Antibacterial action of bismuth in relation to Campylobacter pyloridis colonization and gastritis

Effect of colloidal bismuth subcitrate on symptoms and gastric histology in non-ulcer dyspepsia. A double blind placebo controlled study

The aim of this study was to determine the effect of colloidal bismuth subcitrate (De Nol) on symptoms and gastric histology in patients with non-ulcer dyspepsia. In a single centre trial, patients with food related upper abdominal pain not caused by ulcer disease were randomised to receive one tablet of colloidal bismuth subcitrate or matching placebo four times daily for eight weeks. Seventy three patients were entered and 51 completed the trial: 28 patients in the colloidal bismuth subcitrate group and 23 in the placebo group. Overall there was no difference between the two groups in terms of symptom relief. Among patients with histological gastritis (n = 23), however, those who took colloidal bismuth subcitrate used fewer antacid tablets (for three of four fortnightly periods) and were more likely to become asymptomatic (eight of 11 v three of 12, p less than 0.05); their gastritis was more likely to resolve (five of 10 v 0 of 12, p less than 0.025) and their gastric biopsies more likely to become negative for Helicobacter like organisms (eight of nine v 0 of 12, p less than 0.001) when compared with patients taking placebo. In contrast, patients who did not have gastritis in their index biopsies (n = 28) fared similarly whether they received colloidal bismuth subcitrate or placebo. Our results indicate that the administration of colloidal bismuth subcitrate benefited non-ulcer dyspepsia patients with gastritis but had no effect on those without.

Helicobacter pylori: controversies and an approach to management

Helicobacter pylori (formerly, Campylobacter pylori) is a gram-negative, spiral-shaped bacterium with a strong affinity for gastric-type epithelium. Convincing evidence indicates that H. pylori plays an etiologic role in the development of chronic, nonspecific gastritis, and it may play an important role in the pathogenesis of duodenal ulcer disease. An etiologic role for this organism in chronic gastric ulceration, nonulcer dyspepsia, and gastric carcinoma is not established. Whereas the diagnosis of H. pylori infection is relatively straightforward, the questions of when and how to treat the infection do not have established answers. A high rate of recrudescence follows most currently used therapeutic interventions. Until the pathogenicity of H. pylori in clinical disease is further supported and additional treatment trials have been completed, a conservative management approach is recommended.

Campylobacter pylori and gastroduodenal disease

Campylobacter pylori is a newly described, spiral-shaped, gram-negative bacillus that is oxidase positive, catalase positive, and urease positive and grows slowly in culture. Although observed in human tissue at the beginning of the century, it was not cultured until 1982. Because there are significant morphological and genetic differences between this organism and other species of Campylobacter, it will probably be reclassified in a new genus. Current information indicates that the organism primarily resides in the stomach tissue of humans and nonhuman primates and may occasionally spread to the esophagus or other parts of the alimentary tract under appropriate conditions. Significant evidence has accumulated in the last several years to show that it causes gastritis, and there is mounting evidence that it may participate in the development of duodenal ulcers. It may also be associated with gastric ulcers and nonulcer dyspepsia. It can be detected in patients by culture of biopsy specimens or histological staining of biopsy tissue. Indirect evidence for the presence of the organism can be obtained by detection of urease in a tissue biopsy specimen, by urea breath tests, or by detection of specific antibody. It may not be necessary to implement these procedures for routine use, however, until the role of the organism can be defined better. Ultimately, the discovery of this organism may lead to radical changes in the diagnosis and treatment of gastric disease.

Microbiological aspects of Helicobacter pylori (Campylobacter pylori)

The human gastric pathogen Campylobacter pylori has recently been reclassified as Helicobacter pylori, and a related spiral bacterium found in the stomach of ferrets has been designated Helicobacter mustelae. The general microbiological features of Helicobacter pylori are delineated here, with details of phenotypic differences between Helicobacter pylori and Helicobacter mustelae; comparisons are made with Wolinella succinogenes and Campylobacter jejuni. The Helicobacter organisms possess an external glycocalyx which can be visualised by electron microscopy, and which may be involved in bacterial adherence. The finding of soluble and cell-associated haemagglutinins of Helicobacter pylori is reported. Detection of Helicobacter pylori in clinical specimens, susceptibility of the organism to antibacterial agents, and other aspects of practical and clinical significance are briefly reviewed.

Binding and killing of bacteria by bismuth subsalicylate

Bismuth subsalicylate (BSS) is a compound without significant aqueous solubility that is widely used for the treatment of gastrointestinal disorders. BSS was able to bind bacteria of diverse species, and these bound bacteria were subsequently killed. A 4-log10 reduction of viable bacteria occurred within 4 h after a 10 mM aqueous suspension of BSS was inoculated with 2 x 10(6) Escherichia coli cells per ml. Binding and killing were dependent on the levels of inoculated bacteria, and significant binding but little killing of the exposed bacteria occurred at an inoculum level of 2 x 10(9) E. coli per ml. Intracellular ATP decreased rapidly after exposure of E. coli to 10 mM BSS and, after 30 min, was only 1% of the original level. Extracellular ATP increased after exposure to BSS, but the accumulation of extracellular ATP was not sufficient to account for the loss of intracellular ATP. The killing of bacteria exposed to BSS may have been due to cessation of ATP synthesis or a loss of membrane integrity. Bactericidal activity of BSS was also investigated in a simulated gastric juice at pH 3. Killing of E. coli at this pH was much more rapid than at pH 7 and was apparently due to salicylate released by the conversion of BSS to bismuth oxychloride. It is proposed that the binding and killing observed for BSS contribute to the efficacy of this compound against gastrointestinal infections such as traveler's diarrhea.

Pharmacokinetics and toxicity of bismuth compounds

Inorganic bismuth salts are poorly soluble in water: solubility is influenced by the acidity of the medium and the presence of certain compounds with (hydr)oxy or sulfhydryl groups. The analysis of bismuth in biological material is not standardised and is subject to large variation; it is difficult to compare data from different studies, and older data should be approached with caution. The normal concentration of bismuth in blood is between 1 and 15 micrograms/L, but absorption from oral preparations produces a significant rise. Distribution of bismuth in the organs is largely independent of the compound administered or the route of administration: the concentration in kidney is always highest and the substance is also retained there for a long time. It is bound to a bismuth-metal binding protein in the kidney, the synthesis of which can be induced by the metal itself. Elimination from the body takes place by the urinary and faecal routes, but the exact proportion contributed by each route is still unknown. Elimination from blood displays multicompartment pharmacokinetics, the shortest half-life described in humans being 3.5 minutes, and the longest 17 to 22 years. A number of toxic effects have been attributed to bismuth compounds in humans: nephropathy, encephalopathy, osteoarthropathy, gingivitis, stomatitis and colitis. Whether hepatitis is a side effect, however, is open to dispute. Each of these adverse effects is associated with certain bismuth compounds. Bismuth encephalopathy occurred in France as an epidemic of toxicity and was associated with the intake of inorganic salts including bismuth subnitrate, subcarbonate and subgallate. In the prodromal phase patients developed problems in walking, standing or writing, deterioration of memory, changes in behaviour, insomnia and muscle cramps, together with several psychiatric symptoms. The manifest phase started abruptly and was characterised by changes in awareness, myoclonia, astasia and/or abasia and dysarthria. Patients recovered spontaneously after discontinuation of bismuth. Intestinal lavage, forced diuresis and haemodialysis have been tried without positive effects on the clinical condition of the patient or on blood bismuth concentration, and the use of dimercaprol as an antidote has produced reports of both positive and negative findings. To confirm the diagnosis of bismuth encephalopathy, it is essential to find elevated bismuth concentrations in blood, plasma, serum or CSF. A safety level of 50 micrograms/L and an alarm level of 100 micrograms/L have been suggested in the past, but no proof is available to support the choice of these levels.(ABSTRACT TRUNCATED AT 400 WORDS)

Bismuth accumulates in the body during treatment with tripotassium dicitrato bismuthate

Bismuth concentration was measured in plasma, dried leucocytes and urine in nine patients before, during and after treatment with tripotassium dicitrato bismuthate (De-Noltab 2 b.d.) for 6 weeks. During treatment there was an 8.5-fold rise in median plasma bismuth concentration (P less than 0.01), a non-significant doubling of leucocyte bismuth content, and a 349-fold rise in 24-h urinary bismuth excretion (P less than 0.01). The significantly increased urinary bismuth excretion continued for at least 3 months after cessation of treatment with tripotassium dicitrato bismuthate, indicating accumulation of bismuth during treatment with this drug.

Campylobacter pylori and peptic ulcer disease

Campylobacter pylori is now known to be the most common and important cause of gastritis, and C. pylori infections have been associated with duodenal ulcer, gastric ulcer, nonulcer dyspepsia, and gastric cancer. Although it has been only possible to culture C. pylori for about 5 yr, there are already sufficient data available to allow us to develop the basic framework that relates C. pylori gastritis to the causation of peptic ulcer disease. We review the data and propose mechanisms that implicate C. pylori as an important factor in the pathogenesis of peptic ulcer disease and consider the therapeutic implications. What we now know about C. pylori begins to unravel some of the mysteries surrounding peptic ulcer disease.

Comparative in vitro activities of six new fluoroquinolones and other oral antimicrobial agents against Campylobacter pylori

The in vitro susceptibilities of 56 clinical isolates of Campylobacter pylori to six new fluoroquinolones and other oral antimicrobial agents were determined by an agar dilution technique. Ciprofloxacin was the most active of the fluoroquinolones (MIC for 90% of strains tested [MIC90], 0.05 microgram/ml). Other fluoroquinolones had variable activities, although most isolates were moderately susceptible to fleroxacin (MIC90, 4 micrograms/ml) and lomefloxacin (MIC90, 4 micrograms/ml).

The source of Campylobacter pylori

Sera from 98 abattoir workers were tested for IgG as well as for IgA to Campylobacter pylori, C. jejuni and Klebsiella. Clerical workers had significantly lower C. pylori and C. jejuni antibody levels than any of the groups in direct contact with freshly cut animal parts. No difference was found for antibodies to Klebsiella. Twenty-nine non-clerical workers with high IgG antibody levels against C. pylori consented to upper gastrointestinal endoscopy. C. pylori associated gastritis was found in all 29, and 4 weeks of colloidal bismuth subcitrate (240 mg/twice daily) was prescribed. On repeat testing at 3 months, all showed a decrease in IgG antibody levels to C. pylori but not to C. jejuni, whereas 18 untreated non-endoscoped workers showed no change. These findings raise the possibility that C. pylori infection is a zoonosis.

Colloidal bismuth in the treatment of duodenal ulceration: the benefit for the patient

Colloidal bismuth subcitrate (CBS) heals gastric and duodenal ulcers better than placebo and at rates similar to those observed with the commonly used H2-antagonists. Indeed, healing of duodenal ulcers may be more rapid than with cimetidine during the first month of treatment. When treatment is withdrawn, however, relapse is slower after CBS than after the H2-antagonists. The mechanism is uncertain but may be related to the ability of CBS to suppress Campylobacter pylori infection. The clinical implications of this difference in relapse rates are discussed. Preliminary data suggest that duodenal ulcer patients who are rendered C. pylori-negative for a prolonged period may be relatively immune to relapse. If confirmed, and if a suitably effective regimen can be found, this will transform the management of this difficult clinical problem.

Review of the modes of action of colloidal bismuth subcitrate

In recent years considerable progress has been made to elucidate the modes of action of colloidal bismuth subcitrate (CBS). CBS accelerates the healing of experimental chronic ulcers in rats by the formation of occlusive complexes and/or the accumulation of epidermal growth factor (EGF) in the ulcer crater. CBS exhibits gastric protection (cytoprotection) against, for example, ethanol lesions. Microscopic analysis of these lesions reveals that CBS protects against deep mucosal necrosis but not superficial injury, a property also found with prostaglandins. Dose-dependent increases in gastric prostaglandin E2 (PGE2) and bicarbonate secretion were found after CBS, in both animals and human volunteers. CBS in normal clinical doses increases PGE2 output from the gastric mucosa of human volunteers. Gastric injury in human volunteers produced by unbuffered aspirin is also reduced by concomitant administration of CBS, whereby PGE2 production is inhibited. This indicates that CBS exerts its gastric protection by both prostaglandin- and non-prostaglandin-mediated mechanisms. Campylobacter pylori is considered to be a causative factor of chronic antral gastritis and is a potential prerequisite for peptic ulcer disease. CBS, in contrast to other anti-ulcer drugs, prevents the growth of C. pylori in vitro. CBS eradicates C. pylori in patients and resolves chronic antral gastritis. The favourable relapse rates with CBS might be explained by the permanent eradication of C. pylori.

Campylobacter pylori as a pathogenetic factor in duodenal ulcer: the case for

This debate addresses whether Campylobacter pylori contributes to the development and maintenance of chronic peptic ulcer disease. C. pylori may be both an aggressive factor and may also impair mucosal defence. C. pylori causes the inevitably ulcer-associated gastritis and duodenitis and eradication of the C. pylori infection is associated with resolution of the inflammation and virtual elimination of the problem of duodenal ulcer relapse. A model is suggested that requires two separate factors to combine to cause chronic duodenal ulcer disease with other environmental factors (e.g. smoking) modifying the interaction between C. pylori and genetic susceptibility. Both genetic susceptibility and C. pylori infection are required to produce duodenal ulcer disease; neither alone is sufficient. C. pylori is the most important factor in the pathogenesis of duodenal ulcer disease because it is the only pathogenetic factor that can be easily reversed by medical therapy.

Rapid diagnosis of Campylobacter pylori by brush cytology

Campylobacter pylori (CP) was demonstrated in 67.2% of 67 patients using cytology as compared to 65.7% by histology. Brush cytology is thus found to be superior to all other methods available to date for the detection of CP. It is rapid, simple, and has a high specificity.

The potential impact of Campylobacter pylori on the treatment of duodenal ulcer disease

In most studies the association between Campylobacter pylori infection, Type B gastritis and duodenal and gastric ulceration is extremely strong. The best evidence for it having an aetiological role is at present in Type B gastritis. It should be remembered, however, that serological studies show carriage of the organism to be common also in the general population. An attempt is made here to gain some idea of the clinical impact of C. pylori infection in duodenal ulcer disease by analysing clinical trials, and in particular relapse data, in which an agent which suppresses C. pylori is used (colloidal bismuth subcitrate) and compared with one which does not (an H2-receptor antagonist). A mathematical model based on the data from these studies predicts that the prevalence of active duodenal ulceration will be twice as common in a group of subjects treated repeatedly upon relapse with an H2-receptor antagonist as in a group treated with colloidal bismuth. Other possible mechanisms are discussed but the ability of bismuth to suppress C. pylori infection is perhaps the best available explanation at present. Early data from several centres suggest that patients who can be rendered C. pylori negative over a prolonged period of time are relatively immune from relapse of their duodenal ulcers. If confirmed this observation may well transform the long-term management of duodenal ulcer disease.

Prospective double-blind trial of duodenal ulcer relapse after eradication of Campylobacter pylori

100 consecutive patients with both duodenal ulcer and Campylobacter pylori infection were followed up to see whether eradication of C pylori affected ulcer healing or relapse. Patients were randomly assigned to 8 weeks of treatment with cimetidine or colloidal bismuth subcitrate (CBS), with tinidazole or placebo being given concurrently from days 1 to 10, inclusive. Endoscopy, biopsy, and culture were done at entry, in weeks 10, 22, 34, and 62, and whenever symptoms recurred. There was no maintenance therapy. C pylori persisted in all of the cimetidine-treated patients and in 95% of those treated with cimetidine/tinidazole, but was eradicated in 27% of the CBS/placebo group and 70% of the CBS/tinidazole group. When C pylori persisted, 61% of duodenal ulcers healed and 84% relapsed. When C pylori was cleared 92% of ulcers healed (p less than 0.001) and only 21% relapsed during the 12 month follow-up period (p less than 0.0001).

Tripotassium dicitrate bismuthate and ranitidine in duodenal ulcer. Healing and influence on recurrence

One hundred patients were entered into a double-blind, double-dummy comparison of tripotassium dicitrate bismuthate (TDB) versus ranitidine, to evaluate short-term healing rates, and successfully healed patients were then entered into a follow-up phase to observe relapse rates. At 4 weeks 84% of patients treated with TDB and 68% of those treated with ranitidine had healed. At 8 weeks these figures had risen to 96% and 90%, respectively (p = NS). After a year's follow-up study 84% of patients healed initially with ranitidine had relapsed, whereas in the case of patients healed initially with TDB the relapse rate was 67% (p less than 0.05). The results confirm that in the short term, TDB is as effective as ranitidine, whereas the significantly better protection against relapse offered by TDB compared with ranitidine underlines the importance of restoring mucosal defence, an approach that to date has been somewhat overlooked.

Treatment of Campylobacter pylori-associated antral gastritis in children with bismuth subsalicylate and ampicillin

We evaluated the efficacy of medical therapy, consisting of liquid bismuth subsalicylate prescribed either in combination with oral ampicillin (n = 15) or alone (n = 1), in the clearing of bacterial colonization on the antrum in 16 children with Campylobacter pylori-associated antral gastritis. We also examined the effects of medical treatment on altering the severity of associated antral inflammation. Eight patients had upper gastrointestinal tract hemorrhage, two had acute gastric outlet obstruction, and 10 had symptoms of episodic epigastric abdominal pain. Duodenal ulcers were demonstrated in 10 of the 16 patients; in the other six, C. pylori-associated antral gastritis was documented without evidence of acute peptic ulceration. Seven days after a 6-week course of medical therapy, repeat upper endoscopy plus mucosal biopsy specimens showed that C. pylori colonization of the antrum had cleared in 12 of the 16 (75%) patients. Inflammation in the antrum improved in all patients in whom colonization by C. pylori was eradicated. In contrast, in the four with persistent colonization of the antrum, the severity of antral gastritis had not improved (p less than 0.01). Clinical symptoms improved in 9 of 12 patients in whom C. pylori colonization was no longer present, whereas subjective symptoms were unaffected in those with continued bacterial colonization of the antrum (p less than 0.05). We conclude that oral bismuth subsalicylate, in conjunction with ampicillin, can eradicate C. pylori colonization of the antrum, and that clearing of C. pylori is correlated with an improvement in the associated antral gastritis and clinical symptoms. These findings provide additional support for the hypothesis that these gastric organisms could play an etiologic role in primary antral gastritis and peptic ulcer disease.

Colloidal bismuth subcitrate. A review of its pharmacodynamic and pharmacokinetic properties, and its therapeutic use in peptic ulcer disease

Colloidal bismuth subcitrate (CBS) possesses at least equal efficacy with histamine H2-receptor antagonist drugs in the treatment of peptic ulcer disease. However, CBS has the advantage of slower ulcer relapse rates than those seen after initial healing with the H2-antagonists. It has been postulated that this effect may be partly due to the antibacterial properties of CBS against Campylobacter pylori, a bacterium found in the gastric mucosa and gastric metaplasia within the duodenum of most patients with peptic ulcer and closely associated with gastritis. However, the role of C. pylori in the aetiology of peptic disease is far from clear. The mechanism by which CBS heals ulcers has not been fully elucidated, but several actions may be involved. CBS and mucus form a glycoprotein-bismuth complex in vitro. This provides a diffusion barrier to HCl and may, therefore, provide a protective coating in the ulcer crater which allows healing of the lesion to occur. Prostaglandin E2 production is also stimulated by CBS with subsequent secretion of alkali into the mucus layer. In addition, CBS has a direct inhibitory effect on C. pylori. Administration of CBS results in low levels of bismuth absorption. Most of the ingested bismuth is excreted as bismuth sulphide, causing blackening of the faeces, and the small amount absorbed is excreted in the urine. Bismuth intoxication (encephalopathy) has been reported with prolonged administration of bismuth salts, and there has been 1 report of similar intoxication in a patient receiving unusually high doses of CBS for a prolonged period. However, no such intoxication has been reported with CBS used at its recommended dosage in the acute treatment of peptic ulcer disease, and no other serious adverse effects have been associated with CBS. Tissue accumulation during prolonged therapy seems likely, and the safety of CBS during long term maintenance therapy has not been established. The lack of effect on gastric acid secretion is seen as an added advantage for CBS, since prolonged drug-induced hypochlorhydria has been postulated to have potentially detrimental effects. Thus, while the role of C. pylori in peptic ulceration requires further clarification, CBS would appear to have an important place in the treatment of peptic ulcer disease with the advantage of relatively slow relapse rates after initial healing and treatment discontinuation.

Enzyme-linked immunosorbent assay for detection of immunoglobulin A and G antibodies to Campylobacter pylori

An enzyme-linked immunosorbent assay (ELISA) employing an acid-glycine extract was used to detect IgG and IgA antibodies to Campylobacter pylori in sera from 179 patients with upper gastrointestinal disease, 174 blood donors and 65 children. The incidence of positive ELISA results clearly increased with the severity of histopathologic findings in the antrum mucosa and was also high in patients with peptic ulcers and gastric cancer. The incidence in blood donors and children was much lower and increased with age. The results achieved with the ELISA were similar to those observed previously using the immunoblot method. Differences between whole cell preparation and acid-glycine extract with respect to their protein profiles and immunoblot reactivities were minor. IgM titres were very low and could not be related to histopathological findings, peptic lesions or culture findings. The ELISA may be particularly useful for monitoring the outcome of therapy aimed at eradication of Campylobacter pylori.

Prevention of nitroimidazole resistance in Campylobacter pylori by coadministration of colloidal bismuth subcitrate: clinical and in vitro studies

One hundred patients with duodenal ulceration and Campylobacter pylori in their stomach were entered into a double blind placebo controlled prospective study. Treatment schedules were cimetidine and placebo, or cimetidine and tinidazole, or colloidal bismuth subcitrate (CBS) and placebo, or CBS and tinidazole. Seventeen per cent of isolates of C pylori obtained at the first endoscopy were resistant to tinidazole and 70% of the second isolates from patients given cimetidine and tinidazole became tinidazole resistant. Suspensions of nitroimidazole sensitive cultures of C pylori showed that three of 22 isolates had a nitroimidazole resistant subpopulation. In patients who healed and remained free of C pylori after treatment ulcers recurred less often than in patients who healed but retained C pylori (23% v 73% over 12 months, p less than 0.001).

Bismuth is better

Healing of peptic ulcers with drugs which do not in the least interfere with intragastric acidity has only been described for colloidal bismuth subcitrate (CBS). Healing rates both for duodenal and gastric ulcer are comparable with those obtained with H2-receptor antagonists (HRA). Relapse after CBS healing seems less and delayed compared to HRA-induced healing.

Chronic erosive gastritis--a therapeutic approach with bismuth

37 patients with epigastric pain and chronic erosive gastritis underwent an open controlled therapeutic trial with bismuthsubsalicylate (BS). Group A (21 patients) was treated with BS, liquid, 4 X 314 mg for three weeks, group B (16 patients) with BS tablets, 3 X 300 mg for two weeks. A significant reduction of symptoms (p less than 0.001) and endoscopically assessed chronic erosions (p less than 0.001) was achieved in both groups. Campylobacter pylori was detected in 89% of the patients before treatment, but was absent in 78% of the patients after treatment. The histological grading of antral mucosa showed a significant reduction (p less than 0.001) of polymorphonuclear cell (PML) infiltration after two and three weeks treatment respectively. While in group A PML cells had disappeared from gastric mucosa in all but two patients, in group B 50% of the patients had some degree of PML cell infiltration left in the antral mucosa. This study confirms the beneficial effect of BS in the treatment of C. pylori associated active chronic gastritis and reemphasizes the pathogenetic role of C. pylori in this disease.

Campylobacter pylori

Worldwide Campylobacter pylori is a major cause of active chronic gastritis in man. This curved spiraled microorganism can readily be detected within the mucusgel especially in the antrum, in particular in patients suffering from peptic ulcer disease or non-ulcer dyspepsia, rarely in individuals with normal gastroduodenal mucosa. Increasingly arguments are being presented in support of a pathogenetic role of C. pylori in non-ulcer dyspepsia and in peptic ulcer disease. There is a striking discordance between in vitro antibiotic sensitivity, and in vivo efficacy with respect to suppression or eradication of the organism. At present the combination of colloidal bismuth subcitrate and amoxicilline or tinidazole appears to be encouraging with respect to longterm eradication of this peculiar microorganism. Eradication by antibacterial treatment ultimately may result in histologic normalization of the gastric mucosa. To what extent peptic ulcer disease. There is a striking discordance between in vitro antibiotic sensitivity, and in.

Bismuth: effects on gastritis and peptic ulcer

The healing properties of colloidal bismuth subcitrate (CBS) on peptic ulcer are well established and several studies have shown that healing with CBS is associated with a lower relapse rate than that produced by H2-receptor antagonists. The recent observation that CBS is effective against Campylobacter pylori has shed light on this because recent studies have shown that eradication of C. pylori by CBS leads to resolution of the associated gastritis and this may explain the low relapse rates. CBS is also effective in C. pylori positive patients with non ulcer dyspepsia (NUD) in whom clearance of these organisms from the stomach is associated with significant improvement of the associated gastritis and symptoms.