stephen A Wilcox, Esther Bandala-Sanchez, John M Wentworth, Simon C Barry, Cheryl Y Brown, Jennifer J Couper, Joseph F Petrosino, Anthony T Papenfuss, Leonard C Harrison
To optimise fecal sampling for reproducible analysis of the gut microbiome, we compared different methods of sample collection and sequencing of 16S rRNA genes at two centers. Samples collected from six individuals on three consecutive days were placed in commercial collection tubes (OMNIgeneGut OMR-200) or in sterile screw-top tubes in a home fridge or home freezer for 6-24 h, before transfer and storage at -80 °C. Replicate samples were shipped to centers in Australia and the USA for DNA extraction and sequencing by their respective PCR protocols, and analysed with the same bioinformatic pipeline...
March 12, 2018: Scientific Reports
Ziyu Jiang, Joe Antony Jacob, Jianyue Li, Xiahui Wu, Guoli Wei, Vimalanathan ArunPrasanna, Rajesh Mani, Prasannabalaji Nainangu, Uma Maheshwari Rajadurai, Baoan Chen
Human gut comprises of a huge mixture of microorganisms as they had co-existed for millions of years. The change in co-existence of microbial genera leads to dysbiosis, which creates several disorders in humans. Diet and diet associated agents can have a considerable influence on host health by regulating the gut microbiome, which can thereby maintain the homeostasis of the gut. Analysis of the gut microbiome and the agents that can have an influence on the gut need a profound understanding, which is the need of the hour...
March 9, 2018: Microbial Pathogenesis
Thomas S B Schmidt, Jeroen Raes, Peer Bork
Our understanding of the human gut microbiome continues to evolve at a rapid pace, but practical application of thisknowledge is still in its infancy. This review discusses the type of studies that will be essential for translating microbiome research into targeted modulations with dedicated benefits for the human host.
March 8, 2018: Cell
Pablo Roman, Raquel Abalo, Eva M Marco, Diana Cardona
In recent years, interest in the relationship between gut microbiota and disease states has grown considerably. Indeed, several strategies have been employed to modify the microbiome through the administration of different diets, by the administration of antibiotics or probiotics, or even by transplantation of feces. In the present manuscript, we focus specifically on the potential application of probiotics, which seem to be a safe strategy, in the management of digestive, pain, and emotional disorders. We present evidence from animal models and human studies, notwithstanding that translation to clinic still deserves further investigation...
March 7, 2018: Behavioural Pharmacology
Na Zhao, Supen Wang, Hongyi Li, Shelan Liu, Meng Li, Jing Luo, Wen Su, Hongxuan He
The migration of wild birds plays an important role in the transmission and spread of H5 highly pathogenic avian influenza (HPAI) virus, posing a severe risk to animal and human health. Substantial evidence suggests that altered gut microbial community is implicated in the infection of respiratory influenza virus. However, the influence of H5N1 infection in gut microbiota of migratory birds remains unknown. In January 2015, a novel recombinant H5N1 virus emerged and killed about 100 migratory birds, mainly including whooper swans in Sanmenxia Reservoir Area of China...
2018: Frontiers in Cellular and Infection Microbiology
Lisa F Stinson, Jeffrey A Keelan, Matthew S Payne
The establishment of human gut microbiota commences initially in utero . Meconium-the first fecal material passed after birth-can be used to study fetal gut contents; however, processing meconium samples for microbiome studies presents significant technical challenges. Meconium hosts a low biomass microbiome, is tar-like in texture and contains high concentrations of PCR inhibitors. This study aimed to evaluate four different DNA extraction methods to elucidate the most effective method for bacterial DNA recovery and sequencing analysis from first-pass meconium...
2018: Frontiers in Microbiology
Jason W Arnold, Joshua B Simpson, Jeffrey Roach, Jakub Kwintkiewicz, M Andrea Azcarate-Peril
Large-scale microbiome studies have established that most of the diversity contained in the gastrointestinal tract is represented at the strain level; however, exhaustive genomic and physiological characterization of human isolates is still lacking. With increased use of probiotics as interventions for gastrointestinal disorders, genomic and functional characterization of novel microorganisms becomes essential. In this study, we explored the impact of strain-level genomic variability on bacterial physiology of two novel human Lactobacillus rhamnosus strains (AMC143 and AMC010) of probiotic potential in relation to stress resistance...
2018: Frontiers in Microbiology
Eric Dumonteil, Maria-Jesus Ramirez-Sierra, Silvia Pérez-Carrillo, Christian Teh-Poot, Claudia Herrera, Sébastien Gourbière, Etienne Waleckx
Trypanosoma cruzi is the agent of Chagas disease, transmitted by hematophagous triatomine vectors. Establishing transmission cycles is key to understand the epidemiology of the disease, but integrative assessments of ecological interactions shaping parasite transmission are still limited. Current approaches also lack sensitivity to assess the full extent of this ecological diversity. Here we developed a metabarcoding approach based on next-generation sequencing to identify triatomine gut microbiome, vertebrate feeding hosts, and parasite diversity and their potential interactions...
March 7, 2018: Scientific Reports
Keaton Stagaman, Tara J Cepon-Robins, Melissa A Liebert, Theresa E Gildner, Samuel S Urlacher, Felicia C Madimenos, Karen Guillemin, J Josh Snodgrass, Lawrence S Sugiyama, Brendan J M Bohannan
Economic development is marked by dramatic increases in the incidence of microbiome-associated diseases, such as autoimmune diseases and metabolic syndromes, but the lifestyle changes that drive alterations in the human microbiome are not known. We measured market integration as a proxy for economically related lifestyle attributes, such as ownership of specific market goods that index degree of market integration and components of traditional and nontraditional (more modern) house structure and infrastructure, and profiled the fecal microbiomes of 213 participants from a contiguous, indigenous Ecuadorian population...
January 2018: MSystems
Seungbum Kim, Ruby Goel, Ashok Kumar, Yanfei Qi, Gil Lobaton, Koji Hosaka, Mohammed Mohammed, Eileen M Handberg, Elaine M Richards, Carl J Pepine, Mohan K Raizada
Recent evidence indicates a link between gut pathology and microbiome with hypertension in animal models. However, whether this association exists in humans is unknown. Thus, our objectives in this study were to test the hypotheses that high blood pressure patients have distinct gut microbiomes and that gut epithelial barrier function markers and microbiome composition could predict systolic blood pressure. Fecal samples, analyzed by shotgun metagenomics, displayed taxonomic and functional changes, including altered butyrate production between patients with high blood pressure and reference subjects...
March 5, 2018: Clinical Science (1979-)
Noelia Martínez, Roberto Luque, Christian Milani, Marco Ventura, Oscar Bañuelos, Abelardo Margolles
Bifidobacteria are mutualistic intestinal bacteria and their presence in the human gut has been associated with health-promoting activities. The presence of antibiotic resistance genes in this genus is controversial, since, although bifidobacteria are non-pathogenic microorganisms, they could serve as reservoirs of resistance for intestinal pathogens. However, until now, few antibiotic resistance determinants have been functionally characterized in this genus. In this work, we show that Bifidobacterium breve CECT7263 displays atypical resistance to erythromycin and clindamycin...
March 2, 2018: Applied and Environmental Microbiology
Prem Prashant Chaudhary, Patricia Lynne Conway, Jørgen Schlundt
Methanogens are anaerobic prokaryotes from the domain archaea that utilize hydrogen to reduce carbon dioxide, acetate, and a variety of methyl compounds into methane. Earlier believed to inhabit only the extreme environments, these organisms are now reported to be found in various environments including mesophilic habitats and the human body. The biological significance of methanogens for humans has been re-evaluated in the last few decades. Their contribution towards pathogenicity has received much less attention than their bacterial counterparts...
March 1, 2018: Applied Microbiology and Biotechnology
Ling Xiao, Belinda Van't Land, Phillip A Engen, Ankur Naqib, Stefan J Green, Angie Nato, Thea Leusink-Muis, Johan Garssen, Ali Keshavarzian, Bernd Stahl, Gert Folkerts
Development of Type 1 diabetes (T1D) is influenced by non-genetic factors, such as optimal microbiome development during early life that "programs" the immune system. Exclusive and prolonged breastfeeding is an independent protective factor against the development of T1D, likely via bioactive components. Human Milk Oligosaccharides (HMOS) are microbiota modulators, known to regulate immune responses directly. Here we show that early life provision (only for a period of six weeks) of 1% authentic HMOS (consisting of both long-chain, as well as short-chain structures), delayed and suppressed T1D development in non-obese diabetic mice and reduced development of severe pancreatic insulitis in later life...
March 1, 2018: Scientific Reports
Katri Korpela, Paul Igor Costea, Luis Pedro Coelho, Stefanie Kandels-Lewis, Gonneke Willemsen, Dorret I Boomsma, Nicola Segata, Peer Bork
Vertical transmission of bacteria from mother to infant at birth is postulated to initiate a life-long host-microbe symbiosis, playing an important role in early infant development. However, only the tracking of strictly defined unique microbial strains can clarify where the intestinal bacteria come from, how long the initial colonisers persist and whether colonisation by other strains from the environment can replace existing ones. Using rare single nucleotide variants in fecal metagenomes of infants and their family members, we show strong evidence of selective and persistent transmission of maternal strain populations to the vaginally born infant, and their occasional replacement by strains from the environment, including those from family members, in later childhood...
March 1, 2018: Genome Research
Woojun Park
The host genetic background, complex surrounding environments, and gut microbiome are very closely linked to human and animal health and disease. Although significant correlations between gut microbiota and human and animal health have been revealed, the specific roles of each gut bacterium in shaping human and animal health and disease remain unclear. However, recent omics-based studies using experimental animals and surveys of gut microbiota from unhealthy humans have provided insights into the relationships among microbial community, their metabolites, and human and animal health...
March 2018: Journal of Microbiology / the Microbiological Society of Korea
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