Helicobacter pylori (H.pylori) had been confirmed by the World Health Organization (WHO) as Group 1 carcinogens, in which it has been identified to be related with the development of gastric carcinoma. Gastroesophageal reflux disease (GERD) is less commonly found in Asia, while the number of H.pylori infection is considerably to be higher than that of the Western population. The relationship between H.pylori and GERD still remains ambiguous nowadays. One of the contributing factors affecting the level of gastric secretion might be due to the genetic cause. The aim of this review is to assess whether the current first-line therapy on GERD would be effective or not in relieving the symptoms of the patients with H.pylori infection. / published_or_final_version / Community Medicine / Master / Master of Public Health

No description available.

No description available.

Bibliography: leaves 181-233. / 233 p. : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Investigates pharmacological control of transient lower oesophagal sphincter relaxations as a treatment of gastro-oesophageal reflux. Two major classes of pharmaceutical agents were explored; anticholinergic agents and the GABAb agonist, baclofen. / Thesis (Ph.D.)--University of Adelaide, Dept. of Medicine, 1999

Crohn’s disease (CD) and ulcerative colitis (UC) constitute the two major forms of inflammatory bowel disease (IBD), which are disorders of chronic inflammation in the gastrointestinal tract that are associated with significant morbidity and socioeconomic burden. IBD patients with long-standing intestinal inflammation are more prone to developing colorectal cancer (CRC). Until now, none of the existing IBD treatments is able to heal the mucosal ulcerations satisfactorily. The endocannabinoid system (ECS), which comprises of endogenous cannabinoid ligands, their receptors, and metabolic enzymes, has been implicated in gut homeostasis, visceral sensation, inflammation and gastrointestinal motility. Available studies in rodent models of IBD suggest that enhancing the ECS tone may reduce inflammation and improve mucosal integrity. This evidence indicates that the components of the ECS seem well positioned to exert a protective role in IBD and also to offer a great opportunity for therapeutic exploitation. Despite the role of the ECS in the gut, the presence and function of the components of the ECS is not well characterised in human IBD. The primary aim of the study was to investigate the state of the major components of the ECS in human IBD and to establish whether IBD is associated with any changes of the components of the ECS. Cannabinoid CB1 and CB2 receptors, enzymes for endocannabinoid biosynthesis PLC, “LRAT”, NAPE-PLD and DAGL, and endocannabinoid metabolic enzymes FAAH and MAGL were analysed from colonic tissue samples of CD, UC and control patients by reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR) to determine the relative mRNA expression of the above genes. The RT-qPCR analysis showed that the mRNA expression of PLC, LRAT, and NAPE-PLD were unchanged in both CD and UC, whiles DAGL mRNA was decreased in UC but was unchanged in CD. The endocannabinoid degradation enzymes, FAAH mRNA expression was also unchanged in CD but decreased in UC, whereas the mRNA expression of MAGL was significantly decreased in both CD and UC. NAPE-PLD/FAAH and DAGL/MAGL ratios, an estimation of the balance of AEA and 2-AG levels, showed that AEA and 2-AG levels could be increased and unchanged, respectively, in IBD. The mRNA expression of CB1 was significantly decreased in CD and UC whilst CB2 mRNA expression was unchanged in both forms of IBD. The study demonstrated that the components of the ECS which were investigated were present in colonic tissues of both IBD patients and healthy individuals, but they appear to be off balance in CD and UC patients. The decreased CB1 receptors in IBD patients could be an important modifier in the disease and could also provide a possible pathoaetiological mechanism linking IBD and CRC. Although these findings look promising, more studies with larger sample size are required to characterise the components of the ECS in human IBD.

No description available.

Thesis (PhD)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: Background: Irritable bowel syndrome (IBS) is a common gastrointestinal (GI) disorder. GI symptoms and impaired quality of life affect between 10-20% of all adults, corresponding to about 25-50% of all patients who visit a gastroenterologist’s clinic. In recent years, several novel mechanisms of IBS that likely relate to previously established theories have been identified. Inflammation, postinfectious low-grade inflammation, immunological and genetic predisposition along with altered microbiota are critical in IBS development, while several dietary factors may also play a role in this syndrome. However, none of these factors accounts for the full repertoire of IBS symptoms, and the pathophysiology of this condition is not fully understood. The overarching aim of this study was to investigate the nutrient intakes, GI microbiota and the effect of Lactobacillus plantarum (L.plantarum) 299v in IBS patients. Sub-aims: 1) Update healthcare professionals on current probiotic information and provide an overview of probiotic treatment approaches, with special emphasis on IBS, 2) conduct a well designed randomised, double blind, placebo-controlled trial (RCT) with L. plantarum 299v as part of an intervention and establish whether a course of probiotics may alleviate undesirable symptoms of IBS and improve quality of life, 3) assess nutrient intake in patients with irritable bowel syndrome (IBS) compared to dietary recommendations, 4) validate and assess the reproducibility of food records and 5) identify possible nutrient risk components for establishing GI microbiota involved in IBS and as part of an intervention, determine whether a course of probiotics may alter stool microbiota. Results: 1) A review article published by the author provides an overview of current probiotic treatment options to health care professionals and indicates certain probiotics are a promising therapeutic treatment option for management of IBS symtpoms, 2) the effects of the single strain probiotic, L. plantarum 299v, supplementation was evaluated in a RCT. Compared to placebo, the probiotic supplementation showed no significant reduction in GI symptom severity scores, particularly abdominal pain relief. Quality of life was also not improved in the treatment versus control group. Both the treatment and placebo groups improved significantly over the trial period, indicating a large placebo effect, 3) nutrient intakes of the IBS patients compared to current dietary reference recommendations indicates that this group of patients are at risk for nutrient inadequacies in key macro and micronutrients, 4) the validity and reliability of the dietary data showed good reliability but poor validity as measured by plasma fatty acids and 5) the GI microbiota composition in the phenotypically different diarrhoea-predominant IBS (D-IBS) vs. constipation-predominant IBS (C-IBS) showed that D-IBS patients had significantly lower counts of Lactobacillus plantarum compared to C-IBS patients. The probiotic had no significant effects on the GI microbiota as measured by quantitative polymerase chain reaction (qPCR). It was found that nutrient intakes had a significant impact on the microbiota. Lower fibre intakes were associated with higher Bacteroides spp., lower Bifidobacteria bifidum and Lactobacillus plantarum counts in both IBS groups. Conclusion: Taken together, L.plantarum 299v did not alleviate the GI symptoms of IBS, nor was it associated with significant changes in the GI microbiota. IBS patients may be at risk of key nutrient inadequacies. The influence of nutrient intakes on the GI microbiota provides an attractive explanation as a potential pathophysiological factor for IBS. / AFRIKAANSE OPSOMMING: Agtergrond: Prikkelbare derm-sindroom (PDS) is ‘n algemene gastro-intestinale (GI) stoornis. GI simptome affekteer die lewenskwaliteit van 10-20% van alle volwassenes. Dit stem ooreen met ongeveer 25-50% van alle pasiënte wat ‘n gastroënteroloog konsulteer. Verskeie oorspronklike meganismes vir die ontwikkeling van PDS is onlangs identifiseer. Inflammasie, post-infektiewe lae-graadse inflammasie, immunologiese en genetiese vatbaarheid tesame met veranderde mikrobiota is krities vir die ontwikkeling van PDS. Sekere dieetfaktore mag ook bydraend wees tot hierdie sindroom. Geen van hierdie faktore is egter verantwoordelik vir die volle spektrum van PDS simptome nie en die patofisiologie van die toestand word ook nog nie ten volle verstaan nie. Die oorkoepelende doel van hierdie studie is om nutriëntinname, GI mikrobiota en die uitwerking van L.plantarum 299v in PDS pasiënte bepaal. Sub-doelwitte: 1) Om gesondheidswerkers in te lig aangaande die nuutste inligting oor probiotika en om ‘n oorsig van probiotika behandelingsopsies te verskaf, met spesiale klem op PDS, 2) om ‘n goed beplande ewekansige, dubbel-blinde, plasebo-beheerde kliniese studie met L.plantarum 299v as deel van die intervensie uit te voer om sodoende te bepaal of ‘n kursus probiotika ongewensde simptome van PDS kan verbeter en lewenskwaliteit sodoende verhoog, 3) om nutriëntinname in pasiënte met PDS te bepaal vergeleke met dieet aanbevelings, 4) om die geldigheid en herhaalbaarheid van voedselrekords te bepaal en 5) om moontlike nutriënt risikokomponente vir die ontwikkeling van GI mikrobiota betrokke in PDS te identifiseer en om as deel van ‘n intervensie te bepaal of ‘n kursus probiotika stoelgang mikrobiota patrone verander. Resultate: 1) ‘n Oorsigartikel gepubliseer deur die kandidaat dui probiotika aan as ‘n belowende terapeutiese opsie in die behandeling van PDS simptome, 2) die effek van ‘n enkelstam probiotikum, L.plantarum 299v, is evalueer deur ‘n ewekansige, dubbel-blinde, plasebo-beheerde kliniese studie. Vergeleke met die plasebo, het probiotiese aanvulling geen betekenisvolle vermindering in die GI simptome in PDS pasiënte tot gevolg gehad nie. Lewenskwaliteit het ook nie verbeter in die behandelde versus die kontrole groep nie. Beide die behandelde en plasebo groepe het aansienlik verbeter oor die studietydperk, wat ‘n groot plasebo effek aandui, 3) nutriëntinname van die PDS groep vergeleke met huidige dieetaanbevelings, dui daarop dat hierdie groep pasiënte ‘n risiko het vir die ontwikkeling van kern nutriënttekorte (makro- en mikronutriënte), 4) die geldigheid en betroubaarheid van die dieetdata dui op goeie betroubaarheid, maar swak geldigheid soos bepaal deur plasma vetsure en 5) die dermkanaal mikrobiotiese samestelling in die verskillende fenotipes, diarree-oorheersende PDS (D-PDS) vs. konstipasie-oorheersende PDS (K-PDS) dui daarop dat D-PDS pasiënte aansienlike minder Lactobacillus plantarum gehad het vergeleke met K-PDS pasiënte. Die probiotikum het geen beduidende uitwerking op die oorheersende mikrobiota gehad nie, soos gemeet deur kwantitatiewe polimerase kettingreaksie (kPKR). Daar is gevind dat dieet ‘n beduidende impak op die mikrobiota gehad het. Daar is ‘n verband tussen laer vesel inname en hoёr Bacteroides spp. en laer Bifidobacteria bididum en Lactobacillus plantarum tellings gevind in beide PDS groepe. Gevolgtrekking: Die L.plantarum 299v enkelstam probiotikum het nie die gastrointestinale simptome van PDS pasiënte verlig nie en daar is ook geen beduidende veranderinge in die mikrobiota gevind nie. PDS pasiënte mag ‘n verhoogde risiko toon vir kern nutriënttekorte. Die invloed van nutriëntinname op GI mikrobiota verskaf ‘n belowende verduideliking as ‘n potensiële patofisiologiese faktor in PDS.

Includes bibliographical references. / 59 leaves : / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Various articles published by John Robin Warren on the discovery and pathology of Helicobacter pylori. / Thesis (M.D.)--University of Adelaide, Dept. of Medicine, 2000

published_or_final_version / Medical Sciences / Master / Master of Medical Sciences

A review of the literature revealed that diet plays an important role in serious human noninfectious large bowel diseases including cancer and inflammatory bowel diseases. Dietary protein (especially as red and processed meats) has been implicated as a positive risk factor for colorectal cancer while starch which is not digested in the small intestine (resistant starch, RS) appears to be protective. The series of experiments described in this thesis were aimed to determine the effects of dietary proteins and RS on indices of colon health in an animal model, the laboratory rat. Genetic damage is a prerequisite for carcinogenesis and this was assessed by a specific assay (the comet assay) which gives a measure of DNA strand breaks. Loss of mucus barrier function is thought to contribute to inflammatory bowel disease by permitting bacterial translocation and this was measured optically using a microscope micrometer. Other biomarkers were measured as described below. There were four major experiments. 1. Effects of dietary red meat and casein on colonic DNA damage and interaction with resistant starch Previous studies had shown that higher dietary protein (as casein) induced genetic damage in rat colonocytes and that RS (fed as a high amylose maize starch) was protective. This study was aimed at establishing whether a high protein diet fed as cooked red meat had similar effects and whether RS was protective. Rats were fed diets containing either 15 % or 25% casein or 25% barbecued lean red beef, each with or without 48% high amylose maize starch (as a source of RS) for 4 weeks. As expected, high dietary casein caused a 2-fold increase in colonic single-strand DNA breaks compared with a low casein diet and reduced the thickness of the colonic mucus layer by 41%. High levels of cooked meat caused 26% more DNA damage than the high casein diet but reduced mucus thickness to a similar degree as casein. Addition of RS to the diet abolished the increase in DNA damage and the loss of colonic mucus thickness induced by either high protein diet. It is thought that RS promotes large bowel health through the SCFA produced by the large bowel bacteria. One acid in particular (butyrate) has been associated particularly with promotion of normal large bowel function and protection against disease. In keeping with this hypothesis, caecal and faecal short chain fatty acid pools (including those of butyrate) were increased by inclusion of RS in the diet. DNA damage is an early step in the initiation of cancer and these findings agree with the population data which suggest that total dietary protein and red meat promote risk of colorectal cancer. However, inclusion of resistant starch in the diet could significantly reduce that risk. 2. Differential effects of dietary whey, soy and casein on colonic DNA damage and interaction with resistant starch The preceding experiments showed that high levels of animal-derived proteins increased colonocyte genetic damage and loss of the mucus barrier in rats. This second experiment was designed to determine whether diets high in different types of dairy protein (casein or whey) or a plant protein isolate (soy) had similar adverse effects on colonic DNA and mucus barrier function and whether inclusion of RS in the diet was protective. Adult male Sprague Dawley rats were fed a diet containing 15 % or 25 % casein, whey or soy protein, each with or without 48 % high amylose maize starch for 4 weeks. In confirmation of the earlier studies, higher levels of dietary casein increased colonocyte DNA damage significantly. However, whey did not increase genetic damage. Colonic DNA damage was highest for soy when fed at both 15% and 25% protein in the absence of RS. Inclusion of RS in the diet attenuated colonocyte DNA damage due to higher dietary protein in all three groups. The colonic mucus barrier was thinner in rats fed higher dietary protein but the effect was reversed by feeding RS. Caecal total SCFA and butyrate pools were low in rats fed the digestible starch and were higher in rats fed RS. However, there was no relationship between caecal or faecal SCFA and genetic damage or mucus thickness. Caecal and colonic tissue weight and colon length were higher in rats fed RS, consistent with greater SCFA supply. These data confirm that higher dietary protein of animal (casein) or plant (soy) origin increases genetic damage and loss of the mucus barrier indicating that this is an effect of protein and not its source. These findings accord with the epidemiological data which link dietary protein to greater risk of colorectal cancer and inflammatory bowel disease. However, the data show also that dietary proteins differ in their specific actions on genetic damage and mucus thickness. Further, the data from the feeding of whey suggest that not all proteins are equivalent in their capacity to provoke adverse changes in colonic integrity. While the data show that RS raised large bowel and faecal SCFA, they indicate their levels were not related directly to these biomarkers. 3. Dose response effects of resistant starch on protein induced colonic DNA damage The accumulated data linking greater protein intakes to adverse changes in the colon were obtained at dietary levels which were not unreasonable in terms of animal or human consumption. However, the dietary level of RS which were fed were relatively high (48% by weight) so this study was conducted to determine its effectiveness at lower levels of dietary inclusion. It was also important to ascertain whether there was a dose-response relationship between RS intake and the observed effects. One of the mechanisms proposed for the induction of colorectal cancer by high dietary protein intakes is oxidative damage to DNA. In this experiment, this was done by assaying with endonuclease III. Adult male rats were fed a diet containing 25% casein with 0%, 10%, 20%, 30% or 40% high amylose maize starch for 4 weeks. As in the preceding studies comet tail moment was greatest and the mucus barrier thinnest in rats fed 0% RS. DNA damage was reduced and the mucus barrier thickened in a logarithmic dose-dependent manner by RS. There was no significant difference between dietary groups associated with oxidative DNA damage as measured by endonuclease III. Caecal and faecal short chain fatty acid (SCFA) pools rose with the increased level of dietary RS. DNA damage of colonocytes correlated negatively with caecal SCFA but the strongest correlation was with caecal butyrate, which is consistent with the proposed role of this SCFA in promoting a normal cell phenotype. The data show that RS prevents protein induced colonic DNA damage in a dose-dependent manner. Inclusion of 10% high amylose maize starch was found to be sufficient to oppose colonocyte DNA damage, and to increase caecal and faecal SCFA pools. Intakes of this order are not unreasonable in terms of human consumption of RS. 4. Dose response effects of red and white meat on colonic DNA damage and interaction with resistant starch The accumulated evidence from large prospective human studies links diet to colorectal cancer risk strongly. The evidence from the animal studies described in this thesis that dietary protein induces colonocyte genetic damage supports a role for high protein intakes in increasing risk. Recently, several large epidemiological studies and a meta-analysis of prospective studies have found that consumption of dietary red or processed meats, but not white (poultry) meat, is associated with increased risk of colorectal cancer. This is consistent with the data from the preceding studies that specific proteins affected colonic integrity differentially. A large prospective European study (European Prospective Investigation into Cancer and Nutrition) has reported that dietary fibre was protective. The findings reported in this thesis that RS opposes the effects of high dietary protein accord with that conclusion. This study aimed to compare the effects of cooked red (beef) or white (chicken) meat on DNA damage and mucus barrier thickness in rats. The study was designed to determine whether the relationship between the intakes of these meats was dose-dependent. Double-strand DNA breaks are thought to relate more closely to carcinogenesis than single-strand breaks so both were measured. Adult male Sprague-Dawley rats were fed a diet containing 15%, 25% or 35% cooked beef or cooked chicken each with or without 20% high amylose maize starch for four weeks. Both red and white meat increased colonic DNA damage dose-dependently. However, both single and double strand breaks were significantly greater when the rats were fed the red meat diets compared to those fed the white meat. Colonocyte DNA damage was reduced by the consumption of RS while large bowel SCFA were increased. The findings of this study are consistent with the epidemiological data which show that red meat consumption is associated with greater risk of colorectal cancer but that white meat is not. Summary The data reported in this thesis support the findings of prospective population studies that high dietary protein, red meat in particular, appears to be harmful to the health of the large bowel. However, the data demonstrate also that different protein types have differential effects on the integrity of the colonocyte DNA. Furthermore, the addition of RS to the diet protects against protein-induced colonic DNA damage and maintenance of the colonic mucus barrier, apparently through increased SCFA production by colonic fermentation. The results of these experiments indicate a strong potential for RS to be effective in maintenance of large bowel integrity in the face of high dietary protein. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1292858 / Thesis(Ph.D.)-- School of Molecular and Biomedical Science, 2007.