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Maternal H. pylori is associated with differential fecal microbiota in infants born by vaginal delivery.
Hernandez, CD, Shin, H, Troncoso, PA, Vera, MH, Villagran, AA, Rodriguez-Rivera, SM, Ortiz, MA, Serrano, CA, Borzutzky, A, Dominguez-Bello, MG, et al
Scientific reports. 2020;(1):7305
Abstract
Helicobacter pylori colonization may affect the mucosal immune system through modification of microbiota composition and their interactions with the host. We hypothesized that maternal H. pylori status affects the maternal intestinal microbiota of both mother and newborn. In this study, we determine the structure of the fecal microbiota in mothers and neonates according to maternal H. pylori status and delivery mode. We included 22 mothers and H. pylori infection was determined by fecal antigen test. Eleven mothers (50%) were H. pylori-positive (7 delivering vaginally and 4 by C-section), and 11 were negative (6 delivering vaginally and 5 by C-section). Stool samples were obtained from mothers and infants and the fecal DNA was sequenced. The fecal microbiota from mothers and their babies differed by the maternal H. pylori status, only in vaginal birth, not in C-section delivery. All 22 infants tested negative for fecal H. pylori at 15 days of age, but those born vaginally -and not those by C-section- showed differences in the infant microbiota by maternal H. pylori status (PERMANOVA, p = 0.01), with higher abundance of Enterobacteriaceae and Veillonella, in those born to H. pylori-positive mothers. In conclusion, the structure of the infant fecal microbiota is affected by the maternal H. pylori status only in infants born vaginally, suggesting that the effect could be mediated by labor and birth exposures.
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Sensitivity Analysis of an ENteric Immunity SImulator (ENISI)-Based Model of Immune Responses to Helicobacter pylori Infection.
Alam, M, Deng, X, Philipson, C, Bassaganya-Riera, J, Bisset, K, Carbo, A, Eubank, S, Hontecillas, R, Hoops, S, Mei, Y, et al
PloS one. 2015;(9):e0136139
Abstract
Agent-based models (ABM) are widely used to study immune systems, providing a procedural and interactive view of the underlying system. The interaction of components and the behavior of individual objects is described procedurally as a function of the internal states and the local interactions, which are often stochastic in nature. Such models typically have complex structures and consist of a large number of modeling parameters. Determining the key modeling parameters which govern the outcomes of the system is very challenging. Sensitivity analysis plays a vital role in quantifying the impact of modeling parameters in massively interacting systems, including large complex ABM. The high computational cost of executing simulations impedes running experiments with exhaustive parameter settings. Existing techniques of analyzing such a complex system typically focus on local sensitivity analysis, i.e. one parameter at a time, or a close "neighborhood" of particular parameter settings. However, such methods are not adequate to measure the uncertainty and sensitivity of parameters accurately because they overlook the global impacts of parameters on the system. In this article, we develop novel experimental design and analysis techniques to perform both global and local sensitivity analysis of large-scale ABMs. The proposed method can efficiently identify the most significant parameters and quantify their contributions to outcomes of the system. We demonstrate the proposed methodology for ENteric Immune SImulator (ENISI), a large-scale ABM environment, using a computational model of immune responses to Helicobacter pylori colonization of the gastric mucosa.
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Overview of the phytomedicine approaches against Helicobacter pylori.
Vale, FF, Oleastro, M
World journal of gastroenterology. 2014;(19):5594-609
Abstract
Helicobacter pylori (H. pylori) successfully colonizes the human stomach of the majority of the human population. This infection always causes chronic gastritis, but may evolve to serious outcomes, such as peptic ulcer, gastric carcinoma or mucosa-associated lymphoid tissue lymphoma. H. pylori first line therapy recommended by the Maastricht-4 Consensus Report comprises the use of two antibiotics and a proton-pomp inhibitor, but in some regions failure associated with this treatment is already undesirable high. Indeed, treatment failure is one of the major problems associated with H. pylori infection and is mainly associated with bacterial antibiotic resistance. In order to counteract this situation, some effort has been allocated during the last years in the investigation of therapeutic alternatives beyond antibiotics. These include vaccines, probiotics, photodynamic inactivation and phage therapy, which are briefly revisited in this review. A particular focus on phytomedicine, also described as herbal therapy and botanical therapy, which consists in the use of plant extracts for medicinal purposes, is specifically addressed, namely considering its history, category of performed studies, tested compounds, active principle and mode of action. The herbs already experienced are highly diverse and usually selected from products with a long history of employment against diseases associated with H. pylori infection from each country own folk medicine. The studies demonstrated that many phytomedicine products have an anti-H. pylori activity and gastroprotective action. Although the mechanism of action is far from being completely understood, current knowledge correlates the beneficial action of herbs with inhibition of essential H. pylori enzymes, modulation of the host immune system and with attenuation of inflammation.
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Alternative therapies for Helicobacter pylori: probiotics and phytomedicine.
Vítor, JM, Vale, FF
FEMS immunology and medical microbiology. 2011;(2):153-64
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Abstract
Helicobacter pylori is a common human pathogen infecting about 30% of children and 60% of adults worldwide and is responsible for diseases such as gastritis, peptic ulcer and gastric cancer. Treatment against H. pylori is based on the use of antibiotics, but therapy failure can be higher than 20% and is essentially due to an increase in the prevalence of antibiotic-resistant bacteria, which has led to the search for alternative therapies. In this review, we discuss alternative therapies for H. pylori, mainly phytotherapy and probiotics. Probiotics are live organisms or produced substances that are orally administrated, usually in addition to conventional antibiotic therapy. They may modulate the human microbiota and promote health, prevent antibiotic side effects, stimulate the immune response and directly compete with pathogenic bacteria. Phytomedicine consists of the use of plant extracts as medicines or health-promoting agents, but in most cases the molecular mode of action of the active ingredients of these herbal extracts is unknown. Possible mechanisms include inhibition of H. pylori urease enzyme, disruption of bacterial cell membrane, and modulation of the host immune system. Other alternative therapies are also reviewed.
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Review article: Probiotics in gastrointestinal and liver diseases.
Jonkers, D, Stockbrügger, R
Alimentary pharmacology & therapeutics. 2007;:133-48
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Abstract
BACKGROUND Probiotics, defined as live micro-organisms with beneficial effects for the host, are widely applied in gastrointestinal and liver diseases. AIM AND METHOD To review the available evidence of clinical trials on probiotics in gastrointestinal and liver diseases, with a major focus on irritable bowel syndrome, inflammatory bowel disease, pancreatitis and chronic liver diseases. RESULTS Evidence for the therapeutic or preventive application of particular probiotic strains is available for antibiotic-associated diarrhoea, rota-virus-associated diarrhoea and pouchitis. Results are encouraging for irritable bowel syndrome, ulcerative colitis and for reducing side effects by Helicobacter pylori eradication therapies, but are less clear for Crohn's disease, lactose intolerance and constipation. In general, for most of these patient groups, more placebo-controlled methodologically well-designed studies that pay attention to both clinical outcome and mechanistic aspects are required. The application in liver disease and pancreatitis is promising, but more human trials have to be awaited. Possible mechanisms of probiotics include modulation of the intestinal microbiota and the immune system, but different bacterial may have different effects. CONCLUSION Further insight into disease entities and the functioning of probiotic strains is required to be able to select disease-specific strains, which have to be tested in well-designed placebo-controlled studies.