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Nonsteroidal Anti-inflammatory Drugs Alter the Microbiota and Exacerbate Colitis while Dysregulating the Inflammatory Response.
Maseda D, Zackular JP, Trindade B, Kirk L, Roxas JL, Rogers LM, Washington MK, Du L, Koyama T, Viswanathan VK, Vedantam G, Schloss PD, Crofford LJ, Skaar EP, Aronoff DM
(2019) MBio 10:
MeSH Terms: Animals, Anti-Inflammatory Agents, Non-Steroidal, CD4-Positive T-Lymphocytes, Clostridium Infections, Gastrointestinal Microbiome, Indomethacin, Intestinal Mucosa, Mice, Neutrophils, Prostaglandins, Survival Analysis
Show Abstract · Added April 7, 2019
infection (CDI) is a major public health threat worldwide. The use of nonsteroidal anti-inflammatory drugs (NSAIDs) is associated with enhanced susceptibility to and severity of CDI; however, the mechanisms driving this phenomenon have not been elucidated. NSAIDs alter prostaglandin (PG) metabolism by inhibiting cyclooxygenase (COX) enzymes. Here, we found that treatment with the NSAID indomethacin prior to infection altered the microbiota and dramatically increased mortality and the intestinal pathology associated with CDI in mice. We demonstrated that in -infected animals, indomethacin treatment led to PG deregulation, an altered proinflammatory transcriptional and protein profile, and perturbed epithelial cell junctions. These effects were paralleled by increased recruitment of intestinal neutrophils and CD4 cells and also by a perturbation of the gut microbiota. Together, these data implicate NSAIDs in the disruption of protective COX-mediated PG production during CDI, resulting in altered epithelial integrity and associated immune responses. infection (CDI) is a spore-forming anaerobic bacterium and leading cause of antibiotic-associated colitis. Epidemiological data suggest that use of nonsteroidal anti-inflammatory drugs (NSAIDs) increases the risk for CDI in humans, a potentially important observation given the widespread use of NSAIDs. Prior studies in rodent models of CDI found that NSAID exposure following infection increases the severity of CDI, but mechanisms to explain this are lacking. Here we present new data from a mouse model of antibiotic-associated CDI suggesting that brief NSAID exposure prior to CDI increases the severity of the infectious colitis. These data shed new light on potential mechanisms linking NSAID use to worsened CDI, including drug-induced disturbances to the gut microbiome and colonic epithelial integrity. Studies were limited to a single NSAID (indomethacin), so future studies are needed to assess the generalizability of our findings and to establish a direct link to the human condition.
Copyright © 2019 Maseda et al.
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11 MeSH Terms
Evidence for the Role of the Cecal Microbiome in Maintenance of Immune Regulation and Homeostasis.
Chhabra P, Spano AJ, Bowers D, Ren T, Moore DJ, Timko MP, Wu M, Brayman KL
(2018) Ann Surg 268: 541-549
MeSH Terms: Animals, Cecum, Diabetes Mellitus, Experimental, Diabetes Mellitus, Type 1, Female, Gastrointestinal Microbiome, Homeostasis, Humans, Immunoglobulin M, Mice, Mice, Inbred NOD
Show Abstract · Added July 12, 2018
OBJECTIVE (S) - Our objective was to investigate alterations in the cecal microbial composition during the development of type 1 diabetes (T1D) with or without IgM therapy, and correlate these alterations with the corresponding immune profile.
METHODS - (1) Female nonobese diabetic (NOD) mice treated with IgM or saline (n = 20/group) were divided into 5-week-old nondiabetic; 9 to 12-week-old prehyperglycemic stage-1; ≥13-week-old prehyperglycemic stage-2; and diabetic groups. 16S rRNA libraries were prepared from bacterial DNA and deep-sequenced. (2) New-onset diabetic mice were treated with IgM (200 μg on Days 1, 3, and 5) and their blood glucose monitored for 2 months.
RESULTS - Significant dysbiosis was observed in the cecal microbiome with the progression of T1D development. The alteration in microbiome composition was characterized by an increase in the bacteroidetes:firmicutes ratio. In contrast, IgM conserved normal bacteroidetes:firmicutes ratio and this effect was long-lasting. Furthermore, oral gavage using cecal content from IgM-treated mice significantly diminished the incidence of diabetes compared with controls, indicating that IgM specifically affected mucosa-associated microbes, and that the affect was causal and not an epiphenomenon. Also, regulatory immune cell populations (myeloid-derived suppressor cells and regulatory T cells) were expanded and insulin autoantibody production diminished in the IgM-treated mice. In addition, IgM therapy reversed hyperglycemia in 70% of new-onset diabetic mice (n = 10) and the mice remained normoglycemic for the entire post-treatment observation period.
CONCLUSIONS - The cecal microbiome appears to be important in maintaining immune homeostasis and normal immune responses.
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11 MeSH Terms
How and why do gastrointestinal peptides influence food intake?
Woods SC, May-Zhang AA, Begg DP
(2018) Physiol Behav 193: 218-222
MeSH Terms: Animals, Eating, Gastrointestinal Hormones, Humans, Peptides, Satiation
Show Abstract · Added July 2, 2018
Despite the ability of some gastrointestinal hormones to reliably reduce meal size when administered prior to a meal, it is not understood why the repeated administration or genetic knockout of these hormones appear largely ineffective in reducing food intake and body weight. Here, we review evidence that the ability of GI peptides such as cholecystokinin (CCK) to elicit satiation is a consequence of prior learning. Evidence includes first, that the ability of some of these signals to modify food intake depends upon past experience and is malleable with new experience. Additionally, the ability of CCK and other gut signals to reduce food intake may not be hard-wired; i.e., any so-called "satiation" signal that reduces food intake in a single-meal situation may not continue to do so over repeated trials. The individual will respond to the signal only so long as it provides reliable information about caloric content. If a particular signal becomes unreliable, the individual will rely on other signals to end meals. Thus, gut peptides/hormones have important metabolic effects such as mediating absorption, digestion, and many aspects of the distribution of ingested nutrients throughout the body; and, if they have been reliably associated with natural stimuli that mediate satiation, they also inform behavior.
Copyright © 2018. Published by Elsevier Inc.
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6 MeSH Terms
The role of zinc and nutritional immunity in Clostridium difficile infection.
Zackular JP, Skaar EP
(2018) Gut Microbes 9: 469-476
MeSH Terms: Animals, Anti-Bacterial Agents, Clostridium Infections, Clostridium difficile, Disease Models, Animal, Gastrointestinal Microbiome, Humans, Immunity, Mice, Zinc
Show Abstract · Added March 15, 2018
Clostridium difficile in one of the most commonly reported nosocomial pathogens worldwide. Beyond antibiotic use, little is known about the host, microbiota, and environmental factors that contribute to susceptibility to and severity of C. difficile infection (CDI). We recently observed that in a mouse model of CDI, excess dietary zinc (Zn) alters the gut microbiota and decreases resistance to CDI. Moreover, we determined that high levels of Zn exacerbate C. difficile-associated disease and calprotectin-mediated Zn limitation is an essential host response to infection. In this addendum, we discuss how these findings add to our understanding of CDI and consider the potential implications of excess metal intake on the microbiota and infection.
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10 MeSH Terms
Loss of HCN2 leads to delayed gastrointestinal motility and reduced energy intake in mice.
Fisher DW, Luu P, Agarwal N, Kurz JE, Chetkovich DM
(2018) PLoS One 13: e0193012
MeSH Terms: Animals, Blood Glucose, Energy Intake, Female, Gastrointestinal Motility, Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels, Male, Mice, Mice, Inbred C57BL, Mice, Knockout, Mutagenesis, Insertional, Sequence Analysis, DNA
Show Abstract · Added April 2, 2019
Hyperpolarization-activated Cyclic Nucleotide-gated (HCN) channels are important regulators of excitability in neural, cardiac, and other pacemaking cells, which are often altered in disease. In mice, loss of HCN2 leads to cardiac dysrhythmias, persistent spike-wave discharges similar to those seen in absence epilepsy, ataxia, tremor, reduced neuropathic and inflammatory pain, antidepressant-like behavior, infertility, and severely restricted growth. While many of these phenotypes have tissue-specific mechanisms, the cause of restricted growth in HCN2 knockout animals remains unknown. Here, we characterize a novel, 3kb insertion mutation of Hcn2 in the Tremor and Reduced Lifespan 2 (TRLS/2J) mouse that leads to complete loss of HCN2 protein, and we show that this mutation causes many phenotypes similar to other mice lacking HCN2 expression. We then demonstrate that while TRLS/2J mice have low blood glucose levels and impaired growth, dysfunction in hormonal secretion from the pancreas, pituitary, and thyroid are unlikely to lead to this phenotype. Instead, we find that homozygous TRLS/2J mice have abnormal gastrointestinal function that is characterized by less food consumption and delayed gastrointestinal transit as compared to wildtype mice. In summary, a novel mutation in HCN2 likely leads to impaired GI motility, causing the severe growth restriction seen in mice with mutations that eliminate HCN2 expression.
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MeSH Terms
Nomogram predicting the risk of recurrence after curative-intent resection of primary non-metastatic gastrointestinal neuroendocrine tumors: An analysis of the U.S. Neuroendocrine Tumor Study Group.
Merath K, Bagante F, Beal EW, Lopez-Aguiar AG, Poultsides G, Makris E, Rocha F, Kanji Z, Weber S, Fisher A, Fields R, Krasnick BA, Idrees K, Smith PM, Cho C, Beems M, Schmidt CR, Dillhoff M, Maithel SK, Pawlik TM
(2018) J Surg Oncol 117: 868-878
MeSH Terms: Cohort Studies, Female, Follow-Up Studies, Gastrointestinal Neoplasms, Humans, Male, Middle Aged, Neoplasm Recurrence, Local, Neuroendocrine Tumors, Nomograms, Prognosis, Risk Factors, Survival Rate
Show Abstract · Added April 10, 2018
BACKGROUND - The risk of recurrence after resection of non-metastatic gastro-entero-pancreatic neuroendocrine tumors (GEP-NET) is poorly defined. We developed/validated a nomogram to predict risk of recurrence after curative-intent resection.
METHODS - A training set to develop the nomogram and test set for validation were identified. The predictive ability of the nomogram was assessed using c-indices.
RESULTS - Among 1477 patients, 673 (46%) were included in the training set and 804 (54%) in y the test set. On multivariable analysis, Ki-67, tumor size, nodal status, and invasion of adjacent organs were independent predictors of DFS. The risk of death increased by 8% for each percentage increase in the Ki-67 index (HR 1.08, 95% CI, 1.05-1.10; P < 0.001). GEP-NET invading adjacent organs had a HR of 1.65 (95% CI, 1.03-2.65; P = 0.038), similar to tumors ≥3 cm (HR 1.67, 95% CI, 1.11-2.51; P = 0.014). Patients with 1-3 positive nodes and patients with >3 positive nodes had a HR of 1.81 (95% CI, 1.12-2.87; P = 0.014) and 2.51 (95% CI, 1.50-4.24; P < 0.001), respectively. The nomogram demonstrated good ability to predict risk of recurrence (c-index: training set, 0.739; test set, 0.718).
CONCLUSION - The nomogram was able to predict the risk of recurrence and can be easily applied in the clinical setting.
© 2018 Wiley Periodicals, Inc.
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13 MeSH Terms
Patients with familial adenomatous polyposis harbor colonic biofilms containing tumorigenic bacteria.
Dejea CM, Fathi P, Craig JM, Boleij A, Taddese R, Geis AL, Wu X, DeStefano Shields CE, Hechenbleikner EM, Huso DL, Anders RA, Giardiello FM, Wick EC, Wang H, Wu S, Pardoll DM, Housseau F, Sears CL
(2018) Science 359: 592-597
MeSH Terms: Adenomatous Polyposis Coli, Animals, Bacterial Toxins, Bacteroides fragilis, Biofilms, Carcinogenesis, Colon, Colonic Neoplasms, DNA Damage, Escherichia coli, Gastrointestinal Microbiome, Humans, Interleukin-17, Intestinal Mucosa, Metalloendopeptidases, Mice, Peptides, Polyketides, Precancerous Conditions
Show Abstract · Added March 20, 2018
Individuals with sporadic colorectal cancer (CRC) frequently harbor abnormalities in the composition of the gut microbiome; however, the microbiota associated with precancerous lesions in hereditary CRC remains largely unknown. We studied colonic mucosa of patients with familial adenomatous polyposis (FAP), who develop benign precursor lesions (polyps) early in life. We identified patchy bacterial biofilms composed predominately of and Genes for colibactin () and toxin (), encoding secreted oncotoxins, were highly enriched in FAP patients' colonic mucosa compared to healthy individuals. Tumor-prone mice cocolonized with (expressing colibactin), and enterotoxigenic showed increased interleukin-17 in the colon and DNA damage in colonic epithelium with faster tumor onset and greater mortality, compared to mice with either bacterial strain alone. These data suggest an unexpected link between early neoplasia of the colon and tumorigenic bacteria.
Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.
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19 MeSH Terms
Dietary Fatty Acids Control the Species of N-Acyl-Phosphatidylethanolamines Synthesized by Therapeutically Modified Bacteria in the Intestinal Tract.
Dosoky NS, Guo L, Chen Z, Feigley AV, Davies SS
(2018) ACS Infect Dis 4: 3-13
MeSH Terms: Acyltransferases, Animals, Bacteria, Biomarkers, Biosynthetic Pathways, Chromatography, Liquid, Diet, Fatty Acids, Gastrointestinal Microbiome, Lipid Metabolism, Liver, Male, Mice, Phosphatidylethanolamines, Tandem Mass Spectrometry, Temperature
Show Abstract · Added July 17, 2019
Engineering the gut microbiota to produce specific beneficial metabolites represents an important new potential strategy for treating chronic diseases. Our previous studies with bacteria engineered to produce N-acyl-phosphatidylethanolamines (NAPEs), the immediate precursors of the lipid satiety factors N-acyl-ethanolamides (NAEs), found that colonization of these bacteria inhibited development of obesity in C57BL/6J mice fed a high fat diet. Individual NAE species differ in their bioactivities. Intriguingly, colonization by our engineered bacteria resulted in increased hepatic N-stearoyl-ethanolamide (C18:0NAE) levels despite the apparent inability of these bacteria to biosynthesize its precursor N-stearoyl-phosphatidylethanolamine (C18:0NAPE) in vitro. We therefore sought to identify the factors that allowed C18:0NAPE biosynthesis by the engineered bacteria after colonization of the intestinal tract. We found that the species of NAPE biosynthesized by engineered bacteria depends on the species of dietary fatty acids available in the intestine, suggesting a simple method to fine-tune the therapeutic effects of modified microbiota.
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The gastric microbiome, its interaction with Helicobacter pylori, and its potential role in the progression to stomach cancer.
Noto JM, Peek RM
(2017) PLoS Pathog 13: e1006573
MeSH Terms: Adenocarcinoma, Disease Progression, Gastrointestinal Microbiome, Helicobacter Infections, Helicobacter pylori, Humans, Stomach Neoplasms
Added March 14, 2018
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7 MeSH Terms
Bile acids and bariatric surgery.
Albaugh VL, Banan B, Ajouz H, Abumrad NN, Flynn CR
(2017) Mol Aspects Med 56: 75-89
MeSH Terms: Animals, Bile Acids and Salts, Diabetes Mellitus, Type 2, Enterohepatic Circulation, Gastrectomy, Gastric Bypass, Gastrointestinal Microbiome, Gene Expression Regulation, Glucose, Homeostasis, Humans, Insulin Resistance, Obesity, Morbid, Receptors, Cytoplasmic and Nuclear, Receptors, G-Protein-Coupled, Rodentia, Signal Transduction
Show Abstract · Added June 6, 2017
Bariatric surgery, specifically Roux-en-Y gastric bypass (RYGB) and vertical sleeve gastrectomy (VSG), are the most effective and durable treatments for morbid obesity and potentially a viable treatment for type 2 diabetes (T2D). The resolution rate of T2D following these procedures is between 40 and 80% and far surpasses that achieved by medical management alone. The molecular basis for this improvement is not entirely understood, but has been attributed in part to the altered enterohepatic circulation of bile acids. In this review we highlight how bile acids potentially contribute to improved lipid and glucose homeostasis, insulin sensitivity and energy expenditure after these procedures. The impact of altered bile acid levels in enterohepatic circulation is also associated with changes in gut microflora, which may further contribute to some of these beneficial effects. We highlight the beneficial effects of experimental surgical procedures in rodents that alter bile secretory flow without gastric restriction or altering nutrient flow. This information suggests a role for bile acids beyond dietary fat emulsification in altering whole body glucose and lipid metabolism strongly, and also suggests emerging roles for the activation of the bile acid receptors farnesoid x receptor (FXR) and G-protein coupled bile acid receptor (TGR5) in these improvements. The limitations of rodent studies and the current state of our understanding is reviewed and the potential effects of bile acids mediating the short- and long-term metabolic improvements after bariatric surgery is critically examined.
Copyright © 2017 Elsevier Ltd. All rights reserved.
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17 MeSH Terms