Risk factors for small-bowel mucosal breaks in chronic low-dose aspirin users: data from a prospective multicenter capsule endoscopy registry

Impact of proton pump inhibitors on the risk of small bowel or colorectal bleeding: A systematic review and meta-analysis

BACKGROUND

Several studies have suggested that the mucosal protective effects of proton pump inhibitors (PPIs) do not extend beyond the duodenum; however, PPIs may cause lower gastrointestinal (LGI) injury, although these relationships have not yet been fully elucidated.

METHODS

We searched all the relevant studies published until September 2022 that examined the risk of PPIs for LGI bleeding. We performed a meta-analysis of the risk of LGI bleeding (small bowel (SB) or colorectal bleeding) between PPI users and non-users. A subgroup analysis of patients consuming aspirin or nonsteroidal anti-inflammatory drugs (NSAIDs) was also performed.

RESULTS

Twelve studies with 341,063 participants were included in this meta-analysis. The use of PPIs was associated with the risk of LGI bleeding (odds ratio [OR] [95% confidence interval [CI]] = 1.42 [1.16-1.73]; hazard ratio [HR] [95% CI] = 3.23 [1.56-6.71]). An association between PPI use and the risk of LGI bleeding was also identified in the subgroup of aspirin or NSAID users (OR [95% CI] = 1.64 [1.49-1.80]; HR [95% CI] = 6.55 [2.01-21.33]). In the bleeding site-specific analyses, the risk of SB bleeding was associated with PPI use (OR [95% CI] = 1.54 [1.30-1.84]).

CONCLUSIONS

PPI use was associated with an increased risk of LGI bleeding, particularly SB bleeding. This association was particularly pronounced among aspirin and NSAID users. Inappropriate PPI prescriptions should be avoided in patients with LGI bleeding and a low risk of upper gastrointestinal disease.

Guidelines on optimizing the use of proton pump inhibitors: PPI stewardship

Proton pump inhibitors (PPIs) have been available for over three decades and are among the most commonly prescribed medications. They are effective in treating a variety of gastric acid-related disorders. They are freely available and based on current evidence, use of PPIs for inappropriate indications and duration appears to be common. Over the years, concerns have been raised on the safety of PPIs as they have been associated with several adverse effects. Hence, there is a need for PPI stewardship to promote the use of PPIs for appropriate indication and duration. With this objective, the Indian Society of Gastroenterology has formulated guidelines on the rational use of PPIs. The guidelines were developed using a modified Delphi process. This paper presents these guidelines in detail, including the statements, review of literature, level of evidence and recommendations. This would help the clinicians in optimizing the use of PPIs in their practice and promote PPI stewardship.

Bulbar and post-bulbar duodenal ulcers: characteristics based on location

OBJECTIVES

Most research on duodenal ulcers has focused on bulbar ulcers; details on post-bulbar ulcers remain largely unknown. This study was conducted to determine the characteristics of patients with post-bulbar duodenal ulcers depending on their location.

METHODS AND MATERIALS

We conducted a retrospective study of hospitalized patients newly diagnosed with duodenal ulcers on endoscopy at a tertiary referral center in Japan between April 2004 and March 2019. Five hundred fifty-one patients diagnosed with duodenal ulcers were extracted for analysis.

RESULTS

Ulcers were observed only in the bulbus in 383 cases, only in the post-bulbar duodenum in 82 cases, and were co-existing in both areas in 86 cases. The Bulbar group had less comorbidities and was more likely to have atrophic gastritis, while the Post-bulbar and Co-existing groups were more likely to be admitted for non-gastrointestinal conditions. Regular acid suppressant use was more common in the post-bulbar group than in the Bulbar group. Bulbar ulcers were associated with a shorter length of stay relative to post-bulbar and co-existing ulcers, but ulcer location was not an independent predictor of length of stay. Patients with co-existing bulbar and post-bulbar ulcers have characteristics similar to those with post-bulbar ulcers alone.

CONCLUSION

Patients with post-bulbar ulcers and those with co-existing bulbar and post-bulbar ulcers have different characteristics and outcomes relative to patients with bulbar ulcers.

Proton Pump Inhibitors Increase the Risk of Nonsteroidal Anti-inflammatory Drug-Related Small-Bowel Injury: A Systematic Review With Meta-analysis

INTRODUCTION

Conflicting results exist on the association between proton-pump inhibitor (PPI) and nonsteroidal anti-inflammatory drug (NSAID)-related small-bowel damage. The aim of this study was to determine whether PPIs increased the risk of NSAID-related small-bowel damage by meta-analysis.

METHODS

A systematic electronic search in PubMed, Embase, and Web of Science was conducted from the time the database was created until March 31, 2022, for studies reporting associations between PPI use and outcomes, including the endoscopy-verified prevalence of small-bowel injury, mean number of small-bowel injuries per patient, change in hemoglobin level, and risk of small-bowel bleeding in subjects taking NSAIDs. Meta-analytical calculations for odds ratio (OR) and mean difference (MD) were performed with the random-effects model and interpreted with 95% confidence intervals (CIs).

RESULTS

Fourteen studies comprising 1996 subjects were included. Pooled analysis demonstrated that concomitant use of PPIs significantly increased the prevalence and number of endoscopy-verified small-bowel injuries (prevalence: OR = 3.00; 95% CI: 1.74-5.16; number: MD = 2.30; 95% CI: 0.61-3.99) and decreased hemoglobin levels (MD = -0.50 g/dL; 95% CI: 0.88 to -0.12) in NSAID users but did not change the risk of small-bowel bleeding (OR = 1.24; 95% CI: 0.80-1.92). Subgroup analysis demonstrated that PPIs significantly increased the prevalence of small-bowel injury in subjects taking nonselective NSAIDs (OR = 7.05; 95% CI: 4.70-10.59, 4 studies, I 2 = 0) and COX-2 inhibitors (OR = 4.00; 95% CI: 1.18-13.60, 1 study, no calculated I 2 ) when compared with COX-2 inhibitors alone.

DISCUSSION

PPIs increased the risk of NSAID-related small-bowel damage, and the clinical significance of higher prevalence of small-bowel injuries should be studied in the future.

Small Intestinal Perforation Caused by Enteric-coated Low-dose Aspirin

A 77-year-old man presented with abdominal pain for 1 week. He was taking enteric-coated low-dose aspirin (LDA) to prevent secondary cardiovascular events and a proton pump inhibitor (PPI). Computed tomography indicated a small intestinal perforation; thus, small intestine resection was performed. Two months after surgery, he experienced a recurrence of the perforation. Since his repeated perforation was suspected to be due to LDA, LDA was discontinued. He has experienced no further recurrence since then. This is the first case of small intestinal perforation caused by enteric-coated LDA. Enteric-coated LDA may cause small intestinal perforation in patients with severe atherosclerosis under PPI administration.

Small-bowel capsule endoscopy and device-assisted enteroscopy for diagnosis and treatment of small-bowel disorders: European Society of Gastrointestinal Endoscopy (ESGE) Guideline - Update 2022

MR1: ESGE recommends small-bowel capsule endoscopy as the first-line examination, before consideration of other endoscopic and radiological diagnostic tests for suspected small-bowel bleeding, given the excellent safety profile of capsule endoscopy, its patient tolerability, and its potential to visualize the entire small-bowel mucosa.Strong recommendation, moderate quality evidence. MR2: ESGE recommends small-bowel capsule endoscopy in patients with overt suspected small-bowel bleeding as soon as possible after the bleeding episode, ideally within 48 hours, to maximize the diagnostic and subsequent therapeutic yield.Strong recommendation, high quality evidence. MR3: ESGE does not recommend routine second-look endoscopy prior to small-bowel capsule endoscopy in patients with suspected small-bowel bleeding or iron-deficiency anemia.Strong recommendation, low quality evidence. MR4: ESGE recommends conservative management in those patients with suspected small-bowel bleeding and high quality negative small-bowel capsule endoscopy.Strong recommendation, moderate quality evidence. MR5: ESGE recommends device-assisted enteroscopy to confirm and possibly treat lesions identified by small-bowel capsule endoscopy.Strong recommendation, high quality evidence. MR6: ESGE recommends the performance of small-bowel capsule endoscopy as a first-line examination in patients with iron-deficiency anemia when small bowel evaluation is indicated.Strong recommendation, high quality evidence. MR7: ESGE recommends small-bowel capsule endoscopy in patients with suspected Crohn's disease and negative ileocolonoscopy findings as the initial diagnostic modality for investigating the small bowel, in the absence of obstructive symptoms or known bowel stenosis.Strong recommendation, high quality evidence. MR8: ESGE recommends, in patients with unremarkable or nondiagnostic findings from dedicated small-bowel cross-sectional imaging, small-bowel capsule endoscopy as a subsequent investigation if deemed likely to influence patient management.Strong recommendation, low quality evidence. MR9: ESGE recommends, in patients with established Crohn's disease, the use of a patency capsule before small-bowel capsule endoscopy to decrease the capsule retention rate.Strong recommendation, moderate quality evidence. MR10: ESGE recommends device-assisted enteroscopy (DAE) as an alternative to surgery for foreign bodies retained in the small bowel requiring retrieval in patients without acute intestinal obstruction.Strong recommendation, moderate quality evidence. MR11: ESGE recommends DAE-endoscopic retrograde cholangiopancreatography (DAE-ERCP) as a first-line endoscopic approach to treat pancreaticobiliary diseases in patients with surgically altered anatomy (except for Billroth II patients).Strong recommendation, moderate quality evidence.

Lactobacillus complex capsules ameliorate aspirin-related small intestinal mucosal injury: a prospective, randomized, controlled clinical trial

OBJECTIVES

Aspirin can reduce cardiovascular disease risk; however, it can increase the risk of gastrointestinal injury. Lactobacilli have some protective effects; however, there are few studies on their effects on humans. This study investigates the effects of Lactobacillus complex capsule treatment on the aspirin-related small intestinal mucosal injury.

METHODS

This single-center, prospective, randomized controlled clinical trial included 69 patients using enteric-coated aspirin for >1 month between May and December 2019. After baseline magnetically controlled capsule endoscopy (MCCE), patients with aspirin-related small intestinal mucosal injury were randomly assigned (1:1) to receive enteric-coated aspirin and Lactobacillus complex capsules containing a combination of Lactobacillus rhamnosus I, Lactobacillus rhamnosus II, and Enterococcus faecium (probiotics group) or enteric-coated aspirin only (control group) for 2 months. After treatment, the patient underwent MCCE again. The primary outcome was the change in small intestinal mucosal injury scores from baseline to post-intervention.

RESULTS

Twenty-five patients in the probiotics group and 28 in the control group completed the trial. The decrease in small intestinal mucosal injury scores from baseline to post-intervention was significantly greater in the probiotics group than that in the control group (p < .001). The improvement rates of red spots and erosions in the probiotics group were higher compared with the control group (p = .027 and .022, respectively), and the improvement rate of small intestinal ulcers in the probiotics group was 75.0%; however, there was no improvement in the control group.

CONCLUSION

Lactobacillus complex capsules can ameliorate aspirin-related small intestinal mucosal injury.

Risk factors for small-intestinal mucosal breaks beyond aspirin

BACKGROUND AND AIM

There remains lots of unknowns for small intestinal mucosal breaks (SIMBs). The application of magnetic controlled capsule endoscope (MCCE) may provide a better understanding of SIMBs. The aim of our study was to investigate the prevalence and characteristics of SIMBs in the general population as well as risk factors for SIMBs other than aspirin.

METHODS

Clinical data on individuals who visited our institute between January 2019 and February 2021 for MCCE examination as a health check were collected and analyzed retrospectively. All study participants must have completed the small bowel inspection. Multivariate analysis was employed to reveal the independent risk factors for SIMBs.

RESULTS

A total of 1599 participants, 103 of whom were aspirin users, were finally included. The prevalence of SIMBs was 8.3% (132/1599) in all participants, with 36.9% (38/103) in aspirin users and 6.3% (94/1496) in non-aspirin users. The multivariate analysis showed that in addition to aspirin (OR: 6.17, 95% CI: 3.25-11.58), obesity (OR: 2.30, 95% CI: 1.38-3.92) and smoking (OR: 1.85, 95% CI: 1.56-3.20) were also independent risk factors for SIMBs. Jejunum involvement was more common in aspirin users (20/38, 52.6%), while ilium involvement was more common in non-aspirin users (58/94, 61.7%). Moderate SIMBs (erosions) were more common in aspirin users (17/38, 44.7%), while severe SIMBs (large erosions/ulcers) were more common in non-aspirin users (17/94, 18.1%).

CONCLUSIONS

The risk factors for SIMBs include aspirin as well as smoking and obesity, and the severity and distributive features of SIMBs differ between aspirin users and non-aspirin users.

Proton Pump Inhibitors and In-Hospital Gastrointestinal Bleeding in Patients With Acute Coronary Syndrome Receiving Dual Antiplatelet Therapy

OBJECTIVE

To evaluate the association between proton pump inhibitor (PPI) use and in-hospital gastrointestinal (GI) bleeding in patients with acute coronary syndrome (ACS) taking dual antiplatelet therapy (DAPT).

PATIENTS AND METHODS

This study is based on the Improving Care for Cardiovascular Disease in China-ACS project, an ongoing collaborative registry and quality improvement project of the American Heart Association and the Chinese Society of Cardiology. A total of 25,567 patients with ACS taking DAPT from 172 hospitals from July 1, 2017, through December 31, 2018, were included. Multivariable Cox regression and propensity score-matched analyses were used to evaluate the association between PPI use and in-hospital GI bleeding.

RESULTS

Of these patients with ACS, 63.9% (n=16,332) were prescribed PPIs within 24 hours of admission. Patients using PPIs had a higher rate of GI bleeding compared with those not using PPIs (1.0% vs 0.5%; P<.001). In the multivariable Cox regression analysis, early PPI use was associated with a 58% higher risk of GI bleeding (hazard ratio, 1.58; 95% CI, 1.15 to 2.18; P=.005). Further propensity score matching attenuated the association but still showed that patients using PPIs had a higher rate of GI bleeding (0.8% vs 0.6%; P=.04).

CONCLUSION

In China, PPIs are widely used within 24 hours of admission in patients with ACS taking DAPT. An increased risk of GI bleeding is observed in inpatients with early PPI use. Randomized trials on early use of PPIs in patients with ACS receiving DAPT are warranted.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT02306616.

NSAID-Associated Small Intestinal Injury: An Overview From Animal Model Development to Pathogenesis, Treatment, and Prevention

With the wide application of non-steroidal anti-inflammatory drugs (NSAIDs), their gastrointestinal side effects are an urgent health burden. There are currently sound preventive measures for upper gastrointestinal injury, however, there is a lack of effective defense against lower gastrointestinal damage. According to a large number of previous animal experiments, a variety of NSAIDs have been demonstrated to induce small intestinal mucosal injury in vivo. This article reviews the descriptive data on the administration dose, administration method, mucosal injury site, and morphological characteristics of inflammatory sites of various NSAIDs. The cells, cytokines, receptors and ligands, pathways, enzyme inhibition, bacteria, enterohepatic circulation, oxidative stress, and other potential pathogenic factors involved in NSAID-associated enteropathy are also reviewed. We point out the limitations of drug modeling at this stage and are also pleased to discover the application prospects of chemically modified NSAIDs, dietary therapy, and many natural products against intestinal mucosal injury.

Review article: drug-induced small bowel injury

BACKGROUND

Drug-induced gastrointestinal injury has been increasingly reported, but its exact incidence is not known. The small and large intestines represent the most affected sites of injury, accounting for 20%-40% of all gastrointestinal side effects.

AIM

To provide an updated literature review detailing medications linked to the development of small bowel injury.

METHODS

We conducted a literature search on PubMed from its inception to May 1, 2021. We included English-language original studies, meta-analyses, systematic reviews, review articles and case reports.

RESULTS

Drug-induced enteropathy can range from asymptomatic histological changes resulting in a subtle, self-limited disease to a chronic inflammatory condition mimicking inflammatory bowel disease, or bowel perforation. Endoscopy can demonstrate erythema, mucosal friability, oedema, erosions, ulcers or strictures in severe cases. Histology may include mucosal erosions and ulcerations, focal active enteritis, villous atrophy, epithelial apoptosis or necrotising enteritis. A well-established association has been found with the use of nonsteroidal anti-inflammatory drugs, immunosuppressants, chemotherapeutic agents, antibiotics, immunotherapies, etanercept and olmesartan. Possible associations have been reported with other biologic agents, medications used for glycemic control, antihypertensives, cholinesterase inhibitors, potassium and iron supplements, with conflicting data regarding contraceptives/hormonal therapy and isotretinoin.

CONCLUSION

Physicians should be aware of the manifestations of drug-induced enteropathy as early recognition can lead to prompt discontinuation of the offending therapy and, therefore, a reduced risk of future complications.

Impact of non-antibiotic drugs on the human intestinal microbiome

INTRODUCTION

The gut microbiota is composed of trillions of microbial cells and viruses that interact with hosts. The composition of the gut microbiota is influenced by several factors including age, diet, diseases, or medications. The impact of drugs on the microbiota is not limited to antibiotics and many non-antibiotic molecules significantly alter the composition of the intestinal microbiota.

AREAS COVERED

This review focuses on the impact of four of the most widely prescribed non-antibiotic drugs in the world: Proton-pump inhibitors, metformin, statins, and non-steroidal anti-inflammatory. We conducted a systematic review by searching online databases including Medline, Web of science, and Scopus for indexed articles published in English until February 2021. We included studies assessing the intestinal microbiome alterations associated with proton pump inhibitors (PPIs), metformin, statins, and nonsteroidal anti-inflammatory drugs (NSAIDs). Only studies using culture-independent molecular techniques were included.

EXPERT OPINION

The taxonomical signature associated with non-antibiotic drugs are not yet fully described, especially in the field of metabolomic. The identification of taxonomic profiles associated a specific molecule provides information on its mechanism of action through interaction with the intestinal microbiota. Many side effects could be related to the dysbiosis induced by these molecules.

A novel gene associated with small bowel bleeding in patients taking low-dose aspirin

OBJECTIVE

We have previously revealed the clinical factors and genetic polymorphisms associated with gastrointestinal mucosal injury and bleeding, induced by low-dose aspirin (LDA). After performing genome-wide analysis of single nucleotide polymorphisms (SNPs) using the Drug Metabolizing Enzymes and Transporters (DMET) system among drug metabolism and transporter genes, certain SNPs were found to increase the risk for LDA-induced small bowel bleeding. The aim of this study was to identify the SNPs involved in LDA-induced small bowel bleeding.

SUBJECTS AND METHODS

Subjects were patients taking LDA, with small bowel bleeding diagnosed using capsule endoscopy. We investigated the clinical characteristics and the previously identified SNPs, that were examined by the DNA direct sequence method.

RESULTS

56 patients with bleeding and 410 controls taking LDA were enrolled. The risk factors associated with small bowel bleeding included smoking, cerebrovascular diseases, chronic renal failure, non-steroidal anti-inflammatory drug (NSAID) or anticoagulants combination, and two SNPs (CYP4F11 20043G>A (D446N) rs1060463, GSTP1 313A>G rs1695). After propensity score matching, GSTP1 rs1695 was significantly associated with small bowel bleeding.

CONCLUSION

The GSTP1 SNP may be a predictive marker for small bowel bleeding among patients taking LDA.

Effect of Weikang Capsule () on Aspirin-Related Gastric and Small Intestinal Mucosal Injury

OBJECTIVE

To investigate the effects of Weikang Capsule (, WKC) on aspirin-related gastric and small intestinal mucosal injury by magnetically controlled capsule endoscopy (MCCE).

METHODS

Patients taking enteric-coated aspirin aged 40-75 years were enrolled in Beijing Anzhen Hospital, Capital Medical University from January 2019 to December 2019. The patients continued taking aspirin Tablet (100 mg per day) and underwent MCCE before and after 1-month combined treatment with WKC (0.9 g per time orally, 3 times per day). The gastrointestinal symptom score, gastric Lanza score, the duodenal, jejunal and ileal mucosal injury scores were used to evaluate the gastrointestinal injury before and after treatment. Adverse events including nausea, vomiting, abdominal pain, abdominal distension, abdominal discomfort, dizziness, or headache during MCCE and combined treatment were observed and recorded.

RESULTS

Twenty-two patients (male/female, 13/9) taking enteric-coated aspirin aged 59.5 ± 11.3 years with a duration of aspirin use of 28.0 (1.0, 48.0) months were recruited. Compared with pre-treatment, the gastrointestinal symptom rating scale scores, gastric Lanza scores, and duodenal mucosal injury scores were significantly reduced after 1-month WKC treatment (P<0.05), and jejunal and ileal mucosal injury scores showed no obvious change. No adverse events occurred during the trial.

CONCLUSIONS

WKC can alleviate gastrointestinal symptoms, as well as gastric and duodenal mucosal injuries, in patients taking enteric-coated aspirin; it does not aggravate jejunal or ileal mucosal injury, which may be an effective alternative for these patients (Clinical trial registry No. ChiCTR1900025451).

Effect of a proton-pump inhibitor on intestinal microbiota in patients taking low-dose aspirin

BACKGROUND AND AIM

Low-dose aspirin (LDA) administration prevents cerebral infarction and myocardial infarction, but many studies found an association with mucosal injury. Proton-pump inhibitors (PPIs) can prevent gastric and duodenal mucosal damage, but they may exacerbate small-intestinal mucosal injury by altering the microbiota. We aimed to assess the effect of PPIs on the intestinal flora of LDA users.

METHODS

Thirty-two recruited patients, who received LDA (100 mg/day) but did not take PPIs, were divided into 15 patients additionally receiving esomeprazole (20 mg/day) and 17 patients additionally receiving vonoprazan (10 mg/day). On days 0, 30, 90, and 180, the microbiota of each patient was examined by terminal restriction fragment length polymorphism analysis, and the serum gastrin, hemoglobin, and hematocrit levels were measured.

RESULTS

Additional PPI administration increased the proportion of Lactobacillales in the microbiota of LDA users. This trend was more prevalent in the vonoprazan group (p < 0.0001) than in the esomeprazole group (p = 0.0024). The Lactobacillales proportion was positively correlated with the gastrin level (r = 0.5354). No significant hemoglobin or hematocrit level reduction was observed in subjects receiving LDA with additional PPI.

CONCLUSIONS

Additional PPI administration increased the Lactobacillales proportion in the microbiota of LDA users. The positive correlation between the gastrin level and the proportion of Lactobacillales suggested that the change in the intestinal flora was associated with the degree of suppression of gastric acid secretion. Additional oral PPI did not significantly promote anemia, but the risk of causing PPI-induced small-intestinal mucosal injury in LDA users should be considered.

Rebamipide ameliorates indomethacin-induced small intestinal damage and proton pump inhibitor-induced exacerbation of this damage by modulation of small intestinal microbiota

Non-steroidal anti-inflammatory drugs (NSAIDs) induce small intestinal damage. It has been reported that rebamipide, a mucoprotective drug, exerts a protective effect against NSAID-induced small intestinal damage; however, the underlying mechanism remains unknown. In this study, we investigated the significance of the small intestinal microbiota in the protective effect of rebamipide against indomethacin-induced small intestinal damage in mice. A comprehensive analysis of the 16S rRNA gene sequencing revealed an alteration in the composition of the small intestinal microbiota at the species level, modulated by the administration of rebamipide and omeprazole. The transplantation of the small intestinal microbiota of the mice treated with rebamipide suppressed the indomethacin-induced small intestinal damage. Omeprazole, a proton pump inhibitor, exacerbated the indomethacin-induced small intestinal damage, which was accompanied by the alteration of the small intestinal microbiota. We found that the transplantation of the small intestinal microbiota of the rebamipide-treated mice ameliorated indomethacin-induced small intestinal damage and the omeprazole-induced exacerbation of the damage. These results suggest that rebamipide exerts a protective effect against NSAID-induced small intestinal damage via the modulation of the small intestinal microbiota, and that its ameliorating effect extends also to the exacerbation of NSAID-induced small intestinal damage by proton pump inhibitors.

Aspirin in the Prevention of Cardiovascular Disease and Cancer

More than a century after its synthesis, daily aspirin, given at a low dose, is a milestone treatment for the secondary prevention of cardiovascular disease (CVD). Its role in primary prevention of CVD is still debated. Older randomized controlled trials showed that aspirin reduced the low incidence of myocardial infarction but correspondingly increased the low incidence of serious gastrointestinal bleeds without altering mortality. More recent trials see the benefit attenuated, perhaps obscured by other cardioprotective practices, while the bleeding risk remains, especially in older patients. Indirect evidence, both preclinical and clinical, suggests that aspirin may protect against sporadic colorectal cancer and perhaps other cancers. However, further studies are still necessary to warrant the consumption of aspirin for primary prevention of CVD and cancer by apparently healthy individuals.

Proton-pump inhibitors are associated with a high false-positivity rate in faecal immunochemical testing

BACKGROUND

False-positivity rates in faecal immunochemical test (FIT) can be affected by drug exposure. We aimed to assess the association between proton pump inhibitors (PPI) consumption and false positive (FP) results in a colorectal cancer (CRC) screening programme using electronic prescription records.

METHODS

A retrospective cohort study within a population-based screening program for CRC from 2010 to 2016 was performed. Participants with a conclusive FIT result and with prescription electronic data were included. An FP result was defined as having a positive FIT (≥ 20 µg haemoglobin/g faeces) and a follow-up colonoscopy without intermediate or high-risk lesions or CRC. Screening data were anonymously linked to the public data analysis program for health research and innovation (PADRIS) database that recorded patient diseases history and reimbursed medication. PPI exposure was defined as having retrieved at least one dispensation of PPI three months prior to the FIT.

RESULTS

A total of 89,199 tests (of 46,783 participants) were analysed, 4824 (5.4%) tested positive and the proportion of FP was 53.5%. Overall, 17,544 participants (19.7%) were PPI users prior to FIT performance. PPI exposure increased the probability of obtaining an FP FIT result from 50.4 to 63.3% (adjusted OR 1.39; 95% CI 1.18-1.65). Nonsteroidal anti-inflammatory drugs, acetylsalicylic acid, antibiotics, and laxatives were also associated with an FP result. The effect of PPI was independent and showed a synergistic interaction with nonsteroidal anti-inflammatory drugs.

CONCLUSION

PPIs increase FIT positivity at the expense of FP results. The recommendation to avoid their use before FIT performance could reduce up to 3% of colonoscopies and 9% of FP results.

[Gastrointestinal Bleeding in Patients with Coronary Heart Disease: Preventive Options]

Extensive use of antithrombotic drugs (ATD) in patients with ischemic heart disease (IHD), on the one hand, provides a considerable decrease in the risk for development of life-threatening cardiovascular complications but on the other hand, is associated with a risk of gastrointestinal bleedings (GIB), which may develop in 0.5-1.0 % of patients. In such cases, the major measures for prevention of GIB are strict adherence to indications for the ATD treatment, detection and analysis of risk factors for GIB and their elimination as far as feasible. For evaluation of GIB risk in patients with IHD, the PRECISE-DAPT and DAPT, HAS-BLED scales should be used. If the risk factors are non-modifiable the therapeutic tactics for further management of these patients should be strictly individual with determining the nature of damage, degree of a risk for present and possible complications, and the range of required therapeutic and diagnostic measures. The use of ATD requires monitoring of the patient's condition to timely detect and treat GI complications.

[NSAID enteropathy]

Nonsteroidal anti-inflammatory drugs (NSAIDs) are one of the most commonly used drugs in the world, and their side effects are very high. First of all, these are NSAID gastropathy, but in the long term, 5070% of NSAIDs cause damage to the small intestine (NSAID enteropathy), sometimes with serious consequences. To date, no drugs have been proposed with proven effectiveness to prevent this side effect. Apparently, this is not due to the fully clarified mechanism of pathogenesis. The most promising is the hypothesis of the participation of individual representatives of microflora in the development of enteropathy. Therefore, modulating the intestinal flora with the help of probiotics can be the basic therapeutic strategy for the prevention and treatment of such damage.

Effect of Proton Pump Inhibitors on Risks of Upper and Lower Gastrointestinal Bleeding among Users of Low-Dose Aspirin: A Population-Based Observational Study

Estimates of the effect of proton pump inhibitors (PPIs) on risks of upper and lower gastrointestinal bleeding (UGIB and LGIB) among low-dose aspirin users in routine clinical practice are variable (UGIB) or lacking (LGIB). We aimed to establish these risks in the same observational study population. Using UK primary care data, we followed 199,049 new users of low-dose aspirin (75–300 mg/day) and matched non-users at start of follow-up to identify incident UGIB/LGIB cases. In nested case–control analyses, adjusted odds ratios (ORs) were calculated for concomitant PPI use vs. past (discontinued) PPI use among current low-dose aspirin users. For UGIB (n = 987), ORs (95% CIs) were 0.69 (0.54–0.88) for >1 month PPI use and 2.65 (1.62–4.3) for ≤1 month PPI use. Among the latter group, ORs (95% CIs) were 3.05 (1.75–5.33) for PPI initiation after start of aspirin therapy, and 1.66 (0.63–4.36) for PPI initiation on/before start of aspirin therapy. For LGIB (n = 1428), ORs (95% CIs) were 0.98 (0.81–1.17) for >1 month PPI use and 1.12 (0.73–1.71) for ≤1 month PPI use. Among low-dose aspirin users, maintaining PPI use (>1 month) was associated with a significantly reduced UGIB risk. Neither short nor long-term PPI use affected LGIB risk.

NSAID-Gut Microbiota Interactions

Nonsteroidal anti-inflammatory drugs (NSAID)s relieve pain, inflammation, and fever by inhibiting the activity of cyclooxygenase isozymes (COX-1 and COX-2). Despite their clinical efficacy, NSAIDs can cause gastrointestinal (GI) and cardiovascular (CV) complications. Moreover, NSAID use is characterized by a remarkable individual variability in the extent of COX isozyme inhibition, therapeutic efficacy, and incidence of adverse effects. The interaction between the gut microbiota and host has emerged as a key player in modulating host physiology, gut microbiota-related disorders, and metabolism of xenobiotics. Indeed, host-gut microbiota dynamic interactions influence NSAID disposition, therapeutic efficacy, and toxicity. The gut microbiota can directly cause chemical modifications of the NSAID or can indirectly influence its absorption or metabolism by regulating host metabolic enzymes or processes, which may have consequences for drug pharmacokinetic and pharmacodynamic properties. NSAID itself can directly impact the composition and function of the gut microbiota or indirectly alter the physiological properties or functions of the host which may, in turn, precipitate in dysbiosis. Thus, the complex interconnectedness between host-gut microbiota and drug may contribute to the variability in NSAID response and ultimately influence the outcome of NSAID therapy. Herein, we review the interplay between host-gut microbiota and NSAID and its consequences for both drug efficacy and toxicity, mainly in the GI tract. In addition, we highlight progress towards microbiota-based intervention to reduce NSAID-induced enteropathy.

Gastric acid inhibitor aggravates indomethacin-induced small intestinal injury via reducing Lactobacillus johnsonii

Proton pump inhibitors (PPIs) alter the composition of the intestinal microbiome, exacerbating indomethacin (IND)-induced small intestinal damage. Vonoprazan fumarate inhibits gastric acid secretion using a different mechanism from PPIs. We investigated the effects of both drugs on the intestinal microbiome and IND-induced small intestinal damage. We sought to clarify whether PPI-induced dysbiosis and worsening of the damage were due to a specific drug class effect of PPIs. Rabeprazole administration increased operational taxonomic unit numbers in the small intestines of C57BL/6 J mice, whereas the difference was not significant in the vonoprazan-treated group but exhibited a trend. Permutational multivariate analysis of variance of the unweighted UniFrac distances showed significant differences between vehicle- and vonoprazan- or rabeprazole-treated groups. L. johnsonii was the predominant microbial species, and the population ratio decreased after vonoprazan and rabeprazole administration. The vonoprazan- and rabeprazole-treated groups showed increased IND-induced damage. This high sensitivity to IND-induced damage was evaluated by transplantation with contents from the small intestine of mice treated with either vonoprazan or rabeprazole. Supplementation of L. johnsonii orally in mice treated with rabeprazole and vonoprazan prevented the increase in IND-induced small intestinal damage. In conclusion, both rabeprazole and vonoprazan aggravated NSAID-induced small intestinal injury by reducing the population of L. johnsonii in the small intestine via suppressing gastric acid secretion.

Prevalence of Gastric and Small-Intestinal Mucosal Injury in Elderly Patients Taking Enteric-Coated Aspirin by Magnetically Controlled Capsule Endoscopy

Objective

To investigate aspirin-related gastric and small-intestinal mucosal injury in elderly patients by magnetically controlled capsule endoscopy (MCCE).

Methods

Patients taking enteric-coated aspirin attending the outpatient department of Beijing Anzhen Hospital, Capital Medical University, from September 2017 to July 2019 underwent MCCE to assess injury to the gastric and small-intestinal mucosa. The patients were divided into the elderly group (age ≥ 60 years) and middle-aged group (45 years ≤ age < 60 years), and their clinical data were evaluated.

Results

Sixty-eight patients (34 per group) taking enteric-coated aspirin were recruited, and the elderly and middle-aged groups did not differ significantly in sex, history of smoking, history of alcohol consumption, body mass index, or accompanying diseases. In the elderly and middle-aged groups, the gastric Lanza scores were 2.0 (2.0, 3.0) and 2.0 (1.0, 3.0; P = 0.192), the numbers of patients with small-intestinal mucosal injuries (at least one erosion and/or ulcer) were 30 (88.2%) and 15 (44.1%; P < 0.001), the numbers of patients with more severe small-intestinal mucosal injuries (larger erosion and/or ulcer) were 11 (32.4%) and 3 (8.8%; P = 0.033), the numbers of patients with ileal erosion were 22 (64.7%) and 8 (23.5%; P = 0.001), and the durations of aspirin use were 30.0 (12.0, 120.0) and 10.5 (2.0–48.0) months (P = 0.007), respectively.

Conclusions

The rate of small-intestinal mucosal injury was significantly higher in elderly than in middle-aged patients taking enteric-coated aspirin, especially the rate of ileal erosion. MCCE enables the monitoring of aspirin-related gastric and small-intestinal mucosal injury in elderly patients, which can guide treatment decision making.

Screening for Gastric and Small Intestinal Mucosal Injury with Magnetically Controlled Capsule Endoscopy in Asymptomatic Patients Taking Enteric-Coated Aspirin

Objective

To investigate gastric and small intestinal mucosal injury in asymptomatic patients taking enteric-coated aspirin using magnetically controlled capsule endoscopy.

Methods

Patients taking enteric-coated aspirin (aspirin group) and healthy controls (control group) were recruited from Beijing Anzhen Hospital, Capital Medical University, between September 2017 and May 2018, and undertook magnetically controlled capsule endoscopy.

Results

Twenty-six subjects were recruited to the aspirin group and twenty-six to the control group; the median Gastrointestinal Symptom Rating Scale scores were 3.50 and 3.00 (P = 0.200), the median gastric Lanza scores were 2.50 and 1.00 (P < 0.001), the small intestinal Lanza scores were 1.00 and 0.00 (P < 0.001), the gastric controlled examination times were 50.0 and 51.0 min (P = 0.171), the small intestinal transit times were 240.0 and 238.0 min (P = 0.654), and the capsule excretion times were 24.0 and 24.0 hours (P = 0.956), respectively.

Conclusions

Rates of gastric and small intestinal mucosal injuries were significantly higher in patients without obvious gastrointestinal symptoms taking enteric-coated aspirin compared to healthy controls. Magnetically controlled capsule endoscopy constitutes a safe, real-time screening modality for gastric and small intestinal mucosal injury in patients taking enteric-coated aspirin.

Proton pump inhibitor usage and nonsteroidal anti-inflammatory drugs-associated small intestinal injury: How to balance risks and benefits

Proton pump inhibitors (PPIs) are widely used in the treatment of acid-related diseases and can effectively prevent upper gastrointestinal damage associated with nonsteroidal anti-inflammatory drugs (NSAIDs). However, recent studies have shown that PPIs cannot protect from NSAIDs-associated small bowel injury, and may even aggravate intestinal injury by altering the intestinal flora. This article will discuss the risks associated with the combined use of NSAIDs and PPIs, as well as how to balance risks and benefits of PPIs treatment, and provide a brief review of strategies for the prevention of NSAIDs-associated small bowel injury.

Dual antiplatelet therapy does not affect the incidence of low-dose aspirin-induced small intestinal mucosal injury in patients after percutaneous coronary intervention for coronary stenosis: a multicenter cross-sectional study

Although low-dose aspirin (LDA) is known to induce small intestinal mucosal injury, the effect of dual antiplatelet therapy (DAPT; LDA + clopidogrel) on small intestinal mucosa in patients after percutaneous coronary intervention (PCI) for coronary stenosis is unknown. Fifty-one patients with a history of PCI and LDA use were enrolled, and 45 eligible patients were analyzed. Patients were grouped based on DAPT (DAPT: n = 10 and non-DAPT: n = 35) and proton pump inhibitor (PPI) use (PPI user: n = 22 and PPI-free patients: n = 23) to compare small intestinal endoscopic findings. The relationship between LDA-use period and small intestinal endoscopic findings was also examined. Multivariate analysis was performed to identify risk factors for LDA-induced mucosal injury using age, sex, DAPT, PPI, gastric mucoprotective drug, and LDA-use period. The rate of small intestinal mucosal injury incidence did not significantly differ between DAPT and non-DAPT patients (50% vs 51.1%, respectively; p = 0.94), or PPI users and PPI-free patients (50% vs 52.2%, respectively; p = 0.88). Additionally, LDA-use period of ≤24 months (n = 15) yielded a significantly higher rate of small intestinal mucosal injury incidence than LDA-use period >24 months (n = 30) (80% vs 36.7%, respectively; p = 0.006). Multivariate analysis revealed that a LDA-use period of ≤24 months was a significant risk factor for small intestinal mucosal injury (odds ratio: 19.5, 95% confidence interval: 2.48–154.00, p = 0.005). Following PCI for coronary stenosis, neither DAPT nor PPI affected LDA-induced small intestinal mucosal injury. Moreover, patients who used LDA within the last 24 months were at a greater risk of small intestinal mucosal injury.

NSAIDs and the small bowel

PURPOSE OF REVIEW

The review describes the effects of NSAID gastrointestinal toxicity on the small bowel, wherein injury is as prevalent as in the gastroduodenum. This is well documented by capsule endoscopy, which also provides an endoscopic endpoint for novel treatment strategies.

RECENT FINDINGS

Appreciation of the prevalence of NSAID enteropathy has grown with capsule endoscopy and the use of composite end points that include obscure haemoglobin decreases in clinical studies. Along with dual cyclo-oxygenase isoform inhibition, gram-negative antigen presentation plays a role in the pathogenesis of NSAID enteropathy. The concomitant use of proton pump inhibitor (PPI) agents with both selective and nonselective NSAIDs in gastroduodenal protection exacerbates endoscopic enteropathy, which is thought to be due to intestinal dysbiosis. Strategies for small bowel mucosal protection include prostaglandin repletion and augmenting the intestinal flora.

SUMMARY

NSAID- related enteropathy is common and often presents subclinically. The most common presentation is anaemia, which may be less common in those on cyclo-oxygenase (COX)-2 inhibitors than nonselective NSAIDs. PPI use worsens NSAID enteropathy with more occult bleeding and ulceration and has been linked to gram-negative intestinal dysbiosis. If NSAID cessation is not possible, COX-2 inhibition without PPI therapy should be considered in patients with upper gastrointestinal risk factors. Mucoprotective agents such as misoprostol and rebamipide show promise and probiotics may have a future role.

Microscopic colitis-microbiome, barrier function and associated diseases

Microscopic colitis (MC) is a chronic inflammatory bowel disease (IBD) with little in terms of endoscopic abnormalities and is frequently associated with other autoimmune diseases. The peak incidence of the disease is in middle aged or older populations, mostly females. The pathogenesis of MC is complex, multifactorial and poorly understood. Current concepts revolve around innate immunity or microbiome alterations as well as gut barrier dysfunction, all of which lead to the development of subtle inflammatory lesions in gut mucosa. The results of numerous basic and clinical studies involving molecular techniques as well as advanced endoscopic imaging revealed the important role of both intrinsic (e.g., hormonal) as well as extrinsic (e.g., NSAIDs and PPIs) factors in the modulation of gastrointestinal microbiome and MC pathogenesis. Capsule endoscopy as well confocal endomicroscopy imaging, alongside standard endoscopic techniques offer new tools in the evaluation of MC patients and allow their better stratification for novel treatment protocols based on modulation of gut microbiome and barrier function.

Effect of egualen sodium hydrate on small-intestinal mucosal damage induced by low-dose aspirin: a prospective randomized clinical trial

Low-dose aspirin, which is widely used to reduce the risk of cardio- and cerebrovascular thrombosis, often induces gastroenteropathy by increasing the permeability of the mucosa. However, therapeutic strategies for patients with low-dose aspirin-induced small intestinal injury have not been determined. We evaluated the preventative effect of egualen sodium hydrate, a gastro-protective agent that suppresses indomethacin-induced small-intestinal damage in rats, against small-intestinal mucosal damage induced by low-dose aspirin in healthy adult male volunteers. Participants were randomly allocated to receive aspirin 100 mg/kg daily (control group, n = 10) or aspirin 100 mg/kg plus egualen sodium 30 mg daily (egualen sodium group, n = 10). Small intestinal mucosal injury was evaluated by capsule endoscopy two weeks after initiation of drug administration. Fecal analyses (occult blood test, immunochemical test, transferrin measurement and calprotectin measurement) were carried out before and after treatment. Egualen sodium significantly suppressed the total number of small intestinal injuries detected by capsule endoscopy and the positive ratio for the fecal occult blood test. Daily use of 30 mg of egualen sodium showed a preventative effect on low-dose aspirin-induced small intestinal injury. Since acid suppression therapy was reported to exacerbate NSAIDs-induced enteropathy via dysbiosis, egualen sodium may be useful for patients treated with low-dose aspirin.

Associations between drugs and small-bowel mucosal bleeding: Multicenter capsule-endoscopy study

BACKGROUND AND AIM

Although several drugs may induce small-bowel mucosal injuries, it is unclear whether these injuries contribute to overt small-bowel bleeding. This study was designed to evaluate the associations between drug use and small-bowel mucosal injury and between these mucosal injuries and overt bleeding in a disease-relevant population.

METHODS

We retrospectively studied patients with suspected small-bowel diseases who underwent capsule endoscopy between 2010 and 2013. Drug exposure, Charlson Comorbidity Index, smoking, and alcohol consumption were assessed before capsule endoscopy. Adjusted odds ratios (AOR) and confidence intervals (CI) were estimated for small-bowel mucosal injury and small-bowel overt bleeding.

RESULTS

In total, 850 patients were analyzed during the study period. Median age was 64 years, and 544 patients (64.0%) were men. Among the patients with small-bowel mucosal injury (n = 60) and without mucosal injury (n = 705), use of non-steroidal anti-inflammatory drugs (NSAIDs) (AOR 1.8, 95% CI 1.01-3.31) was significantly associated with an increased risk of small-bowel mucosal injury compared with non-use. Patients with small-bowel mucosal injury with overt bleeding (n = 85) and without overt bleeding (n = 60) were compared, and no significant difference between the groups in the usage rates for NSAIDs, thienopyridine, other antiplatelets, anticoagulants, acetaminophen, tramadol hydrochloride, or steroids was revealed, even after adjusting for confounders.

CONCLUSION

Although the use of NSAIDs was significantly associated with an increased risk of small-bowel mucosal injury, no significant associations were observed between the use of such drugs and small-bowel overt bleeding.

Characteristics of Nonsteroidal Anti-Inflammatory Drugs (NSAIDs)-Induced Small Bowel Injury Identified by Single-Balloon Endoscopy or Capsule Endoscopy

BACKGROUND The special features of nonsteroidal anti-inflammatory drugs (NSAIDs) enteropathy were partially clarified by single-balloon endoscopy(SBE). We aimed to investigate the characteristics of NSAIDs injuries that were differ from other ulcer diseases and efficacy of SBE compared with capsule endoscopy(CE). MATERIAL AND METHODS 1,644 symptomatic patients (221 patients taking NSAIDs) hospitalized between January 2006 and March 2016 were recruited and underwent SBE and/or CE. RESULTS NSAIDs damages were identified in 110 patients (49.77%). The special features of NSAIDs lesions included: variform, superficial, multiple and irregular arrangement; <1 cm in diameter (67.27%); the location in jejunum and ileum was similar; ileocecal valve was rarely influenced (20.91%). The specificity and positive predictive value of SBE for diagnosing NSAIDs breaks were higher than CE (95.74% vs. 80.00%; 95.45% vs. 81.63%, p<0.05). There were no differences in the detection rate and the diagnostic accuracy rate of small bowel diseases between SBE and CE in the NSAIDs group (69.4% vs. 66.3% and 83.58% vs. 80.65%, p>0.05 respectively). The consistency in diagnosing NSAIDs breaks for the 2 methods was 82.61%. More tiny lesions at the distal ileum were detected by SBE. Four patients misdiagnosed by CE got accurate diagnose through biopsy by SBE. Three patients with active bleeding caused by NSAIDs-induced ulcers underwent hemostasis successfully by SBE. CONCLUSIONS NSAIDs injuries might be distinguished from other diseases by endoscopic features and biopsy through SBE, which appeared to be an effective method for diagnosis and treatment.

Proton pump inhibitor therapy did not increase the prevalence of small-bowel injury: A propensity-matched analysis

Background

Previous studies have reported that the suppression of acid secretion by using proton pump inhibitors (PPIs) results in dysbiosis of the small-bowel microbiota, leading to exacerbated small-bowel injuries, including erosions and ulcers. This study was designed to assess the association between PPI therapy and small-bowel lesions after adjustment for the differences in baseline characteristics between users and non-users of PPIs.

Methods

We retrospectively studied patients suspected to be suffering from small-bowel diseases, who underwent capsule endoscopy between 2010 and 2013. We used propensity matching to adjust for the differences in baseline characteristics between users and non-users of PPIs. The outcomes included the prevalence of small-bowel lesions: erosion, ulcer, angioectasia, varices, and tumor.

Results

We selected 327 patient pairs for analysis after propensity matching, and found no significant differences in the prevalence of small-bowel injuries, including erosions and ulcers, between users and non-users of PPIs. Two subgroup analyses of the effect of the type of PPI and the effect of PPI therapy in users and non-users of nonsteroidal anti-inflammatory drugs indicated no significant differences in the prevalence of small-bowel injuries in these two groups.

Conclusion

PPI therapy did not increase the prevalence of small-bowel injury, regardless of the type of PPI used and the use of nonsteroidal anti-inflammatory drugs.

Aspirin and omeprazole for secondary prevention of cardiovascular disease in patients at risk for aspirin-associated gastric ulcers

INTRODUCTION

Cardiovascular disease is the most important cause of morbidity and mortality in the world and low-dose aspirin is considered the cornerstone of the cardiovascular disease prevention. However, low-dose aspirin use is associated with gastrointestinal adverse effects in the whole gastrointestinal tract. In this setting, co-therapy with a proton pump inhibitor is the most accepted strategy to reduce aspirin related upper gastrointestinal damage. In addition, some adverse effects have been described with proton pump inhibitors long term use. Areas covered: Low-dose aspirin related beneficial and adverse effects in cardiovascular system and gastrointestinal tract are reviewed. In addition, this manuscript summarizes current data on upper gastrointestinal damage prevention and adverse events with proton pump inhibition. Finally, we discuss the benefit/risk ratio of proton pump inhibitor use in patients at risk of gastrointestinal damage taking low-dose aspirin. Expert commentary: Nowadays, with the current available evidence, the combination of low-dose aspirin with proton pump inhibitor is the most effective therapy for cardiovascular prevention in patients at high gastrointestinal risk. However, further studies are needed to discover new effective strategies with less related adverse events.

Investigation of Small Bowel Abnormalities in HIV-Infected Patients Using Capsule Endoscopy

HIV infection is reportedly associated with an increased permeability of the intestinal epithelium and can cause HIV enteropathy, which occurs independently of opportunistic infections. However, the characteristics of small bowel abnormalities attributable to HIV infection are rarely investigated. In the present study, we assessed the intestinal mucosal changes found in HIV-infected patients and compared them with the mucosa of healthy control subjects using capsule endoscopy (CE). Three of the 27 HIV-infected patients harbored gastrointestinal opportunistic infections and were thus excluded from subsequent analyses. The endoscopic findings of CE in HIV-infected patients were significantly higher than those in control subjects (55% versus 10%, P = 0.002); however, most lesions, such as red spots or tiny erosions, were unlikely to cause abdominal symptoms. After validating the efficacy of CE for the diagnosis of villous atrophy, we found that the prevalence of villous atrophy was 54% (13/24) among HIV-infected patients. Interestingly, villous atrophy persisted in patients receiving long-term antiretroviral therapy, though most of them exhibited reconstituted peripheral blood CD4+ T cells. Although we could not draw any conclusions regarding the development of small bowel abnormalities in HIV-infected patients, our results may provide some insight regarding the pathogenesis of HIV enteropathy.

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.

Is a fecal occult blood test a useful tool for judging whether to perform capsule endoscopy in low-dose aspirin users with negative colonoscopy and esophagogastroduodenoscopy?

BACKGROUND

Aspirin use is reportedly not to be associated with fecal immunochemical occult blood test (FIT) false-positive results for the detection of colorectal cancer. The need for additional small bowel exploration in FIT-positive, low-dose aspirin users with a negative colonoscopy is controversial. The aim of this study was to assess the ability of FIT to judge whether capsule endoscopy (CE) should be performed in low-dose aspirin users with negative colonoscopy and esophagogastroduodenoscopy findings by comparing FIT results with CE findings.

METHODS

A total of 264 consecutive low-dose aspirin users with negative colonoscopy and esophagogastroduodenoscopy who were scheduled to undergo CE at five hospitals in Japan were enrolled. Patients had been offered FIT prior to the CE. The association between the FIT results and the CE findings was then assessed.

RESULTS

One hundred and fifty-seven patients were included in the final analysis. Eighty-four patients (53.5 %) had positive FIT results. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of positive FIT results for small bowel ulcers were 0.56, 0.47, 0.30, and 0.73, respectively. Furthermore, the NPV of positive FIT results for severe small bowel injury (Lewis score ≥790) was markedly high (0.90). When the analysis was performed only in low-dose aspirin users with anemia, the sensitivity of the positive FIT results was notably improved (0.72).

CONCLUSIONS

Small bowel evaluation using CE is not recommended for FIT-negative, low-dose aspirin users. However, small bowel evaluation using CE should be considered in both FIT-positive and anemic low-dose aspirin users.

Protons pump inhibitor treatment and lower gastrointestinal bleeding: Balancing risks and benefits

Proton pump inhibitors (PPIs) represent a milestone in the treatment of acid-related diseases, and are the mainstay in preventing upper gastrointestinal bleeding in high-risk patients treated with nonsteroidal anti-inflammatory drugs (NSAIDs) or low-dose aspirin. However, this beneficial effect does not extend to the lower gastrointestinal tract. PPIs do not prevent NSAID or aspirin-associated lower gastrointestinal bleeding (LGB). PPIs may increase both small bowel injury related to NSAIDs and low-dose aspirin treatment and the risk of LGB. Recent studies suggested that altering intestinal microbiota by PPIs may be involved in the pathogenesis of NSAID-enteropathy. An increase in LGB hospitalization rates may occur more frequently in older patients with more comorbidities and are associated with high hospital resource utilization, longer hospitalization, and increased mortality. Preventive strategies for NSAID and aspirin-associated gastrointestinal bleeding should be directed toward preventing both upper and lower gastrointestinal damage. Future research should be directed toward identifying patients at low-risk for gastrointestinal events associated with the use of NSAIDs or aspirin to avoid inappropriate PPI prescribing. Alternatively, the efficacy of new pharmacologic strategies should be evaluated in high-risk groups, with the aim of reducing the risk of both upper and lower gastrointestinal bleeding in these patients.

Colchicine prevents NSAID-induced small intestinal injury by inhibiting activation of the NLRP3 inflammasome

The inflammasome is a large, multiprotein complex that consists of a nucleotide-binding oligomerization domain-like receptor (NLR), an apoptosis-associated speck-like protein containing a caspase recruitment domain, and pro-caspase-1. Activation of the inflammasome results in cleavage of pro-caspase-1 into cleaved caspase-1, which promotes the processing of pro-interleukin (IL)-1β into mature IL-1β. We investigated the effects of colchicine on non-steroidal anti-inflammatory drug (NSAID)-induced small intestinal injury and activation of the NLR family pyrin domain-containing 3 (NLRP3) inflammasome. Colchicine treatment inhibited indomethacin-induced small intestinal injury by 86% (1 mg/kg) and 94% (3 mg/kg) as indicated by the lesion index 24 h after indomethacin administration. Colchicine inhibited the protein expression of cleaved caspase-1 and mature IL-1β, without affecting the mRNA expression of NLRP3 and IL-1β. Although treatment with recombinant IL-1β (0.1 μg/kg) did not change the severity of small intestinal damage, the preventive effects of colchicine were abolished by supplementation with the same dose of recombinant IL-1β. Indomethacin-induced small intestinal damage was reduced by 77%, as determined by the lesion index in NLRP3^−/− mice, and colchicine treatment failed to inhibit small intestinal damage in NLRP3^−/− mice. These results demonstrate that colchicine prevents NSAID-induced small intestinal injury by inhibiting activation of the NLRP3 inflammasome.

Cross-sectional small intestinal surveillance of maintenance hemodialysis patients using video capsule endoscopy: SCHEMA study

BACKGROUND AND STUDY AIMS

Small intestinal pathology in hemodialysis (HD) patients has been studied in only a small number of retrospective case series. One method for noninvasively surveying small intestinal disorders is video capsule endoscopy (VCE). The primary aim of this study was to investigate the prevalence of small intestinal abnormalities among asymptomatic maintenance HD outpatients using VCE. The secondary aim was to assess the clinical impact of these abnormalities.

PATIENTS AND METHODS

This study consisted of two phases. In phase I, a cross-sectional study, a cohort of patients who received maintenance HD three times weekly at an outpatient hemodialysis clinic were studied using VCE. Phase II was a prospective cohort study with follow up for 1 year after VCE.

RESULTS

Fifty-six patients were enrolled in this study, and two were excluded from analysis due to capsule retention in the stomach. The prevalence of small bowel abnormalities in HD patients was 64.8 % (35/54) (95 % confidential interval 52.1 % - 77.6 %). Of 54 patients, 21 (38.9 %) had mucosal lesions, 10 (18.5 %) had vascular lesions, and 4 (7.4 %) had both lesion types. During the 1-year follow-up period, events occurred in four patients. A small bowel-associated event was observed in one patient, who underwent laparoscopy-assisted small intestinal partial resection 3 months after diagnosis by VCE. All patients in whom events were seen had small bowel abnormalities; no events were observed in the VCE-negative group.

CONCLUSIONS

Although asymptomatic maintenance HD patients had a high prevalence of small bowel abnormalities (64.8 %), they did not have a high incidence of small bowel-associated events during the 1-year follow-up.

Acute Middle Gastrointestinal Bleeding Risk Associated with NSAIDs, Antithrombotic Drugs, and PPIs: A Multicenter Case-Control Study

Background

Middle gastrointestinal bleeding (MGIB) risk has not been fully investigated due to its extremely rare occurrence and the need for multiple endoscopies to exclude upper and lower gastrointestinal bleeding. This study investigated whether MGIB is associated with the use of non-steroidal anti-inflammatory drugs (NSAIDs), low-dose aspirin (LDA), thienopyridines, anticoagulants, and proton-pump inhibitors (PPIs), and whether PPI use affects the interactions between MGIB and antithrombotic drugs.

Methods

In this multicenter, hospital-based, case-control study, 400 patients underwent upper and lower endoscopy, 80 had acute overt MGIB and 320 had no bleeding and were matched for age and sex as controls (1:4). MGIB was additionally evaluated by capsule and/or double-balloon endoscopy, after excluding upper and lower GI bleeding. Adjusted odds ratios (AOR) for MGIB risk were calculated using conditional logistic regression. To estimate the propensity score, we employed a logistic regression model for PPI use.

Results

In patients with MGIB, mean hemoglobin level was 9.4 g/dL, and 28 patients (35%) received blood transfusions. Factors significantly associated with MGIB were chronic kidney disease (p<0.001), liver cirrhosis (p = 0.034), NSAIDs (p<0.001), thienopyridines (p<0.001), anticoagulants (p = 0.002), and PPIs (p<0.001). After adjusting for these factors, NSAIDs (AOR, 2.5; p = 0.018), thienopyridines (AOR, 3.2; p = 0.015), anticoagulants (AOR, 4.3; p = 0.028), and PPIs (AOR; 2.0; p = 0.021) were independently associated with MGIB. After adjusting for propensity score, the use of PPIs remained an independent risk factors for MGIB (AOR, 1.94; p = 0.034). No significant interactions were observed between PPIs and NSAIDs (AOR, 0.7; p = 0.637), LDA (AOR, 0.3; p = 0.112), thienopyridine (AOR, 0.7, p = 0.671), or anticoagulants (AOR, 0.5; p = 0.545).

Conclusions

One-third of patients with acute small intestinal bleeding required blood transfusion. NSAIDs, thienopyridines, anticoagulants, and PPIs increased the risk of acute small intestinal bleeding. However, there were no significant interactions found between antithrombotic drugs and PPI use for bleeding risk.

Type 2 Diabetes Mellitus Is Associated with More Serious Small Intestinal Mucosal Injuries

BACKGROUND

Clinical and experimental research has revealed that diabetes mellitus (DM) is characterized by intestinal hypomotility, gut microbial dysbiosis, increased gut permeability, microcirculation disorders, circulatory changes, and dysfunction of intestinal stem cells, which may be linked to inflammation of intestinal mucosa. However, the relationship between type 2 DM (T2DM) and macroscopic small intestinal mucosal injuries is still unclear. Therefore, we retrospectively studied capsule endoscopy data to determine the relationship between T2DM and small intestinal mucosal injuries.

MATERIALS AND METHODS

We compared the records of 38 T2DM patients with those of 152 non-DM patients for small intestinal mucosal injuries. Different types of mucosal injuries and Lewis scores were compared between T2DM and non-DM patients. The relationships between patients with or without different types of diabetic complications and the Lewis score was assessed. Moreover, the relationships between insulin resistance and Lewis score, between HbA1c and Lewis score, were also both assessed.

RESULTS

The prevalence of a villous edema in subjects with T2DM was significantly higher than in those without DM (P < 0.001), but incidence of ulcers was not different (P = 1.000). With T2DM, the Lewis score was also significantly higher (P = 0.002). In addition, subjects with diabetic nephropathy showed significantly higher Lewis scores than patients without diabetic nephropathy (P = 0.033). In Pearson's correlation tests, the homeostasis model assessment of insulin resistance (HOMA-IR) value was correlated positively with the Lewis score (γ = 0.175, P = 0.015), but no statistical correlation was found between HbA1c level and Lewis score (γ = 0.039, P = 0.697).

CONCLUSIONS

Subjects with T2DM, especially those with diabetic nephropathy, have higher Lewis scores and more serious small intestinal mucosal lesions.

Effect of proton-pump inhibitors on the risk of lower gastrointestinal bleeding associated with NSAIDs, aspirin, clopidogrel, and warfarin

BACKGROUND

We investigated the effects of proton-pump inhibitors (PPIs) on lower gastrointestinal bleeding (LGIB) and of their interactions with nonsteroidal anti-inflammatory drugs (NSAIDs), low-dose aspirin, clopidogrel, and warfarin on LGIB risk.

METHODS

We prospectively studied 355 patients emergently hospitalized for LGIB and 8,221 nonbleeding patients. All patients underwent colonoscopy. Smoking, alcohol drinking, drug exposure, and the Charlson comorbidity index score were assessed before colonoscopy. Adjusted odds ratios (AOR) of LGIB were estimated.

RESULTS

LGIB was significantly associated with older age, higher comorbidity index, and NSAID, aspirin, clopidogrel, or warfarin use. PPI use was significantly associated with older age, male sex, being a current alcohol drinker, higher comorbidity index, and NSAID, aspirin, clopidogrel, warfarin, acetaminophen, or corticosteroid use. Multivariate analysis adjusted by the confounding factors revealed LGIB was not significantly associated with PPI use (AOR 0.87; 95 % confidence interval 0.68-1.13; p = 0.311), or specifically with omeprazole (AOR 1.18; p = 0.408), esomeprazole (AOR 0.76; p = 0.432), lansoprazole (AOR 0.93; p = 0.669), or rabeprazole (AOR 0.63; p = 0.140). In the interaction model, no significant interactions were observed between PPIs and NSAIDs (AOR 1.40; p = 0.293), aspirin (AOR 1.09; p = 0.767), clopidogrel (AOR 0.99, p = 0.985), or warfarin (AOR 1.52; p = 0.398).

CONCLUSIONS

This large case-control study demonstrated that PPI use did not lead to an increased risk of LGIB, regardless of the type of PPI used. Further, LGIB risk was not affected by PPI use, irrespective of concomitant therapy with NSAIDs, low-dose aspirin, clopidogrel, or warfarin.

Risk factors for small bowel bleeding in chronic nonsteroidal anti-inflammatory drug users

OBJECTIVE

The incidence of nonsteroidal anti-inflammatory drugs (NSAIDs)-induced enteropathy is currently increasing. However, the predictors of small bowel bleeding (SBB) associated with NSAIDs are unknown. This study aimed to assess the risk factors of SBB in chronic NSAIDs users.

METHODS

We retrospectively compared the medical records of 147 patients receiving NSAIDs in a tertiary-care setting (31 with SBB and 116 without previous bleeding events) and analyzed the predictors of SBB.

RESULTS

In total, 31 patients underwent video capsule endoscopy to detect SBB, 74.2% of whom showed the evidence of SBB. Non-invasive treatment was performed in 90.3% of the patients. Multivariate logistic regression analysis revealed that the presence of coronary artery disease [adjusted odds ratio (aOR) 12.43, 95% confidence interval (CI) 1.19-130.34, P = 0.04], use of thienopyridine (aOR 16.93, 95% CI 3.78-75.72, P < 0.001) and prior use of rebamipide (aOR 0.31, 95% CI 0.12-0.82, P = 0.02) were independently associated with SBB in NSAIDs users.

CONCLUSIONS

Coronary artery disease and co-use of thienopyridine were associated with SBB in NSAIDs users. The patients with coronary artery disease co-using thienopyridine need to be monitored for the occurrence of SBB when they were prescribed with NSAIDs.

Small bowel injury in low-dose aspirin users

The use of low-dose aspirin (LDA) is well known to be associated with an increased risk of serious upper gastrointestinal complications, such as peptic ulceration and bleeding. Until recently, attention was mainly focused on aspirin-induced damage of the stomach and duodenum. However, recently, there has been growing interest among gastroenterologists on the adverse effects of aspirin on the small bowel, especially as new endoscopic techniques, such as capsule endoscopy (CE) and balloon-assisted endoscopy, have become available for the evaluation of small bowel lesions. Preliminary CE studies conducted in healthy subjects have shown that short-term administration of LDA can induce mild mucosal inflammation of the small bowel. Furthermore, chronic use of LDA results in a variety of lesions in the small bowel, including multiple petechiae, loss of villi, erosions, and round, irregular, or punched-out ulcers. Some patients develop circumferential ulcers with stricture. In addition, to reduce the incidence of gastrointestinal lesions in LDA users, it is important for clinicians to confirm the differences in the gastrointestinal toxicity between different types of aspirin formulations in clinical use. Some studies suggest that enteric-coated aspirin may be more injurious to the small bowel mucosa than buffered aspirin. The ideal treatment for small bowel injury in patients taking LDA would be withdrawal of aspirin, however, LDA is used as an antiplatelet agent in the majority of patients, and its withdrawal could increase the risk of cardiovascular/cerebrovascular morbidity and mortality. Thus, novel means for the treatment of aspirin-induced enteropathy are urgently needed.

Nonsteroidal anti-inflammatory drugs, proton pump inhibitors, and gastrointestinal injury: contrasting interactions in the stomach and small intestine

Nonsteroidal anti-inflammatory drugs (NSAIDs) and proton pump inhibitors (PPIs) are among the most frequently prescribed groups of drugs worldwide. The use of NSAIDs is associated with a high number of significant adverse effects. Recently, the safety of PPIs has also been challenged. Capsule endoscopy studies reveal that even low-dose NSAIDs are responsible for gut mucosal injury and numerous clinical adverse effects, for example, bleeding and anemia, that might be difficult to diagnose. The frequent use of PPIs can exacerbate NSAID-induced small intestinal injury by altering intestinal microbiota. Thus, the use of PPI is considered to be an independent risk factor associated with NSAID-associated enteropathy. In this review, we discuss this important clinical problem and review relevant aspects of epidemiology, pathophysiology, and management. We also present the hypothesis that even minor and subclinical injury to the intestinal mucosa can result in significant, though delayed, metabolic consequences, which may seriously affect the health of an individual. PubMed was searched using the following key words (each key word alone and in combination): gut microbiota, microbiome, non-steroidal anti inflammatory drugs, proton pump inhibitors, enteropathy, probiotic, antibiotic, mucosal injury, enteroscopy, and capsule endoscopy. Google engine search was also carried out to identify additional relevant articles. Both original and review articles published in English were reviewed.