Proton pump inhibitor use and the risk of small intestinal bacterial overgrowth: a meta-analysis

Proton Pump Inhibitors: Review of Emerging Concerns

First introduced in 1989, proton pump inhibitors (PPIs) are among the most widely utilized medications worldwide, both in the ambulatory and inpatient clinical settings. The PPIs are currently approved by the US Food and Drug Administration for the management of a variety of gastrointestinal disorders including symptomatic peptic ulcer disease, gastroesophageal reflux disease, and nonulcer dyspepsia as well as for prevention of gastrointestinal bleeding in patients receiving antiplatelet therapy. PPIs inhibit gastric acid secretion, and the most commonly associated adverse effects include abdominal pain, diarrhea, and headache. Although PPIs have had an encouraging safety profile, recent studies regarding the long-term use of PPI medications have noted potential adverse effects, including risk of fractures, pneumonia, Clostridium difficile diarrhea, hypomagnesemia, vitamin B₁₂ deficiency, chronic kidney disease, and dementia. These emerging data have led to subsequent investigations to assess these potential risks in patients receiving long-term PPI therapy. However, most of the published evidence is inadequate to establish a definite association between PPI use and the risk for development of serious adverse effects. Hence, when clinically indicated, PPIs can be prescribed at the lowest effective dose for symptom control.

Proton Pump Inhibitors Independently Protect Against Early Allograft Injury or Chronic Rejection After Lung Transplantation

BACKGROUND

Acid reflux has been associated with poor outcomes following lung transplantation. Unlike surgical fundoplication, the role of noninvasive, pharmacologic acid suppression remains uncertain.

AIMS

To assess the relationship between post-transplant acid suppression with proton pump inhibitors (PPI) or histamine-2 receptor antagonists (H2RA) and onset of early allograft injury or chronic rejection following lung transplantation.

METHODS

This was a retrospective cohort study of lung transplant recipients at a tertiary center in 2007-2014. Patients with pre-transplant antireflux surgery were excluded. Time-to-event analysis using the Cox proportional hazards model was applied to assess acid suppression therapy and onset of acute or chronic rejection, defined histologically and clinically. Subgroup analyses were performed to assess PPI versus H2RA use.

RESULTS

A total of 188 subjects (60% men, mean age 54, follow-up 554 person-years) met inclusion criteria. During follow-up, 115 subjects (61.5%) developed rejection, with all-cause mortality of 27.6%. On univariate analyses, acid suppression and BMI, but not other patient demographics, were associated with rejection. The Kaplan-Meier curve demonstrated decreased rejection with use of acid suppression therapy (log-rank p = 0.03). On multivariate analyses, acid suppression (HR 0.39, p = 0.04) and lower BMI (HR 0.67, p = 0.04) were independently predicted against rejection. Subgroup analyses demonstrated that persistent PPI use was more protective than H2RA or no antireflux medications.

CONCLUSIONS

Post-lung transplant exposure to persistent PPI therapy results in the greatest protection against rejection in lung transplant recipients, independent of other clinical predictors including BMI, suggesting that PPI may have antireflux or anti-inflammatory effects in enhancing allograft protection.

Is It Useful to Administer Probiotics Together With Proton Pump Inhibitors in Children With Gastroesophageal Reflux?

Background/Aims

Gastroesophageal reflux disease (GERD) is a frequent condition diagnosed in children and treated with proton pump inhibitors (PPI). Long-term PPI administration can alter intestinal bacterial population by suppressing the gastric acid barrier and may cause diarrhea. The aim of this study is to evaluate the prevalence of small intestinal bacterial overgrowth assessed by glucose hydrogen breath test among children that received 12 weeks of PPI with or without probiotics (Lactobacillus reuteri DSM 17938) associated, compared to controls.

Methods

Glucose hydrogen breath test was performed before PPI treatment and after 12 weeks of PPI treatment to 128 consecutive children with GERD (1–18 years old) and a control group (120 healthy children). The children with GERD were randomized into 2 groups: placebo group (64 who received PPI and placebo for 12 weeks) and probiotics group (64 who received PPI and probiotics for 12 weeks).

Results

After 12 weeks of treatment, dysbiosis was detected among 56.2% of children from placebo group (36/64), compared to 6.2% of children from the probiotics group (4/64, P < 0.001). Bacterial overgrowth was detected in 5% of controls (6/120). Probiotics group had a lower prevalence of dysbiosis, similar to controls (P = 0.740).

Conclusion

Probiotics administration decreased the rate of dysbiosis among children treated with PPI.

Acid-Suppressive Therapy and Risk of Infections: Pros and Cons

This narrative review summarises the benefits, risks and appropriate use of acid-suppressing drugs (ASDs), proton pump inhibitors and histamine-2 receptor antagonists, advocating a rationale balanced and individualised approach aimed to minimise any serious adverse consequences. It focuses on current controversies on the potential of ASDs to contribute to infections-bacterial, parasitic, fungal, protozoan and viral, particularly in the elderly, comprehensively and critically discusses the growing body of observational literature linking ASD use to a variety of enteric, respiratory, skin and systemic infectious diseases and complications (Clostridium difficile diarrhoea, pneumonia, spontaneous bacterial peritonitis, septicaemia and other). The proposed pathogenic mechanisms of ASD-associated infections (related and unrelated to the inhibition of gastric acid secretion, alterations of the gut microbiome and immunity), and drug-drug interactions are also described. Both probiotics use and correcting vitamin D status may have a significant protective effect decreasing the incidence of ASD-associated infections, especially in the elderly. Despite the limitations of the existing data, the importance of individualised therapy and caution in long-term ASD use considering the balance of benefits and potential harms, factors that may predispose to and actions that may prevent/attenuate adverse effects is evident. A six-step practical algorithm for ASD therapy based on the best available evidence is presented.

Proton pump inhibitors are associated with accelerated development of cirrhosis, hepatic decompensation and hepatocellular carcinoma in noncirrhotic patients with chronic hepatitis C infection: results from ERCHIVES

BACKGROUND

Proton pump inhibitors are among the most commonly prescribed medications in the United States. Their safety in cirrhosis has recently been questioned, but their overall effect on disease progression in noncirrhotic patients with chronic liver disease remains unclear.

AIM

To determine the impact of proton pump inhibitors on the progression of liver disease in noncirrhotic patients with hepatitis C virus (HCV) infection.

METHODS

Using the electronically retrieved cohort of HCV-infected veterans (ERCHIVES) database, we identified all subjects who received HCV treatment and all incident cases of cirrhosis, hepatic decompensation and hepatocellular carcinoma. Proton pump inhibitor use was measured using cumulative defined daily dose. Multivariate Cox regression analysis was performed after adjusting univariate predictors of cirrhosis and various indications for proton pump inhibitor use.

RESULTS

Among 11 526 eligible individuals, we found that exposure to proton pump inhibitors was independently associated with an increased risk of developing cirrhosis (hazard ratio [HR]: 1.32; 95% confidence interval: [1.17, 1.49]). This association remained robust to sensitivity analysis in which only patients who achieved sustained virologic response were analysed as well as analysis excluding those with alcohol abuse/dependence. Proton pump inhibitor exposure was also independently associated with an increased risk of hepatic decompensation (HR: 3.79 [2.58, 5.57]) and hepatocellular carcinoma (HR: 2.01 [1.50, 2.70]).

CONCLUSIONS

In patients with chronic HCV infection, increasing proton pump inhibitor use is associated with a dose-dependent risk of progression of chronic liver disease to cirrhosis, as well as an increased risk of hepatic decompensation and hepatocellular carcinoma.

Meta-analysis: proton pump inhibitors moderately increase the risk of small intestinal bacterial overgrowth

The use of proton pump inhibitors (PPIs) may potentially predispose to the development of small intestinal bacterial overgrowth (SIBO), but this association is controversial due to conflicting results from studies conducted to date. The aim of this meta-analysis was to evaluate the association between the use of PPIs and the risk of SIBO. We systematically searched the online PubMed, Embase, and Cochrane Library databases and Web of Science for relevant articles published up to November 2016. Two researchers identified and extracted data independent of each other. The pooled analysis was performed using the generic inverse-variance random-effects model. Subgroup and sensitivity analysis were conducted to assess the stability and heterogeneity of the pooled results. The risk of publication bias was evaluated by assessing for funnel plot asymmetry and by Egger's test and Begg's test. A total of 19 articles met the eligibility criteria for the meta-analysis, reporting on 7055 subjects. The pooled odds ratio (OR) showed a statistically significant association between increased risk of SIBO and PPI use (OR 1.71, 95% confidence interval 1.20-2.43). Subgroup analyses demonstrated an association between SIBO and PPI use in studies that employed small bowel aspirates culture and glucose hydrogen breath tests (GHBT) as diagnostic tests for SIBO. Our meta-analysis suggests that the use of PPI moderately increases the risk of SIBO, thereby highlighting the need for appropriate prescribing of PPIs.

Influence of proton pump inhibitors in the development of spontaneous bacterial peritonitis

AIM

To investigate whether the use of proton pump inhibitors (PPIs) increases the incidence of spontaneous bacterial peritonitis (SBP) in patients with cirrhosis and ascites.

METHODS

An historical cohort study was carried out in cirrhotic outpatients with ascites followed in a specialized clinic at a tertiary hospital in Southern Brazil. Patient charts were reviewed to collect information on the variables of interest as the use of PPIs. Primary outcome was defined as development of SBP during the study period. SBP was diagnosed based on ascitic fluid polymorphonuclear cell count ≥ 250 cells/mm³ without evidence of an intra-abdominal, surgically treatable source of infection.

RESULTS

Of 738 cirrhotic patients, 582 (58.2% male) were enrolled, with mean age of 53.6 ± 12 years. Hepatitis C virus infection (36.2%) and alcohol abuse (25.6%) were the main etiologies of cirrhosis. The presence of ascites was detected in 299 (51.4%) patients during the development of the study. Nineteen patients with previous diagnosis of SBP undergoing secondary prophylaxis and 22 patients with insufficient PPI data were further excluded. Of 258 patients with ascites, 151 used PPIs, and 34 developed SBP (22.5%). Among 107 non-users of PPIs, 23 developed SBP (21.5%) (HR = 1.44, 95%CI: 0.85-2.47, P = 0.176). The median follow-up time of patients using PPI was 27 mo vs 32 mo for non-users. Univariate analysis of the risk factors associated with the development of SBP revealed a significant association of SPB with the severity of liver disease according to the Child-Turcotte-Pugh (CTP) score. Multivariate analysis confirmed that CTP score was the only independent variable influencing the occurrence of SBP. Survival at 60 mo (Kaplan-Meier analysis) was similar in users and non-users of PPI, independently of the presence of SBP (58.4% vs 62.7% respectively, P = 0.66). For patients with SBP, survival at 60 mo was 55.1%, vs 61.7% in patients without SBP (P = 0.34).

CONCLUSION

In conclusion, the rate of SBP was not significantly different in users or non-users of PPIs in this cohort of cirrhotic with ascites.

Protective effect of coptisine free base on indomethacin-induced gastric ulcers in rats: Characterization of potential molecular mechanisms

AIMS

The aim of this study was to comparatively investigate the potential gastroprotective effect and underlying mechanisms of coptisine free base (CFB, 8-hydroxy-7, 8-dihydrocoptisine), berberine and lansoprazole against indomethacin-induced gastric ulcer in rats.

MATERIALS AND METHODS

CFB (10, 20 and 40mg/kg), berberine (20mg/kg) and lansoprazole (30mg/kg) were orally administrated to rats prior to indometacin ingestion, and gastric lesions were evaluated macroscopically and histologically, and further analyzed by ELISA, qRT-PCR and Western blot.

KEY FINDINGS

CFB exerted comparable or superior gastroprotective effect to berberine in protecting against indomethacin-induced gastric injury. CFB pretreatment significantly enhanced the levels of superoxide dismutase (SOD) and glutathione (GSH), and markedly decreased the malonaldehyde (MDA) content. CFB administration effectively suppressed the levels of myeloperoxidase (MPO), interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α) and angiotensin II (Ang II). Besides, CFB substantially up-regulated the mRNA expressions of cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2), and promoted gastric mucosal prostaglandin E₂ level (PGE₂). Furthermore, CFB pretreatment remarkably increased the translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) from cytosol into the nucleus, and the expression of heme oxygenase-1 (HO-1), while significantly decreased the expression of mitogen activated protein Kinase Kinase 6 (MKK6) and translocation of p38 mitogen-activated protein kinase (p38 MAPK).

SIGNIFICANCE

This was the first investigation reporting the anti-ulcer effect of protoberberine alkaloid free base on in vivo rodent model. The gastroprotective mechanism of CFB might involve favorable regulation of antioxidant and anti-inflammatory status mediated, at least partially, by the Nrf2 signaling pathway and p38 MAPK translocation.

Proton-pump inhibitors: understanding the complications and risks

Proton-pump inhibitors (PPIs) are the most effective therapy for the full spectrum of gastric-acid-related diseases. However, in the past decade, a steadily increasing list of complications following long-term use of PPIs has been reported. Their potent acid-suppressive action induces several structural and functional changes within the gastric mucosa, including fundic gland polyps, enterochromaffin-like cell hyperplasia and hypergastrinaemia, which can be exaggerated in the presence of Helicobacter pylori infection. As discussed in this Review, most associations of PPIs with severe adverse events are not based on sufficient evidence because of confounding factors and a lack of plausible mechanisms. Thus, a causal relationship remains unproven in most associations, and further studies are needed. Awareness of PPI-associated risks should not lead to anxiety in patients but rather should induce the physician to consider the appropriate dosing and duration of PPI therapy, including long-term monitoring strategies in selected groups of patients because of their individual comorbidities and risk factors.

The relationship between non-alcoholic fatty liver disease and small intestinal bacterial overgrowth among overweight and obese children and adolescents

BACKGROUND

The increasing rate of obesity and overweight among children has highlighted nonalcoholic fatty liver disease (NAFLD) as the most common cause of chronic pediatric liver diseases. There are many publications supporting the idea that gut microbiota is altered in NAFLD. The aim of this study was to evaluate the prevalence of NAFLD among overweight and obese children with and without small intestinal bacterial overgrowth (SIBO) compared to a control group and to assess if intestinal dysbiosis represents a risk factor for NAFLD.

METHODS

One hundred and twenty-five overweight and obese children aged 10-18 years and 120 controls matched for age and gender were enrolled. SIBO was assessed by glucose hydrogen breath test (GHBT) in all subjects. NAFLD was assessed in all children using abdominal imaging and laboratory findings.

RESULTS

Of 125 obese children enrolled, 47 (37.6%) presented intestinal dysbiosis and 78 (62.4%) were SIBO negative. Only four (3.3%) controls were SIBO positive. NAFLD was detected in 28/47 (59.5%) of the SIBO positive obese group, compared to 8/78 (10.2%) of the SIBO negative obese group (p<0.001) and 0/120 (0%) controls (p<0.001). Children from the SIBO positive obese group had higher rates of elevated aminotransferases levels: aspartate aminotransferases (ASAT) (53.1% vs. 6.4%; p<0.001) and alanine aminotransferase (ALAT) (59.5% vs. 7.6%; p<0.001), hypertension (23.4% vs. 5.1%; p=0.002) and metabolic syndrome (44.6% vs. 9%; p=0.002) compared to the SIBO negative obese group.

CONCLUSIONS

Obese children with SIBO have an increased risk for developing NAFLD. The relationship between intestinal dysbiosis and diet can influence the gut-liver axis.

From clinical uncertainties to precision medicine: the emerging role of the gut barrier and microbiome in small bowel functional diseases

Over the last decade, remarkable progress has been made in the understanding of disease pathophysiology. Many new theories expound on the importance of emerging factors such as microbiome influences, genomics/omics, stem cells, innate intestinal immunity or mucosal barrier complexities. This has introduced a further dimension of uncertainty into clinical decision-making, but equally, may shed some light on less well-understood and difficult to manage conditions. Areas covered: Comprehensive review of the literature on gut barrier and microbiome relevant to small bowel pathology. A PubMed/Medline search from 1990 to April 2017 was undertaken and papers from this range were included. Expert commentary: The scenario of clinical uncertainty is well-illustrated by functional gastrointestinal disorders (FGIDs). The movement towards achieving a better understanding of FGIDs is expressed in the Rome IV guidelines. Novel diagnostic and therapeutic protocols focused on the GB and SB microbiome can facilitate diagnosis, management and improve our understanding of the underlying pathological mechanisms in FGIDs.

Proton Pump Inhibitors in Gastroesophageal Reflux Disease: Friend or Foe

PURPOSE OF REVIEW

Proton pump inhibitor (PPI) use in gastroesophageal reflux disease (GERD) has been redefined, in light of recent advances highlighting GERD phenotypes that respond to PPIs, and fresh revelations of potential risks of long-term PPI therapy.

RECENT FINDINGS

Erosive esophagitis predicts excellent response to PPI therapy, but non-erosive reflux disease (NERD) with abnormal reflux parameters on ambulatory reflux monitoring also demonstrates a similar response. In contrast, response is suboptimal in the absence of abnormal reflux parameters. In this setting, if an alternate appropriate indication for PPI therapy does not coexist, risks may outweigh benefits of PPI therapy. Adverse events from long-term PPI therapy continue to be reported, most based on association rather than cause-and-effect. Appropriate indications need to be established before embarking on long-term PPI therapy. Future research will define true risks of long-term PPI therapy, and develop alternate management options for acid peptic diseases.

25 Years of Proton Pump Inhibitors: A Comprehensive Review

Proton pump inhibitors (PPIs) were clinically introduced more than 25 years ago and have since proven to be invaluable, safe, and effective agents for the management of a variety of acid-related disorders. Although all members in this class act in a similar fashion, inhibiting active parietal cell acid secretion, there are slight differences among PPIs relating to their pharmacokinetic properties, metabolism, and Food and Drug Administration (FDA)-approved clinical indications. Nevertheless, each is effective in managing gastroesophageal reflux disease and uncomplicated or complicated peptic ulcer disease. Despite their overall efficacy, PPIs do have some limitations related to their short plasma half-lives and requirement for meal-associated dosing, which can lead to breakthrough symptoms in some individuals, especially at night. Longer-acting PPIs and technology to prolong conventional PPI activity have been developed to specifically address these limitations and may improve clinical outcomes.

The Gastric and Intestinal Microbiome: Role of Proton Pump Inhibitors

PURPOSE OF REVIEW

The discovery of Helicobacter pylori and other organisms colonizing the stomach and the intestines has shed some light on the importance of microbiome in maintaining overall health and developing pathological conditions when alterations in biodiversity are present. The gastric acidity plays a crucial role in filtering out bacteria and preventing development of enteric infections. In this article, we discuss the physiology of gastric acid secretion and bacterial contribution to the composition of gastric and intestinal barriers and review the current literature on the role of proton pump inhibitors (PPIs) in the microbial biodiversity of the gastrointestinal tract.

RECENT FINDINGS

Culture-independent techniques, such as 16S rRNA sequencing, have revolutionized our understanding of the microbial biodiversity in the gastrointestinal tract. Luminal and mucosa-associated microbial populations are not identical. Streptococcus is overrepresented in the biopsies of patients with antral gastritis and may also be responsible for the development of peptic ulcer disease. The use of PPIs favors relative streptococcal abundance irrespective of H. pylori status and may explain the persistence of dyspeptic symptoms in patients on PPI therapy. Increased risk of enteric infections has also been seen in patients taking PPIs. The overuse of PPIs leads to significant shift of the gastrointestinal microbiome towards a less healthy state. With the advent of PPIs, many studies have demonstrated the significant changes in the microbial composition of both gastric and intestinal microbiota. Although they are considered relatively safe over-the-counter medications, PPIs in many cases are over- and even inappropriately used. Future studies assessing the safety of PPIs and their role in the development of microbiome changes should be encouraged.

The Benefits of Combination Therapy with Esomeprazole and Rebamipide in Symptom Improvement in Reflux Esophagitis: An International Multicenter Study

Background/Aims

To investigate the effects of esomeprazole and rebamipide combination therapy on symptomatic improvement in patients with reflux esophagitis.

Methods

A total of 501 patients with reflux esophagitis were randomized into one of the following two treatment regimens: 40 mg esomeprazole plus 300 mg rebamipide daily (combination therapy group) or 40 mg esomeprazole daily (monotherapy group). We used a symptom questionnaire that evaluated heartburn, acid regurgitation, and four upper gastrointestinal symptoms. The primary efficacy end point was the mean decrease in the total symptom score.

Results

The mean decreases in the total symptom score at 4 weeks were estimated to be -18.1±13.8 in the combination therapy group and -15.1±11.9 in the monotherapy group (p=0.011). Changes in reflux symptoms from baseline after 4 weeks of treatment were -8.4±6.6 in the combination therapy group and -6.8±5.9 in the monotherapy group (p=0.009).

Conclusions

Over a 4-week treatment course, esomeprazole and rebamipide combination therapy was more effective in decreasing the symptoms of reflux esophagitis than esomeprazole monotherapy.

Impact of Long-Term Proton Pump Inhibitor Therapy on Gut Microbiota in F344 Rats: Pilot Study

Background/Aims

To evaluate changes in gut microbiota composition following long-term proton pump inhibitor (PPI) treatment.

Methods

Twenty-four-week-old F344 rats were fed diets with (n=6) or without (n=5) lansoprazole for 50 weeks. Profiles of luminal microbiota in the terminal ileum were then analyzed. Pyrosequencing of the 16S rRNA gene was performed using an FLX genome sequencer (454 Life Sciences/Roche).

Results

Rats treated with lansoprazole showed significantly reduced body weights compared to controls (lansoprazole-treated rats and controls, 322.3±15.3 g vs 403.2±5.2 g, respectively, p<0.001). However, stool frequencies and consistencies did not differ between the two groups. The composition of the gut microbiota in lansoprazole-treated rats was quite different from that of the controls. In the controls, the microbiota profiles obtained from the terminal ileum showed a predominance of Proteobacteria (93.9%) due to the abundance of Escherichia and Pasteurella genera. Conversely, lansoprazole-treated rats showed an elevated population of Firmicutes (66.9%), which was attributed to an increased ratio of Clostridium g4 to Lactobacillus genera.

Conclusions

This preliminary study suggests that long-term administration of PPI may cause weight loss and changes to the microbiota in the terminal ileum.

PMK-S005 Alleviates Age-Related Gastric Acid Secretion, Inflammation, and Oxidative Status in the Rat Stomach

Background/Aims

The aim of this study was to evaluate the effect of the synthetic S-allyl-l-cysteine (SAC) PMK-S005 on gastric acid secretion, inflammation, and antioxidant enzymes in aging rats.

Methods

The rats were divided into four groups at 31 weeks of age and were continuously fed a diet containing a vehicle control, PMK-S005 (5 or 10 mg/kg), or lansoprazole (5 mg/kg). Gastric acid secretion and connective tissue thickness of the lamina propria were evaluated at 74 weeks and 2 years of age. Tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and COX-2 levels were measured by using enzyme-linked immunosorbent assays (ELISAs) or Western blot assays. Levels of antioxidant enzymes, including heme oxyganase 1 (HO-1) and NAD(P)H:quinone oxidoreductase 1 (NQO-1), were also measured.

Results

As the rats aged, gastric acid secretion significantly decreased, and the connective tissue of the lamina propria increased. However, 74-week-old rats in the PMK-S005 group exhibited greater levels of gastric acid secretion than those of the control and lansoprazole groups. The increase of TNF-α, IL-1β, and COX-2 expression in 74-week and 2-year-old control rats were inhibited by PMK-S005. In addition, the decrease in HO-1 and NQO-1 protein expression that occurred with aging was inhibited by PMK-S005 in the 74-week-old rats.

Conclusions

These results suggest that PMK-S005 has therapeutic potential as an antiaging agent to ameliorate age-related gastric acid secretion, inflammation, and oxidative stress in the stomach.

Complications of Proton Pump Inhibitor Therapy

Safety issues associated with proton pump inhibitors (PPIs) have recently attracted widespread media and lay attention. Gastroenterologists are frequently asked about the appropriateness of PPI therapy for specific patients. Furthermore, some patients may have had PPI therapy discontinued abruptly or inappropriately due to safety concerns. Faced with such a wide variety of potentially serious adverse consequences, prescribers need to evaluate the evidence objectively to discern the likelihood that any reported association might actually be causal. Here, we review many of the proposed adverse consequences of PPI therapy and apply established criteria for the determination of causation. We also consider the potential contribution of residual confounding in many of the reported studies. Evidence is inadequate to establish causal relationships between PPI therapy and many of the proposed associations. Residual confounding related to study design and the overextrapolation of quantitatively small estimates of effect size have probably led to much of the current controversy about PPI safety. In turn, this has caused unnecessary concern among patients and prescribers. The benefits of PPI therapy for appropriate indications need to be considered, along with the likelihood of the proposed risks. Patients with a proven indication for a PPI should continue to receive it in the lowest effective dose. PPI dose escalation and continued chronic therapy in those unresponsive to initial empiric therapy is discouraged.

Proton pump inhibitors: Risks of long-term use

Proton pump inhibitors are among the most commonly prescribed classes of drugs, and their use is increasing, in particular for long-term treatment, often being over-prescribed and used for inappropriate conditions. In recent years, considerable attention has been directed towards a wide range of adverse effects, and even when a potential underlying biological mechanism is plausible, the clinical evidence of the adverse effect is often weak. Several long-term side effects have been investigated ranging from interaction with other drugs, increased risk of infection, reduced intestinal absorption of vitamins and minerals, and more recently kidney damage and dementia. The most recent literature regarding these adverse effects and their association with long-term proton pump inhibitor treatment is reviewed, and the mechanisms through which these possible complications might develop are discussed.

Small intestinal bacterial overgrowth and celiac disease: A systematic review with pooled-data analysis

BACKGROUND

A link between small intestinal bacterial overgrowth (SIBO) and celiac disease (CD) has been hypothesized.

METHODS

Literature search was performed in main medical databases. Methods of analysis/inclusion criteria were based on Preferred Reporting Items for Systematic reviews and Meta-Analyses recommendations. The end-point was to estimate, by a pooled-data analysis, SIBO prevalence in CD. Proportions/percentages and their 95% confidence intervals (CI) were calculated by inverse variance method, whereas odd ratios (OR) and their 95% CI were estimated, where available, based on the Mantel-Haenszel method. Data were entered into the RevMan 5.3 software.

KEY RESULTS

Eleven articles fulfilled considered criteria. The pooled mean prevalence of SIBO in CD was 20% (95% CI of 10%-30%). In comparison to asymptomatic controls, CD was associated to higher risk of SIBO, with an OR of 10.52 (95% CI 2.69-41.21, P=.0007). Jejunal aspirate culture assessed SIBO prevalence of 11% (95% CI 3%-19%) in CD, whereas breath tests detected a higher value (23%, 95% CI 10%-37%). The pooled prevalence of SIBO in CD patients who were symptomatic despite a GFD was 28% (95% CI 10%-47%), higher than in asymptomatic celiac patients (pooled prevalence of 10%, with a 95% CI of 3%-16%), despite not statistically significant (P=.06). When GFD-unresponsive CD was defined only by clinical persistence of symptoms, the prevalence of SIBO was higher than in the case of villous atrophy association (31% vs 16% P=.33).

CONCLUSIONS

The heterogeneity of available studies may not support a relationship SIBO-CD. Nevertheless, SIBO could be more common in CD when symptoms do not improve after GFD.

Lung disease severity in idiopathic pulmonary fibrosis is more strongly associated with impedance measures of bolus reflux than pH parameters of acid reflux alone

BACKGROUND

Gastroesophageal reflux (GER) has been associated with idiopathic pulmonary fibrosis (IPF). Pathogenesis may be related to chronic micro-aspiration. We aimed to assess objective measures of GER on multichannel intraluminal impedance and pH study (MII-pH) and their relationship with pulmonary function testing (PFT) results, and to compare the performance of pH/acid reflux parameters vs corresponding MII/bolus parameters in predicting pulmonary dysfunction in IPF.

METHODS

This was a retrospective cohort study of IPF patients undergoing prelung transplant evaluation with MII-pH off acid suppression, and having received PFT within 3 months. Patients with prior fundoplication were excluded. Severe pulmonary dysfunction was defined using diffusion capacity of the lung for carbon monoxide (DLCO) ≤40%. Six pH/acid reflux parameters with corresponding MII/bolus reflux measures were specified a priori. Multivariate analyses were applied using forward stepwise logistic regression. Predictive value of each parameter for severe pulmonary dysfunction was calculated by area-under-the-receiver-operating-characteristic-curve or c-statistic.

KEY RESULTS

Forty-five subjects (67% M, age 59, 15 mild-moderate vs 30 severe) met criteria for inclusion. Patient demographics and clinical characteristics were similar between pulmonary dysfunction groups. Abnormal total reflux episodes and prolonged bolus clearance time were significantly associated with pulmonary dysfunction severity on univariate and multivariate analyses. No pH parameters were significant. The c-statistic of each pH parameter was lower than its MII counterpart in predicting pulmonary dysfunction.

CONCLUSIONS & INFERENCES

MII/bolus reflux, but not pH/acid reflux, was associated with pulmonary dysfunction in prelung transplant patients with IPF. MII-pH may be more valuable than pH testing alone in characterizing GER in IPF.

Small intestinal bacterial overgrowth as a cause for irritable bowel syndrome: guilty or not guilty?

PURPOSE OF REVIEW

Small intestinal bacterial overgrowth (SIBO) has been proposed as a cause of irritable bowel syndrome (IBS). However, this relationship has been subject to controversy. This review aims to provide a current perspective on the SIBO-IBS hypothesis.

RECENT FINDINGS

Case-control studies evaluating the prevalence of SIBO in IBS and healthy individuals have shown conflicting results. Moreover, the tests available in routine clinical practice to diagnose SIBO are not valid and lack both sensitivity and specificity. Hence, interpreting the effect of interventions based on these tests is fraught with uncertainty. Furthermore, the SIBO-IBS hypothesis has paved the way to assess antibiotic therapy in nonconstipated IBS, with rifaximin, a nonabsorbable antibiotic, showing modest but significant clinical benefit. However, individuals were not tested for SIBO and the mechanism of action of rifaximin in IBS remains to be elucidated. Preliminary data suggest that rifaximin decreases microbial richness and previous studies have noted antibacterial interventions in IBS to reduce colonic fermentation and improve symptoms. The advent of rapid culture-independent molecular techniques is a promising tool that will seek to clarify and advance our understanding of the gut microbial function.

SUMMARY

The SIBO-IBS hypothesis lacks convincing evidence but remains under scrutiny. The mechanism resulting in symptom improvement after rifaximin treatment in some IBS individuals requires exploration. Novel molecular techniques provide an exciting and challenging opportunity to explore the host-gut microbiota interaction.

Correlation between proton pump inhibitors and risk of pyogenic liver abscess

BACKGROUND/OBJECTIVE

Little is known about the relationship between proton pump inhibitors use and pyogenic liver abscess. The objective of this study was to evaluate the correlation between proton pump inhibitors use and pyogenic liver abscess in Taiwan.

METHODS

This was a population-based case-control study using the database of the Taiwan National Health Insurance Program since 2000 to 2011. Subjects aged 20 to 84 who experienced their first episode of pyogenic liver abscess were enrolled as the case group (n = 1372). Randomly selected subjects aged 20 to 84 without pyogenic liver abscess were enrolled as the control group (n = 1372). Current use, early use, and late use of proton pump inhibitors was defined as subjects whose last one tablet for proton pump inhibitors was noted ≤30 days, between 31 to 90 days and ≥91 days before the date of admission for pyogenic liver abscess. Subjects who never received a prescription for proton pump inhibitors were defined as nonusers of proton pump inhibitors. A multivariable unconditional logistic regression model was used to measure the odds ratio and 95% confidence interval to evaluate the correlation between proton pump inhibitors use and pyogenic liver abscess.

RESULTS

After adjusting for confounders, the adjusted odds ratio of pyogenic liver abscess was 7.59 for subjects with current use of proton pump inhibitors (95% confidence interval 5.05, 11.4), when compared with nonusers.

CONCLUSIONS

Current use of proton pump inhibitors is associated with a greater risk of pyogenic liver abscess.

Short article: Risk of small intestinal bacterial overgrowth with chronic use of proton pump inhibitors in children

BACKGROUND

Some theorize that prolonged use of proton pump inhibitors (PPIs) may increase the risk of small intestinal bacterial overgrowth (SIBO). Chronic acid suppression and resultant hypochlorhydria may lead to an altered intraluminal environment, which, in turn, may promote the growth of bacteria in the small intestine. A handful of studies measured the risk of SIBO in adults taking PPIs and obtained mixed results; however, this risk has not been exclusively measured in children.

AIM

This study aimed to measure the risk of SIBO in children taking PPI versus those not taking PPI.

PATIENTS AND METHODS

This was a prospective cohort study. Evaluation of SIBO was performed using the glucose hydrogen breath test. Patients younger than 18 years of age taking a PPI longer than 6 months were compared with healthy control participants. After ingestion of glucose substrate, breath samples were obtained every 15 min for 2 h. An increase in breath hydrogen or methane above 12 ppm was considered diagnostic of SIBO.

RESULTS

Overall, 83 participants were tested, of whom 56 were taking PPIs. SIBO was detected in five (8.9%) of the 56 participants taking PPI versus one (3.7%) of the 27 participants in the control group (P=0.359), with a relative risk of 2.4 (95% confidence interval: 0.29-19.6).

CONCLUSION

To our knowledge, this is the first study in the English literature measuring the risk of SIBO in children taking PPIs. Our results indicate a potential risk of SIBO in chronic PPI users; however, this is not statistically significant. This is an important finding as PPIs are readily prescribed for children and are often taken longer than 6 months' duration.

Proton pump inhibitor is a risk factor for recurrence of common bile duct stones after endoscopic sphincterotomy - propensity score matching analysis

Background and study aims Recurrence of common bile duct stones (CBDS) in patients treated with endoscopic sphincterotomy (ES) can lead to deterioration in their quality of life. Although the pathology and related factors are unclear, we speculated that proton pump inhibiter (PPI) administration increases the risk of CBDS recurrence by altering the bacterial mixture in the bile duct. Patients and methods The primary endpoint of this retrospective study was recurrence-free period. Several independent variables considered to have a relationship with CBDS recurrence including PPI use were analyzed using a COX proportional hazard model, with potential risk factors then evaluated by propensity score matching analysis. Results A total of 219 patients were analyzed, with CBDS recurrence found in 44. Analysis of variables using a COX proportional hazard model demonstrated that use of PPIs and ursodeoxycholic acid (UDCA), as well as the presence of periampullary diverticula (PD) each had a hazard ratio (HR) value greater than 1 (HR 2.2, P = 0.007; HR 2.0, P = 0.02; HR 1.9, P = 0.07; respectively). Furthermore, propensity score matching analysis revealed that the mean recurrence-free period in the oral PPI cohort was significantly shorter as compared with the non-PPI cohort (1613 vs. 2587 days, P = 0.014). In contrast, neither UDCA administration nor PD presence was found to be a significant factor in that analysis (1557 vs. 1654 days, P = 0.508; 1169 vs. 2011 days, P = 0.121; respectively). Conclusion Our results showed that oral PPI administration is a risk factor for CBDS recurrence in patients who undergo ES.

The Risks and Benefits of Long-term Use of Proton Pump Inhibitors: Expert Review and Best Practice Advice From the American Gastroenterological Association

BACKGROUND & AIMS

The purpose of this review is to evaluate the risks associated with long-term use of proton pump inhibitors (PPIs), focusing on long-term use of PPIs for three common indications: gastroesophageal reflux disease (GERD), Barrett's esophagus (BE), and non-steroidal anti-inflammatory drug (NSAID) bleeding prophylaxis.

METHODS

The recommendations outlined in this review are based on expert opinion and on relevant publications from PubMed, EMbase, and the Cochrane library (through July 2016). To identify relevant ongoing trials, we queried clinicaltrials.gov. To assess the quality of evidence, we used a modified approach based on the GRADE Working Group. The Clinical Practice Updates Committee of the American Gastroenterological Association has reviewed these recommendations. Best Practice Advice 1: Patients with GERD and acid-related complications (ie, erosive esophagitis or peptic stricture) should take a PPI for short-term healing, maintenance of healing, and long-term symptom control. Best Practice Advice 2: Patients with uncomplicated GERD who respond to short-term PPIs should subsequently attempt to stop or reduce them. Patients who cannot reduce PPIs should consider ambulatory esophageal pH/impedance monitoring before committing to lifelong PPIs to help distinguish GERD from a functional syndrome. The best candidates for this strategy may be patients with predominantly atypical symptoms or those who lack an obvious predisposition to GERD (eg, central obesity, large hiatal hernia). Best Practice Advice 3: Patients with Barrett's esophagus and symptomatic GERD should take a long-term PPI. Best Practice Advice 4: Asymptomatic patients with Barrett's esophagus should consider a long-term PPI. Best Practice Advice 5: Patients at high risk for ulcer-related bleeding from NSAIDs should take a PPI if they continue to take NSAIDs. Best Practice Advice 6: The dose of long-term PPIs should be periodically reevaluated so that the lowest effective PPI dose can be prescribed to manage the condition. Best Practice Advice 7: Long-term PPI users should not routinely use probiotics to prevent infection. Best Practice Advice 8: Long-term PPI users should not routinely raise their intake of calcium, vitamin B12, or magnesium beyond the Recommended Dietary Allowance (RDA). Best Practice Advice 9: Long-term PPI users should not routinely screen or monitor bone mineral density, serum creatinine, magnesium, or vitamin B12. Best Practice Advice 10: Specific PPI formulations should not be selected based on potential risks.

Small Intestinal Bacterial Overgrowth and Other Intestinal Disorders

Gut microbiota is the largest organ of the human body. Although growth of bacteria more than 10⁵ colony forming unit (CFU) per milliliter in culture of upper gut aspirate is used to diagnosis small intestinal bacterial overgrowth (SIBO), 10³ CFU or more is being considered to suggest the diagnosis, particularly if colonic type bacteria are present in the upper gut. Although neither very sensitive nor specific, hydrogen breath tests are widely used to diagnose SIBO. Rifaximin is the best treatment for SIBO due to its broad spectrum, lack of systemic absorption, and safety profile.

When is proton pump inhibitor use appropriate?

Proton pump inhibitor (PPI) therapy is commonly used outside of Food and Drug Administration indication for a broad range of conditions such as extra-esophageal reflux and PPI-responsive esophageal eosinophilia. While this may be appropriate in some scenarios, it has also resulted in widespread inappropriate PPI use. At the same time, data suggesting adverse effects of long-term PPI therapy are multiplying, albeit mainly from low quality studies. The systematic review by Scarpignato et al. (BMC Med 14:179, 2016) addresses this dilemma with a comprehensive analysis of the risks and benefits of PPI use. The authors concluded that, while PPIs are highly efficacious in erosive acid-peptic disorders, efficacy is not equaled in other conditions. In some instances, they found no supportive evidence of benefit. With respect to side effects, they indicated that the questionable harms associated with PPI therapy do not outweigh the benefits afforded by appropriate PPI use. However, inappropriate PPI use results in increased healthcare costs and unnecessary exposure to potential adverse effects. Ideally, PPI therapy should be personalized, based on indication, effectiveness, patient preference, and risk assessment.Please see related article: http://bmcmedicine.biomedcentral.com/articles/10.1186/s12916-016-0718-z .

Levothyroxine therapy and impaired clearance are the strongest contributors to small intestinal bacterial overgrowth: Results of a retrospective cohort study

AIM

To identify a set of contributors, and weight and rank them on a pathophysiological basis.

METHODS

Patients who have undergone a lactulose or glucose hydrogen breath test to rule out small intestinal bacterial overgrowth (SIBO) for various clinical symptoms, including diarrhoea, weight loss, abdominal pain, cramping or bloating, were seen as eligible for inclusion in a retrospective single-centre study. Clinical data such as co-morbidities, medication, laboratory parameters and other possible risk factors have been identified from the electronic data system. Cases lacking or with substantially incomplete clinical data were excluded from the analysis. Suspected contributors were summarised under four different pathophysiological pathways (impaired gastric acid barrier, impaired intestinal clearance, immunosuppression and miscellaneous factors including thyroid gland variables) and investigated using the χ² test, Student’s t-test and logistic regression models.

RESULTS

A total of 1809 patients who had undergone hydrogen breath testing were analysed. Impairment of the gastric acid barrier (gastrectomy, odds ratio: OR = 3.5, PPI therapy OR = 1.4), impairment of intestinal clearance (any resecting gastric surgery OR = 2.6, any colonic resection OR = 1.9, stenosis OR = 3.4, gastroparesis OR = 3.4, neuropathy 2.2), immunological factors (any drug-induced immunosuppression OR = 1.8), altered thyroid gland metabolism (hypothyroidism OR = 2.6, levothyroxine therapy OR = 3.0) and diabetes mellitus (OR = 1.9) were associated significantly to SIBO. Any abdominal surgery, ileocecal resection, vagotomy or IgA-deficiency did not have any influence, and a history of appendectomy decreased the risk of SIBO. Multivariate analysis revealed gastric surgery, stenoses, medical immunosuppression and levothyroxine to be the strongest predictors. Levothyroxine therapy was the strongest contributor in a simplified model (OR = 3.0).

CONCLUSION

The most important contributors for the development of SIBO in ascending order are immunosuppression, impairment of intestinal clearance and levothyroxine use, but they do not sufficiently explain its emergence.

Microbiota Plays a Key Role in Non-Steroidal Anti-Inflammatory Drug-Induced Small Intestinal Damage

BACKGROUND

Non-steroidal anti-inflammatory drugs (NSAIDs) damage the small intestine by causing multiple erosions and ulcers. However, to date, no established therapies and prophylactic agents are available to treat such damages. We reviewed the role of intestinal microbiota in NSAID-induced intestinal damage and identified potential therapeutic candidates.

SUMMARY

The composition of the intestinal microbiota is an important factor in the pathophysiology of NSAID-induced small intestinal damage. Once mucosal barrier function is disrupted due to NSAID-induced prostaglandin deficiency and mitochondrial malfunction, lipopolysaccharide from luminal gram-negative bacteria and high mobility group box 1 from the injured epithelial cells activate toll-like receptor 4-signaling pathway and nucleotide-binding oligomerization domain-like receptor family, pyrin domain-containing 3 inflammasome; this leads to the release of proinflammatory cytokines such as tumor necrosis factor-α and interleukin-1β. Proton pump inhibitors (PPIs) are often used for the prevention of NSAID-induced injuries to the upper gastrointestinal tract. However, several studies indicate that PPIs may induce dysbiosis, which may exacerbate the NSAID-induced small intestinal damage. Our recent research suggests that probiotics and rebamipide could be used to prevent NSAID-induced small intestinal damage by regulating the intestinal microbiota. Key Messages: Intestinal microbiota plays a key role in NSAID-induced small intestinal damage, and modulating the composition of the intestinal microbiota could be a new therapeutic strategy for treating this damage.

Consensus report: faecal microbiota transfer - clinical applications and procedures

BACKGROUND

Faecal microbiota transplantation or transfer (FMT) aims at replacing or reinforcing the gut microbiota of a patient with the microbiota from a healthy donor. Not many controlled or randomised studies have been published evaluating the use of FMT for other diseases than Clostridium difficile infection, making it difficult for clinicians to decide on a suitable indication.

AIM

To provide an expert consensus on current clinical indications, applications and methodological aspects of FMT.

METHODS

Well-acknowledged experts from various countries in Europe have contributed to this article. After literature review, consensus has been achieved by repetitive circulation of the statements and the full manuscript among all authors with intermittent adaptation to comments (using a modified Delphi process). Levels of evidence and agreement were rated according to the GRADE system. Consensus was defined a priori as agreement by at least 75% of the authors.

RESULTS

Key recommendations include the use of FMT in recurrent C. difficile infection characterised by at least two previous standard treatments without persistent cure, as well as its consideration in severe and severe-complicated C. difficile infection as an alternative to total colectomy in case of early failure of antimicrobial therapy. FMT in inflammatory bowel diseases (IBD), irritable bowel syndrome (IBS) and metabolic syndrome should only be performed in research settings.

CONCLUSIONS

Faecal microbiota transplantation or transfer is a promising treatment for a variety of diseases in which the intestinal microbiota is disturbed. For indications other than C. difficile infection, more evidence is needed before more concrete recommendations can be made.

Proton Pump Inhibitors Increase Risk for Hepatic Encephalopathy in Patients With Cirrhosis in A Population Study

BACKGROUND & AIMS

Hepatic encephalopathy (HE) is a serious complication of cirrhosis and is associated with gut dysbiosis. Proton pump inhibitors (PPIs), frequently prescribed to patients with cirrhosis, can contribute to small-bowel bacterial overgrowth. We investigated whether PPI predisposes patients with cirrhosis to HE using a large database of patients.

METHODS

We performed a case-control study nested within a sample of Taiwan National Health Insurance beneficiaries (n = 1,000,000), followed up longitudinally from 1998 through 2011. Patients with cirrhosis and an occurrence of HE (n = 1166) were selected as the case cohort and matched to patients without HE (1:1, controls) for sex, enrollment time, end point time, follow-up period, and advanced cirrhosis. Information on prescribed drugs, drug dosage, supply days, and numbers of dispensed pills was extracted from the Taiwan National Health Insurance database. PPI use was defined as more than 30 cumulative defined daily doses (cDDDs); PPI nonuse was defined as 30 cDDDs or fewer. We performed logistic regression analyses to estimate the association between PPI use and the occurrence of HE.

RESULTS

Among patients with cirrhosis and an occurrence of HE, 38% (n = 445) had a history of PPI use before HE occurrence. We observed a relationship between dose of PPI taken and HE risk. The confounder-adjusted odd ratios were 1.41 (95% confidence interval [CI], 1.09-1.84), 1.51 (95% CI, 1.11-2.06), and 3.01 (95% CI, 1.78-5.10) for patients with 30-120 cDDDs, 120-365 cDDDs, and more than 365 cDDDs, respectively, compared with PPI nonusers. All categories of PPIs, except rabeprazole, were associated with an increased risk of HE.

CONCLUSIONS

Based on an analysis of data from Taiwan National Health Insurance beneficiaries, we found that use of PPIs in patients with cirrhosis increases the risk for HE; risk increases with dose. It therefore is important for health care providers to carefully consider prolonged PPI use by patients with cirrhosis.

Prevalence of Small Intestinal Bacterial Overgrowth in Multiple Sclerosis: a Case-Control Study from China

OBJECTIVE

It's hypothesized that gastrointestinal microbiota might play an important role in pathogenesis of multiple sclerosis (MS). The aim of the present study was to assess the prevalence of small intestinal bacterial overgrowth (SIBO) in MS patients compared with sex and age matched controls without MS.

METHODS

The present study was a case-control type, it included 118 patients with definitive MS and 118 age-sex matched controls. Progression of disability was assessed using the Multiple Sclerosis Severity Score (MSSS). All patients and controls underwent the glucose breath test to assess SIBO.

RESULTS

Forty-five of the 118 MS patients were SIBO positive (38.14%; 95%CI: 29.37%-46.90%) compared with 10 of 118 in the control group (8.47%; 95% confidence interval [CI]: 3.45%-13.50%); the difference was statistically significant (P<0.0001; Odds ratios (OR), 4.50; 95% CI, 2.38-8.50). In addition, 102 out of the 118 patients (86.4%) presented at least one GI symptom. Constipation (78.0%), Bloating (46.6%), and fecal incontinence (44.1%) were common. Multivariate analysis showed that expanded disability status scale (EDSS) score and MSSS were the only factors associated with the SIBO-positive status in MS patients (OR, 3.44; 95% CI, 1.56-6.99; and OR, 2.76; 95% CI, 1.42-4.94, respectively).

CONCLUSION

SIBO is highly prevalent in Chinese patients with MS. Further analytical work is required to establish a causal association between SIBO and MS risk and progression.

Small Intestinal Bacterial Overgrowth: A Primary Care Review

Gastrointestinal symptoms are commonly seen in the primary care setting.¹ These patient presentations can be nonspecific, leading to a broad differential diagnosis. Small intestinal bacterial overgrowth is a clinical entity that can present with many of these nonspecific gastrointestinal symptoms. The recent interest in the microbiome by those in the medical and lay communities has made this syndrome all the more relevant. This review gives the primary care provider an up-to-date understanding of the etiology, risk factors and predisposing factors, presentation, diagnostic testing, and management of small intestinal bacterial overgrowth.

Effective and safe proton pump inhibitor therapy in acid-related diseases - A position paper addressing benefits and potential harms of acid suppression

BACKGROUND

The introduction of proton pump inhibitors (PPIs) into clinical practice has revolutionized the management of acid-related diseases. Studies in primary care and emergency settings suggest that PPIs are frequently prescribed for inappropriate indications or for indications where their use offers little benefit. Inappropriate PPI use is a matter of great concern, especially in the elderly, who are often affected by multiple comorbidities and are taking multiple medications, and are thus at an increased risk of long-term PPI-related adverse outcomes as well as drug-to-drug interactions. Herein, we aim to review the current literature on PPI use and develop a position paper addressing the benefits and potential harms of acid suppression with the purpose of providing evidence-based guidelines on the appropriate use of these medications.

METHODS

The topics, identified by a Scientific Committee, were assigned to experts selected by three Italian Scientific Societies, who independently performed a systematic search of the relevant literature using Medline/PubMed, Embase, and the Cochrane databases. Search outputs were distilled, paying more attention to systematic reviews and meta-analyses (where available) representing the best evidence. The draft prepared on each topic was circulated amongst all the members of the Scientific Committee. Each expert then provided her/his input to the writing, suggesting changes and the inclusion of new material and/or additional relevant references. The global recommendations were then thoroughly discussed in a specific meeting, refined with regard to both content and wording, and approved to obtain a summary of current evidence.

RESULTS

Twenty-five years after their introduction into clinical practice, PPIs remain the mainstay of the treatment of acid-related diseases, where their use in gastroesophageal reflux disease, eosinophilic esophagitis, Helicobacter pylori infection, peptic ulcer disease and bleeding as well as, and Zollinger-Ellison syndrome is appropriate. Prevention of gastroduodenal mucosal lesions (and symptoms) in patients taking non-steroidal anti-inflammatory drugs (NSAIDs) or antiplatelet therapies and carrying gastrointestinal risk factors also represents an appropriate indication. On the contrary, steroid use does not need any gastroprotection, unless combined with NSAID therapy. In dyspeptic patients with persisting symptoms, despite successful H. pylori eradication, short-term PPI treatment could be attempted. Finally, addition of PPIs to pancreatic enzyme replacement therapy in patients with refractory steatorrhea may be worthwhile.

CONCLUSIONS

Overall, PPIs are irreplaceable drugs in the management of acid-related diseases. However, PPI treatment, as any kind of drug therapy, is not without risk of adverse effects. The overall benefits of therapy and improvement in quality of life significantly outweigh potential harms in most patients, but those without clear clinical indication are only exposed to the risks of PPI prescription. Adhering with evidence-based guidelines represents the only rational approach to effective and safe PPI therapy. Please see related Commentary: doi: 10.1186/s12916-016-0724-1 .

Association Between Proton Pump Inhibitors and Microscopic Colitis

Objective: Microscopic colitis (MC) is a chronic inflammatory disease of the colon that is characterized by chronic, watery, nonbloody diarrhea. Concern regarding a potential association between proton-pump inhibitors (PPIs) and MC has recently emerged. We sought to systematically review and summarize the evidence for the potential association between PPIs and MC. Data Sources: We systematically searched EMBASE, MEDLINE, Cochrane Database of Systematic Reviews, International Pharmaceutical Abstracts, and Google Scholar using the terms proton-pump inhibitors (omeprazole, lansoprazole, dexlansoprazole, rabeprazole, pantoprazole, or esomeprazole), microscopic colitis, collagenous colitis, and lymphocytic colitis. Study Selection: Full-text, English-language reports of case reports/series, observational studies, experimental studies, and systematic reviews/meta-analyses published between January 2000 to August 2016 were included. Bibliographies from pertinent publications were reviewed for additional references. Outcome was defined as the development of biopsy-confirmed MC. Data Extraction/Synthesis: A total of 19 publications were identified: 5 case control studies and 14 case reports/series (encompassing a total of 32 cases). All studies were limited by small sample sizes. Risk of MC by dose or specific PPI agent was not investigated in any of the studies. A review of the current body of evidence reveals a possible association between PPIs and MC. Conclusions: There is a need for large observational studies of high quality to examine the differential effect of specific PPIs and whether the magnitude of association is dose dependent. Given their widespread use, clinicians should routinely question whether patients are receiving unnecessary treatment with PPIs and discontinue therapy where appropriate.

Small intestinal bacterial overgrowth is associated with irritable bowel syndrome and is independent of proton pump inhibitor usage

BACKGROUND

Current knowledge suggests that small intestinal overgrowth participates in the pathogenesis of irritable bowel syndrome. It is questionable if this association is modulated by intake of proton pump inhibitors (PPIs).

METHODS

In a prospective study, quantitative cultures of duodenal aspirates were performed for aerobic species in 897 consecutive patients undergoing upper GI tract endoscopy. SIBO was defined as equal to or more than 10(3) cfu/ml. The effect of PPI intake on the relationship between SIBO and IBS was the primary endpoint.

RESULTS

Analysis among patients without any history of PPI intake (n = 713) showed that odds ratio (OR) for IBS in the event of SIBO was 5.63 (3.73-8.51, p < 0.0001); this was 4.16 (1.91-9.06) when analysis was done among patients with history of PPI intake (n = 184, p: 0.498 between patients without and with PPI intake). Multiple logistic regression analysis found that factors independently associated with SIBO were age above or equal to 60 years (OR: 2.36), body mass index more than or equal to 22 kg/m(2) (OR: 0.60), presence of IBS (OR: 6.29), type 2 diabetes mellitus (OR: 1.59) and gastritis (OR: 0.47).

CONCLUSIONS

The association between IBS and SIBO was completely independent from PPI intake. Although gastritis was protective against SIBO, results show that PPI intake cannot prime SIBO.

Impact of long-term gastric acid suppression on spontaneous bacterial peritonitis in patients with advanced decompensated liver cirrhosis

OBJECTIVE

Recent studies have presented conflicting results on the association between gastric acid suppression and spontaneous bacterial peritonitis (SBP). The long-term effects of gastric acid suppression on SBP in cirrhotic patients remain unclear. This study evaluated the risk of SBP in advanced decompensated cirrhotic patients with long-term gastric acid suppression.

METHODS

Using the Taiwan National Health Insurance Research Database, we identified 4788 patients with decompensated cirrhosis from 1998 to 2011. The SBP incidence rate was compared among proton pump inhibitor (PPI), H2-receptor antagonist (H2RA), and control cohorts. Multivariate Cox proportional hazards regressions analysis was conducted to confirm the association between gastric acid suppression and SBP.

RESULTS

Totally, 4788 patients were analyzed: 1870 in the PPI cohort, 1728 in the H2RA cohort, and 1190 in the control cohort. The overall incidences of SBP were 16.8, 11.9, and 9.80 per 1000 person-years in the PPI, H2RA, and control cohorts, respectively. The adjusted hazard ratio (aHR) of SBP during the follow-up period was 1.16- (95% confidence interval [CI], 0.72-1.86) and 1.00-fold (95% CI, 0.63-1.57) higher in the PPI and H2RA cohorts, respectively, than in the control cohort; the result was non-significant. Compared with the control cohort, patients with >180days of PPI therapy had significantly higher risks of SBP, with an aHR of 2.28 (95% CI, 1.37-3.78).

CONCLUSIONS

Long-term PPI use is associated with a high risk of SBP in advanced decompensated cirrhotic patients. Well-designed prospective studies are necessary to evaluate the safety of long-term PPI use in such patients.

Bacterial infections in cirrhosis: A critical review and practical guidance

Bacterial infection is common and accounts for major morbidity and mortality in cirrhosis. Patients with cirrhosis are immunocompromised and increased susceptibility to develop spontaneous bacterial infections, hospital-acquired infections, and a variety of infections from uncommon pathogens. Once infection develops, the excessive response of pro-inflammatory cytokines on a pre-existing hemodynamic dysfunction in cirrhosis further predispose the development of serious complications such as shock, acute-on-chronic liver failure, renal failure, and death. Spontaneous bacterial peritonitis and bacteremia are common in patients with advanced cirrhosis, and are important prognostic landmarks in the natural history of cirrhosis. Notably, the incidence of infections from resistant bacteria has increased significantly in healthcare-associated settings. Serum biomarkers such as procalcitonin may help to improve the diagnosis of bacterial infection. Preventive measures (e.g., avoidance, antibiotic prophylaxis, and vaccination), early recognition, and proper management are required in order to minimize morbidity and mortality of infections in cirrhosis.

Atopic dermatitis and the intestinal microbiota in humans and dogs

The prevalence of human and canine allergic diseases is commonly perceived to be increasing. Suggested predisposing factors in people and dogs include increased allergen load, increased exposure to pollutants, reduced family size, reduced microbial load and less exposure to infection at a young age, increasingly urbanised environment, and changes in dietary habits. Genetic make‐up may provide a template for phenotypic predisposition which is strongly influenced by our diet and environment leading to constant regulation of gene expression. One way in which diet can alter gene expression is via its effects on the gut flora or microbiota, the collection of microbes residing in the gastrointestinal tract. The resident microbiota is important in maintaining structural and functional integrity of the gut and in immune system regulation. It is an important driver of host immunity, helps protect against invading enteropathogens, and provides nutritional benefits to the host. Disruption of the microbiota (dysbiosis) may lead to severe health problems, both in the gastrointestinal tract and extra‐intestinal organ systems. The precise mechanisms by which the intestinal microbiota exerts its effects are only beginning to be unravelled but research is demonstrating close links between gut microflora and many factors involved in the pathogenesis of atopic dermatitis (AD). AD and indeed any other ‘skin disease’, may be seen as a possible manifestation of a more systemic problem involving gut dysbiosis and increased intestinal permeability, which may occur even in the absence of gastrointestinal signs. Manipulation of the canine intestinal microbiota as a method for modifying atopy, may be attempted in many ways including avoidance of certain foods, supplementation with probiotics and prebiotics, optimising nutrient intake, minimising stress, antimicrobial therapy, correction and prevention of low stomach acid, and faecal microbiota transplantation (FMT).

Systematic review and meta-analysis: Small intestinal bacterial overgrowth in chronic pancreatitis

BACKGROUND

Evidence on small intestinal bacterial overgrowth (SIBO) in patients with chronic pancreatitis (CP) is conflicting.

AIM

The purpose of this study was to perform a systematic review and meta-analysis on the prevalence of SIBO in CP and to examine the relationship of SIBO with symptoms and nutritional status.

METHODS

Case-control and cross-sectional studies investigating SIBO in CP patients were analysed. The prevalence of positive tests was pooled across studies, and the rate of positivity between CP cases and controls was calculated.

RESULTS

= 59.7%). The relationship between symptoms and SIBO in CP patients varied across studies, and the treatment of SIBO was associated with clinical improvement.

CONCLUSIONS

One-third of CP patients have SIBO, with a significantly increased risk over controls, although results are heterogeneous, and studies carry several limitations. The impact of SIBO and its treatment in CP patients deserve further investigation.

Small Bowel Bacterial Overgrowth in Children

OBJECTIVES

The aim of study was to perform a comprehensive review of the pathogenesis, available diagnostic procedures, prevalence, clinical manifestations, and consequences of small bowel bacterial overgrowth (SBBO) as well as treatment options in the pediatric population.

METHODS

A literature search including MEDLINE, PubMed, and Web of Science databases was performed.

RESULTS

SBBO is found in a variety of childhood conditions in which the normal homeostatic mechanisms restricting bacterial colonization in the small bowel are disturbed by congenital or acquired anatomical abnormalities, diminished gastric acid secretion, congenital alteration of intestinal motility or acquired small bowel diseases, or other chronic disorders including primary or acquired immunodeficiency. Data show that SBBO may be an underrecognized cause of pediatric morbidity. Although several diagnostic tests for SBBO determination are available, each has its drawbacks and limitations. Indeed, there is still no "criterion standard" for SBBO diagnosis in the pediatric population. Owing to lack of established guidelines and few published interventional studies that assess the effectiveness of SBBO therapy, treatment of children with SBBO remains empiric and comprises antibiotic or probiotic therapy.

CONCLUSIONS

Further research is needed to determine the clinical impact of SBBO and to establish diagnostic and therapeutic guidelines applicable to children.

Small Intestinal Bacterial Overgrowth in Patients with Refractory Functional Gastrointestinal Disorders

Background/Aims

Small intestinal bacterial overgrowth (SIBO) is considered to be involved in the pathogenesis of functional gastrointestinal disorders (FGID). However, the prevalence and clinical conditions of SIBO in patients with FGID remain to be fully elucidated. Here, we examined the frequency of SIBO in patients with refractory FGID.

Methods

We prospectively enrolled patients with refractory FGID based on Rome III criteria. A glucose hydrogen breath test (GHBT) was performed using a gas analyzer after an overnight fast, with breath hydrogen concentration measured at baseline and every 15 minutes after administration of glucose for a total of 3 hours. A peak hydrogen value ≥ 10 ppm above the basal value between 60 and 120 minutes after administration of glucose was diagnosed as SIBO.

Results

A total of 38 FGID patients, including 11 with functional dyspepsia (FD), 10 with irritable bowel syndrome (IBS), and 17 with overlapping with FD and IBS, were enrolled. Of those, 2 (5.3%) were diagnosed with SIBO (one patient diagnosed with FD; the other with overlapping FD and IBS). Their symptoms were clearly improved and breath hydrogen levels decreased to normal following levofloxacin administration for 7 days.

Conclusions

Two patients initially diagnosed with FD and IBS were also diagnosed with SIBO as assessed by GHBT. Although the frequency of SIBO is low among patients with FGID, it may be important to be aware of SIBO as differential diagnosis when examining patients with refractory gastrointestinal symptoms, especially bloating, as a part of routine clinical care.

Asymptomatic gastric bacterial overgrowth after bariatric surgery: are long-term metabolic consequences possible?

BACKGROUND

Patients with postbariatric bacterial overgrowth were reinvestigated after a follow-up of 15 years. It was hypothesized that systemic associations analogous to those reported for whole gut microbiome would be revealed.

METHODS

Patients (n = 37, 70.3 % females, 42.4 ± 9.9 years old, preoperative BMI 53.5 ± 10.6 kg/m(2), current BMI 32.8 ± 10.8 kg/m(2)), all submitted to RYGB on account of morbid obesity, were followed during 176.8 ± 25.7 months. Blood tests included fasting blood glucose, HbA1c, liver and pancreatic enzymes, and lipid fractions. Bacterial overgrowth was diagnosed by quantitative culture of gastric fluid in both the excluded remnant and the gastric pouch, with the help of double-balloon enteroscopy. Absolute counts of aerobes and anaerobes in both gastric reservoirs were correlated with nutritional and biochemical measurements, aiming to identify clinically meaningful associations.

RESULTS

Patients denied diarrhea, abdominal pain, weight loss, or other symptoms related to bacterial overgrowth. Biochemical profile including enzymes was also acceptable, indicating a stable condition. Positive correlation of bacterial count in either segment of the stomach was demonstrated for BMI and gamma-glutamyl transferase, whereas negative correlation occurred regarding fasting blood glucose.

CONCLUSIONS

An antidiabetic role along with deleterious consequences for weight loss and liver function are possible in such circumstances. Such phenotype is broadly consistent with reported effects for the whole gut microbiome. Prospective controlled studies including molecular analysis of gastrointestinal fluid, and simultaneous profiling of the entire microbiome, are necessary to shed more light on these findings.

Proton Pump Inhibitors Alter Specific Taxa in the Human Gastrointestinal Microbiome: A Crossover Trial

We conducted an open-label crossover trial to test whether proton pump inhibitors (PPIs) affect the gastrointestinal microbiome to facilitate Clostridium difficile infection (CDI). Twelve healthy volunteers each donated 2 baseline fecal samples, 4 weeks apart (at weeks 0 and 4). They then took PPIs for 4 weeks (40 mg omeprazole, twice daily) and fecal samples were collected at week 8. Six individuals took the PPIs for an additional 4 weeks (from week 8 to 12) and fecal samples were collected from all subjects at week 12. Samples were analyzed by 16S ribosomal RNA gene sequencing. We found no significant within-individual difference in microbiome diversity when we compared changes during baseline vs changes on PPIs. There were, however, significant changes during PPI use in taxa associated with CDI (increased Enterococcaceae and Streptococcaceae, decreased Clostridiales) and taxa associated with gastrointestinal bacterial overgrowth (increased Micrococcaceae and Staphylococcaceae). In a functional analysis, there were no changes in bile acids on PPIs, but there was an increase in genes involved in bacterial invasion. These alterations could provide a mechanism by which PPIs predispose to CDI. ClinicalTrials.gov ID NCT01901276.