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Garrett, Wendy

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Garrett

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Wendy

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Garrett, Wendy

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Now showing 1 - 10 of 23
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    A single-cell survey of the small intestinal epithelium
    (2018) Haber, Adam L.; Biton, Moshe; Rogel, Noga; Herbst, Rebecca; Shekhar, Karthik; Smillie, Christopher; Burgin, Grace; Delorey, Toni M.; Howitt, Michael R.; Katz, Yarden; Tirosh, Itay; Beyaz, Semir; Dionne, Danielle; Zhang, Mei; Raychowdhury, Raktima; Garrett, Wendy; Rozenblatt-Rosen, Orit; Shi, Hai; Yilmaz, Omer; Xavier, Ramnik; Regev, Aviv
    Intestinal epithelial cells (IECs) absorb nutrients, respond to microbes, provide barrier function and help coordinate immune responses. We profiled 53,193 individual epithelial cells from mouse small intestine and organoids, and characterized novel subtypes and their gene signatures. We showed unexpected diversity of hormone-secreting enteroendocrine cells and constructed their novel taxonomy. We distinguished between two tuft cell subtypes, one of which expresses the epithelial cytokine TSLP and CD45 (Ptprc), the pan-immune marker not previously associated with non-hematopoietic cells. We also characterized how cell-intrinsic states and cell proportions respond to bacterial and helminth infections. Salmonella infection caused an increase in Paneth cells and enterocytes abundance, and broad activation of an antimicrobial program. In contrast, Heligmosomoides polygyrus caused an expansion of goblet and tuft cell populations. Our survey highlights new markers and programs, associates sensory molecules to cell types, and uncovers principles of gut homeostasis and response to pathogens.
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    Fluoride Depletes Acidogenic Taxa in Oral but Not Gut Microbial Communities in Mice
    (American Society for Microbiology, 2017) Yasuda, Koji; Hsu, Tiffany; Gallini, Carey; Mclver, Lauren J.; Schwager, Emma; Shi, Andy; DuLong, Casey; Schwager, Randall N.; Abu-Ali, Galeb; Franzosa, Eric; Garrett, Wendy; Huttenhower, Curtis; Morgan, Xochitl C.
    ABSTRACT Fluoridation of drinking water and dental products prevents dental caries primarily by inhibiting energy harvest in oral cariogenic bacteria (such as Streptococcus mutans and Streptococcus sanguinis), thus leading to their depletion. However, the extent to which oral and gut microbial communities are affected by host fluoride exposure has been underexplored. In this study, we modeled human fluoride exposures to municipal water and dental products by treating mice with low or high levels of fluoride over a 12-week period. We then used 16S rRNA gene amplicon and shotgun metagenomic sequencing to assess fluoride’s effects on oral and gut microbiome composition and function. In both the low- and high-fluoride groups, several operational taxonomic units (OTUs) belonging to acidogenic bacterial genera (such as Parabacteroides, Bacteroides, and Bilophila) were depleted in the oral community. In addition, fluoride-associated changes in oral community composition resulted in depletion of gene families involved in central carbon metabolism and energy harvest (2-oxoglutarate ferredoxin oxidoreductase, succinate dehydrogenase, and the glyoxylate cycle). In contrast, fluoride treatment did not induce a significant shift in gut microbial community composition or function in our mouse model, possibly due to absorption in the upper gastrointestinal tract. Fluoride-associated perturbations thus appeared to have a selective effect on the composition of the oral but not gut microbial community in mice. Future studies will be necessary to understand possible implications of fluoride exposure for the human microbiome. IMPORTANCE: Fluoride has been added to drinking water and dental products since the 1950s. The beneficial effects of fluoride on oral health are due to its ability to inhibit the growth of bacteria that cause dental caries. Despite widespread human consumption of fluoride, there have been only two studies of humans that considered the effect of fluoride on human-associated microbial communities, which are increasingly understood to play important roles in health and disease. Notably, neither of these studies included a true cross-sectional control lacking fluoride exposure, as study subjects continued baseline fluoride treatment in their daily dental hygiene routines. To our knowledge, this work (in mice) is the first controlled study to assess the independent effects of fluoride exposure on the oral and gut microbial communities. Investigating how fluoride interacts with host-associated microbial communities in this controlled setting represents an effort toward understanding how common environmental exposures may potentially influence health.
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    Fusobacterium nucleatum in Colorectal Carcinoma Tissue According to Tumor Location
    (Nature Publishing Group, 2016) Mima, Kosuke; Cao, Yin; Chan, Andrew; Qian, Zhi Rong; Nowak, Jonathan; Masugi, Yohei; Shi, Yan; Song, Mingyang; da Silva, Annacarolina; Gu, Mancang; Li, Wanwan; Hamada, Tsuyoshi; Kosumi, Keisuke; Hanyuda, Akiko; Liu, Li; Kostic, Aleksandar; Giannakis, Marios; Bullman, Susan; Brennan, Caitlin; Milner, Danny; Baba, Hideo; Garraway, Levi; Meyerhardt, Jeffrey; Garrett, Wendy; Huttenhower, Curtis; Meyerson, Matthew; Giovannucci, Edward; Fuchs, Charles; Nakashima, Reiko; Ogino, Shuji
    Objectives: Evidence suggests a possible role of Fusobacterium nucleatum in colorectal carcinogenesis, especially in right-sided proximal colorectum. Considering a change in bowel contents and microbiome from proximal to distal colorectal segments, we hypothesized that the proportion of colorectal carcinoma enriched with F. nucleatum might gradually increase along the bowel subsites from rectum to cecum. Methods: A retrospective, cross-sectional analysis was conducted on 1,102 colon and rectal carcinomas in molecular pathological epidemiology databases of the Nurses’ Health Study and the Health Professionals Follow-up Study. We measured the amount of F. nucleatum DNA in colorectal tumor tissue using a quantitative PCR assay and equally dichotomized F. nucleatum-positive cases (high vs. low). We used multivariable logistic regression analysis to examine the relationship of a bowel subsite variable (rectum, rectosigmoid junction, sigmoid colon, descending colon, splenic flexure, transverse colon, hepatic flexure, ascending colon, and cecum) with the amount of F. nucleatum. Results: The proportion of F. nucleatum-high colorectal cancers gradually increased from rectal cancers (2.5% 4/157) to cecal cancers (11% 19/178), with a statistically significant linear trend along all subsites (P<0.0001) and little evidence of non-linearity. The proportion of F. nucleatum-low cancers was higher in rectal, ascending colon, and cecal cancers than in cancers of middle segments. Conclusions: The proportion of F. nucleatum-high colorectal cancers gradually increases from rectum to cecum. Our data support the colorectal continuum model that reflects pathogenic influences of the gut microbiota on neoplastic and immune cells and challenges the prevailing two-colon (proximal vs. distal) dichotomy paradigm.
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    Computational meta'omics for microbial community studies
    (European Molecular Biology Organization, 2013) Segata, Nicola; Boernigen, Daniela; Tickle, Timothy L; Morgan, Xochitl C; Garrett, Wendy; Huttenhower, Curtis
    Complex microbial communities are an integral part of the Earth's ecosystem and of our bodies in health and disease. In the last two decades, culture-independent approaches have provided new insights into their structure and function, with the exponentially decreasing cost of high-throughput sequencing resulting in broadly available tools for microbial surveys. However, the field remains far from reaching a technological plateau, as both computational techniques and nucleotide sequencing platforms for microbial genomic and transcriptional content continue to improve. Current microbiome analyses are thus starting to adopt multiple and complementary meta'omic approaches, leading to unprecedented opportunities to comprehensively and accurately characterize microbial communities and their interactions with their environments and hosts. This diversity of available assays, analysis methods, and public data is in turn beginning to enable microbiome-based predictive and modeling tools. We thus review here the technological and computational meta'omics approaches that are already available, those that are under active development, their success in biological discovery, and several outstanding challenges.
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    Gut microbiome composition and function in experimental colitis during active disease and treatment-induced remission
    (Springer Nature, 2014) Rooks, Michelle G; Veiga, Patrick; Wardwell-Scott, Leslie H; Tickle, Timothy; Segata, Nicola; Michaud, Monia; Gallini, Carey; Beal, Chloé; van Hylckama-Vlieg, Johan ET; Ballal, Sonia; Morgan, Xochitl C; Glickman, Jonathan; Gevers, Dirk; Huttenhower, Curtis; Garrett, Wendy
    Dysregulated immune responses to gut microbes are central to inflammatory bowel disease (IBD), and gut microbial activity can fuel chronic inflammation. Examining how IBD-directed therapies influence gut microbiomes may identify microbial community features integral to mitigating disease and maintaining health. However, IBD patients often receive multiple treatments during disease flares, confounding such analyses. Preclinical models of IBD with well-defined disease courses and opportunities for controlled treatment exposures provide a valuable solution. Here, we surveyed the gut microbiome of the T-bet−/− Rag2−/− mouse model of colitis during active disease and treatment-induced remission. Microbial features modified among these conditions included altered potential for carbohydrate and energy metabolism and bacterial pathogenesis, specifically cell motility and signal transduction pathways. We also observed an increased capacity for xenobiotics metabolism, including benzoate degradation, a pathway linking host adrenergic stress with enhanced bacterial virulence, and found decreased levels of fecal dopamine in active colitis. When transferred to gnotobiotic mice, gut microbiomes from mice with active disease versus treatment-induced remission elicited varying degrees of colitis. Thus, our study provides insight into specific microbial clades and pathways associated with health, active disease and treatment interventions in a mouse model of colitis.
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    Human microbiome science: vision for the future, Bethesda, MD, July 24 to 26, 2013
    (BioMed Central, 2014) Ravel, Jacques; Blaser, Martin J; Braun, Jonathan; Brown, Eric; Bushman, Frederic D; Chang, Eugene B; Davies, Julian; Dewey, Kathryn G; Dinan, Timothy; Dominguez-Bello, Maria; Erdman, Susan E; Finlay, B Brett; Garrett, Wendy; Huffnagle, Gary B; Huttenhower, Curtis; Jansson, Janet; Jeffery, Ian B; Jobin, Christian; Khoruts, Alexander; Kong, Heidi H; Lampe, Johanna W; Ley, Ruth E; Littman, Dan R; Mazmanian, Sarkis K; Mills, David A; Neish, Andrew S; Petrof, Elaine; Relman, David A; Rhodes, Rosamond; Turnbaugh, Peter J; Young, Vincent B; Knight, Rob; White, Owen
    A conference entitled ‘Human microbiome science: Vision for the future’ was organized in Bethesda, MD from July 24 to 26, 2013. The event brought together experts in the field of human microbiome research and aimed at providing a comprehensive overview of the state of microbiome research, but more importantly to identify and discuss gaps, challenges and opportunities in this nascent field. This report summarizes the presentations but also describes what is needed for human microbiome research to move forward and deliver medical translational applications.
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    Functional profiling of the gut microbiome in disease-associated inflammation
    (BioMed Central, 2013) Börnigen, Daniela; Morgan, Xochitl C; Franzosa, Eric; Ren, Boyu; Xavier, Ramnik; Garrett, Wendy; Huttenhower, Curtis
    The microbial residents of the human gut are a major factor in the development and lifelong maintenance of health. The gut microbiota differs to a large degree from person to person and has an important influence on health and disease due to its interaction with the human immune system. Its overall composition and microbial ecology have been implicated in many autoimmune diseases, and it represents a particularly important area for translational research as a new target for diagnostics and therapeutics in complex inflammatory conditions. Determining the biomolecular mechanisms by which altered microbial communities contribute to human disease will be an important outcome of current functional studies of the human microbiome. In this review, we discuss functional profiling of the human microbiome using metagenomic and metatranscriptomic approaches, focusing on the implications for inflammatory conditions such as inflammatory bowel disease and rheumatoid arthritis. Common themes in gut microbial ecology have emerged among these diverse diseases, but they have not yet been linked to targetable mechanisms such as microbial gene and genome composition, pathway and transcript activity, and metabolism. Combining these microbial activities with host gene, transcript and metabolic information will be necessary to understand how and why these complex interacting systems are altered in disease-associated inflammation.
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    A reproducible approach to high-throughput biological data acquisition and integration
    (PeerJ Inc., 2015) Börnigen, Daniela; Moon, Yo Sup; Rahnavard, Gholamali; Waldron, Levi; McIver, Lauren; Shafquat, Afrah; Franzosa, Eric; Miropolsky, Larissa; Sweeney, Christopher; Morgan, Xochitl C.; Garrett, Wendy; Huttenhower, Curtis
    Modern biological research requires rapid, complex, and reproducible integration of multiple experimental results generated both internally and externally (e.g., from public repositories). Although large systematic meta-analyses are among the most effective approaches both for clinical biomarker discovery and for computational inference of biomolecular mechanisms, identifying, acquiring, and integrating relevant experimental results from multiple sources for a given study can be time-consuming and error-prone. To enable efficient and reproducible integration of diverse experimental results, we developed a novel approach for standardized acquisition and analysis of high-throughput and heterogeneous biological data. This allowed, first, novel biomolecular network reconstruction in human prostate cancer, which correctly recovered and extended the NFκB signaling pathway. Next, we investigated host-microbiome interactions. In less than an hour of analysis time, the system retrieved data and integrated six germ-free murine intestinal gene expression datasets to identify the genes most influenced by the gut microbiota, which comprised a set of immune-response and carbohydrate metabolism processes. Finally, we constructed integrated functional interaction networks to compare connectivity of peptide secretion pathways in the model organisms Escherichia coli, Bacillus subtilis, and Pseudomonas aeruginosa.
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    From cell biology to the microbiome: An intentional infinite loop
    (The Rockefeller University Press, 2015) Garrett, Wendy
    Cell biology is the study of the structure and function of the unit or units of living organisms. Enabled by current and evolving technologies, cell biologists today are embracing new scientific challenges that span many disciplines. The eclectic nature of cell biology is core to its future and remains its enduring legacy.
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    Sequence-Based Discovery of Bradyrhizobium enterica in Cord Colitis Syndrome
    (New England Journal of Medicine (NEJM/MMS), 2013) Bhatt, Ami; Freeman, Sam; Herrera, Alex Francisco; Pedamallu, Chandra Sekhar; Gevers, Dirk; Duke, Fujiko; Jung, Joonil; Michaud, Monia; Walker, Bruce; Young, Sarah; Earl, Ashlee M.; Kostic, Aleksander D.; Ojesina, Akinyemi Ifedapo; Hasserjian, Robert; Ballen, Karen Kuhn; Chen, Yi-Bin; Hobbs, Gabriela; Antin, Joseph; Soiffer, Robert; Baden, Lindsey; Garrett, Wendy; Hornick, Jason; Marty, Francisco; Meyerson, Matthew
    BACKGROUND—Immunosuppression is associated with a variety of idiopathic clinical syndromes that may have infectious causes. It has been hypothesized that the cord colitis syndrome, a complication of umbilical-cord hematopoietic stem-cell transplantation, is infectious in origin. METHODS—We performed shotgun DNA sequencing on four archived, paraffin-embedded endoscopic colon-biopsy specimens obtained from two patients with cord colitis. Computational subtraction of human and known microbial sequences and assembly of residual sequences into a bacterial draft genome were performed. We used polymerase-chain-reaction (PCR) assays and fluorescence in situ hybridization to determine whether the corresponding bacterium was present in additional patients and controls. RESULTS—DNA sequencing of the biopsy specimens revealed more than 2.5 million sequencing reads that did not match known organisms. These sequences were computationally assembled into a 7.65-Mb draft genome showing a high degree of homology with genomes of bacteria in the bradyrhizobium genus. The corresponding newly discovered bacterium was provisionally named Bradyrhizobium enterica. PCR identified B. enterica nucleotide sequences in biopsy specimens from all three additional patients with cord colitis whose samples were tested, whereas B. enterica sequences were absent in samples obtained from healthy controls and patients with colon cancer or graft-versus-host disease. CONCLUSIONS—We assembled a novel bacterial draft genome from the direct sequencing of tissue specimens from patients with cord colitis. Association of these sequences with cord colitis suggests that B. enterica may be an opportunistic human pathogen.