Proton pump inhibitors exacerbate NSAID-induced small intestinal injury by inducing dysbiosis

In vitro and in vivo studies on the metabolism and pharmacokinetics of the selective gut microbial β-glucuronidase targeting compound Inh 1

In vitro studies using rat, mouse, and human microsomes and hepatocytes on the bacterial β-glucuronidase inhibitor 1-((6,8-dimethyl-2-oxo-1,2-dihydroquinolin-3-yl)methyl)-3-(4-ethoxyphenyl)-1-(2-hydroxyethyl)thiourea) (Inh 1) revealed extensive metabolism in all species.The intrinsic clearances of Inh 1 in human, mouse, and rat hepatic microsomes were 30.9, 67.8, and 201 µL/min/mg, respectively. For intact hepatocytes intrinsic clearances of 21.6, 96.0, and 129 µL/min/106 cells were seen for human, mouse and rat, respectively.The metabolism of Inh 1 involved an uncommon desulphurisation reaction in addition to oxidation, deethylation, and conjugation reactions at multiple sites. Six metabolites were detected in microsomal incubations in human and rat, and seven for the mouse. With hepatocytes, 18 metabolites were characterised, 9 for human, and 11 for mouse and rat.Following IV administration to mice (3 mg/kg), plasma concentrations of Inh 1 exhibited a monophasic decline with a terminal elimination half-life of 0.91 h and low systemic clearance (11.8% of liver blood flow). After PO dosing to mice (3 mg/kg), peak observed Inh 1 concentrations of 495 ng/mL were measured 0.5 h post dose, declining to under 10 ng/mL at 8 h post dose. The absolute oral bioavailability of Inh 1 in the mouse was ca. 26%.

Multiple drug-delivery strategies to enhance the pharmacological and toxicological properties of Mefenamic acid

OBJECTIVE

To improve the biological and toxicological properties of Mefenamic acid (MA), the galactosylated prodrug of MA named MefeGAL was included in polymeric solid dispersions (PSs) composed of poly(glycerol adipate) (PGA) and Pluronic® F68 (MefeGAL-PS). MefeGAL-PS was compared with polymeric solid formulations of MA (MA-PS) or a mixture of equal ratio of MefeGAL/MA (Mix-PS).

METHODS

The in vitro and in vivo pharmacological and toxicological profiles of PSs have been investigated. In detail, we evaluated the anti-inflammatory (carrageenan-induced paw edema test), analgesic (acetic acid-induced writhing test) and ulcerogenic activity in mice after oral treatment. Additionally, the antiproliferative activity of PSs was assessed on in vitro models of colorectal and non-small cell lung cancer.

RESULTS

When the PSs were resuspended in water, MefeGAL's, MA's and their mixture's apparent solubilities improved due to the interaction with the polymeric formulation. By comparing the in-vivo biological performance of MefeGAL-PS with that of MA, MefeGAL and MA-PS, it was seen that MefeGAL-PS exhibited the same sustained and delayed analgesic and anti-inflammatory profile as MefeGAL but did not cause gastrointestinal irritation. The pharmacological effect of Mix-PS was present from the first hours after administration, lasting about 44 hours with only slight gastric mucosa irritation. In-vitro evaluation indicated that Mix-PS had statistically significant higher cytotoxicity than MA-PS and MefeGAL-PS.

CONCLUSIONS

These preliminary data are promising evidence that the galactosylated prodrug approach in tandem with a polymer-drug solid dispersion formulation strategy could represent a new drug delivery route to improve the solubility and biological activity of NSAIDs.

Clinical effects of a combination of phenylbutazone and omeprazole on chronic lameness in Mongolian horses

BACKGROUND

Phenylbutazone (PBZ) is the most commonly used drug to treat symptoms of lameness in horses; however, it is associated with adverse effects such as gastric ulcer syndrome (EGUS). Interestingly, many practitioners prescribe omeprazole (OME) concurrently with PBZ to prevent the development of EGUS. However, the efficacy and safety of this practice in Mongolian horses with chronic lameness remain unknown.

OBJECTIVES

To evaluate the clinical effects of a combination of PBZ and OME on chronic lameness in Mongolian horses.

STUDY DESIGN

Randomised block experimental design.

METHODS

Eighteen Mongolian horses with lameness score was ≥3 points, were divided into three treatment groups, with six horses in each group: placebo (CON), PBZ (4.4 mg/kg PO q. 24 h), or PBZ plus OME (4 mg/kg PO q. 24 h; PBZ + OME) in a randomised block design based on the initial lameness score. The horses were treated for 15 days. During this period, weekly gastroscopy, and physiological and biochemical tests were performed.

RESULTS

Both PBZ (median 1.0, interquartile range [IQR]: 0.8-1.3; p = 0.01) and PBZ + OME (median 1.0, IQR: 1.0-1.0; p = 0.01) significantly decreased the lameness score compared with before administration. In addition, PBZ significantly increased the equine glandular gastric disease (EGGD) score (3.0 ± 0.6, p < 0.001), GT-17 content (293.4 ± 21.8 pg/mL, p < 0.001), and pepsinogen-1 (PG1) content (295.3 ± 38.3 ng/mL, p < 0.001) compared with CON or PBZ + OME. However, it significantly reduced the total protein (53.6 ± 1.5 g/L, p < 0.05) and albumin (25.5 ± 1.8 g/L, p < 0.05) contents. Nevertheless, compared with PBZ, PBZ + OME significantly decreased the EGGD score (0.3 ± 0.5, p < 0.001) and significantly increased the gastric fluid pH (7.3 ± 0.5, p < 0.001), total protein content (62.5 ± 4.6 g/L, p = 0.009), and albumin content (29.4 ± 1.1 g/L, p = 0.004). Meanwhile, they significantly diminished the gastrin 17 (GT-17) (162.0 ± 21.0 pg/mL, p < 0.001) and PG1 (182.4 ± 22.5 ng/mL, p < 0.001) contents.

MAIN LIMITATIONS

Individual differences in horses were larger, but the sample size was small. There was larger interval between observations for each index.

CONCLUSIONS

Compared with PBZ alone, PBZ + OME had no therapeutic effect on chronic lameness; however, it reduced the occurrence of EGGD in Mongolian horses. Horses may be protected against chronic lameness and PBZ-induced EGGD by increasing the pH value, decreasing serum PG1 and GT-17 content, and preventing the reduction of myeloperoxidase content.

Prospective Randomized Controlled Clinical Trial of the Long-Term Effects of Omeprazole on Healthy Dogs

The use of omeprazole as a preventive treatment for gastrointestinal ulcers in veterinary medicine has been questioned during previous years. The aim of the present study is to assess the long-term effect of omeprazole on cobalamin and serum gastrin levels in healthy dogs. Eighteen healthy dogs were included: 10 in the control group and 8 in the omeprazole group. Three samples were collected: before starting the treatment (T0), 30 days after the start of treatment (T1), and at 60 days (T2). The mean cobalamin value (ng/L) in the control group was 481.4 (±293.70) at T0, 481.4 (±170.21) at T1, and 513.2 (±174.50) at T2. In the omeprazole group, the values were 424.62 (±161.57) at T0, 454.5 (±160.96) at T1, and 414.87 (±127.90) at T2. No statistically significant changes were detected in cobalamin levels between the three-time period in both study groups. These results agree with previous findings in felines but contrast with human medicine studies. The median gastrin values (pg/mL) in the control group were 62.45 [30.17-218.75] at T0, 76.06 [30.67-199.87] at T1, and 63.02 [35.81-176.06] at T2. The median gastrin value in the omeprazole group was 67.59 [55.96-101.60] at T0, 191.77 [75.31-1901.77] at T1, and 128.16 [43.62-1066.46] at T2. Statistically significant differences were detected (p = 0.008), indicating an increase in gastrin levels after initiating treatment with omeprazole. In conclusion, the increased levels of gastrin observed in this population underscore the importance of conducting a comprehensive clinical assessment to identify potential gastrointestinal disorders, particularly in consideration of the usage of omeprazole as a preventive treatment.

Effects of 1-kestose on microbiome changes caused by vonoprazan: a randomized, double-blind, placebo-controlled pilot study

BACKGROUND AND AIM

Potassium-competitive acid blockers more strongly suppress the gastric acid barrier than proton pump inhibitors and cause dysbiosis. However, preventive measures in this regard have not been established. We aimed to evaluate whether 1-kestose, a known prebiotic, was effective at alleviating dysbiosis caused by potassium-competitive acid blockers.

METHODS

Patients scheduled to undergo endoscopic resection for superficial gastroduodenal tumors were enrolled and randomized 1:1 to receive either 1-kestose or placebo. All patients were started on potassium-competitive acid blocker (vonoprazan 20 mg/day) and took 1-kestose 10 g/day or placebo (maltose) 5 g/day for 8 weeks. The primary outcome was the effect of 1-kestose on potassium-competitive acid blocker-induced alterations in the microbiome. The fecal microbiome was analyzed before and after potassium-competitive acid blocker treatment via MiSeq (16S rRNA gene V3-V4 region).

RESULTS

Forty patients were enrolled, and 16 in each group were analyzed. In the placebo group, the Simpson index, an alpha diversity, was significantly decreased and relative abundance of Streptococcus was significantly increased by 1.9-fold. In the kestose group, the Simpson index did not change significantly and relative abundance of Streptococcus increased 1.3-fold, but this was not a significant change. In both groups, no adverse events occurred, ulcers were well healed, and pretreatment and posttreatment short-chain fatty acid levels did not differ.

CONCLUSIONS

The potassium-competitive acid blocker caused dysbiosis in the placebo group; this effect was prevented by 1-kestose. Thus, 1-kestose may be useful in dysbiosis treatment.

A gut microbiota-bile acid axis promotes intestinal homeostasis upon aspirin-mediated damage

Aspirin-related gastrointestinal damage is of growing concern. Aspirin use modulates the gut microbiota and associated metabolites, such as bile acids (BAs), but how this impacts intestinal homeostasis remains unclear. Herein, using clinical cohorts and aspirin-treated mice, we identified an intestinal microbe, Parabacteroides goldsteinii, whose growth is suppressed by aspirin. Mice supplemented with P. goldsteinii or its BA metabolite, 7-keto-lithocholic acid (7-keto-LCA), showed reduced aspirin-mediated damage of the intestinal niche and gut barrier, effects that were lost with a P. goldsteinii hdhA mutant unable to generate 7-keto-LCA. Specifically, 7-keto-LCA promotes repair of the intestinal epithelium by suppressing signaling by the intestinal BA receptor, farnesoid X receptor (FXR). 7-Keto-LCA was confirmed to be an FXR antagonist that facilitates Wnt signaling and thus self-renewal of intestinal stem cells. These results reveal the impact of oral aspirin on the gut microbiota and intestinal BA metabolism that in turn modulates gastrointestinal homeostasis.

A dual role of lysophosphatidic acid type 2 receptor (LPAR2) in nonsteroidal anti-inflammatory drug-induced mouse enteropathy

Lysophosphatidic acid (LPA) is a bioactive phospholipid mediator that has been found to ameliorate nonsteroidal anti-inflammatory drug (NSAID)-induced gastric injury by acting on lysophosphatidic acid type 2 receptor (LPAR2). In this study, we investigated whether LPAR2 signaling was implicated in the development of NSAID-induced small intestinal injury (enteropathy), another major complication of NSAID use. Wild-type (WT) and Lpar2 deficient (Lpar2-/-) mice were treated with a single, large dose (20 or 30 mg/kg, i.g.) of indomethacin (IND). The mice were euthanized at 6 or 24 h after IND treatment. We showed that IND-induced mucosal enteropathy and neutrophil recruitment occurred much earlier (at 6 h after IND treatment) in Lpar2-/- mice compared to WT mice, but the tissue levels of inflammatory mediators (IL-1β, TNF-α, inducible COX-2, CAMP) remained at much lower levels. Administration of a selective LPAR2 agonist DBIBB (1, 10 mg/kg, i.g., twice at 24 h and 30 min before IND treatment) dose-dependently reduced mucosal injury and neutrophil activation in enteropathy, but it also enhanced IND-induced elevation of several proinflammatory chemokines and cytokines. By assessing caspase-3 activation, we found significantly increased intestinal apoptosis in IND-treated Lpar2-/- mice, but it was attenuated after DBIBB administration, especially in non-obese diabetic/severe combined immunodeficiency (NOD/SCID) mice. Finally, we showed that IND treatment reduced the plasma activity and expression of autotaxin (ATX), the main LPA-producing enzyme, and also reduced the intestinal expression of Lpar2 mRNA, which preceded the development of mucosal damage. We conclude that LPAR2 has a dual role in NSAID enteropathy, as it contributes to the maintenance of mucosal integrity after NSAID exposure, but also orchestrates the inflammatory responses associated with ulceration. Our study suggests that IND-induced inhibition of the ATX-LPAR2 axis is an early event in the pathogenesis of enteropathy.

Wheat peptides inhibit the activation of MAPK and NF-κB inflammatory pathways and maintain epithelial barrier integrity in NSAID-induced intestinal epithelial injury

The use of non-steroidal anti-inflammatory drugs (NSAIDs) has negative effects on the gastrointestinal tract, but the proton pump inhibitors currently in use only protect against gastrointestinal disease and may even make NSAID-induced enteropathy worse. Therefore, new approaches to treating enteropathy are required. This study aimed to investigate the protective effect of wheat peptides (WPs) against NSAID-induced intestinal damage in mice and their mechanism. Here, an in vivo mouse model was built to investigate the protective and reparative effects of different concentrations of WPs on NSAID-induced intestinal injury. WPs ameliorated NSAID-induced weight loss and small intestinal tissue damage in mice. WP treatment inhibited NSAID-induced injury leading to increased levels of oxidative stress and expression levels of inflammatory factors. WPs protected and repaired the integrity and permeability injury of the intestinal tight junction induced by NSAIDs. An in vitro Caco-2 cell model was built with lipopolysaccharide (LPS). WP pretreatment inhibited LPS-induced changes in the Caco-2 cell permeability and elevated the levels of oxidative stress. WPs inhibited LPS-induced phosphorylation of NF-κB p65 and mitogen-activated protein kinase (MAPK) signaling pathways and reduced the expression of inflammatory factors. In addition, WPs increased tight junction protein expression, which contributed to improved intestinal epithelial dysfunction. Our results suggest that WPs can ameliorate NSAID-induced impairment of intestinal barrier functional integrity by improving intestinal oxidative stress levels and reducing inflammatory factor expression through inhibition of NF-κB p65 and MAPK signaling pathway activation. WPs can therefore be used as potential dietary supplements to reduce NSAID-induced injury of the intestine.

Severe Anemia from Multiple Gastric Hyperplastic Polyps in a Hemodialysis Patient after Long-term Use of a Proton-pump Inhibitor

A 90-year-old man on maintenance hemodialysis was admitted due to severe symptomatic anemia. Biopsies under esophagogastroduodenoscopy demonstrated that the cause of anemia was intermittent blood oozing from multiple gastric hyperplastic polyps. Even after successful eradication of Helicobacter pylori, he showed hypergastrinemia (480 pg/mL) owing to esomeprazole (proton-pump inhibitor) therapy for the past 4.5 years to treat reflux esophagitis. Seven months after we switched esomeprazole to famotidine (H2-receptor antagonist), those gastric polyps and anemia were remarkably ameliorated with lowered gastrin levels. This case indicates that long-term use of a proton-pump inhibitor triggers chronic hypergastrinemia, leading to gastric hyperplastic polyps and subsequent severe anemia.

The impact of proton pump inhibitors on the course of ulcerative colitis: a cohort study of over 10,000 newly diagnosed patients in Norway

BACKGROUND AND AIMS

Proton pump inhibitors (PPI) affect the gastrointestinal microbiota, which is thought to play a role in the pathogenesis of ulcerative colitis (UC). Previous studies suggest an association between PPI use and risk of incident UC as well as disease course. The aim of the study was to examine if PPI exposure is associated with disease course in UC patients.

METHODS

A national cohort consisting of all newly diagnosed UC patients from 2010 to 2020 was defined combining data from Norwegian registries. PPI exposure was included as a time dependent variable with a 30 day time lag from starting the drug. Outcomes were starting advanced therapies including anti-TNF, systemic glucocorticoids, any additional systemic anti-inflammatory medication and undergoing colectomy during follow-up. Time-dependent Cox regressions included the variables PPI use, first systemic glucocorticoid prescription, first UC hospitalization, age-groups and sex.

RESULTS

The study cohort consisted of 10,149 patients with median age 40 years (IQR 27-56) and 56% males. PPI use independently increased the risk of starting advanced therapies (HR 1.54, 95% CI 1.36-1.73, p < 0.005), starting systemic glucocorticoids (HR 1.20, 95% CI 1.07-1.34, p < 0.005), starting any additional anti-inflammatory treatment (HR 1.18, 95%CI 1.05-1.32, p < 0.01) and undergoing colectomy (HR 1.52, 95%CI 1.17-1.98, p < 0.005).

CONCLUSIONS

PPI use was associated with unfavorable outcomes including advanced therapy initiation, additional anti-inflammatory medications and undergoing colectomy. Although further studies are needed, the evidence suggests that PPIs could affect the course of UC and should be used cautiously in UC patients.

Diclofenac and eugenol hybrid with enhanced anti-inflammatory activity through activating HO-1 and inhibiting NF-κB pathway in vitro and in vivo

A series of diclofenac hybrid molecules were synthesized and evaluated for their NO-inhibitory ability in LPS-induced RAW 264.7 macrophage cells. Among them, compound 1 showed the highest NO-inhibitory ability (approximately 66%) and no significant cytotoxicity. Compound 1 exhibited superior NF-κB-inhibitory ability compared to diclofenac through the activation of Nrf2/HO-1 signaling pathway in RAW 264.7. 20 mg/kg compound 1 resulted in remarkable colitis improvement in dextran sulfate sodium (DSS)-induced mice model by up-regulating HO-1 and down-regulating phosphorylation level of NF-κB p65. Moreover, 50 mg/kg dose of compound 1 showed a lower ulcerogenic potential compared to diclofenac in rats. The diclofenac-eugenol hybrid (compound 1) may serve as a novel anti-inflammatory agent based on its role in inhibiting the NF-κB signaling pathway and activating HO-1 expression with no toxicity in vitro and in vivo.

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.

Visceral adipose tissue predicts severity and prognosis of acute pancreatitis in obese patients

Acute pancreatitis is a common systemic inflammatory disease, manifested by a spectrum of severity, ranging from mild in the majority of patients to severe acute pancreatitis. Patients with severe acute pancreatitis suffer from severe local and systemic complications and organ failure, leading to a poor prognosis. The early recognition of the severe condition is important to improve prognosis. Obesity has risen in tandem with an increase in the severity of acute pancreatitis in recent years. Studies have revealed that adipose tissue, particularly visceral adipose tissue is associated with the prognosis of acute pancreatitis. This review discussed the role of visceral adipose tissue in obese patients with acute pancreatitis and explored the possible mechanism involved.

Proton pump inhibitors may enhance the risk of digestive diseases by regulating intestinal microbiota

Proton pump inhibitors (PPIs) are the most used acid-inhibitory drugs, with a wide range of applications in the treatment of various digestive diseases. However, recently, there has been a growing number of digestive complications linked to PPIs, and several studies have indicated that the intestinal flora play an important role in these complications. Therefore, developing a greater understanding of the role of the gut microbiota in PPI-related digestive diseases is essential. Here, we summarize the current research on the correlation between PPI-related digestive disorders and intestinal flora and establish the altered strains and possible pathogenic mechanisms of the different diseases. We aimed to provide a theoretical basis and reference for the future treatment and prevention of PPI-related digestive complications based on the regulation of the intestinal microbiota.

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.

Long-Term Use of Proton Pump Inhibitors Disrupts Intestinal Tight Junction Barrier and Exaggerates Experimental Colitis

BACKGROUND

Proton pump inhibitors [PPIs] are widely used to treat a number of gastro-oesophageal disorders. PPI-induced elevation in intragastric pH may alter gastrointestinal physiology. The tight junctions [TJs] residing at the apical intercellular contacts act as a paracellular barrier. TJ barrier dysfunction is an important pathogenic factor in inflammatory bowel disease [IBD]. Recent studies suggest that PPIs may promote disease flares in IBD patients. The role of PPIs in intestinal permeability is not clear.

AIM

The aim of the present study was to study the effect of PPIs on the intestinal TJ barrier function.

METHODS

Human intestinal epithelial cell culture and organoid models and mouse IBD models of dextran sodium sulphate [DSS] and spontaneous enterocolitis in IL-10-/- mice were used to study the role of PPIs in intestinal permeability.

RESULTS

PPIs increased TJ barrier permeability via an increase in a principal TJ regulator, myosin light chain kinase [MLCK] activity and expression, in a p38 MAPK-dependent manner. The PPI-induced increase in extracellular pH caused MLCK activation via p38 MAPK. Long-term PPI administration in mice exaggerated the increase in intestinal TJ permeability and disease severity in two independent models of DSS colitis and IL-10-/- enterocolitis. The TJ barrier disruption by PPIs was prevented in MLCK-/- mice. Human database studies revealed increased hospitalizations associated with PPI use in IBD patients.

CONCLUSIONS

Our results suggest that long-term use of PPIs increases intestinal TJ permeability and exaggerates experimental colitis via an increase in MLCK expression and activity.

Investigation of Enterogermina's Protective and Restorative Mechanisms on the Gut Microbiota with PPI, Using SHIME Technology

Proton pump inhibitors (PPIs) are commonly prescribed medications associated with changes in the gut microbiome and dysbiosis when used long-term. Probiotics, such as Enterogermina^® (containing four strains of Bacillus clausii) reduce side effects from triple therapy with PPI+antibiotics. We aim to assess the ability of this probiotic in preventing and/or treating the dysbiosis induced by PPI use. Faecal samples from six healthy donors were used to colonise a Triple-Mucosal-Simulator of the Human Intestinal Microbial Ecosystem^® model with added ileal compartment. Changes in the microbial community composition and metabolite production were measured for PPI alone (control), PPI+Enterogermina (preventative), and Enterogermina treatment after PPI (curative). Differences were assessed by one-way ANOVA with Tukey's multiple comparisons test. The model was shown to replicate some of the effects of long-term PPI use. There were significant changes in microbial diversity and an increase in butyrate levels in the preventative and curative arms, indicative of a beneficial effect to gut health. Probiotic use countered some of the effects of PPI use: Streptococcus bovis levels increased in the control arm but reduced following probiotic treatment. These results show that probiotic treatment with B. clausii may have beneficial effects on the gut microbiota following PPI treatment.

Oral omeprazole and diclofenac intake is associated with increased faecal calprotectin levels: a randomised open-label clinical trial

BACKGROUND AND AIM

Nonsteroidal anti-inflammatory drugs and proton pump inhibitors are known to affect the diagnostics of gastrointestinal disorders. The aim of this study was to investigate to what extent omeprazole, diclofenac or co-administration of these affects faecal calprotectin levels and the normalisation interval after cessation.

METHODS

Participants received 20 mg omeprazole daily for 2 weeks in the first sequence, 50 mg oral diclofenac three times daily for 2 weeks in the second and co-administration of these for 2 weeks in the third, with washout periods in between. The first two sequences were randomised to a different order. Faecal calprotectin was measured on days 0, 4, 7, 14, 21, 28 and 35 and thereafter at 7-day intervals until normalisation in each sequence.

RESULTS

Thirty-two healthy volunteers were included. During drug intake, 39% on diclofenac (median 70.8 µg/g; range 50.2-1080 µg/g), 53% on omeprazole (median 85.3 µg/g; range 51.1-249 µg/g) and 69% on omeprazole + diclofenac (median 101.5 µg/g; range 51.5-532 µg/g) had faecal calprotectin levels above normal. In the diclofenac sequence, faecal calprotectin returned to normal in all participants within 2 weeks of cessation and in the omeprazole and co-administration sequences, within 3 weeks of cessation. No statistical significant difference was found with respect to drug order.

CONCLUSION

Short-term intake of omeprazole, diclofenac or co-administration appears to increase faecal calprotectin levels. In patients with increased faecal calprotectin on omeprazole alone or in combination with diclofenac, a repeated faecal calprotectin test is recommended at least 3 weeks after cessation. On diclofenac alone, it is sufficient to repeat the faecal calprotectin test 2 weeks after cessation.

A novel drug-like water-soluble small molecule Focal Adhesion Kinase (FAK) activator promotes intestinal mucosal healing

Non-steroidal anti-inflammatory drugs (NSAIDs) injure the proximal and distal gut by different mechanisms. While many drugs reduce gastrointestinal injury, no drug directly stimulates mucosal wound healing. Focal adhesion kinase (FAK), a non-receptor tyrosine kinase, induces epithelial sheet migration. We synthesized and evaluated a water-soluble FAK-activating small molecule, M64HCl, with drug-like properties. Monolayer wound closure and Western blots measured migration and FAK phosphorylation in Caco-2 ​cells, in vitro kinase assays established FAK activation, and pharmacologic tests assessed drug-like properties. 30 ​mg/kg/day M64HCl was administered in two murine small intestine injury models for 4 days. M64HCl (0.1-1000 ​nM) dose-dependently increased Caco-2 FAK-Tyr 397 phosphorylation, without activating Pyk2 and accelerated Caco-2 monolayer wound closure. M64HCl dose-responsively activates the FAK kinase domain vs. the non-salt M64, increasing the V_max of ATP-binding. Pharmacologic tests suggested M64HCl has drug-like properties and is enterally absorbed. M64HCl 25 ​mg/kg/day continuous infusion promoted healing of ischemic jejunal ulcers and indomethacin-induced small intestinal injury in C57Bl/6 mice. M64HCl-treated mice exhibited smaller ulcers 4 days after ischemic ulcer induction or indomethacin injury. Renal histology and plasma creatinine were normal. Mild hepatic inflammatory changes and ALT elevation were similar among M64HCl-treated mice and controls. M64HCl was concentrated in kidney and gastrointestinal mucosa and functional nephrectomy studies suggested predominantly urinary excretion. Little toxicity was observed in vitro or in single-dose mouse toxicity studies until >1000x higher than effective concentrations. M64HCl, a water-soluble FAK activator, promotes epithelial restitution and intestinal mucosal healing and may be useful to treat gut mucosal injury.

The effect of rebamipide on non-steroidal anti-inflammatory drug-induced gastro-enteropathy: a multi-center, randomized pilot study

BACKGROUND/AIMS

Non-steroidal anti-inflammatory drugs (NSAIDs) are commonly-used medications, and ailments such as arthritis or heart disease, require long-term use of these drugs, which can induce gastroenteropathy with bleeding and ulcers. This study investigated the associations between efficacy, safety, and gastrointestinal symptoms linked to rebamipide and proton pump inhibitor administration in patients requiring long-term NSAID use.

METHODS

This study was a multi-center, randomized, open-labeled, pilot design.

RESULTS

Thirty-three patients were included. Of these, 15 were included in the study group and 18 were in the control group. NSAID-induced gastric ulcers, which were the primary outcome of this study, did not occur in either the study or control group. Changes in the number of small bowel erosions and ulcers were -0.6 ± 3.06 in the study group and 1.33 ± 4.71 in the control group. The number of subjects with mucosal breaks (defined as multiple erosions and/or ulcers) was three (20%) in the study group and six (40%) in the control group (p = 0.427). No serious adverse events occurred in either group. However, dyspepsia and skin rashes occurred in six patients (31.58%) in the study group and 13 (65%) in the control group (p = 0.036).

CONCLUSION

Although statistically significant differences were not generated, possibly as a result of the small sample size, mucosal breaks observed via capsule endoscopy revealed that rebamipide was likely to be more effective than lansoprazole in preventing small intestine damage caused by NSAIDs. Furthermore, fewer side-effects emerged with rebamipide.

Non-Steroidal Anti-Inflammatory Drugs and Associated Toxicities in Horses

Effective pain management in horses can be a challenge despite the understanding that appropriate analgesia improves animal welfare and increases treatment success. The administration of NSAID drugs, particularly phenylbutazone and flunixin, are common practice in equine veterinary patients. Known for their analgesic and anti-inflammatory properties, NSAIDs are used for the treatment of a variety of conditions in horses, from gastrointestinal to orthopedic pain. Despite extensive usage, NSAIDs have a narrow margin of safety and the body of literature documenting the efficacy and side effects of different NSAIDs is broad. The three main side effects associated with excessive or prolonged NSAID usage in horses include gastroduodenal ulceration, right dorsal colitis (RDC) and renal papillary necrosis. The use of cyclooxygenase-2 selective NSAIDS, such as firocoxib, are theoretically safer. The aim of this paper is to review the current literature on the use and efficacy of different NSAIDs, summarise the associated side effects of NSAID usage and evaluate the current state of knowledge for the diagnosis and treatment of such toxicities.

The influence of different proton pump inhibitors and potassium-competitive acid blockers on indomethacin-induced small intestinal injury

BACKGROUND AND AIM

The influence of gastric acid inhibitors (GAIs) on nonsteroidal anti-inflammatory drug (NSAID)-induced enteropathy is controversial. Herein, the influences of different GAIs on NSAID-induced intestinal injury and the underlying mechanisms are clarified.

METHODS

Indomethacin (IND; 10 mg/kg/day) was administered to mice to induce small intestinal injury. Disease activity was examined macroscopically and histologically. The permeability of small intestine was evaluated by measuring plasma lipopolysaccharide levels. 16S rDNA sequencing was performed to determine the composition of intestinal flora.

RESULTS

Among the four GAIs, ilaprazole (IPZ) significantly attenuated IND-induced small intestinal injury and maintained the integrity of the mucosal barrier. Omeprazole (OPZ) and vonoprazan (VPZ) ameliorated ulceration without significant differences, while rabeprazole (RPZ) failed to protect against the injury. To explore the potential mechanism, we investigated changes in the gut microbiota mediated by GAIs. After 5-day administration, GAIs significantly altered the composition of the gut microbiota. The IND group had a significant decrease in alpha diversity compared with the control group, and this decrease was reversed by OPZ and IPZ treatment, respectively. After IPZ treatment, the community membership was more assembled in the control group than the IND group. Further, we found that Lactobacillus was significantly increased in the groups of OPZ, IPZ, and VPZ, while Bacteroides was significantly increased in the RPZ group.

CONCLUSION

Our results indicated that GAIs have different influences on the mucosal barrier, possibly by altering the composition of intestinal microbiota, and the impacts mediated by various GAIs in the IND-induced intestinal damage model seem different.

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.

Verification of the fCAL turbo immunoturbidimetric assay for measurement of the fecal calprotectin concentration in dogs and cats

The concentration of calprotectin in feces (fCal) is a clinically useful marker of chronic gastrointestinal inflammation in humans and dogs. No commercial assay is widely available to measure fCal in small animal medicine, to date. Thus, we verified the immunoturbidimetric fCAL turbo assay (Bühlmann) of fCal for canine and feline fecal extracts by determining linearity, spiking and recovery, and intra-assay and inter-assay variability. We determined RIs, temporal variation over 3 mo, and effect of vaccination and NSAID treatment. Observed:expected (O:E) ratios (x̄ ± SD) for serial dilutions of feces were 89–131% (106 ± 9%) in dogs and 77–122% (100 ± 12%) in cats. For spiking and recovery, the O:E ratios were 90–118% (102 ± 11%) in dogs and 83–235% (129 ± 42%) in cats. Intra- and inter-assay CVs for canine samples were ≤19% and ≤7%, and for feline samples ≤22% and ≤21%. Single-sample RIs were <41 μg/g for dogs and <64 μg/g for cats. With low reciprocal individuality indices, using population-based fCal RIs is appropriate, and moderate fCal changes between measurements (dogs 44.0%; cats: 43.2%) are considered relevant. Cats had significant (but unlikely relevant) fCal increases post-vaccination. Despite individual fCal spikes, no differences were seen during NSAID treatment. The fCAL turbidimetric assay is linear, precise, reproducible, and sufficiently accurate for measuring fCal in dogs and cats. Careful interpretation of fCal concentrations is warranted in both species during the peri-vaccination period and for some patients receiving NSAID treatment.

β(2→1) chicory and β(2→1)-β(2→6) agave fructans protect the human intestinal barrier function in vitro in a stressor-dependent fashion

Dietary fibers such as fructans can protect the intestinal epithelial barrier integrity, but the mechanisms underlying this protection are not completely understood. We aimed to study the protective effect of β(2→1)-β(2→6) branched graminan-type fructans (GTFs) on gut epithelial barrier function that was disrupted by three different agents which impact the barrier function via different cellular mechanisms. The effects of GTFs were compared with those of linear β(2→1) inulin-type fructans (ITFs). T84 intestinal epithelial monolayers were incubated with GTFs and ITFs. Afterwards, the monolayers were challenged with the barrier disruptors calcium ionophore A23187, 12-myristate 13-acetate (PMA) and deoxynivalenol (DON). Transepithelial resistance was measured with an electric cell-substrate impedance sensing system. All fructans studied prevented the barrier disruption induced by A23187. ITF II protected from the disruptive effects of PMA. However, none of the studied fructans influenced the disruption induced by DON. As a measure of disruption-induced inflammation, interleukin-8 (IL-8) production by the intestinal epithelium was determined by ELISA. The production of IL-8 induced by A23187 was decreased by all fructans, whereas IL-8 production induced by DON decreased only upon pre-treatment with ITF II. None of the studied fructans prevented PMA induced IL-8 production. GTFs just like ITFs can influence the barrier function and inflammatory processes in gut epithelial cells in a structure-dependent fashion. These distinct protective effects are dependent on the different signaling pathways that lead to gut barrier disruption.

Adaptive antimicrobial resistance, a description of microbial variants, and their relevance to periprosthetic joint infection

Periprosthetic joint infection (PJI) is a difficult complication requiring a comprehensive eradication protocol. Cure rates have essentially stalled in the last two decades, using methods of antimicrobial cement joint spacers and parenteral antimicrobial agents. Functional spacers with higher-dose antimicrobial-loaded cement and antimicrobial-loaded calcium sulphate beads have emphasized local antimicrobial delivery on the premise that high-dose local antimicrobial delivery will enhance eradication. However, with increasing antimicrobial pressures, microbiota have responded with adaptive mechanisms beyond traditional antimicrobial resistance genes. In this review we describe adaptive resistance mechanisms that are relevant to the treatment of PJI. Some mechanisms are well known, but others are new. The objective of this review is to inform clinicians of the known adaptive resistance mechanisms of microbes relevant to PJI. We also discuss the implications of these adaptive mechanisms in the future treatment of PJI. Cite this article: Bone Joint J 2022;104-B(5):575-580.

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.

Pyroptosis-Induced Inflammation and Tissue Damage

Programmed cell deaths are pathways involving cells playing an active role in their own destruction. Depending on the signaling system of the process, programmed cell death can be divided into two categories, pro-inflammatory and non-inflammatory. Pyroptosis is a pro-inflammatory form of programmed cell death. Upon cell death, a plethora of cytokines are released and trigger a cascade of responses from the neighboring cells. The pyroptosis process is a double-edged sword, could be both beneficial and detrimental in various inflammatory disorders and disease conditions. A physiological outcome of these responses is tissue damage, and sometimes death of the host. In this review, we focus on the inflammatory response triggered by pyroptosis, and resulting tissue damage in selected organs.

Microbiome Profile and Molecular Pathways Alterations in Gastrointestinal Tract by Hydrogen Sulfide-Releasing Nonsteroidal Anti-Inflammatory Drug (ATB-352): Insight into Possible Safer Polypharmacy

Aims: Nonsteroidal anti-inflammatory drugs, including ketoprofen, induce adverse effects within the gastrointestinal (GI)-tract. Hydrogen sulfide (H₂S) is an antioxidative gaseous mediator contributing to GI-protection. We aimed to evaluate the GI safety of a novel H₂S-releasing derivative of ketoprofen (ATB-352) versus classic ketoprofen and the molecular mechanisms of their activity after chronic treatment in experimental animal models. Results: Ketoprofen (10 mg/kg/day) administered intragastrically for 7 days in contrast with ATB-352 (14 mg/kg/day) reduced mucosal H₂S content inducing GI damage with significantly increased injury score, altered intestinal microbiome profile, and modulation of more than 50% of 36 investigated molecular sensors (e.g., mammalian target of rapamycin or suppressor of cytokine signaling 3 [SOCS3]). Polypharmacy with aspirin (10 mg/kg/day) enhanced ketoprofen toxicity not affecting GI safety of ATB-352. Omeprazole (20 mg/kg/day) decreased ketoprofen-induced injury to the level of ATB-352 alone. Both compounds combined or not with aspirin or omeprazole maintained the ability to inhibit cyclooxygenase (COX) activity manifested by decreased prostaglandin production. Innovation and Conclusions: Ketoprofen-induced H₂S-production decrease and intestinal microbiome profile alterations lead to GI toxicity observed on macro-/microscopic and molecular levels. Ketoprofen but not ATB-352 requires concomitant treatment with omeprazole to eliminate GI adverse effects. ATB-352 applied alone or in a polypharmacy setting with aspirin effectively inhibited COX and maintained GI safety due to H₂S-release. Neither compound affected DNA oxidation in the GI mucosa, but ATB-352 had lower impact on molecular oxidative/inflammatory response pathways and intestinal microbiome. The GI safety of ATB-352 could be due to the involvement of heme oxygenase 1 and SOCS3 pathway activation. Antioxid. Redox Signal. 36, 189-210.

NSAID-Induced Enteropathy Affects Regulation of Hepatic Glucose Production by Decreasing GLP-1 Secretion

BACKGROUND/AIM

Given their widespread use and their notorious effects on the lining of gut cells, including the enteroendocrine cells, we explored if chronic exposure to non-steroidal anti-inflammatory drugs (NSAIDs) affects metabolic balance in a mouse model of NSAID-induced enteropathy.

METHOD

We administered variable NSAIDs to C57Blk/6J mice through intragastric gavage and measured their energy balance, glucose hemostasis, and GLP-1 levels. We treated them with Exendin-9 and Exendin-4 and ran a euglycemic-hyperinsulinemic clamp.

RESULTS

Chronic administration of multiple NSAIDs to C57Blk/6J mice induces ileal ulcerations and weight loss in animals consuming a high-fat diet. Despite losing weight, NSAID-treated mice exhibit no improvement in their glucose tolerance. Furthermore, glucose-stimulated (glucagon-like peptide -1) GLP-1 is significantly attenuated in the NSAID-treated groups. In addition, Exendin-9-a GLP-1 receptor antagonist-worsens glucose tolerance in the control group but not in the NSAID-treated group. Finally, the hyper-insulinemic euglycemic clamp study shows that endogenous glucose production, total glucose disposal, and their associated insulin levels were similar among an ibuprofen-treated group and its control. Exendin-4, a GLP-1 receptor agonist, reduces insulin levels in the ibuprofen group compared to their controls for the same glucose exchange rates.

CONCLUSIONS

Chronic NSAID use can induce small intestinal ulcerations, which can affect intestinal GLP-1 production, hepatic insulin sensitivity, and consequently, hepatic glucose production.

Efficacy of complementary medicine for nonsteroidal anti-inflammatory drug-induced small intestinal injuries: A narrative review

Nonsteroidal anti-inflammatory drug-induced small bowel injuries (NSIs) have been largely ignored for decades due to the focus on nonsteroidal anti-inflammatory drug gastropathy. With the visualization of the small intestines enabled by video capsule endoscopy, the frequency and severity of NSIs have become more evident. NSIs have a complex pathophysiology, and no effective preventive or treatment options have been proven. Complementary and alternative medicine (CAM) has been used to treat disorders of the small intestine, and more research on its effectiveness for NSIs has been conducted.We reviewed the current evidence and mechanisms of action of CAMs on NSI. Clinical and experimental studies on the effect of CAMs on NSIs were performed using 10 databases.Twenty-two studies (3 clinical and 19 in vivo experimental studies) were included in the final analysis involving 10 kinds of CAMs: bovine colostrum, Orengedokuto (coptis), muscovite, licorice, grape seed, wheat, brown seaweed, Ganoderma lucidum fungus mycelia, Chaenomeles speciosa (sweet) Nakai (muguasantie), and Jinghua Weikang capsule. The mechanisms of CAM include an increase in prostaglandin E2, reparation of the enteric nervous system, inhibition of pro-inflammatory cytokines, reduction of intestinal permeability and enteric bacterial numbers, decrease in oxidative stress, and modulation of small intestinal motility.CAM may be a novel alternative option for treating and preventing NSI, and further studies on human and animal models with relevant comorbidities are warranted.

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.

Gut microbiota changes in patients with spondyloarthritis: A systematic review

OBJECTIVE

Gut microbiota has been proposed as a pivotal role in the progression of Spondyloarthritis (SpA), however diverse results remain to be synthesized. We performed a systematic review to collect evidence on the characteristic of the gut microbiota in patients with SpA, as compared to controls.

METHODS

We systematically searched MEDLINE, EMBASE, Cochrane Database of Systematic Reviews, and Cochrane Central Register of Controlled Trials databases, through June 1, 2021 for studies that compared gut microbiota of cases with SpA versus healthy controls.

RESULTS

Of 3756 records identified, 28 studies from 23 articles were included in the analysis. Results of β-diversity showed SpA patients hold a significantly different microbial composition compared with controls. Several taxa-level differences of gut microbiota between SpA (and its subtypes) cases and controls were identified. Fourteen studies including only patients with ankylosing spondylitis (AS) reported increased amounts of Actinobacteria, Dialister, Streptococcus, and Clostridium bolteae, and decreased amounts of Bacteroidales and Parasutterella in AS cases versus controls in ≥ 3 studies. Dialister invisus was increased in axial-SpA cases versus controls in 3 studies. Bacteroides fragilis was increased in enthesitis-related arthritis (ERA) cases versus controls in 2 studies. For all SpA studies, Proteobacteria, Enterobacteriaceae, and Bacteroidaceae were increased, whereas Bacteroidetes, Bacteroidales, and Akkermansia were decreased in cases versus controls in ≥ 3 studies. Over 40% of the studies showed comparable data of both sex and age between cases and controls.

CONCLUSION

The microbial characteristics of SpA summarized in the systematic review laid the groundwork for evidence-based microbial treatment. The microbial variance among subtypes of SpA remains to be explored. Further studies are needed to elucidate how the altered microbiota participate in the pathogenesis of SpA.

Ketogal Safety Profile in Human Primary Colonic Epithelial Cells and in Mice

In our previous studies, a ketorolac–galactose conjugate (ketogal) showed prolonged anti-inflammatory and analgesic activity, causing less gastric ulcerogenic effect and renal toxicity than its parent drug ketorolac. In order to demonstrate the safer profile of ketogal compared to ketorolac, histopathological changes in the small intestine and liver using three staining techniques before and after repeated oral administration in mice with ketorolac or an equimolecular dose of its galactosylated prodrug ketogal were assessed. Cytotoxicity and oxidative stress parameters were evaluated and compared in ketorolac- and ketogal-treated Human Primary Colonic Epithelial cells at different concentrations and incubation times. Evidence of mitochondrial oxidative stress was found after ketorolac treatment; this was attributable to altered mitochondrial membrane depolarization and oxidative stress parameters. No mitochondrial damage was observed after ketogal treatment. In ketorolac-treated mice, severe subepithelial vacuolation and erosion with inflammatory infiltrates and edematous area in the intestinal tissues were noted, as well as alterations in sinusoidal spaces and hepatocytes with foamy cytoplasm. In contrast, treatment with ketogal provided a significant improvement in the morphology of both organs. The prodrug clearly demonstrated a safer profile than its parent drug both in vitro and ex vivo, confirming that ketogal is a strategic alternative to ketorolac.

Co-factors, Microbes, and Immunogenetics in Celiac Disease to Guide Novel Approaches for Diagnosis and Treatment

Celiac disease (CeD) is a frequent immune-mediated disease that affects not only the small intestine but also many extraintestinal sites. The role of gluten proteins as dietary triggers, HLA-DQ2 or -DQ8 as major necessary genetic predisposition, and tissue transglutaminase (TG2) as mechanistically involved autoantigen, are unique features of CeD. Recent research implicates many cofactors working in synergism with these key triggers, including the intestinal microbiota and their metabolites, nongluten dietary triggers, intestinal barrier defects, novel immune cell phenotypes, and mediators and cytokines. In addition, apart from HLA-DQ2 and -DQ8, multiple and complex predisposing genetic factors and interactions have been defined, most of which overlap with predispositions in other, usually autoimmune, diseases that are linked to CeD. The resultant better understanding of CeD pathogenesis, and its manifold manifestations has already paved the way for novel therapeutic approaches beyond the lifelong strict gluten-free diet, which poses a burden to patients and often does not lead to complete mucosal healing. Thus, supported by improved mouse models for CeD and in vitro organoid cultures, several targeted therapies are in phase 2-3 clinical studies, such as highly effective gluten-degrading oral enzymes, inhibition of TG2, cytokine therapies, induction of tolerance to gluten ingestion, along with adjunctive and preventive approaches using beneficial probiotics and micronutrients. These developments are supported by novel noninvasive markers of CeD severity and activity that may be used as companion diagnostics, allow easy-to perform and reliable monitoring of patients, and finally support personalized therapy for CeD.

The influence of gut microbiome on progression of overactive bladder symptoms: a community-based 3-year longitudinal study in Aomori, Japan

PURPOSE

To assess the influence of gut microbiome on overactive bladder (OAB) symptoms progression.

METHODS

This was a 3-year longitudinal study, Hirosaki in Japan. We assessed OAB symptoms and reviewed the medication records of each subject in 2016. We extracted 16S rRNA genes from fecal samples and analyzed gut microbiomes via next-generation sequencing. We evaluated the changes in urinary urgency (UU) and/or urgent urinary incontinence (UUI) from 2016 to 2019. We defined UU/UUI-progression as exacerbation of UU and/or UUI. We compared the clinical backgrounds and microbiota structure between UU/UUI-progression subjects and non-progression (controls). We assessed the impact of gut microbiome on the UU/UUI-progression via multivariate logistic regression analyses.

RESULTS

Of 669 subjects, 126 were UU/UUI-progression subjects. These subjects had a higher age and prevalence of proton pump inhibitor (PPI) use (14% vs. 5.4%, P = 0.003), irritable bowel syndrome, sleep disturbance, and metabolic syndrome than those without. We found the different microbiota structures between subjects with UU/UUI-progression and those without. A higher relative abundance of genus Streptococcus (harmful bacterial genus for human health) appeared in UU/UUI-progression subjects (3.8% vs. 2.3%, P < 0.001). Multivariate analysis revealed that age ≥ 65 years, current smoking, sleep disturbance, metabolic syndrome, and genus Streptococcus (Odds ratio: 1.05, P = 0.029) were independent risk factors for UU/UUI-progression. PPI use turned to be a significant risk factor on a multivariate analysis without including genus Streptococcus.

CONCLUSIONS

Gut microbiome might be associated with a risk for OAB symptoms progression. PPI use might cause gut dysbiosis and increase this risk.

Research progress of non-steroidal anti-inflammatory drug-induced small intestinal injury

Non-steroidal anti-inflammatory drugs (NSAIDs) are used widely around the world because of their anti-inflammatory, analgesic, and antiplatelet activity. However, long-term application of NSAIDs can lead to complications. Previously, the clinical attention was dedicated to the NSAID-induced upper gastrointestinal complications. Recently, the detection rate of small intestinal damage related to NSAIDs has increased due to the wide use of endoscopes such as capsule endoscopy and double-balloon colonoscopy. Although the majority of patients have no significant symptoms, there are still a small percentage of patients who develop obvious symptoms or complicated ulcers that require therapeutic intervention. Despite significant advances in our understanding of NSAIDs, the treatment modality and regimen for NSAID-induced small intestinal damage have remained relatively unclear. This article will provide a comprehensive overview of NSAID-induced small intestinal damage with regard to the epidemiology, clinical manifestations, diagnosis, risk factors, pathogenesis, and treatment, in order to provide informative evidence for clinical practice.

Mucoprotective drugs can prevent and treat nonsteroidal anti-inflammatory drug-induced small bowel enteropathy: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Small bowel enteropathy (SBE) is a complication of nonsteroidal anti-inflammatory drug (NSAID) therapy occurring in 71% of NSAID users. We aimed to analyse the efficacy and safety of medications to prevent and treat NSAID-induced SBE in randomized controlled trials (RCTs).

METHODS

This review was registered on PROSPERO (CRD42021223371). We systematically searched four databases until 20 October for comparing mucoprotective (MP), antibiotic and probiotic treatments to placebo, proton-pump inhibitors (PPIs) or histamine-2 (H2) receptor antagonists in NSAID-associated small intestinal injuries. The main outcomes were mucosal integrity, mucosal breaks after treatment, mucosal injury improvement and complete healing of mucosal breaks. Meta-analytical calculations for weighted mean differences (WMDs) and odds ratios (ORs) were performed with the random-effects model and interpreted with 95% confidence intervals (CIs).

RESULTS

A total of 18 RCTs were included in the quantitative synthesis. MP medications administered preventively reduced the number of mucosal erosions (WMD = -1.24, CI: -2.15 to -0.34) and lead to a significantly lower chance of developing mucosal breaks after treatment (OR = 0.38, CI: 0.16-0.93). MP therapy was associated with a higher rate of complete healing of mucosal breaks (OR = 5.39, CI: 2.79-10.42). In the qualitative synthesis, there were tendencies for a lower increase in the mean number of mucosal breaks and reddened lesions with prophylactic and a higher decrease in mucosal breaks with therapeutic MP drug administration.

CONCLUSION

MP treatment administered with NSAIDs can prevent and reduce small intestinal mucosal lesions.

Malvidin Protects against and Repairs Peptic Ulcers in Mice by Alleviating Oxidative Stress and Inflammation

Peptic ulcer episodes cause damage to the stomach and intestine, with inflammatory cell infiltration and oxidative stress as the main players. In this study, we investigated the potential of anthocyanidin malvidin for preventive and curative peptic ulcer treatment. The anthocyanidin effects were examined in gastric ulcer mouse models induced by ethanol, non-steroidal anti-inflammatory drugs (NSAIDs), ischemia-reperfusion (IR), acetic acid and duodenal ulcer induced by polypharmacy. Expression levels of oxidative and inflammatory genes were measured to investigate the mechanism of anthocyanin activity. At a dose of 5 mg·kg⁻¹, Malvidin prevented gastric ulcer induction by ethanol, NSAID and repaired the tissue after 6 days of IR. Moreover, the anthocyanidin accelerated the healing of acetic acid-induced ulcer, increased the gene expression of EGF and COX-1, and downregulated MMP-9. Anthocyanin treatment mitigated the effect of polypharmacy on inflammation and oxidative stress observed in the intestine. Additionally, the compound downregulated cytokine expression and TLR4 and upregulated HMOX-1 and IL-10, exhibiting protective activity in the mouse gut. Malvidin thus prevented gastric and duodenal ulcers due to prominent anti-inflammatory and antioxidative effects on the gastrointestinal tract that were related to gene expression modulation and an increase in endogenous defense mechanisms.

Anti-inflammatory effects of DA-9601, an extract of Artemisia asiatica, on aceclofenac-induced acute enteritis

DA-9601 is an extract obtained from Artemisia asiatica, which has been reported to have anti-inflammatory effects on gastrointestinal lesions; however, its possible anti-inflammatory effects on the small intestine have not been studied yet. Therefore, in this study, we investigated the protective effects of DA-9601 against the ACF-induced small intestinal inflammation. Inflammation of the small intestine was confirmed by histological studies and the changes in the CD4⁺ T cell fraction induced by the inflammation-related cytokines, and the inflammatory reactions were analyzed. Multifocal discrete small necrotic ulcers with intervening normal mucosa were frequently observed after treatment with ACF. The expression of IL-6, IL-17, and TNF-α genes was increased in the ACF group; however, it was found to have been significantly decreased in the DA-9601 treated group. In addition, DA-9601 significantly decreased the levels of proinflammatory mediators such as IL-1β, GM-CSF, IFN-γ, and TNF-α; the anti-inflammatory cytokine IL-10, on the other hand, was observed to have increased. It is known that inflammatory mediators related to T cell imbalance and dysfunction continuously activate the inflammatory response, causing chronic tissue damage. The fractions of IFN-γ⁺ Th1 cells, IL-4⁺ Th2 cells, IL-9⁺ Th9 cells, IL-17⁺ Th17 cells, and Foxp3⁺ Treg cells were significantly decreased upon DA-9601 treatment. These data suggest that the inflammatory response induced by ACF is reduced by DA-9601 via lowering of the expression of genes encoding the inflammatory cytokines and the concentration of inflammatory mediators. Furthermore, DA-9601 inhibited the acute inflammatory response mediated by T cells, resulting in an improvement in ACF-induced enteritis.

Asymptomatic small intestinal ulcerative lesions: Obesity and Helicobacter pylori are likely to be risk factors

It is often difficult to explain why ulcerative lesions are found in the small intestine because there are no obvious aggressors such as gastric acid. In particular, the treatment of small intestinal ulcerative lesions in asymptomatic patients with no symptoms, normal physical examinations, and normal blood test findings is not well documented. According to a summary of capsule endoscopy studies in healthy subjects, approximately 10% of subjects have small intestinal mucosal breaks. The number of mucosal breaks in these instances is approximately 1-3. We examined small intestinal mucosal breaks in healthy subjects recruited from our past two studies. Mucosal breaks were observed in approximately 10% of subjects, and the average number was 0.24 ± 1.21. The number of mucosal breaks in the small intestine was correlated with body mass index and was significantly higher in Helicobacter pylori-infected subjects and higher in males. These results indicate that 1-2 small ulcerative lesions, such as erosions in the small intestine, can be considered to be in the normal range, and close examination is not required. It is assumed that a follow-up medical examination is required for such asymptomatic persons. The presence of many small ulcerative lesions or an unequivocal ulcer indicates an abnormality for which close examination is desired. However, in many cases, it is sufficient to scrutinize after detecting anemia, but it is difficult to make a judgment due to insufficient reports, and future studies are required.

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.

Performance of the faecal immunochemical test for the detection of colorectal neoplasms and the role of proton pump inhibitors in their diagnostic accuracy

AIM

The faecal immunochemical test (FIT) is currently utilized in both symptomatic and screening populations, but little is known about factors that affect its performance. For example, proton pump inhibitor (PPI) therapy has been purported to increase false negative rates. This has significant implications given the extent of PPI prescriptions. The aim of this work was to evaluate the performance of the FIT for the detection of colorectal neoplasms and the impact of PPI therapy on its diagnostic accuracy.

METHOD

Symptomatic patients referred on the suspected cancer pathway and those on polyp surveillance between 2015 and 2019 were approached to participate. Estimates of the accuracy of FIT at different cut-off levels in diagnosing colorectal neoplasms were made. Logistic regression was used to assess the effect of PPIs on the FIT results.

RESULTS

A total of 667 participants were eligible for the final analysis. At a cut-off of 10 μg/g faeces, the overall sensitivity and specificity of FIT for the detection of colorectal cancer (CRC) was 0.85 (95% CI 0.71-0.94) and 0.81 (95% CI 0.78-0.84), respectively. For the detection of advanced neoplasia, the sensitivity was 0.70 (95% CI 0.58-0.79) and the specificity was 0.83 (95% CI 0.80-0.86). At higher thresholds, the sensitivity steadily declined whilst specificity increased. PPI therapy did not have a significant effect on performance of the FIT.

CONCLUSION

FIT is a good rule-out test for the detection of CRC and advanced neoplasia at lower thresholds. PPI therapy does not appear to have an effect on its diagnostic performance.

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.

Preventive and therapeutic effects of Lactobacillus rhamnosus SHA113 and its culture supernatant on alcoholic gastric ulcers

BACKGROUND

Alcoholic gastric ulcers are currently a common upper gastrointestinal disease with a high recurrence rate, causing gastric perforation or even gastric cancer in severe cases. Lactobacillus rhamnosus was previously found to prevent alcoholic gastric ulcers, but its therapeutic effects were not illustrated.

AIMS

This study aims to illustrate the preventive and therapeutic effects of L. rhamnosus SHA113 cells and their culture supernatant on alcoholic gastric ulcers and explore the related mechanisms.

METHODS

An alcoholic gastric ulcer model was established by feeding mice with 75% ethanol once at a dosage of 10 ml per kg body weight. The L. rhamnosus SHA113 cells (SHA) and their culture supernatant (SHA-FS) were separately used to feed mice for 2 weeks before ethanol injury in preventive experiments and for 2 days after ethanol injury in therapeutic experiments. The mechanisms were analyzed in view of anti-oxidant and anti-inflammatory activities and intestinal barrier functions.

RESULTS

The preventive effects of SHA-FS were much better than those of SHA via similar mechanisms, such as promoting the secretion of mucus, improving the antioxidant capacity of the gastric mucosa, and inhibiting inflammation. In terms of the therapeutic effects, SHA-FS and SHA could accelerate the healing of damaged ulcers by improving the secretion of tight junction proteins and mucus proteins, increasing angiogenesis, and inhibiting the apoptosis of gastric epithelial cells.

CONCLUSION

L. rhamnosus SHA113 and its culture supernatant had preventive and therapeutic effects on alcoholic gastric ulcers via anti-oxidant and anti-inflammatory pathways and the promotion of healing of damaged ulcers by enhancing intestinal barrier functions, respectively.

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.

Divergent trends of hospitalizations for upper and lower gastrointestinal bleeding based on population prescriptions of aspirin, proton pump inhibitors and Helicobacter pylori eradication therapy: Trends of upper and lower gastrointestinal bleeding

BACKGROUND

With the increasing use of medications that alter the risk of gastrointestinal bleeding (GIB), comprising aspirin, proton pump inhibitors (PPIs), and Helicobacter pylori eradication therapies, the trends of GIB are evolving.

OBJECTIVE

The aim of this study is to determine and predict the trends of GIB and to evaluate the effects of population prescriptions of these medications on GIB incidences.

METHODS

We retrieved patients hospitalized for GIB in all public hospitals in Hong Kong between 2009 and 2019. Monthly age- and sex-standardized GIB data were fitted and predicted, based on population prescriptions of aspirin, nonsteroidal anti-inflammatory drugs (NSAIDs), anticoagulants, other antiplatelet drugs, PPIs, and H. pylori therapies, using autoregressive integrated moving average model for time series analysis.

RESULTS

The incidence of upper GIB (UGIB) showed a clear declining trend while lower GIB (LGIB) decreased slightly. Older population (>80 years) had the greatest decline in UGIB but was associated with an increase in LGIB. Prescriptions of PPIs and aspirin increased significantly with time. PPIs prescriptions were negatively associated with UGIB incidence (coefficient log(PPIs) -4.58; 95% confidence interval [CI]: -5.69, -3.47). H. pylori eradication in the previous month showed a nonsignificant trend on UGIB (coefficient -0.14; 95% CI: -0.30, 0.02). In contrast, aspirin increased the incidences of UGIB (coefficient 0.06; 95% CI: 0.04, 0.07) and LGIB (coefficient 0.04; 95% CI: 0.03, 0.05). NSAIDs, anticoagulants, and other antiplatelet drugs were not significantly associated with the trend of either UGIB or LGIB. UGIB is predicted to decline continuously but LGIB is projected to rise, particularly with increasing use of aspirin.

CONCLUSIONS

UGIB incidences were decreasing and had been surpassed by LGIB. Based on population prescriptions of aspirin and PPIs, divergent trends of upper and lower GIB are expected, especially in elderly.

A comprehensive time course and correlation analysis of indomethacin-induced inflammation, bile acid alterations and dysbiosis in the rat small intestine

It has been proposed that changes in microbiota due to nonsteroidal anti-inflammatory drugs (NSAIDs) alter the composition of bile, and elevation of hydrophobic secondary bile acids contributes to small intestinal damage. However, little is known about the effect of NSAIDs on small intestinal bile acids, and whether bile alterations correlate with mucosal injury and dysbiosis. Here we determined the ileal bile acid metabolome and microbiota 24, 48 and 72 h after indomethacin treatment, and their correlation with each other and with tissue damage in rats. In parallel with the development of inflammation, indomethacin increased the ileal proportion of glycine and taurine conjugated bile acids, but not bile hydrophobicity. Firmicutes decreased with time, whereas Gammaproteobacteria increased first, but declined later and were partially replaced by Bilophila, Bacteroides and Fusobacterium. Mucosal injury correlated negatively with unconjugated bile acids and Gram-positive bacteria, and positively with taurine conjugates and some Gram-negative taxa. Strong positive correlation was found between Lactobacillaceae, Ruminococcaceae, Clostridiaceae and unconjugated bile acids. Indomethacin-induced dysbiosis was not likely due to direct antibacterial effects or alterations in luminal pH. Here we provide the first detailed characterization of indomethacin-induced time-dependent alterations in small intestinal bile acid composition, and their associations with mucosal injury and dysbiosis. Our results suggest that increased bile hydrophobicity is not likely to contribute to indomethacin-induced small intestinal damage.