Conventional dose of omeprazole alters gastric flora

Prevalence and risk factors for Candida esophagitis among human immunodeficiency virus-negative individuals

BACKGROUND

Candida esophagitis (CE) is among the commonest esophageal infections and is known as an opportunistic fungal infection mostly affecting people living with the human immunodeficiency virus (HIV). However, some medical conditions might predispose HIV-negative individuals to esophageal candidiasis. The epidemiology and associated endoscopic findings of CE among people without HIV have rarely been reported.

AIM

To investigate the prevalence of CE among HIV-negative persons, and determine risk factors predicting CE.

METHODS

Between January 2015 and December 2018, all consecutive outpatients who underwent routine esophagogastroduodenoscopy as part of health check-ups at their own expense at the Health Check-up Center of the Kaohsiung Veterans General Hospital, Taiwan, were recruited in this study. Those with positive HIV serology results were excluded. Sociodemographic and clinical characteristics including age, gender, economic status, smoking history, alcohol consumption, tea and coffee consumption, underlying diseases, body fat percentage, body mass index, endoscopic findings, and Helicobacter pylori infection status were carefully reviewed. CE was confirmed by endoscopic biopsy and pathological assessment with hematoxylin and eosin and periodic acid-Schiff staining. To evaluate independent factors predicting the development of CE, we conducted a univariate analysis of clinical characteristics. The variables found to be significant via univariate analysis were subsequently included in a multivariable analysis of potential risk factors for CE development.

RESULTS

A total of 11802 participants were included in this study. Forty-seven (0.4%) were confirmed as having CE by pathological examination. Univariate analysis identified older age, the presence of chronic kidney disease, alcohol consumption, and steroid use (P = 0.023, < 0.001, 0.033, and 0.004, respectively) as significantly associated with CE. Multivariable analysis revealed older age [adjusted odds ratio (OR) = 1.027; 95%CI: 1.001-1.053; P = 0.045], chronic kidney disease (adjusted OR = 13.470; 95%CI: 4.574-39.673; P < 0.001), alcohol consumption (adjusted OR = 2.103; 95%CI: 1.151-3.844; P = 0.016), and steroid use (adjusted OR = 24.255; 95%CI: 5.343-110.115; P < 0.001) as independent risk factors for CE development. The presence of dysphagia was associated with severe CE (P = 0.021).

CONCLUSION

The prevalence of CE among HIV-negative persons was 0.4% in Taiwan. Independent risk factors for CE were older age, chronic kidney disease, alcohol consumption, and steroid use.

Beyond Helicobacter: dealing with other variants of gastritis-an algorithmic approach

In daily practice, the presence of inflammation in gastric biopsies prompts a mental algorithm, an early question being whether the lesion present is Helicobacter-associated. If Helicobacter organisms are not found, then there is a further algorithm, governed by the predominant type of inflammatory cells present, and the presence of other features such as intraepithelial lymphocytosis, a subepithelial collagen band, granulomas, coexisting chronic inflammation, focality, and superimposed reactive changes including erosions and ulcers. Each of these generates its own differential diagnosis. If no inflammation is present, then the two major changes specifically looked for are the changes associated with hypergastrinaemia, by far the most common cause of which is treatment with proton pump inhibitors, and reactive changes. These may be present with and without accompanying inflammation, and, when the epithelial changes dominate, the term gastropathy is preferred. In this article, we present an approach to non-Helicobacter inflammation and gastropathies.

Influence of microbiota on immunity and immunotherapy for gastric and esophageal cancers

Gastric and esophageal cancers are multifactorial and multistage-involved malignancy. While the impact of gut microbiota on overall human health and diseases has been well documented, the influence of gastric and esophageal microbiota on gastric and esophageal cancers remains unclear. This review will discuss the reported alteration in the composition of gastric and esophageal microbiota in normal and disease conditions, and the potential role of dysbiosis in carcinogenesis and tumorigenesis. This review will also discuss how dysbiosis stimulates local and systemic immunity, which may impact on the immunotherapy for cancer.

Predictors of esophageal candidiasis among patients attending endoscopy unit in a tertiary hospital, Tanzania: a retrospective cross-sectional study

Background

Esophageal candidiasis is a common disease among patients with impaired cell mediated immunity. In the current study, we report esophageal candidiasis among patients with various co-morbidities attending the endoscopic unit at the Bugando Medical Centre.

Methods

This retrospective study was conducted from June to September 2015. All data of the patients who attended the endoscopic unit between 2009 and 2014 were retrieved and analyzed.

Results

A total of 622 patients who underwent oesophagogastroduodenoscopy were analyzed. A slight majority 334/622(53.7%) of patients were female. Out of 622 patients; 35(5.6%) had esophageal candidiasis. Decrease in age (OR 1.1, 95%CI; 1.0–1.1), female sex (OR 3.8, 95%CI; 1.1–13.1), drinking alcohol (OR 17.1, 95%CI; 4.9–58.9), smoking (OR 8.3, 95%CI; 1.7–41.0), antibiotic use (OR 5.7, 95%CI; 2.0–16.4), positive HIV status (OR 10.3, 95%CI; 4.6–6.0) and presence of peptic ulcer disease (OR 13.2, 95%CI; 3.5–49.0) independently predicted esophageal candidiasis.

Conclusion

Patients with a history of drinking alcohol, smoking, use of antibiotics and those with chronic diseases such as peptic ulcers were at high risk of developing esophageal candidiasis. Further studies are needed to identify Candida spp. and their anti-fungal susceptibility for proper management of esophageal candidiasis in HIV and non-HIV individuals.

Acid suppressing therapy as a risk factor for Candida esophagitis

Studies were reviewed from PubMed for risk factors for the development, recurrence, prevention and therapy of Candida esophagitis, and for mechanisms induced by acid-suppressing therapy potentially influencing these factors. Documented observations included greatly increased Candida populations in the mouth, esophagus, stomach, and upper small intestine induced by acid-suppressing therapy. Among patients without HIV disease, PPI consumers more frequently had developed Candida esophagitis than did non-consumers and had also developed its recurrences more frequently. Similar phenomena associated with H2 -blocker use were less intense, and the possibility of similar phenomena in patients with HIV disease apparently had not yet been examined in spite of their high frequency of this disorder. PPI-induced elimination of the gastric acid barrier is a major mechanism leading to oro-pharyngeal and esophageal candida colonization, while PPI-induced impairment of absorption of most orally administered antifungal agents may limit the prophylactic and therapeutic success of these agents. These observations suggest potential value in limiting PPI use in populations of patients with Candida infections including esophagitis, as well as in patients at risk for their development, and also suggest that post-PPI rebound acid hypersecretion may provide additional anti-Candida benefit. Studies designed to develop the risk-benefit ratios of PPI use in these patients deserve investigation with high priority appropriate for studies in patients with HIV disease.

Epigastric Distress Caused by Esophageal Candidiasis in 2 Patients Who Received Sorafenib Plus Radiotherapy for Hepatocellular Carcinoma: Case Report

Sorafenib followed by fractionated radiotherapy (RT) has been shown to decrease the phagocytic and candidacidal activities of antifungal agents due to radiosensitization. Moreover, sorafenib has been shown to suppress the immune system, thereby increasing the risk for candida colonization and infection. In this study, we present the 2 hepatocellular carcinoma (HCC) patients suffered from epigastric distress caused by esophageal candidiasis who received sorafenib plus RT. Two patients who had received sorafenib and RT for HCC with bone metastasis presented with hiccups, gastric ulcer, epigastric distress, anorexia, heart burn, and fatigue. Empiric antiemetic agents, antacids, and pain killers were ineffective at relieving symptoms. Panendoscopy revealed diffuse white lesions in the esophagus. Candida esophagitis was suspected. Results of periodic acid-Schiff staining were diagnostic of candidiasis. Oral fluconazole (150 mg) twice daily and proton-pump inhibitors were prescribed. At 2-weak follow-up, esophagitis had resolved and both patients were free of gastrointestinal symptoms. Physicians should be aware that sorafenib combined with RT may induce an immunosuppressive state in patients with HCC, thereby increasing their risk of developing esophagitis due to candida species.

Fluconazole Resistant Candida Oesophagitis in Immunocompetent Patients: Is Empirical Therapy Justifiable?

INTRODUCTION

C. albicans (Candida albicans) is the foremost cause of fungal oesophagitis, however other species such as Candida tropicalis, Candida krusei and Candida stellatoidea have also been implicated to cause this condition. Although, numerous studies have identified risk factors for C. albicans oesophagitis, data for non- C. albicans species is still sparse.

AIM

To determine the aetiology of Candida oesophagitis in our medical centre over a two year period. Additionally, to investigate predisposing conditions for oesophageal candidiasis caused by different Candida species.

MATERIAL AND METHODS

All consecutive patients posted for upper gastrointestinal endoscopy at the endoscopy unit of a tertiary care hospital in north India with findings consistent with oesophagitis were screened for the presence of Candida oesophagitis by performing KOH (potassium hydroxide) examination and culture on SDA (Sabouraud's dextrose agar). Antifungal susceptibility testing as per CLSI guidelines was performed for fluconazole, a most common empirically prescribed antifungal for the condition.

RESULTS

A total of 1868 patients with no known immune-compromised condition underwent upper gastroscopy at our centre during the study period. The prevalence of Candida oesophagitis was 8.7% (n = 163). C. albicans was recovered from majority of infections (52.1%), followed by C. tropicalis (24%), C. parapsilosis (13.4%), C. glabrata (6.9%) and C. krusei (3.6%). Alarmingly, among the C. albicans isolates 8.6% were resistant to fluconazole.

CONCLUSION

With rising reports of antifungal drug resistance among the isolates of Candida species, an increasing prevalence of this organism could have an impact on the treatment of Candidal oesophagitis and it should be approached with caution by the clinician.

Relationship between clinical factors and severity of esophageal candidiasis according to Kodsi's classification

Severe Candida esophagitis (CE) may lead to development of strictures, hemorrhage, esophagotracheal fistula, and a consequent decrease in quality of life. Although the severity of CE has been classified based on macroscopic findings on endoscopy, the clinical significance remains unknown. The aim of the study was to elucidate the predictive clinical factors for endoscopic severity of CE. Patients who underwent upper endoscopy and answered questionnaires were prospectively enrolled. Smoking, alcohol, human immunodeficiency virus (HIV) infection, diabetes mellitus, chronic renal failure, liver cirrhosis, systemic steroids use, proton pump inhibitor use, H2 blocker use, and gastrointestinal (GI) symptoms were assessed on the same day of endoscopy. GI symptoms including epigastric pain, heartburn, reflux, hunger cramps, nausea, dysphagia, and odynophagia were assessed on a 7-point Likert scale. Endoscopic severity was classified as mild (Kodsi's grade I/II) or severe (grade III/IV). Of 1855 patients, 71 (3.8%) were diagnosed with CE (mild, n = 48; severe, n = 23). In the CE patients, 50.0% (24/48) in the mild group and 23.1% (6/23) in the severe group did not have any GI symptoms. In HIV-infected patients (n = 17), a significant correlation was found between endoscopic severity and declining CD4 cell count (Spearman's rho = -0.90; P < 0.01). Multivariate analysis revealed that GI symptoms (odds ratio [OR], 3.32) and HIV infection (OR, 3.81) were independently associated with severe CE. Patients in the severe group experienced more epigastric pain (P = 0.02), reflux symptoms (P = 0.04), dysphagia (P = 0.05), and odynophagia (P < 0.01) than those in the mild group. Of the GI symptoms, odynophagia was independently associated with severe CE (OR 9.62, P = 0.02). In conclusion, the prevalence of CE in adults who underwent endoscopy was 3.8%. Silent CE was found in both mild and severe cases. Endoscopic severity was associated with characteristic GI symptoms and comorbidity of HIV infection. A decline in immune function correlated with CE disease progression.

Gastric microbiota is altered in oesophagitis and Barrett's oesophagus and further modified by proton pump inhibitors

Gastro-oesophageal reflux can cause inflammation, metaplasia, dysplasia and cancer of the oesophagus. Despite the increased use of proton pump inhibitors (PPIs) to treat reflux, the incidence of oesophageal adenocarcinoma has increased rapidly in Europe and in the United States in the last 25 years. The reasons for this increase remain unclear. In this study, we aimed to determine whether the microbiota of the gastric refluxate and oesophageal biopsies differs between patients with heartburn and normal-appearing oesophageal mucosa versus patients with abnormal oesophageal mucosa [oesophagitis or Barrett's oesophagus (BE)] and to elucidate the effect of PPIs on the bacterial communities using 16S rRNA gene pyrosequencing. Significant differences in the composition of gastric fluid bacteria were found between patients with heartburn and normal oesophageal tissue versus patients with oesophagitis or BE, but in the oesophagus-associated microbiota differences were relatively modest. Notably, increased levels of Enterobacteriaceae were observed in the gastric fluid of oesophagitis and BE patients. In addition, treatment with PPIs had dramatic effects on microbial communities both in the gastric fluids and the oesophageal tissue. In conclusion, gastric fluid microbiota is modified in patients with oesophagitis and BE compared with heartburn patients with normal biopsies. Furthermore, PPI treatment markedly alters gastric and oesophageal microbial populations. Determining whether the changes in bacterial composition caused by PPIs are beneficial or harmful will require further investigation.

Acid suppression therapy as a risk factor for Candida esophagitis

BACKGROUND/AIM

As the prevalence of reflux esophagitis increases, so does the use of gastric acid suppressants. This study aimed to document the prevalence of Candida esophagitis (CE) at a single Korean university hospital over the last 5 years and to evaluate its risk factors.

METHODS

To investigate the prevalence of CE, we conducted a retrospective analysis of 55,314 individuals who underwent a screening esophagogastroduodenoscopy as part of a health check-up between January 2006 and December 2010 at Kyung Hee University Hospital in Seoul, Korea. A total of 250 patients who were treated for CE between January 2008 and August 2011 and 500 age- and sex-matched non-CE patients were enrolled in this study. The rates of recent gastric acid suppression therapy and other well-known risk factors in the two groups were compared.

RESULTS

The prevalence of CE was 0.35 % and increased each year (linear-by-linear association, P = 0.001). Univariate analysis showed that gastric acid suppression therapy, malignancy, DM and steroid therapy were related to CE. Multivariate analysis also showed that gastric acid suppression therapy (OR 5.11, 95 % CI 2.92-8.93 and P < 0.001), malignancy (OR 18.68, 95 % CI 6.37-54.75 and P < 0.001), DM (OR 2.67, 95 % CI 1.70-4.21 and P < 0.001) and steroids therapy (OR 6.74, 95 % CI 1.37-33.05 and P = 0.019) were related to CE.

CONCLUSIONS

The prevalence of CE in Korea is increasing. Also, our results indicate that acid suppression therapy is a meaningful risk factor for CE.

Prevalence and risk factors of esophageal candidiasis in healthy individuals: a single center experience in Korea

PURPOSE

Esophageal candidiasis (EC) is the most frequent opportunistic fungal infection in immunocompromised host. However, we have found EC in healthy individuals through esophagogastroduodenoscopy (EGD). The aim of this study was to determine the prevalence and risk factors for EC in healthy individuals.

MATERIALS AND METHODS

We retrospectively reviewed the medical records of 281 patients who had been incidentally diagnosed with EC. We also conducted age and sex matched case control study to identify the risk factor for EC.

RESULTS

The prevalence of EC was 0.32% (281/88125). The most common coexisting EGD finding was reflux esophagitis (49/281, 17.4%). An antifungal agent was prescribed in about half of EC, 139 cases (49.5%). Follow-up EGD was undertaken in 83 cases (29.5%) and 20 cases of candidiasis was persistently found. Case control study revealed EC were more often found in user of antibiotics (p=0.015), corticosteroids (p=0.002) and herb medication (p=0.006) as well as heavy drinking (p<0.001).

CONCLUSION

The prevalence of EC was 0.32% (281/88125) in Korea. Use of antibiotics, corticosteroids and herb as well as heavy drinking were significant risk factors for EC in healthy individuals.

Potential immunological consequences of pharmacological suppression of gastric acid production in patients with multiple sclerosis

Corticosteroids are standard treatment for patients with multiple sclerosis experiencing acute relapse. Because dyspeptic pain is a common side effect of this intervention, patients can be given a histamine receptor-2 antagonist, proton pump inhibitor or antacid to prevent or ameliorate this disturbance. Additionally, patients with multiple sclerosis may be taking these medications independent of corticosteroid treatment. Interventions for gastric disturbances can influence the activation state of the immune system, a principal mediator of pathology in multiple sclerosis. Although histamine release promotes inflammation, activation of the histamine receptor-2 can suppress a proinflammatory immune response, and blocking histamine receptor-2 with an antagonist could shift the balance more towards immune stimulation. Studies utilizing an animal model of multiple sclerosis indicate that histamine receptor-2 antagonists potentially augment disease activity in patients with multiple sclerosis. In contrast, proton pump inhibitors appear to favor immune suppression, but have not been studied in models of multiple sclerosis. Antacids, histamine receptor-2 antagonists and proton pump inhibitors also could alter the intestinal microflora, which may indirectly lead to immune stimulation. Additionally, elevated gastric pH can promote the vitamin B12 deficiency that patients with multiple sclerosis are at risk of developing. Here, we review possible roles of gastric acid inhibitors on immunopathogenic mechanisms associated with multiple sclerosis.

Benign post-esophagectomy gastrocardiac fistula

The development of a gastrocardiac fistula is a rare complication following retrosternal gastric conduit creation. We report a case of a 64-year-old male who presented three years after esophagectomy with massive hematemesis. A fistulous connection between his gastric conduit and right ventricle was identified and successfully treated. Although the patient had an atypical presentation and lacked most of the commonly cited risk factors, the combination of peptic ulcer disease and Candida overgrowth resulted in the formation of a gastrocardiac fistula. Adherence to treatment principles including prompt surgical intervention, adequate coverage of the repair, and antimicrobial therapy against Candida species provides the highest likelihood of success in addressing this potentially lethal disease process.

Candida esophagitis: species distribution and risk factors for infection

Although Candida albicans is the main cause of fungal esophagitis, other species such as C. tropicalis, C. krusei and C. stellatoidea have also been implicated. Several studies have identified risk factors for C. albicans esophagitis. However, data for non-C. albicans species is still sparse. The aim of this study was to determine the etiology of Candida esophagitis in our medical centre over an 18-month period. Additionally, we aimed to investigate predisposing conditions for esophageal candidosis caused by different Candida species. A total of 21,248 upper gastroscopies were performed in Santa Casa Complexo Hospitalar between January 2005 and July 2006. The prevalence of Candida esophagitis was 0.74% (n = 158). C. albicans caused the vast majority of infections (96.2%), followed by C. tropicalis (2.5%), C. lusitaniae (0.6%) and C. glabrata (0.6%). There were 81 women (51.3%) and 77 men (48.7%). No case of mixed infection occurred. Concomitant oral candidosis was documented for 10.8% (n = 17). Most of cases (55.1%) involved outpatients. Around one fifth of patients in our cohort had no identifiable risk factors for esophageal candidosis (20.8%). Since nearly all infections were caused by C. albicans we were not able to determine risk factors for esophagitis caused by other Candida species.

Proton pump inhibitors: actions and reactions

Proton pump inhibitors are the second most commonly prescribed drug class in the United States. The increased utilization of PPIs parallels the rising incidence of reflux disease. Owing to their clinical efficacy and relative lack of tachyphylaxis, PPIs have largely displaced H-2 receptor antagonists in the treatment of acid peptic disorders. The elevation of intragastric pH and subsequent alterations of gastric physiology induced by PPIs may yield undesired effects within the upper GI tract. The ubiquity of the various types of H(+), K(+)-ATPase could also contribute to non-gastric effects. PPIs may influence physiology in other ways, such as inducing transepithelial leak.

Oesophageal candidiasis in elderly patients: risk factors, prevention and management

This article reviews risk factors, prevention and management of oesophageal candidiasis (OC) in the elderly. Putative risk factors for OC in the elderly include old age itself, malignant disease, antibacterial and corticosteroid use, chronic obstructive pulmonary disease, acid suppression treatment, oesophageal dysmotility and other local factors, diabetes mellitus and HIV/AIDS. We have found evidence for a risk association between OC in the elderly and malignant disease (both haematological and non-haematological), antibacterial therapy and corticosteroid (including inhaled corticosteroids) use. We also found evidence of an association between OC in the elderly and oesophageal dysmotility or HIV/AIDS, but little direct evidence of an association between diabetes or old age per se. The literature on OC in the elderly is not large. The published series evaluating OC in this age group are small in size, often do not contain controls and mostly contain only limited information about the age of the patients. Prevention of OC is mainly the avoidance of exposure to the risk factors wherever possible. Specific measures such as highly active antiretroviral therapy in AIDS, prophylactic fluconazole when receiving chemotherapy for malignancy, using spacing devices, mouth rinsing soon after inhalation of corticosteroids and avoiding the use of cortiocosteroids just before bedtime are useful. OC is often responsive to a 2- to 3-week course of oral fluconazole, but resistance may be encountered in AIDS or in the presence of uncorrected anatomical factors in the oesophagus. Itraconazole solution, voriconazole or caspofungin may be used in refractory cases. Use of amphotericin B is restricted because of its narrow therapeutic index.

Vegetative Clostridium difficile survives in room air on moist surfaces and in gastric contents with reduced acidity: a potential mechanism to explain the association between proton pump inhibitors and C. difficile-associated diarrhea?

Proton pump inhibitors (PPIs) have been identified as a risk factor for Clostridium difficile-associated diarrhea (CDAD), though the mechanism is unclear because gastric acid does not kill C. difficile spores. We hypothesized that the vegetative form of C. difficile, which is killed by acid, could contribute to disease pathogenesis if it survives in room air and in gastric contents with elevated pH. We compared the numbers of C. difficile spores and vegetative cells in stools of patients prior to and during the treatment of CDAD. We assessed the survival of vegetative cells on moist or dry surfaces in room air versus anaerobic conditions and in human gastric contents, in pH-adjusted gastric contents, and in gastric contents from individuals receiving PPI therapy. Stool samples obtained from patients prior to the initiation of antibiotic treatment for C. difficile contained approximately 10-fold more vegetative cells than spores. On dry surfaces, vegetative C. difficile cells died rapidly, whereas they remained viable for up to 6 h on moist surfaces in room air. Vegetative C. difficile cells had only marginal survival in gastric contents at low pH; adjustment to a pH of >5 resulted in survival similar to that in the phosphate-buffered saline control. The survival of vegetative C. difficile in gastric contents obtained from patients receiving PPIs was also increased at a pH of >5. The ability of the vegetative form of C. difficile to survive on moist surfaces and in gastric contents with an elevated pH suggests a potential mechanism by which PPI therapy could increase the risk of acquiring C. difficile.

Gastric microbiota in elderly patients fed via nasogastric tubes for prolonged periods

Aspiration of oropharyngeal contents is a constant threat for elderly patients fed via a nasogastric tube (NGT). Colonization of the oropharynx of these patients by pathological flora and the development of biofilms on the feeding tube has been documented recently. In addition, the presence of the NGT may interfere with the gastro-oesophageal sphincter, leading to gastro-oesophageal reflux. Thus, the passage of pathogenic bacteria in both directions is facilitated. The purpose of this study was to explore the microbiota of the gastric juice and the oropharynx in NGT-fed elderly patients. Samples of gastric juice were drawn after an overnight fast, and microbial cultures and direct pH measurement were performed. Concomitant cultures were obtained from the oropharynx. Overall, 107 gastric and oropharyngeal cultures were obtained from 52 subjects. Pathogenic flora (Gram-negative bacteria or Staphylococcus aureus) were isolated from 74% of stomach samples and from 69% of oropharynx samples. Proteus spp. (26%) and Escherichia coli (22%) were the most common isolates in the gastric juice, and Proteus spp. (24%) and Pseudomonas spp. (21%) were the most common isolates in the oropharynx. Similarity in the composition of the oropharynx and gastric flora was observed in most cases. The gastric pH was relatively high (4.57 +/- 0.65 at 3 h after feeding and 4.2 +/- 0.9 at 12 h after feeding) and was highly correlated with the isolation of pathogenic bacteria (r = 0.58, P < 0.01). These results support the view that in addition to the oropharynx, the stomach of NGT-fed elderly patients constitutes a reservoir of pathogens that could be associated with the risk of aspiration pneumonia. The cause of the high gastric pH and its relation to pathogenic bacteria warrants further study.

Review article: physiologic and clinical effects of proton pump inhibitors on non-acidic and acidic gastro-oesophageal reflux

The control of oesophageal acid exposure through gastric acid inhibition, as the basis for gastro-oesophageal reflux disease (GERD) treatment, arose from the apparent pH dependency of erosive oesophagitis and relationship to GERD symptoms. The current perception is that reflux disease is an entirely acid-mediated condition, and antisecretory therapies, particularly proton pump inhibitors, are the treatment of choice for patients with erosive and non-erosive reflux disease. A positive patient response to an empiric trial of proton pump inhibitor (PPI) therapy, or the 'PPI test', is commonly suggested as a method of GERD diagnosis. Recent studies have modified our understanding of the relationship between oesophageal acid exposure and GERD pathology, manifestations and symptoms. Whereas the use of PPIs to reduce oesophageal acid exposure in patients with erosions is associated with increased healing rates, non-erosive reflux disease patients are less likely to have an abnormal oesophageal pH profile. Patterns of oesophageal acid exposure, particularly nocturnal oesophageal acid exposure, have been linked to increased disease severity. Non-acidic reflux and the effect of PPIs on this parameter, including bile reflux and the toxicity of bile acids, may also be an important factor in GERD. This article explores some of these assumptions, practices and relationships, including: the association between oesophageal acid exposure and erosive and non-erosive gastro-oesophageal reflux disease; the effect of PPIs on oesophageal acid exposure in erosive oesophagitis patients; the influence of nocturnal acid secretion in GERD and the use of PPIs to control this parameter; the relevance of the PPI test for reflux disease diagnosis; and PPI influence on non-acidic reflux.

Normalization of oesophageal pH does not guarantee control of duodenogastro-oesophageal reflux in Barrett's oesophagus

BACKGROUND

Proton-pump inhibitors are effective at preventing the acid component of gastro-oesophageal refluxate from entering the oesophagus. It is not clear whether proton-pump inhibitors prevent duodenogastro-oesophageal reflux.

AIM

To measure oesophageal exposure to duodenogastro-oesophageal refluxate while on proton-pump inhibitors in patients with Barrett's oesophagus.

METHODS

Twenty-five patients (23 male) with Barrett's oesophagus underwent 24 h oesophageal pH and Bilitec 2000 monitoring while on omeprazole 40 mg/day (n = 19) or omeprazole 60 mg/day (n = 6). All patients were undergoing argon plasma ablation of their Barrett's epithelium as part of a clinical trial and the Bilitec measurements were only carried out after the ablation had been completed.

RESULTS

20 of 25 (80%) patients had a normal oesophageal pH profile. Fifteen of the 25 (60%) had abnormal oesophageal exposure to bile as measured by Bilitec 2000. Of the 20 patients who had a normal 24 h oesophageal pH profile, 11 (55%) had pathological exposure to bile in their oesophagus.

CONCLUSION

Complete acid suppression does not guarantee elimination of duodenogastro-oesophageal reflux.

Influence of gastric colonization with Candida albicans on ulcer healing in rats: effect of ranitidine, aspirin and probiotic therapy

OBJECTIVE

Candida albicans frequently inhabits the gastrointestinal tract of humans leading to gastrointestinal candidiasis, especially following suppression of gastric acidity, but studies on the relation between this fungal infection and gastric pathology are limited due to lack of convenient animal models resembling Candida infection in humans. MATERIAL AND METHODS. We compared the effects of C. albicans and vehicle inoculation on gastric secretion and healing of gastric ulcers induced by acetic acid in rats treated with 1) ranitidine (30 mg kg(-1) day(-1) s.c.) and 2) aspirin (ASA) (60 mg kg(-1) day(-1) i.g.) with or without probiotic bacteria Lactobacillus acidophillus. At day 0 and at 4, 15 and 25 days after ulcer induction, the ulcer area, the gastric blood flow (GBF), the quantitative gastric cultures of Candida and the expression of mRNAs for pro-inflammatory cytokines IL-1beta and TNF-alpha and growth factors EGF and TGFalpha were assessed in the gastric mucosa.

RESULTS

Gastric acid output was reduced by over 40% soon after Candida inoculation and this effect persisted during all time intervals tested. The area of ulcers in control rats significantly decreased at day 15 and the ulcers disappeared almost completely after 25 days of their induction. In contrast, the ulcers were present until day 25 in Candida-inoculated rats followed by a fall in GBF and a rise in plasma gastrin levels, these effects being significantly attenuated by the co-treatment with Lactobacillus. Candidiasis was accompanied by up-regulation of mRNA for IL-1beta, TNF-alpha, EGF and TGFalpha and a significant increment in plasma IL-1beta and TNF-alpha levels.

CONCLUSIONS

1) Persistent colonization with Candida could be achieved in rats treated with antisecretory agents or non-steroidal anti-inflammatory drugs (NSAIDs) such as ASA; 2) candidiasis reduces gastric acid secretion, while delaying ulcer healing possibly due to the impairment in GBF in the ulcer area and enhanced expression and release of IL-1beta and TNFalpha and 3) probiotic therapy could be useful in the treatment against the deleterious action of fungal infection on the healing of pre-existing gastric ulcers.

Predisposing factors and clinical symptoms in HIV-negative patients with Candida oesophagitis: are they always present?

Candida oesophagitis (CO) is scarce among immunocompetent patients. This study aimed at evaluating predisposing factors, clinical symptoms and endoscopic findings in this group. We retrospectively reviewed 55 patients diagnosed as CO endoscopically (whitish plaques) and cytologically (fungal mycelia on brush cytology). Carcinoma, diabetes, acid suppression, steroids, gastric surgery and oesophageal motility disorders were considered as predisposing factors. Twenty of 55 patients lacked any predisposing factor for CO. These patients were more frequently asymptomatic (8/20) when compared with those with known predisposing factors (5/35) (p = 0.031). Moreover, dysphagia was more prevalent in the latter group (24/35 vs. 8/20; p = 0.039). Endoscopic findings correlated with the presence of neither predisposing factors nor symptoms (Wilcoxon p > 0.05). Thus, CO can be discovered in patients without apparent predisposing risk factors and clinical symptoms. Further studies are needed to elucidate the mechanisms of transition from colonisation to infection.

Clinical findings and risk factors for Candida esophagitis in outpatients

We retrospectively reviewed 18 patients with endoscopically discovered Candida esophagitis to more fully characterize this entity and identify predisposing conditions. Candida esophagitis was defined by the presence of fungal mycelia on brush cytology. Only two patients had an associated malignancy. Other possible predisposing risk factors were acid suppressive therapy (14 patients), prior gastric surgery (five), mucosal barrier injury (four), inhaled steroid use (four), oral steroid use (three), esophageal motility disorders (three), rheumatologic disorders (three), prior antibiotic use (two) and diabetes mellitus (two). The majority of patients had more than one proposed risk factor. Ten (56%) were treated with antifungal therapy. Thus, Candida esophagitis was infrequently seen in patients with associated malignancy. Prospective evaluation of predisposing conditions and treatment is recommended.

Enterococcus gastritis

Helicobacter pylori infection is the most common cause of gastritis with its associated sequelae. Gastritis secondary to other bacteria is rare. This report describes Enterococcus-associated gastritis in a 59-year-old diabetic man. Nine months after receiving treatment for H. pylori-associated gastritis, he underwent endoscopy to confirm H. pylori eradication and to evaluate the status of previously seen ulcers. Mucosal biopsy specimens revealed severe active but focal gastritis adjacent to gram-positive coccobacilli in short to long chains with no H. pylori. Culture grew an Enterococcus similar to E. hirae and E. durans. No treatment was given, and endoscopy done 2 months later showed complete resolution of the gastritis and absence of H. pylori or enterococci. Our patient's gastritis represents a previously undescribed manifestation of Enterococcus infection. It is possible that the presence of NSAID gastric mucosal injury and diabetes predisposed this individual to the development of transient Enterococcus gastritis.

Intragastric volatile N-nitrosamines, nitrite, pH, and Helicobacter pylori during long-term treatment with omeprazole

BACKGROUND & AIMS

This study evaluated the effect of long-term gastric acid suppressive therapy with omeprazole on intragastric levels of carcinogenic N-nitrosamines and related parameters.

METHODS

Forty-five patients on long-term omeprazole medication (mean, 35 months) and 13 healthy subjects without medication participated. Volatile N-nitrosamines were determined in gastric juice and urine. Intragastric pH, nitrite, nitrate, and H. pylori status were determined. DNA isolated from gastric biopsy specimens was analyzed for precarcinogenic alkyl-DNA adducts.

RESULTS

The intragastric pH in patients was significantly higher compared with controls (P = 0.0001). Gastric nitrite levels in patients were nonsignificantly higher. There was no difference in total levels of intragastric volatile N-nitrosamines between patients and controls, however, urinary N-nitrosodimethylamine excretion was higher in patients (P = 0.001). On omeprazole, Helicobacter pylori-positive vs. -negative patients had a nonsignificantly higher intragastric nitrite level and higher urinary N-nitrosodimethylamine excretion. No alkyl-DNA adducts could be detected in gastric epithelium.

CONCLUSIONS

Increased intragastric pH caused by long-term treatment with omeprazole does not result in increased intragastric levels of nitrite and volatile N-nitrosamines. The significantly higher urinary N-nitrosamine excretion implies the risk of increased endogenous formation of N-nitrosamines during long-term omeprazole treatment. This risk may be higher in H. pylori-positive patients.

Contamination of gastrostomy feeding systems in children in a home-based enteral nutrition program

BACKGROUND

There are few data concerning the risk of contamination of enteral feeding systems via gastrostomy in children, and none for conditions that pertain to home-based care.

METHODS

To investigate the risk of contamination of enteral feeding systems during the home-based care of 20 children receiving gastrostomy tube feeding, five samples were taken for analysis: two samples before the enteral feeding period (gastrostomy, enteral feeding system) and three after this period (gastrostomy, distal giving set, liquid remained in container). Microorganisms were identified and counted. Different factors were studied to elucidate their role in bacterial colonization: acid suppressive therapy, gastrostomy tube or button, hanging feeding time, rate of enteral feeding, gastric pullulation and retrograde contamination, manipulation error, and use of open or closed enteral feeding systems.

RESULTS

Overgrowth was defined as a microorganismal load exceeding 10(4) colony-forming units (cfu)/mL. Overgrowth was present in 85% of gastrostomy samples before enteral nutrition started. Most microorganisms belonged to gastric flora. Some bacteria had an environmental origin or derived from cutaneous flora. Forty-five percent of the lines showed overgrowth at the end of enteral nutrition period, mainly with the same microorganism found in the gastrostomy. Closed enteral bags remained sterile, even if manipulation error occurred. Duration, rate of enteral feeding, and acid suppression treatment were not risk factors for overgrowth.

CONCLUSIONS

Retrograde contamination of gastrostomy feeding systems occurs frequently. The preferential use of closed enteral feeding systems is recommended for home-based enteral nutrition programs.

Gastric mucosal morphological consequences of acid suppression: a balanced view

In the chapter, an analysis of the literature on the relationship between Helicobacter pylori, the use of proton pump inhibitors and the development of atrophic gastritis is presented, and the difficulties of classifying gastritis and the new possibilities of quantifying chronic inflammation by morphometric analysis are discussed. The issue surrounding the necessity of eradicating H. pylori in H. pylori-positive patients has still not been solved. Most studies have now accepted that proton pump inhibitors indeed accelerate the onset of atrophic gastritis in H. pylori-positive patients, but evidence against such an association was published in one recent (Scandinavian) study; conclusions from this study have, however, been challenged by several groups. Some data are available on the efficacy of H. pylori eradication with regard to the prevention of atrophy. The limited significance of the development of parietal cell protrusions and fundic gland cysts is better understood, but much less is known of the development and long-term consequence of H. pylori-induced autoimmune gastritis. Finally, recent studies in H. pylori-positive patients indicate that treatment with proton pump inhibitors may promote bacterial N-nitrosation formation. These data taken together suggest that the eradication of H. pylori may be based not only on morphological arguments, but also on bacterial alterations in the gastric milieu.

Non-Helicobacter pylori bacterial flora during acid-suppressive therapy: differential findings in gastric juice and gastric mucosa

BACKGROUND

Intragastric growth of non-Helicobacter pylori bacteria commonly occurs during acid-suppressive therapy. The long-term clinical consequences are still unclear.

AIM

To investigate the luminal and mucosal bacterial growth during gastric acid inhibition, in relation to the type and duration of acid-inhibitory treatment, as well as to concomitant H. pylori infection.

METHODS

A total of 145 patients on continuous acid inhibition with either proton pump inhibitors (n=109) or histamine2-receptor antagonists (H(2)RAs, n=36) for gastro-oesophageal reflux disease, and 75 dyspeptic patients without acid inhibition (control group) were included. At endoscopy, fasting gastric juice was obtained for pH measurement and bacteriological culture. Gastric biopsy specimens were examined for detection of H. pylori (immunohistochemistry) and of non-H. pylori bacteria (modified Giemsa stain-positive and immunohistochemistry-negative at the same location).

RESULTS

Non-H. pylori flora was detected in the gastric juice of 92 (41.8%) patients and in the gastric mucosa of 109 (49.6%) patients. In gastric juice, prevalence rate for non-H. pylori bacteria was higher in patients taking proton pump inhibitors than controls and those taking H(2)RAs (58.7% vs. 22.6% and vs. 30.6%, P < 0.0001 and P < 0.003, respectively), but did not differ statistically between H(2)RAs and controls. In gastric mucosa, prevalence rates for non-H. pylori bacteria were higher in patients taking proton pump inhibitors and H(2)RAs than in the controls (antrum: 46.9% and 48.6% vs. 25%, P < 0.05 for both; corpus: 52.2% and 56.8% vs. 23.7%, P < 0.001 for both), but did not differ between proton pump inhibitors and H(2)RAs. Both luminal and mucosal growth of non-H. pylori bacteria were significantly greater in H. pylori-positive than -negative patients taking proton pump inhibitors (P < 0.05 for both). Luminal growth of non-H. pylori flora increased with the intragastric pH level, whilst mucosal bacterial growth increased with the duration of acid inhibition.

CONCLUSIONS

Non-H. pylori flora not only contaminates the gastric juice but also colonizes the gastric mucosa of a large proportion of patients treated long-term with acid inhibition. The relationship between H. pylori and non-H. pylori bacteria in the pathogenesis of atrophic gastritis and gastric cancer needs further elucidation.

The prescribing of acid suppressants prior to the endoscopic diagnosis of Barrett's oesophagus and oesophagitis

BACKGROUND

There has been a dramatic rise in incidences of Barrett's oesophagus and oesophageal adenocarcinoma. It has been suggested that the introduction and use of acid suppression therapy may be a factor in the rising incidences of Barrett's oesophagus and oesophageal adenocarcinoma.

METHODS

This was a record linkage study, using a prescribing database and an endoscopy database. Patients who had undergone their first endoscopy during the period 1992-1995 and received the diagnosis of Barrett's oesophagus or oesophagitis were identified. The prescribing of acid suppressants was compared for the 3 years prior to endoscopy, between those with Barrett's oesophagus and those with oesophagitis.

RESULTS

There was no significant difference between the Barrett's patients and the oesophagitis patients in the proportion that had been exposed to acid suppression therapy (53.4% vs. 51.7%, P=0.704). The mean number of days of prescribing among those who had been exposed to acid suppression therapy was higher in the Barrett's group (340.5 vs. 237.0 days, P=0.001).

CONCLUSIONS

Patients with Barrett's oesophagus have received more acid suppressant therapy prior to diagnosis. The reasons for this are not clear. However, 46.6% of Barrett's patients have not been exposed to acid suppressant therapy.

Bacterial colonization and healing of gastric ulcers: the effects of epidermal growth factor

Experimental gastric ulcers are rapidly colonized by various bacteria, resulting in significantly impaired healing. Epidermal growth factor (EGF) is capable of preventing bacterial colonization of the healthy intestinal mucosa. In this study, we examined the possibility that EGF accelerates gastric ulcer healing by reducing bacterial colonization of the ulcer. Gastric ulcers were induced by serosal application of acetic acid. The effect of daily administration of EGF on ulcer healing and bacterial colonization was assessed and compared with the effect of daily treatment with broad-spectrum antibiotics. EGF administration reduced colonization levels and accelerated ulcer healing as effectively as the antibiotic treatment. EGF was without effect on acid secretion or neutrophil infiltration into the ulcer. Bacterial growth was not inhibited in the presence of EGF in vitro. These results demonstrate that EGF reduces bacterial colonization during an established infection of a compromised mucosal surface. This effect may contribute to the ability of EGF to accelerate gastric ulcer healing. This effect is acid independent and not due to an anti-inflammatory effect or to direct bactericidal actions.

Biology of gastroesophageal reflux disease: pathophysiology relating to medical and surgical treatment

This chapter reviews the biology of gastroesophageal reflux disease, relating pathophysiology to medical and surgical therapy. Various definitions of the disease are presented and workable criteria are developed to identify patients with the disease. The central importance of the lower esophageal high-pressure zone as a barrier to reflux is emphasized, along with an analysis of its biomechanical alteration in disease. The composition of the refluxed gastric juice is characterized in regard to its potential for mucosal injury. Evidence is provided that cardiac-type mucosa is an acquired sequel to acid-induced squamous mucosal injury in the terminal esophagus. A hypothesis regarding the process of intestinalization of cardiac-type mucosa to form Barrett's esophagus is presented. An integrated concept of the pathophysiology of gastroesophageal reflux disease is constructed. Practical concepts regarding the treatment of gastroesophageal reflux disease are developed, based on a review of studies on the natural history of the disease and the long-term outcome of therapy.