Rifaximin-extended intestinal release induces remission in patients with moderately active Crohn's disease

Gut-directed therapeutics in inflammatory bowel disease

PURPOSE OF REVIEW

Tissue-directed therapies (TDTs) provide potential advantages, including improved tolerance, safety, and efficacy. This review provides a conceptual framework for understanding intestinal TDT and summarizes the current landscape of TDT in inflammatory bowel disease (IBD).

RECENT FINDINGS

Vedolizumab, a mAb targeting the gut homing α4β7 integrin, served as revolutionary proof-of-principle for the power of advanced TDT in IBD. The development of other monoclonal antibodies targeting cell adhesion molecules followed including abrilumab (α4β7), etrolizumab (β7), and ontamalimab (MAdCAM-1). MORF-057, an oral small molecule inhibitor of α4β7, is now in development for ulcerative colitis. Efforts have also been made toward gut specific JAK inhibitors. Microbiome-based therapies, including engineered probiotics, bacteriophages, and postbiotics, are gaining interest. There are also a number of innovative drug delivery methods, including engineered yeast, hydrogels, and nanoparticles, and viral-based gene therapy.

SUMMARY

Gut-targeted therapies range from novel variations on traditional drugs (i.e., mAbs and small molecules) to microbiome-based therapeutics and engineered delivery systems. They can be used alone or in combination with currently available therapies. Future directions should focus on the development of tried-and-true modalities (mAbs, small molecules) as well as the microbiome and more innovative delivery systems.

Novel therapeutic effects of rifaximin in combination with methylprednisolone for LPS-induced ‎oxidative stress and inflammation in mice‎: ‎An in vivo study

Cytokine-releasing syndrome (CRS) is a special form of ‎‎systemic inflammatory response syndrome provoked by ‎factors ‎like viral infections and certain immunomodulatory drugs.‎ To elucidate the potential ‎role of rifaximin (RIF) and its combination with methylprednisolone (MP) against the development and ‎progression of CRS in ‎mice.‎ This experiment consists of two parts: protective and therapeutic interventions. The protective experiment: in the induction group, mice received an intraperitoneal injection (IP) of 5 mg/kg lipopolysaccharide (LPS) without intervention. The other group received various drugs before the induction by three days, then observed for an additional two days (50 mg/kg MP, 50 mg/kg RIF, and a combination of 25 mg/kg RIF with 25 mg/kg MP. The second part of the study involves the therapeutic potential; all groups received similar doses of drugs to that received in the prevention groups, except LPS induction was given first, and after one hour, the mice received daily doses of the drugs for five days. At the end of the experiment, blood and tissue samples were obtained. Mice treated with RIF and its combination with MP showed improved serum TNF-α, IL-6, IL-8, IL-1β, INF-γ, MDA, and GSH in both prevention and therapeutic groups. Histopathologically, mice treated with rifaximin and its combination with MP ameliorates the tissue damage in both lung and liver tissues following LPS induction. In conclusion, rifaximin showed protective and therapeutic effects in LPS-induced cytokine storms in mice through anti-inflammatory and antioxidant mechanisms, and its combination with methylprednisolone showed additive/ synergistic action.

A Pilot Study of the Effectiveness of a Short Course of Rifaximin 2200 mg/day on Abdominal Symptoms and its Effects on Quality of Life in Patients with Moderate to Severe Diarrhea-Predominant Irritable Bowel Syndrome

BACKGROUND AND OBJECTIVE

Rifaximin is used to treat diarrhea-predominant irritable bowel syndrome (IBS-D). However, determining the most effective regimen remains a challenge. This study aimed to evaluate the effectiveness and safety of a 10-day high-dose course of rifaximin (2200 mg/day) and its effects on both abdominal symptoms and quality of life (QOL) in patients with IBS-D.

METHOD

Adult patients with moderate to severe IBS-D (Rome IV) and fecal urgency and bloating were prescribed rifaximin 1100 mg twice daily for 10 days. Demographic information, the IBS Symptom Severity Index (IBS-SSI) score (using a 7-point Likert scale), and Bristol Stool Scale (BSS) score were recorded at baseline, day 10, and 4 weeks after treatment cessation. IBS Symptom Severity Score (IBS-SSS) and IBS-QOL scores were recorded at baseline and day 10. Any drug adverse effects were recorded.

RESULTS

In total, 39 patients completed the study. Average scores for all abdominal symptoms and BSS showed significant improvement at day 10 and 4 weeks after treatment cessation (all p < 0.001). A significant improvement was seen in IBS-SSS and overall IBS-QOL score at day 10 (p < 0.001), with the highest improvement (31%) in interference with activity. Moreover, composite improvement rates were 38.64% for all abdominal symptoms, together with BSS < 5, bi-composite (66.67% for abdominal pain + bloating; 61.54% for abdominal pain + urgency), and 56.41% for tri-composite (abdominal pain + bloating + urgency) symptoms. Notably, no serious adverse effects were reported, and the adherence rate was 94.9%.

CONCLUSIONS

Abdominal symptoms and overall QOL, especially in social and work dimensions, significantly improved in patients with moderate to severe IBS-D following a regimen of rifaximin 2200 mg/day, which was well tolerated.

Host-pathobiont interactions in Crohn's disease

The mammalian intestine is colonized by trillions of microorganisms that are collectively referred to as the gut microbiota. The majority of symbionts have co-evolved with their host in a mutualistic relationship that benefits both. Under certain conditions, such as in Crohn's disease, a subtype of inflammatory bowel disease, some symbionts bloom to cause disease in genetically susceptible hosts. Although the identity and function of disease-causing microorganisms or pathobionts in Crohn's disease remain largely unknown, mounting evidence from animal models suggests that pathobionts triggering Crohn's disease-like colitis inhabit certain niches and penetrate the intestinal tissue to trigger inflammation. In this Review, we discuss the distinct niches occupied by intestinal symbionts and the evidence that pathobionts triggering Crohn's disease live in the mucus layer or near the intestinal epithelium. We also discuss how Crohn's disease-associated mutations in the host disrupt intestinal homeostasis by promoting the penetration and accumulation of pathobionts in the intestinal tissue. Finally, we discuss the potential role of microbiome-based interventions in precision therapeutic strategies for the treatment of Crohn's disease.

Commensal microbiome and gastrointestinal mucosal immunity: Harmony and conflict with our closest neighbor

BACKGROUND

The gastrointestinal tract contains a wide range of microorganisms that have evolved alongside the immune system of the host. The intestinal mucosa maintains balance within the intestines by utilizing the mucosal immune system, which is controlled by the complex gut mucosal immune network.

OBJECTIVE

This review aims to comprehensively introduce current knowledge of the gut mucosal immune system, focusing on its interaction with commensal bacteria.

RESULTS

The gut mucosal immune network includes gut-associated lymphoid tissue, mucosal immune cells, cytokines, and chemokines. The connection between microbiota and the immune system occurs through the engagement of bacterial components with pattern recognition receptors found in the intestinal epithelium and antigen-presenting cells. This interaction leads to the activation of both innate and adaptive immune responses. The interaction between the microbial community and the host is vital for maintaining the balance and health of the host's mucosal system.

CONCLUSION

The gut mucosal immune network maintains a delicate equilibrium between active immunity, which defends against infections and damaging non-self antigens, and immunological tolerance, which allows for the presence of commensal microbiota and dietary antigens. This balance is crucial for the maintenance of intestinal health and homeostasis. Disturbance of gut homeostasis leads to enduring or severe gastrointestinal ailments, such as colorectal cancer and inflammatory bowel disease. Utilizing these factors can aid in the development of cutting-edge mucosal vaccines that have the ability to elicit strong protective immune responses at the primary sites of pathogen invasion.

Antibiotic Therapy for Active Crohn's Disease Targeting Pathogens: An Overview and Update

Crohn's disease (CD) is a multifactorial chronic disorder that involves a combination of factors, including genetics, immune response, and gut microbiota. Therapy includes salicylates, immunosuppressive agents, corticosteroids, and biologic drugs. International guidelines do not recommend the use of antibiotics for CD patients, except in the case of septic complications. Increasing evidence of the involvement of gut bacteria in this chronic disease supports the rationale for using antibiotics as the primary treatment for active CD. In recent decades, several pathogens have been reported to be involved in the development of CD, but only Escherichia coli (E. coli) and Mycobacterium avium paratubercolosis (MAP) have aroused interest due to their strong association with CD pathogenesis. Several meta-analyses have been published concerning antibiotic treatment for CD patients, but randomized trials testing antibiotic treatment against E. coli and MAP have not shown prolonged benefits and have generated conflicting results; several questions are still unresolved regarding trial design, antibiotic dosing, the formulation used, the treatment course, and the outcome measures. In this paper, we provide an overview and update of the trials testing antibiotic treatment for active CD patients, taking into account the role of pathogens, the mechanisms by which different antibiotics act on harmful pathogens, and antibiotic resistance. Finally, we also present new lines of study for the future regarding the use of antibiotics to treat patients with active CD.

Antibiotics for inflammatory bowel disease: Current status

There is abundant literature reporting about the use of antibiotics in inflammatory bowel disease (IBD), but their role in the management of IBD is not entirely clear. Diverse infectious organisms have been implicated in the pathogenesis of Crohn's disease. Also, infections are believed to be a trigger for flares of ulcerative colitis. The benefit of the routine use of antibiotics in IBD is equivocal. However, there are certain situations, where antibiotics have a clear role and evidence of benefit: perianal fistula, intra-abdominal abscesses in Crohn's disease, acute pouchitis and infection-related flares. However, there is a lack of supportive evidence for the routine use of antibiotics in all disease-related flares. Evidence indicates a lack of benefit of intravenous antibiotics in acute severe ulcerative colitis and only limited benefit in active ulcerative colitis. Limited evidence suggests the role of a combination of oral antibiotics in pediatric ulcerative colitis. Certain targeted antibiotic regimens have been used in IBD. In ulcerative colitis, limited evidence suggests the benefit of the use of an antibiotic cocktail directed against Fusobacterium varium. Therapy directed against Escherichia coli does not seem to have a benefit in inflammatory Crohn's disease. In Crohn's disease, antimycobacterial therapy may result in symptomatic improvement but no durable benefit. Antitubercular therapy (ATT), on the contrary, may result in fibrotic transformation, suggesting a need to avoid misdiagnosis and limit the duration of ATT in Crohn's disease. This review assesses the published literature with respect to antibiotic use and provides guidance to clinicians in appropriate antibiotic use in various situations in the setting of IBD.

Pathogens in Crohn's Disease: The Role of Adherent Invasive Escherichia coli

In Crohn's disease (CD), gut dysbiosis is marked by the prevalence of pathogenic bacterial species. Although several microbes have been reported as risk factors or causative agents of CD, it is not yet clear which is the real trigger of the disease. Thirty years ago, a new pathovar of Escherichia coli strain was isolated in the ileal mucosa of CD patients. This strain, called adherent invasive E. coli (AIEC), for its ability to invade the intestinal mucosa, could represent the causative agent of the disease. Several authors studied the mechanisms by which the AIEC penetrate and replicate within macrophages, and release inflammatory cytokines sustaining inflammation. In this review we will discuss about the role of AIEC in the pathogenesis of CD, the virulence factors mediating adhesion and invasion of AIEC in mucosal tissue, the environmental conditions improving AIEC survival and replication within macrophages. Finally, we will also give an overview of the new strategies developed to limit AIEC overgrowth.

Interaction between mitochondria and microbiota modulating cellular metabolism in inflammatory bowel disease

Inflammatory bowel disease (IBD) is a prototypic complex disease in the gastrointestinal tract that has been increasing in incidence and prevalence in recent decades. Although the precise pathophysiology of IBD remains to be elucidated, a large body of evidence suggests the critical roles of mitochondria and intestinal microbiota in the pathogenesis of IBD. In addition to their contributions to the disease, both mitochondria and gut microbes may interact with each other and modulate disease-causing cell activities. Therefore, we hypothesize that dissecting this unique interaction may help to identify novel pathways involved in IBD, which will further contribute to discovering new therapeutic approaches to the disease. As poorly treated IBD significantly affects the quality of life of patients and is associated with risks and complications, successful treatment is crucial. In this review, we stratify previously reported experimental and clinical observations of the role of mitochondria and intestinal microbiota in IBD. Additionally, we review the intercommunication between mitochondria, and the intestinal microbiome in patients with IBD is reviewed along with the potential mediators for these interactions. We specifically focus on their roles in cellular metabolism in intestinal epithelial cells and immune cells. To this end, we propose a potential therapeutic intervention strategy for IBD.

Neurodegenerative and Neurodevelopmental Diseases and the Gut-Brain Axis: The Potential of Therapeutic Targeting of the Microbiome

The human gut microbiome contains the largest number of bacteria in the body and has the potential to greatly influence metabolism, not only locally but also systemically. There is an established link between a healthy, balanced, and diverse microbiome and overall health. When the gut microbiome becomes unbalanced (dysbiosis) through dietary changes, medication use, lifestyle choices, environmental factors, and ageing, this has a profound effect on our health and is linked to many diseases, including lifestyle diseases, metabolic diseases, inflammatory diseases, and neurological diseases. While this link in humans is largely an association of dysbiosis with disease, in animal models, a causative link can be demonstrated. The link between the gut and the brain is particularly important in maintaining brain health, with a strong association between dysbiosis in the gut and neurodegenerative and neurodevelopmental diseases. This link suggests not only that the gut microbiota composition can be used to make an early diagnosis of neurodegenerative and neurodevelopmental diseases but also that modifying the gut microbiome to influence the microbiome-gut-brain axis might present a therapeutic target for diseases that have proved intractable, with the aim of altering the trajectory of neurodegenerative and neurodevelopmental diseases such as Alzheimer's disease, Parkinson's disease, multiple sclerosis, autism spectrum disorder, and attention-deficit hyperactivity disorder, among others. There is also a microbiome-gut-brain link to other potentially reversible neurological diseases, such as migraine, post-operative cognitive dysfunction, and long COVID, which might be considered models of therapy for neurodegenerative disease. The role of traditional methods in altering the microbiome, as well as newer, more novel treatments such as faecal microbiome transplants and photobiomodulation, are discussed.

ESPEN guideline on Clinical Nutrition in inflammatory bowel disease

The present guideline is an update and extension of the ESPEN scientific guideline on Clinical Nutrition in Inflammatory Bowel Disease published first in 2017. The guideline has been rearranged according to the ESPEN practical guideline on Clinical Nutrition in Inflammatory Bowel Disease published in 2020. All recommendations have been checked and, if needed, revised based on new literature, before they underwent the ESPEN consensus procedure. Moreover, a new chapter on microbiota modulation as a new option in IBD treatment has been added. The number of recommendations has been increased to 71 recommendations in the guideline update. The guideline is aimed at professionals working in clinical practice, either in hospitals or in outpatient medicine, and treating patients with IBD. General aspects of care in patients with IBD, and specific aspects during active disease and in remission are addressed. All recommendations are equipped with evidence grades, consensus rates, short commentaries and links to cited literature.

Mild Crohn's Disease: Definition and Management

PURPOSE OF REVIEW

Crohn's Disease (CD) is a chronic inflammatory disease that can lead to progressive damage to the gastrointestinal tract and significant disability. Early, "top-down" biologic therapy is recommended in moderate-to-severe CD to induce remission and to prevent hospitalization and complications. However, an estimated 20-30% of patients with CD have a mild disease course and may not garner sufficient benefit from expensive, immunosuppressing agents to justify their risks. Herein, we review characteristics of patients with mild CD, the available options for disease treatment and monitoring, and future directions of research.

RECENT FINDINGS

For ambulatory outpatients with low-risk, mild, ileal or ileocolonic CD, induction of remission with budesonide is recommended. For colonic CD, sulfasalazine is a reasonable choice, although other aminosalicylates have no role in the treatment of CD. No large, randomized trial has supported the use of antibiotics or antimycobacterials in the treatment of CD. Partial Enteral Nutrition and Crohn's Disease Exclusion Diets may be appropriate for inducing remission in some adult patients, with trials ongoing. Select patients with mild-to-moderate CD may benefit from maintenance therapy with azathioprines or gut specific biologics, such as vedolizumab. The role of complementary and alternative medicine is not well defined. The identification, risk stratification, and monitoring of patients with mild CD can be a challenging clinical scenario. Some patients with low risk of disease progression may be appropriate for initial induction of remission with budesonide or sulfasalazine, followed by close clinical monitoring. Future research should focus on pre-clinical biomarkers to stratify disease, novel therapies with minimal systemic immune suppression, and validation of rigorous clinical monitoring algorithms.

Gastrointestinal disorders and intestinal bacteria: Advances in research and applications in therapy

Intestinal bacteria coexist with humans and play a role in suppressing the invasion of pathogens, producing short-chain fatty acids, producing vitamins, and controlling the immune system. Studies have been carried out on culturable bacterial species using bacterial culture methods for many years. However, as metagenomic analysis of bacterial genes has been developed since the 1990s, it has recently revealed that many bacteria in the intestine cannot be cultured and that approximately 1,000 species and 40 trillion bacteria are present in the gut microbiota. Furthermore, the composition of the microbiota is different in each disease state compared with the healthy state, and dysbiosis has received much attention as a cause of various diseases. Regarding gastrointestinal diseases, dysbiosis has been reported to be involved in inflammatory bowel disease, irritable bowel syndrome, and non-alcoholic steatohepatitis. Recent findings have also suggested that dysbiosis is involved in colon cancer, liver cancer, pancreatic cancer, esophageal cancer, and so on. This review focuses on the relationship between the gut microbiota and gastrointestinal/hepatobiliary diseases and also discusses new therapies targeting the gut microbiota.

The Pregnane X Receptor and Indole-3-Propionic Acid Shape the Intestinal Mesenchyme to Restrain Inflammation and Fibrosis

BACKGROUND & AIMS

Fibrosis is a common complication of inflammatory bowel diseases (IBDs). The pregnane X receptor (PXR) (encoded by NR1I2) suppresses intestinal inflammation and has been shown to influence liver fibrosis. In the intestine, PXR signaling is influenced by microbiota-derived indole-3-propionic acid (IPA). Here, we sought to assess the role of the PXR in regulating intestinal inflammation and fibrosis.

METHODS

Intestinal inflammation was induced using dextran sulfate sodium (DSS). Fibrosis was assessed in wild-type (WT), Nr1i2^-/-, epithelial-specific Nr1i2^-/-, and fibroblast-specific Nr1i2^-/- mice. Immune cell influx was quantified by flow cytometry and cytokines by Luminex. Myofibroblasts isolated from WT and Nr1i2^-/- mice were stimulated with cytomix or lipopolysaccharide, and mediator production was assessed by quantitative polymerase chain reaction and Luminex.

RESULTS

After recovery from DSS-induced colitis, WT mice exhibited fibrosis, a response that was exacerbated in Nr1i2^-/- mice. This was correlated with greater neutrophil infiltration and innate cytokine production. Deletion of the PXR in fibroblasts, but not the epithelium, recapitulated this phenotype. Inflammation and fibrosis were reduced by IPA administration, whereas depletion of the microbiota exaggerated intestinal fibrosis. Nr1i2-deficient myofibroblasts were hyperresponsive to stimulation, producing increased levels of inflammatory mediators compared with WT cells. In biopsies from patients with active Crohn's disease (CD) and ulcerative colitis (UC), expression of NR1I2 was reduced, correlating with increased expression of fibrotic and innate immune genes. Finally, both CD and UC patients exhibited reduced levels of fecal IPA.

CONCLUSIONS

These data highlight a role for IPA and its interactions with the PXR in regulating the mesenchyme and the development of inflammation and fibrosis, suggesting microbiota metabolites may be a vital determinant in the progression of fibrotic complications in IBD.

Effects of Low-dose and High-dose Rifaximin in the Treatment of Covert Hepatic Encephalopathy

BACKGROUND AND AIMS

Rifaximin is effective in preventing and treating hepatic encephalopathy (HE). This study aimed to investigate the efficacy and safety of different dosages of rifaximin in the treatment of cirrhotic patients with covert HE (CHE).

METHODS

In this single-center, randomized, controlled, open-label study, CHE was diagnosed using a combination of the psychometric HE score and the EncephalApp Stroop test. Cirrhotic patients with CHE were recruited and randomly assigned to low-dose rifaximin 800 mg/day, high-dose rifaximin (1,200 mg/day), and control groups, and were treated for 8 weeks. The sickness impact profile (SIP) scale was used to evaluate the health-related quality of life (HRQOL) of patients. Forty patients were included in the study, 12 were assigned to the low-dose group, 14 to the high-dose group, and 14 patients to the control group.

RESULTS

The percentage of patients with CHE reversal was significantly higher in both the low-dose (41.67%, 5/12) and high-dose (57.14%, 8/14) groups than in the control group (7.14%, 1/14) at 8 weeks (p=0.037 and p=0.005, respectively). In addition, both doses of rifaximin resulted in significant improvement of the total SIP score compared with the control group. There were no significant differences in the CHE reversal rate, total SIP score improvement, and incidence of adverse event between the low-dose and high-dose groups (p>0.05).

CONCLUSIONS

Low-dose rifaximin reverses CHE and improves HRQOL in cirrhotic patients with comparable effects and safety to high-dose rifaximin.

Targeted suppression of human IBD-associated gut microbiota commensals by phage consortia for treatment of intestinal inflammation

Human gut commensals are increasingly suggested to impact non-communicable diseases, such as inflammatory bowel diseases (IBD), yet their targeted suppression remains a daunting unmet challenge. In four geographically distinct IBD cohorts (n = 537), we identify a clade of Klebsiella pneumoniae (Kp) strains, featuring a unique antibiotics resistance and mobilome signature, to be strongly associated with disease exacerbation and severity. Transfer of clinical IBD-associated Kp strains into colitis-prone, germ-free, and colonized mice enhances intestinal inflammation. Stepwise generation of a lytic five-phage combination, targeting sensitive and resistant IBD-associated Kp clade members through distinct mechanisms, enables effective Kp suppression in colitis-prone mice, driving an attenuated inflammation and disease severity. Proof-of-concept assessment of Kp-targeting phages in an artificial human gut and in healthy volunteers demonstrates gastric acid-dependent phage resilience, safety, and viability in the lower gut. Collectively, we demonstrate the feasibility of orally administered combination phage therapy in avoiding resistance, while effectively inhibiting non-communicable disease-contributing pathobionts.

Fecal Stream Diversion Changes Intestinal Environment, Modulates Mucosal Barrier, and Attenuates Inflammatory Cells in Crohn's Disease

BACKGROUND

The intestinal environment plays important roles in mucosal barrier homeostasis and intestinal inflammation, as clarified in studies using experimental animals but not in humans.

AIMS

We investigated whether environmental changes in the fecal stream cause phenotypic changes in the human mucosal barrier.

METHODS

We obtained human ileal samples after fecal stream diversions in patients with rectal cancer or Crohn's disease. We investigated the bacterial load and diversity in the human defunctioned ileum, defined as the anal side of the ileum relative to the ileostomy. We also examined the epithelium and lamina propria cell phenotypes in the defunctioned ileum.

RESULTS

After fecal stream diversion, bacterial loads decreased significantly in the defunctioned ileum. Based on the Chao1, Shannon, and observed species indices, the diversity of mucosa-associated microbiota was lower in the defunctioned ileum than in the functional ileum. Moreover, the healthy defunctioned ileum showed reductions in villous height, goblet cell numbers, and Ki-67+ cell numbers. Additionally, interferon-γ+, interleukin-17+, and immunoglobulin A+ cell abundance in the lamina propria decreased. After the intestinal environment was restored with an ileostomy closure, the impaired ileal homeostasis recovered. The defunctioned ileum samples from patients with Crohn's disease also showed reductions in interferon-γ+ and interleukin-17+ cell numbers.

CONCLUSIONS

Fecal stream diversion reduced the abundance and diversity of intestinal bacteria. It also altered the intestinal mucosal barrier, similar to the alterations observed in germ-free animals. In patients with Crohn's disease, Th1 and Th17 cell numbers were attenuated, which suggests that the host-microbiome interaction is important in disease pathogenesis.

Role of Bile Acids and Nuclear Receptors in Acupuncture in Improving Crohn's Disease

Nuclear receptors (NRs) are ligand-dependent transcription factors that regulate the transcription of target genes. Bile acids (BAs) can be used as effector molecules to regulate physiological processes in the gut, and NRs are important receptors for bile acid signaling. Relevant studies have shown that NRs are closely related to the occurrence of Crohn's disease (CD). Although the mechanism of NRs in CD has not been clarified completely, growing evidence shows that NRs play an important role in regulating intestinal immunity, mucosal barrier, and intestinal flora. NRs can participate in the progress of CD by mediating inflammation, immunity, and autophagy. As the important parts of traditional Chinese medicine (TCM) therapy, acupuncture and moxibustion in the treatment of CD curative mechanism can get a lot of research support. At the same time, acupuncture and moxibustion can regulate the changes of related NRs. Therefore, to explore whether acupuncture can regulate BA circulation and NRs expression and then participate in the disease progression of CD, a new theoretical basis for acupuncture treatment of CD is provided.

Rifaximin Therapy for Patients With Metronidazole-Unresponsive Clostridium difficile Infection

Background

Clostridium difficile infection (CDI) is a leading cause of hospital-acquired diarrhea. Rifaximin is an antibiotic that offers marginal resistance to C. difficile bacteria. This study was conducted to evaluate the efficacy of rifaximin in metronidazole non-responsive CDI patients.

Methods

A cross-sectional study was performed from August 2019 to May 2020 at the Lahore General Hospital, Lahore, Pakistan. A total of 200 cases were included. Patients who developed diarrhea after receiving antibiotics for seven days and a positive C. difficile toxin stool test as detected by the enzyme immunoassay (BioCheck, Inc., CA) were diagnosed with CDI. Only patients who were unresponsive to metronidazole therapy were enrolled in our analysis. Two groups were formed. The intervention group was administered 200 mg tablets of rifaximin three times a day for 10 days. For patients in the control group, no new treatment was started. The efficacy of rifaximin was defined in terms of the resolution of diarrhea after two weeks of therapy and a negative stool test. All data were recorded in a predefined pro forma.

Results

The mean age of 45.41 ± 8.54 years was found in the intervention group. The majority of the patients were aged 35-50 years. The majority of the patients had watery diarrhea, abdominal cramping, and loss of appetite on presentation. Rifaximin was found to be significantly effective in the resolution of symptoms of CDI, which was previously unresponsive to metronidazole (p<0.00001). it was found that the duration of diarrhea of more than three weeks was significantly associated with failure of therapy (p=0.03).

Conclusion

We concluded that rifaximin therapy is effective for patients of CDI non-responsive to metronidazole in more than 65% of the cases. Even though several new developments are made to address the concerned subject, such as microbiota transplantation, antibiotics, and immunotherapy, rifaximin can be considered for patients with metronidazole non-responsive CDI.

[Functional Gastrointestinal Disorders in Patients with Inflammatory Bowel Disease]

With emerging more effective drugs, the therapeutic goal of inflammatory bowel disease (IBD) has progressed from clinical remission to mucosal healing. Although the inflammation could be controlled more effectively than before, symptoms such as abdominal pain and bowel habit change is still bothersome to some IBD patients. Recently, these "refractory functional gastrointestinal symptoms" in quiescent IBD patients has been paid more attention. The pathophysiology could be multifactorial with genetics, change in gut motility associated with post inflammatory condition, increased permeability, impaired colorectal function, visceral hypersensitivity and gut microbiota. Because both IBD and functional gastrointestinal disease (FGID) could share similar symptoms and some pathophysiology, it is sometimes challenging to distinguish them exactly. However, to reduce the risk of overtreatment or insufficient control of inflammation, exact diagnosis of functional disease or symptoms in quiescent IBD patients is important. Because there is limited randomized controlled trials or prospective study currently, most of the therapeutic approach in IBD patients are empirical or referred to those of functional gastrointestinal disorders. However, approaches based on pathophysiological mechanisms could give appropriate therapies for both IBD and FGIDs.

Therapeutic efficacy of rifaximin loaded tamarind gum polysaccharide nanoparticles in TNBS induced IBD model Wistar rats

Background

Rifaximin is a non-systemic antibiotic used in the treatment of inflammatory bowel disease (IBD). Antibiotics are demonstrating a significant role in the treatment of IBD by altering the dysbiotic colonic microbiota and decreases the immunogenic and inflammatory response in the patient population. Mucoadhesive colon targeted nanoparticles provide the site-specific delivery and extended stay in the colon. Since the bacteria occupy the lumen, spread over the surface of epithelial cells, and adhere to the mucosa, delivering the rifaximin as a nanoparticles with the mucoadhesive polymer enhances the therapeutic efficacy in IBD. The objective was to fabricate and characterize the rifaximin loaded tamarind gum nanoparticles and study the therapeutic efficacy in the TNBS-induced IBD model rats.

Materials and methods

The experimentation includes fabrication and characterization of drug excipient compatibility by FTIR. The fabricated nanoparticles were characterized for the hydrodynamic size and zeta potential by photon correlation spectroscopy and also analyzed by TEM. Selected best formulation was subjected to the therapeutic efficacy study in TNBS-induced IBD rats, and the macroscopic, microscopic and biochemical parameters were reported.

Results

The study demonstrated that the formulation TGN1 is best formulation in terms of nanoparticle characterization and hydrodynamic size which showed the hydrodynamic size of 171.4 nm and the zeta potential of -26.44 mV and other parameters such as TEM and drug release studies were also reported.

Conclusions

The therapeutic efficacy study revealed that TGN1 is efficiently reduced the IBD inflammatory conditions as compared to the TNBS control group and reference drug mesalamine group.

Regulation of PXR Function by Coactivator and Corepressor Proteins: Ligand Binding Is Just the Beginning

The pregnane X receptor (PXR, NR1I2) is a nuclear receptor which exerts its regulatory function by heterodimerization with the retinoid-X-receptor α (RXRα, NR2B1) and binding to the promoter and enhancer regions of diverse target genes. PXR is involved in the regulation of drug metabolism and excretion, metabolic and immunological functions and cancer pathogenesis. PXR activity is strongly regulated by the association with coactivator and corepressor proteins. Coactivator proteins exhibit histone acetyltransferase or histone methyltransferase activity or associate with proteins having one of these activities, thus promoting chromatin decondensation and activation of the gene expression. On the contrary, corepressor proteins promote histone deacetylation and therefore favor chromatin condensation and repression of the gene expression. Several studies pointed to clear cell- and ligand-specific differences in the activation of PXR. In this article, we will review the critical role of coactivator and corepressor proteins as molecular determinants of the specificity of PXR-mediated effects. As already known for other nuclear receptors, understanding the complex mechanism of PXR activation in each cell type and under particular physiological and pathophysiological conditions may lead to the development of selective modulators with therapeutic potential.

The Dilemma of Persistent Irritable Bowel Syndrome Symptoms in Patients with Quiescent Inflammatory Bowel Disease

Irritable bowel syndrome and inflammatory bowel disease differ in their natural evolution, etiopathogenesis, diagnostic criteria, and therapeutic approach. However, recent evidence has suggested some similarities in mechanisms underlying symptom development and progression. There is a relevant role for alterations in the microbiome-brain-gut axis in both diseases. The presence of irritable bowel syndrome symptoms in patients with quiescent inflammatory bowel disease is common in clinical practice. To determine the cause of irritable bowel syndrome symptoms in patients with quiescent inflammatory bowel disease is a clinical challenge. This review aims to illustrate possible causes and solutions for these patients.

Randomized Trial of Ciprofloxacin Doxycycline and Hydroxychloroquine Versus Budesonide in Active Crohn's Disease

BACKGROUND

Increased mucosa-associated E. coli are present in Crohn's disease, but their role in pathogenesis is uncertain.

AIMS

To assess efficacy and safety of an antibiotic/hydroxychloroquine combination effective against E. coli inside macrophages.

METHODS

Adults with moderately active disease (CDAI > 220-450 plus C reactive protein ≥ 5 mg/l and/or fecal calprotectin > 250 μg/g) were randomized to receive (open-label) oral budesonide (Entocort CR 9 mg/day 8 weeks, 6 mg/day 2 weeks, 3 mg/day 2 weeks) or oral ciprofloxacin 500 mg bd, doxycycline 100 mg bd, hydroxychloroquine 200 mg tds for 4 weeks, followed by doxycycline 100 mg bd and hydroxychloroquine 200 mg tds for 20 weeks. Primary endpoints were remission (CDAI ≤ 150) at 10 weeks, remission maintained to 24 weeks, and remission maintained to 52 weeks. Patients not responding (CDAI fall by > 70) by 10 weeks were invited to crossover onto the alternative therapy.

RESULTS

Fifty-nine patients were recruited across 8 sites. Including crossover, 39 patients received antibiotics/hydroxychloroquine and 39 received budesonide. At 10 weeks, 24 weeks, and 52 weeks on initial therapy, only 2/27, 2/27, and 1/27 were in remission on antibiotics/hydroxychloroquine compared with 8/32, 1/32, and 1/32 on budesonide (P = 0.092 at 10 weeks). Withdrawals by 10 weeks due to adverse events were seen in 15 receiving antibiotics/hydroxychloroquine and 6 budesonide. Results including crossover were more promising with 9/24 patients receiving antibiotics/hydroxychloroquine per protocol in remission by 24 weeks. No correlation was seen between response to antibiotics/hydroxychloroquine and ASCA/OmpC antibody status or disease location.

CONCLUSION

Overall results with this antibiotic/hydroxychloroquine combination were unimpressive, but long-term remission is seen in some patients and justifies further study.

Antibiotics in pediatric inflammatory bowel diseases: a systematic review

Introduction: Current therapies in pediatric Inflammatory Bowel Diseases (IBD) target the immune system and often fail to sustain long-term remission. There is a high need for development of alternative treatment strategies such as antibiotics in pediatric IBD.Areas covered: This study systematically assessed efficacy and safety of antibiotics in pediatric IBD. CENTRAL, EMBASE, and Medline were searched for Randomized Controlled Trials (RCTs). Quality assessment was conducted with the Cochrane risk-of-bias tool.Expert opinion: Two RCTs (n = 101, 4.4-18 years, 43% male) were included. Both studies had overall low risk of bias. In mild-to-moderate Crohn's disease, azithromycin+metronidazole (AZ+MET) (n = 35) compared to metronidazole (MET) alone (n = 38) did not induce a significantly different response (PCDAI drop ≥12.5 or remission) (p = 0.07). For induction of remission (PCDAI≤10), AZ+MET was more effective than MET (p = 0.025). In Acute Severe Colitis, mean 5-day-PUCAI was significantly lower in the antibiotic (vancomycin, amoxicillin, metronidazole, doxycycline)+intravenous-corticosteroids group (AB+IVCS) (n = 16) compared to IVCS alone (n=12) (p = 0.037), whereas remission (PUCAI<10) did not differ (p = 0.61). No significant drug-related adverse events were reported. Results of this systematic review of antibiotic use highlight the lack of evidence in pediatric IBD. More evidence is needed before widespread implementation in daily practice.

Intestinal Microbiota in Common Chronic Inflammatory Disorders Affecting Children

The incidence and prevalence rate of chronic inflammatory disorders is on the rise in the pediatric population. Recent research indicates the crucial role of interactions between the altered intestinal microbiome and the immune system in the pathogenesis of several chronic inflammatory disorders in children, such as inflammatory bowel disease (IBD) and autoimmune diseases, such as type 1 diabetes mellitus (T1DM) and celiac disease (CeD). Here, we review recent knowledge concerning the pathogenic mechanisms underlying these disorders, and summarize the facts suggesting that the initiation and progression of IBD, T1DM, and CeD can be partially attributed to disturbances in the patterns of composition and abundance of the gut microbiota. The standard available therapies for chronic inflammatory disorders in children largely aim to treat symptoms. Although constant efforts are being made to maximize the quality of life for children in the long-term, sustained improvements are still difficult to achieve. Additional challenges are the changing physiology associated with growth and development of children, a population that is particularly susceptible to medication-related adverse effects. In this review, we explore new promising therapeutic approaches aimed at modulation of either gut microbiota or the activity of the immune system to induce a long-lasting remission of chronic inflammatory disorders. Recent preclinical studies and clinical trials have evaluated new approaches, for instance the adoptive transfer of immune cells, with genetically engineered regulatory T cells expressing antigen-specific chimeric antigen receptors. These approaches have revolutionized cancer treatments and have the potential for the protection of high-risk children from developing autoimmune diseases and effective management of inflammatory disorders. The review also focuses on the findings of studies that indicate that the responses to a variety of immunotherapies can be enhanced by strategic manipulation of gut microbiota, thus emphasizing on the importance of proper interaction between the gut microbiota and immune system for sustained health benefits and improvement of the quality of life of pediatric patients.

Does rifaximin offer any promise in Crohn's disease in remission and concurrent irritable bowel syndrome-like symptoms?

Microbiota plays an important role in many diseases including inflammatory bowel diseases. Inflammatory bowel disease patients can have concurrent irritable bowel syndrome symptoms similar to those associated with a flare. The potential role of gut dysbiosis in the pathogenesis of inflammatory bowel disease provides a rationale for treating such patients with rifaximin. This study aimed to assess the efficacy of rifaximin in the management of irritable bowel syndrome-like symptoms (bloating, abdominal pain, stool consistency) and quality of life in patients with Crohn's disease in remission.The present study included 86 patients with Crohn's disease in remission (fecal calprotectin <50 μg/g, C-reactive protein <0.5 mg/dL, simple endoscopic score for Crohn's disease <2) and associated irritable bowel syndrome-like symptoms (bloating, abdominal pain, diarrhea). These patients were randomly assigned to rifaximin treatment group (44 patients) and the control group (42 patients). Besides the baseline inflammatory bowel disease treatment and antispasmodics (as needed), patients in the rifaximin treatment group received 3 repeated courses of treatment, each course being represented by 1200 mg/d of rifaximin for 10 days and 20 days free of treatment (3 months consecutively); patients in the control group also received antispamodics as needed and were observed for 3 months.Monthly analyses of bloating score, abdominal pain score, stool consistency score, and quality of life score showed significant improvement after treatment in the rifaximin group in contrast with control group. Significantly more patients in the rifaximin group than in the control group met the criteria for adequate improvement of bloating score after 3 months of treatment (59.09% vs 19.04%, P = .01), adequate improvement of abdominal pain score (54.5% vs 21.4%, P = .04), stool consistency score (34.09% vs 14.2%, P = .03), and quality of life score (70.4% vs 21.4%, P < .001).Rifaximin in a dose of 1200 mg/d, 10 d/mo, 3 months consecutively is an effective medication for concurrent irritable bowel syndrome-like symptoms in patients with Crohn's disease in remission.

Bile Acid Signaling in Inflammatory Bowel Diseases

Bile acids are a group of chemically different steroids generated at the host/microbial interface. Indeed, while primary bile acids are the end-product of cholesterol breakdown in the host liver, secondary bile acids are the products of microbial metabolism. Primary and secondary bile acids along with their oxo derivatives have been identified as signaling molecules acting on a family of cell membrane and nuclear receptors collectively known as "bile acid-activated receptors." Members of this group of receptors are highly expressed throughout the gastrointestinal tract and mediate the bilateral communications of the intestinal microbiota with the host immune system. The expression and function of bile acid-activated receptors FXR, GPBAR1, PXR, VDR, and RORγt are highly dependent on the structure of the intestinal microbiota and negatively regulated by intestinal inflammation. Studies from gene ablated mice have demonstrated that FXR and GPBAR1 are essential to maintain a tolerogenic phenotype in the intestine, and their ablation promotes the polarization of intestinal T cells and macrophages toward a pro-inflammatory phenotype. RORγt inhibition by oxo-bile acids is essential to constrain Th17 polarization of intestinal lymphocytes. Gene-wide association studies and functional characterizations suggest a potential role for impaired bile acid signaling in development inflammatory bowel diseases (IBD). In this review, we will focus on how bile acids and their receptors mediate communications of intestinal microbiota with the intestinal immune system, describing dynamic changes of bile acid metabolism in IBD and the potential therapeutic application of targeting bile acid signaling in these disorders.

Host-microbiota interactions in inflammatory bowel disease

The mammalian intestine is colonized by trillions of microorganisms that have co-evolved with the host in a symbiotic relationship. The presence of large numbers of symbionts near the epithelial surface of the intestine poses an enormous challenge to the host because it must avoid the activation of harmful inflammatory responses to the microorganisms while preserving its ability to mount robust immune responses to invading pathogens. In patients with inflammatory bowel disease, there is a breakdown of the multiple strategies that the immune system has evolved to promote the separation between symbiotic microorganisms and the intestinal epithelium and the effective killing of penetrant microorganisms, while suppressing the activation of inappropriate T cell responses to resident microorganisms. Understanding the complex interactions between intestinal microorganisms and the host may provide crucial insight into the pathogenesis of inflammatory bowel disease as well as new avenues to prevent and treat the disease.

The Proteolytic Fraction From Vasconcellea cundinamarcensis Latex Displays Anti-Inflammatory Effect in A Mouse Model of Acute TNBS-Induced Colitis

The proteolytic fraction (P1G10) from Vasconcellea cundinamarcensis, displays gastric protective and healing activities in different skin lesions in mice and human. In an excisional model, this fraction accelerates resolution of lesions and modulates inflammatory mediators. Based on these data, we assessed its anti-inflammatory activity in murine colitis model, induced by 2,4,6-trinitrobenzenesulfonic acid (TNBS) adopted by its physiopathological similarity with human colitis. Twenty four hours after colitis induction followed by three days of treatment, P1G10 at 0.3 and 3.0 mg/Kg induced 30% increase in body weight (p < 0.0001) and ~80% reduction in colon macroscopic damage score (p < 0.05) compared to the untreated TNBS-induced colitis group. Histological analyses showed that 0.3 mg/Kg P1G10 reduced the inflammatory profile and tissue damage (47%, p < 0.05) when it was proteolytically active. Compared to TNBS group, 0.3 mg/Kg P1G10 reduced MPO activity (80%, p < 0.01), MCP-1 (47%, p < 0.05) and TNF-α (50%, no significant) and increased IL-10 (330%, p < 0.001) levels in the supernatant of colonic tissue homogenate. P1G10 treatment also reduced COX-2 expression (60%, p < 0.05) and metalloprotease-2 activity (39%, p < 0.05) while increased globet cell density (140%, p < 0.01), that contributes to mucus layer protection in colonic tissue. Taken together, these findings suggest that low doses of active P1G10 promotes lesion resolution, at least in part by its anti-inflammatory activity, in TNBS-colitis model.

British Society of Gastroenterology consensus guidelines on the management of inflammatory bowel disease in adults

Ulcerative colitis and Crohn's disease are the principal forms of inflammatory bowel disease. Both represent chronic inflammation of the gastrointestinal tract, which displays heterogeneity in inflammatory and symptomatic burden between patients and within individuals over time. Optimal management relies on understanding and tailoring evidence-based interventions by clinicians in partnership with patients. This guideline for management of inflammatory bowel disease in adults over 16 years of age was developed by Stakeholders representing UK physicians (British Society of Gastroenterology), surgeons (Association of Coloproctology of Great Britain and Ireland), specialist nurses (Royal College of Nursing), paediatricians (British Society of Paediatric Gastroenterology, Hepatology and Nutrition), dietitians (British Dietetic Association), radiologists (British Society of Gastrointestinal and Abdominal Radiology), general practitioners (Primary Care Society for Gastroenterology) and patients (Crohn's and Colitis UK). A systematic review of 88 247 publications and a Delphi consensus process involving 81 multidisciplinary clinicians and patients was undertaken to develop 168 evidence- and expert opinion-based recommendations for pharmacological, non-pharmacological and surgical interventions, as well as optimal service delivery in the management of both ulcerative colitis and Crohn's disease. Comprehensive up-to-date guidance is provided regarding indications for, initiation and monitoring of immunosuppressive therapies, nutrition interventions, pre-, peri- and postoperative management, as well as structure and function of the multidisciplinary team and integration between primary and secondary care. Twenty research priorities to inform future clinical management are presented, alongside objective measurement of priority importance, determined by 2379 electronic survey responses from individuals living with ulcerative colitis and Crohn's disease, including patients, their families and friends.

The Gut Microbiome in Inflammatory Bowel Diseases: Diagnostic and Therapeutic Implications

The incidence of chronic inflammatory bowel diseases (IBD) is rising worldwide, and the interaction between the mucosal immune system and the intestinal microbiota is crucial for the understanding of these diseases. Due to new technologies, the data published on the intestinal microbiota has increased rapidly in the recent years. While many findings are descriptive, reporting associations between disease and microbial populations, recent advancement in technology made it possible to ask and answer more functional questions and to elucidate complex interactions between the intestinal microbiota and the mucosal immune system. In addition, first trials influenced the intestinal microbiota with the intention to treat IBD. This review summarizes aspects of the physiological function as well as the inflammation-induced changes of the gut microbiota and the association between the gut microbiota and pathogenesis in IBD. In addition, diagnostic and therapeutic options for treating IBD are reviewed.

British Society of Gastroenterology consensus guidelines on the management of inflammatory bowel disease in adults

Ulcerative colitis and Crohn's disease are the principal forms of inflammatory bowel disease. Both represent chronic inflammation of the gastrointestinal tract, which displays heterogeneity in inflammatory and symptomatic burden between patients and within individuals over time. Optimal management relies on understanding and tailoring evidence-based interventions by clinicians in partnership with patients. This guideline for management of inflammatory bowel disease in adults over 16 years of age was developed by Stakeholders representing UK physicians (British Society of Gastroenterology), surgeons (Association of Coloproctology of Great Britain and Ireland), specialist nurses (Royal College of Nursing), paediatricians (British Society of Paediatric Gastroenterology, Hepatology and Nutrition), dietitians (British Dietetic Association), radiologists (British Society of Gastrointestinal and Abdominal Radiology), general practitioners (Primary Care Society for Gastroenterology) and patients (Crohn's and Colitis UK). A systematic review of 88 247 publications and a Delphi consensus process involving 81 multidisciplinary clinicians and patients was undertaken to develop 168 evidence- and expert opinion-based recommendations for pharmacological, non-pharmacological and surgical interventions, as well as optimal service delivery in the management of both ulcerative colitis and Crohn's disease. Comprehensive up-to-date guidance is provided regarding indications for, initiation and monitoring of immunosuppressive therapies, nutrition interventions, pre-, peri- and postoperative management, as well as structure and function of the multidisciplinary team and integration between primary and secondary care. Twenty research priorities to inform future clinical management are presented, alongside objective measurement of priority importance, determined by 2379 electronic survey responses from individuals living with ulcerative colitis and Crohn's disease, including patients, their families and friends.

Review of pharmacotherapeutic treatments for primary sclerosing cholangitis

BACKGROUND

The objective of this review was to evaluate pharmacotherapeutic treatments for primary sclerosing cholangitis (PSC) through a literature search of current published data. A review of the current clinical data for each treatment is discussed.

METHODS

We conducted a systematic literature search for articles using EMBASE (1980 to April 1, 2018), and MEDLINE (1948 to April 1, 2018) using Ovid, to identify studies investigating various therapies in PSC. Search terms included the following: primary sclerosing cholangitis, cholangitis, sclerosing cholangitis; ursodeoxycholic acid, glucocorticoids, cyclosporine, tacrolimus, methotrexate, azathioprine, 6-mercaptopurine, penicillamine, anti-TNF, antibiotics, and probiotics. We also performed a review of current clinical trials using ClinicalTrials.gov. We considered for review relevant studies published in English, pilot studies, and randomized controlled trials involving human subjects.

RESULTS

Therapies that have been investigated in the management of PSC include those used in search terms and others that were not included in our search parameters. Analysis of published data involving each therapy was explored and none have shown any sustained, significant benefit in the treatment of PSC. In terms of relevance to patient care and clinical practice, this review evaluates and compares various pharmacotherapeutic treatments for PSC where liver transplantation remains the only definitive treatment.

CONCLUSIONS

To date, no clinical study of any drug has demonstrated effectiveness in terms of survival benefit or a decreased need for liver transplantation. More clinical studies are needed, and patients need to be adequately informed before any medical therapy for PSC is undertaken.

Canadian Association of Gastroenterology Clinical Practice Guideline for the Medical Management of Pediatric Luminal Crohn's Disease

BACKGROUND & AIMS

We aim to provide guidance for medical treatment of luminal Crohn's disease in children.

METHODS

We performed a systematic search of publication databases to identify studies of medical management of pediatric Crohn's disease. Quality of evidence and strength of recommendations were rated according to the GRADE (Grading of Recommendation Assessment, Development, and Evaluation) approach. We developed statements through an iterative online platform and then finalized and voted on them.

RESULTS

The consensus includes 25 statements focused on medical treatment options. Consensus was not reached, and no recommendations were made, for 14 additional statements, largely due to lack of evidence. The group suggested corticosteroid therapies (including budesonide for mild to moderate disease). The group suggested exclusive enteral nutrition for induction therapy and biologic tumor necrosis factor antagonists for induction and maintenance therapy at diagnosis or at early stages of severe disease, and for patients failed by steroid and immunosuppressant induction therapies. The group recommended against the use of oral 5-aminosalicylate for induction or maintenance therapy in patients with moderate disease, and recommended against thiopurines for induction therapy, corticosteroids for maintenance therapy, and cannabis in any role. The group was unable to clearly define the role of concomitant immunosuppressants during initiation therapy with a biologic agent, although thiopurine combinations are not recommended for male patients. No consensus was reached on the role of aminosalicylates in treatment of patients with mild disease, antibiotics or vedolizumab for induction or maintenance therapy, or methotrexate for induction therapy. Patients in clinical remission who are receiving immunomodulators should be assessed for mucosal healing within 1 year of treatment initiation.

CONCLUSIONS

Evidence-based medical treatment of Crohn's disease in children is recommended, with thorough ongoing assessments to define treatment success.

Canadian Association of Gastroenterology Clinical Practice Guideline for the Medical Management of Pediatric Luminal Crohn's Disease

BACKGROUND & AIMS

We aim to provide guidance for medical treatment of luminal Crohn's disease in children.

METHODS

We performed a systematic search of publication databases to identify studies of medical management of pediatric Crohn's disease. Quality of evidence and strength of recommendations were rated according to the GRADE (Grading of Recommendation Assessment, Development, and Evaluation) approach. We developed statements through an iterative online platform and then finalized and voted on them.

RESULTS

The consensus includes 25 statements focused on medical treatment options. Consensus was not reached, and no recommendations were made, for 14 additional statements, largely due to lack of evidence. The group suggested corticosteroid therapies (including budesonide for mild to moderate disease). The group suggested exclusive enteral nutrition for induction therapy and biologic tumor necrosis factor antagonists for induction and maintenance therapy at diagnosis or at early stages of severe disease, and for patients failed by steroid and immunosuppressant induction therapies. The group recommended against the use of oral 5-aminosalicylate for induction or maintenance therapy in patients with moderate disease, and recommended against thiopurines for induction therapy, corticosteroids for maintenance therapy, and cannabis in any role. The group was unable to clearly define the role of concomitant immunosuppressants during initiation therapy with a biologic agent, although thiopurine combinations are not recommended for male patients. No consensus was reached on the role of aminosalicylates in treatment of patients with mild disease, antibiotics or vedolizumab for induction or maintenance therapy, or methotrexate for induction therapy. Patients in clinical remission who are receiving immunomodulators should be assessed for mucosal healing within 1 year of treatment initiation.

CONCLUSIONS

Evidence-based medical treatment of Crohn's disease in children is recommended, with thorough ongoing assessments to define treatment success.

Systematic review: outcomes and adverse events from randomised trials in Crohn's disease

BACKGROUND

The suitability of disease activity indices has been challenged, with growing interest in objective measures of inflammation.

AIM

To undertake a systematic review of efficacy and safety outcomes in placebo-controlled randomised controlled trials (RCTs) of patients with Crohn's disease.

METHODS

MEDLINE, EMBASE, CINAHL and Cochrane Library were searched until November 2015, for RCTs of adult Crohn's disease patients treated with medical or surgical therapies. Data on efficacy and safety outcomes, end-point definitions, and measurement instruments were extracted and stratified by publication date (pre-2009 and 2009 onwards).

RESULTS

One hundred and eighty-one RCTs (110 induction and 71 maintenance) were identified, including 23 850 patients. About 92.3% reported clinical efficacy endpoints. The Crohn's Disease Activity Index (CDAI) dominated, defining clinical response or remission in 63.5% of trials (35 definitions of response or remission). CDAI < 150 was the commonest endpoint, but reporting reduced between periods (46.4%-41.1%), whilst use of CDAI100 increased (16.8%-30.4%). Fistula studies most commonly reported fistula closure (9, 90.0%). Reporting of biomarker, endoscopy and histology endpoints increased overall (33.3%-40.6%, 14.4%-30.4% and 3.2%-12.5%, respectively), but were heterogeneous and rarely reported in fistula trials. Patient-reported outcome measures were reported in 41.4% of trials and safety endpoints in 35.4%. Many of the common adverse events relate to disease exacerbation or treatment failure.

CONCLUSIONS

Trial endpoints vary across studies, over time and are distinct in fistula studies. Despite growth in reporting of objective measures of inflammation and in patient-reported outcome measures, there is a lack of standardisation. This confirms the need for a core outcome set for comparative effectiveness research in Crohn's disease.

Antibiotics for induction and maintenance of remission in Crohn's disease

BACKGROUND

Several antibiotics have been evaluated in Crohn's disease (CD), however randomised controlled trials (RCTs) have produced conflicting results.

OBJECTIVES

To assess the efficacy and safety of antibiotics for induction and maintenance of remission in CD.

SEARCH METHODS

We searched MEDLINE, Embase, CENTRAL, the Cochrane IBD Group Specialized Register and Clinicaltrials.gov database from inception to 28 February 2018. We also searched reference lists and conference proceedings.

SELECTION CRITERIA

RCTs comparing antibiotics to placebo or an active comparator in adult (> 15 years) CD patients were considered for inclusion.

DATA COLLECTION AND ANALYSIS

Two authors screened search results and extracted data. Bias was evaluated using the Cochrane risk of bias tool. The primary outcomes were failure to achieve clinical remission and relapse. Secondary outcomes included clinical response, endoscopic response, endoscopic remission, endoscopic relapse, histologic response, histologic remission, adverse events (AEs), serious AEs, withdrawal due to AEs and quality of life. Remission is commonly defined as a Crohn's disease activity index (CDAI) of < 150. Clinical response is commonly defined as a decrease in CDAI from baseline of 70 or 100 points. Relapse is defined as a CDAI > 150. For studies that enrolled participants with fistulizing CD, response was defined as a 50% reduction in draining fistulas. Remission was defined as complete closure of fistulas. We calculated the risk ratio (RR) and corresponding 95% confidence interval (95% CI) for dichotomous outcomes. We calculated the mean difference (MD) and corresponding 95% CI for continuous outcomes. GRADE was used to assess the certainty of the evidence.

MAIN RESULTS

Thirteen RCTs (N = 1303 participants) were eligible. Two trials were rated as high risk of bias (no blinding). Seven trials were rated as unclear risk of bias and four trials were rated as low risk of bias. Comparisons included ciprofloxacin (500 mg twice daily) versus placebo, rifaximin (800 to 2400 mg daily) versus placebo, metronidazole (400 mg to 500 mg twice daily) versus placebo, clarithromycin (1 g/day) versus placebo, cotrimoxazole (960 mg twice daily) versus placebo, ciprofloxacin (500 mg twice daily) and metronidazole (250 mg four time daily) versus methylprednisolone (0.7 to 1 mg/kg daily), ciprofloxacin (500 mg daily), metronidazole (500 mg daily) and budesonide (9 mg daily) versus placebo with budesonide (9 mg daily), ciprofloxacin (500 mg twice daily) versus mesalazine (2 g twice daily), ciprofloxacin (500 mg twice daily) with adalimumab versus placebo with adalimumab, ciprofloxacin (500 mg twice daily) with infliximab versus placebo with infliximab, clarithromycin (750 mg daily) and antimycobacterial versus placebo, and metronidazole (400 mg twice daily) and cotrimoxazole (960 mg twice daily) versus placebo. We pooled all antibiotics as a class versus placebo and antibiotics with anti-tumour necrosis factor (anti-TNF) versus placebo with anti-TNF.The effect of individual antibiotics on CD was generally uncertain due to imprecision. When we pooled antibiotics as a class, 55% (289/524) of antibiotic participants failed to achieve remission at 6 to 10 weeks compared with 64% (149/231) of placebo participants (RR 0.86, 95% CI 0.76 to 0.98; 7 studies; high certainty evidence). At 10 to 14 weeks, 41% (174/428) of antibiotic participants failed to achieve a clinical response compared to 49% (93/189) of placebo participants (RR 0.77, 95% CI 0.64 to 0.93; 5 studies; moderate certainty evidence). The effect of antibiotics on relapse in uncertain. Forty-five per cent (37/83) of antibiotic participants relapsed at 52 weeks compared to 57% (41/72) of placebo participants (RR 0.87, 95% CI 0.52 to 1.47; 2 studies; low certainty evidence). Relapse of endoscopic remission was not reported in the included studies. Antibiotics do not appear to increase the risk of AEs. Thirty-eight per cent (214/568) of antibiotic participants had at least one adverse event compared to 45% (128/284) of placebo participants (RR 0.87, 95% CI 0.75 to 1.02; 9 studies; high certainty evidence). The effect of antibiotics on serious AEs and withdrawal due to AEs was uncertain. Two per cent (6/377) of antibiotic participants had at least one adverse event compared to 0.7% (1/143) of placebo participants (RR 1.70, 95% CI 0.29 to 10.01; 3 studies; low certainty evidence). Nine per cent (53/569) of antibiotic participants withdrew due to AEs compared to 12% (36/289) of placebo participants (RR 0.86, 95% CI 0.57 to 1.29; 9 studies; low certainty evidence) is uncertain. Common adverse events in the studies included gastrointestinal upset, upper respiratory tract infection, abscess formation and headache, change in taste and paraesthesiaWhen we pooled antibiotics used with anti-TNF, 21% (10/48) of patients on combination therapy failed to achieve a clinical response(50% closure of fistulas) or remission (closure of fistulas) at week 12 compared with 36% (19/52) of placebo and anti-TNF participants (RR 0.57, 95% CI 0.29 to 1.10; 2 studies; low certainty evidence). These studies did not assess the effect of antibiotics and anti-TNF on clinical or endoscopic relapse. Seventy-seven per cent (37/48) of antibiotics and anti-TNF participants had an AE compared to 83% (43/52) of anti-TNF and placebo participants (RR 0.93, 95% CI 0.76 to 1.12; 2 studies, moderate certainty evidence). The effect of antibiotics and anti-TNF on withdrawal due to AEs is uncertain. Six per cent (3/48) of antibiotics and anti-TNF participants withdrew due to an AE compared to 8% (4/52) of anti-TNF and placebo participants (RR 0.82, 95% CI 0.19 to 3.45; 2 studies, low certainty evidence). Common adverse events included nausea, vomiting, upper respiratory tract infections, change in taste, fatigue and headache AUTHORS' CONCLUSIONS: Moderate to high quality evidence suggests that any benefit provided by antibiotics in active CD is likely to be modest and may not be clinically meaningful. High quality evidence suggests that there is no increased risk of adverse events with antibiotics compared to placebo. The effect of antibiotics on the risk of serious adverse events is uncertain. The effect of antibiotics on maintenance of remission in CD is uncertain. Thus, no firm conclusions regarding the efficacy and safety of antibiotics for maintenance of remission in CD can be drawn. More research is needed to determine the efficacy and safety of antibiotics as therapy in CD.

AGA Clinical Practice Update on Functional Gastrointestinal Symptoms in Patients With Inflammatory Bowel Disease: Expert Review

DESCRIPTION

The purpose of this clinical practice update review is to describe key principles in the diagnosis and management of functional gastrointestinal (GI) symptoms in patients with inflammatory bowel disease (IBD).

METHODS

The evidence and best practices summarized in this manuscript are based on relevant scientific publications, systematic reviews, and expert opinion where applicable. Best practice advice 1: A stepwise approach to rule-out ongoing inflammatory activity should be followed in IBD patients with persistent GI symptoms (measurement of fecal calprotectin, endoscopy with biopsy, cross-sectional imaging). Best practice advice 2: In those patients with indeterminate fecal calprotectin levels and mild symptoms, clinicians may consider serial calprotectin monitoring to facilitate anticipatory management. Best practice advice 3: Anatomic abnormalities or structural complications should be considered in patients with obstructive symptoms including abdominal distention, pain, nausea and vomiting, obstipation or constipation. Best practice advice 4: Alternative pathophysiologic mechanisms should be considered and evaluated (small intestinal bacterial overgrowth, bile acid diarrhea, carbohydrate intolerance, chronic pancreatitis) based on predominant symptom patterns. Best practice advice 5: A low FODMAP diet may be offered for management of functional GI symptoms in IBD with careful attention to nutritional adequacy. Best practice advice 6: Psychological therapies (cognitive behavioural therapy, hypnotherapy, mindfulness therapy) should be considered in IBD patients with functional symptoms. Best practice advice 7: Osmotic and stimulant laxative should be offered to IBD patients with chronic constipation. Best practice advice 8: Hypomotility agents or bile-acid sequestrants may be used for chronic diarrhea in quiescent IBD. Best practice advice 9: Antispasmodics, neuropathic-directed agents, and anti-depressants should be used for functional pain in IBD while use of opiates should be avoided. Best practice advice 10: Probiotics may be considered for treatment of functional symptoms in IBD. Best practice advice 11: Pelvic floor therapy should be offered to IBD patients with evidence of an underlying defecatory disorder. Best practice advice 12: Until further evidence is available, fecal microbiota transplant should not be offered for treatment of functional GI symptoms in IBD. Best practice advice 13: Physical exercise should be encourage in IBD patients with functional GI symptoms. Best practice advice 14: Until further evidence is available, complementary and alternative therapies should not be routinely offered for functional symptoms in IBD. This Clinical Practice Update was produced by the AGA Institute.

Azithromycin and metronidazole versus metronidazole-based therapy for the induction of remission in mild to moderate paediatric Crohn's disease : a randomised controlled trial

OBJECTIVE

Crohn's disease (CD) pathogenesis associated with dysbiosis and presence of pathobionts in the lumen, intracellular compartments and epithelial biofilms. Azithromycin is active in all three compartments. Our goal was to evaluate if azithromycin-based therapy can improve response and induce remission compared with metronidazole alone in paediatric CD.

DESIGN

This blinded randomised controlled trial allocated children 5-18 years with 10<Pediatric Crohn's Disease Activity Index (PCDAI)≤40 to azithromycin 7.5 mg/kg, 5 days/week for 4 weeks and 3 days/week for another 4 weeks with metronidazole 20 mg/kg/day (group 1) or metronidazole alone (group 2), daily for 8 weeks. Failures from group 2 were offered azithromycin as open label. The primary end point was response defined by a decrease in PCDAI>12.5 or remission using intention to treat analysis.

RESULTS

73 patients (mean age 13.8±3.1 years) were enrolled, 35 to group 1 and 38 to group 2. Response and remission rates at week 8 were identical 23/35 (66%) in group 1 and 17/38 (45%) and 15/38 (39%) in group 2 (P=0.07 and P=0.025, respectively). The needed to treat for remission was 3.7. Faecal calprotectin declined significantly in group 1 (P=0.003) but not in group 2 (p=0.33), and was lower at week 8 (P=0.052). Additional therapy was required in 6/35(17%) from group 1 versus 16/38(42%) in group 2 (P=0.027) by week 8. Among 12 failures in group 2, open-label azithromycin led to remission in 10/12 (83%).

CONCLUSIONS

The combination of azithromycin and metronidazole failed to improve response but was superior for induction of remission and reduction in calprotectin.

TRIAL REGISTRATION NUMBER

NCT01596894.

Treatment Perspectives in Crohn's Disease

BACKGROUND

Crohn's disease (CD) is a chronic immune-mediated disorder of the gastrointestinal tract. The pathophysiological understanding of this disease is limited and no curative therapy is available so far. Therefore, most patients require long-lasting or even life-long immunosuppressive therapies for the suppression of symptoms to improve quality of life and reduction of long-term risks. However, in a relevant subgroup of patients, these therapeutic goals cannot be sufficiently attained.

SUMMARY

Clinically established therapies in active CD comprise corticosteroids and immunosuppressants such as azathioprine. After the introduction of anti-TNFα (Tumor necrosis factor alpha) antibodies, other biologicals (e.g., vedolizumab and ustekinumab) have also been approved. New drugs in the pipeline like filgotinib, upadacitinib, risankizumab or rifaximin could improve the therapy of CD in the near future. Thus, an individualized therapy management, based on optimal selection of therapeutic agents will become more important. Additionally, the local application of mesenchymal stem cells might be helpful in the management of fistulas. Key Messages: The targeted biological therapeutic agents (anti-TNFα antibodies, vedolizumab, ustekinumab) are well established for therapy in CD. There are several new substances in the pipeline with promising results in phase II trials (filgotinib, rifaximin, risankizumab, upadacitinib). The upcoming extension of the therapeutic arsenal will require methods for an optimized selection of substances, thus enabling a more individualized therapy.

Bacteroides ovatus ATCC 8483 monotherapy is superior to traditional fecal transplant and multi-strain bacteriotherapy in a murine colitis model

Background and aims: Bacteriotherapy aimed at addressing dysbiosis may be therapeutic for Inflammatory Bowel Diseases (IBDs). We sought to determine if defined Bacteroides-based bacteriotherapy could be an effective and consistent alternative to fecal microbiota transplantation (FMT) in a murine model of IBD. Methods: We induced experimental colitis in 8- 12-week-old C57BL/6 mice using 2-3% dextran sodium sulfate. Mice were simultaneously treated by oral gavage with a triple-Bacteroides cocktail, individual Bacteroides strains, FMT using stool from healthy donor mice, or their own stool as a control. Survival, weight loss and markers of inflammation (histology, serum amyloid A, cytokine production) were correlated to 16S rRNA gene profiling of fecal and mucosal microbiomes. Results: Triple-Bacteroides combination therapy was more protective against weight loss and mortality than traditional FMT therapy. B. ovatus ATCC8483 was more effective than any individual strain, or a combination of strains, in preventing weight loss, decreasing histological damage, dampening inflammatory response, and stimulating epithelial recovery. Irrespective of the treatment group, overall Bacteroides abundance associated with treatment success and decreased cytokine production while the presence of Akkermansia correlated with treatment failure. However, the therapeutic benefit associated with high Bacteroides abundance was negated in the presence of Streptococcus. Conclusions: Bacteroides ovatus monotherapy was more consistent and effective than traditional FMT at ameliorating colitis and stimulating epithelial recovery in a murine model of IBD. Given the tolerability of Bacteroides ovatus ATCC 8483 in an active, on-going human study, this therapy may be repurposed for the management of IBD in a clinically expedient timeline.

Nuclear Receptors in the Pathogenesis and Management of Inflammatory Bowel Disease

Nuclear receptors (NRs) are ligand-dependent transcription factors that regulate the transcription of target genes. Previous epidemiological and genetic studies have documented the association of NRs with the risk of inflammatory bowel disease (IBD). Although the mechanisms of action of NRs in IBD have not been fully established, accumulating evidence has demonstrated that NRs play complicated roles in regulating intestinal immunity, mucosal barriers, and intestinal flora. As one of the first-line medications for the treatment of IBD, 5-aminosalicylic acid (5-ASA) activates peroxisome proliferator-activated receptor gamma (PPARγ) to attenuate colitis. The protective roles of rifaximin and rifampicin partly depend on promoting pregnane X receptor (PXR) expression. The aims of this review are to discuss the roles of several important NRs, such as PPARγ, PXR, vitamin D receptor (VDR), farnesoid X receptor (FXR), and RAR-related orphan receptor gammat (RORγt), in the pathogenesis of IBD and management strategies based on targeting these receptors.

Antibiotics in inflammatory bowel diseases: do we know what we're doing?

Despite the revolution in inflammatory bowel disease (IBD) treatment over the past two decades with the advent of biological therapies, there remains a substantial proportion of patients with inadequate or unsustained response to existent therapies. The overwhelming focus of IBD therapeutics has been targeting mucosal immunity, however with the developing evidence base pointing to the role of gut microbes in the inflammatory process, renewed focus should be placed on the impact of manipulating the microbiome in IBD management. This review provides an overview of the evidence implicating bacteria in the pathogenesis of gut inflammation in IBD and provides an overview of the evidence of antibiotics in IBD treatment. We also suggest a potential role of antibiotics in clinical practice based on available evidence and clinical experience.

Pathophysiology of NSAID-Associated Intestinal Lesions in the Rat: Luminal Bacteria and Mucosal Inflammation as Targets for Prevention

Non-steroidal anti-inflammatory drugs (NSAIDs) can damage the small intestine, mainly through an involvement of enteric bacteria. This study examined the pathophysiology of NSAID-associated intestinal lesions in a rat model of diclofenac-enteropathy and evaluated the effect of rifaximin on small bowel damage. Enteropathy was induced in 40-week old male rats by intragastric diclofenac (4 mg/kg BID, 14 days). Rifaximin (delayed release formulation) was administered (50 mg/kg BID) 1 h before the NSAID. At the end of treatments, parameters dealing with ileal damage, inflammation, barrier integrity, microbiota composition, and TLR-NF-κB-inflammasome pathway were evaluated. In addition, the modulating effect of rifaximin on NLRP3 inflammasome was tested in an in vitro cell system. Diclofenac induced intestinal damage and inflammation, triggering an increase in tissue concentrations of tumor necrosis factor and interleukin-1β, higher expression of TLR-2 and TLR-4, MyD88, NF-κB and activation of caspase-1. In addition, the NSAID decreased ileal occludin expression and provoked a shift of bacterial phyla toward an increase in Proteobacteria and Bacteroidetes abundance. All these changes were counterbalanced by rifaximin co-administration. This drug was also capable of increasing the proportion of Lactobacilli, a genus depleted by the NSAID. In LPS-primed THP-1 cells stimulated by nigericin (a model to study the NLRP3 inflammasome), rifaximin reduced IL-1β production in a concentration-dependent fashion, this effect being associated with inhibition of the up-stream caspase-1 activation. In conclusion, diclofenac induced ileal mucosal lesions, driving inflammatory pathways and microbiota changes. In conclusion, rifaximin prevents diclofenac-induced enteropathy through both anti-bacterial and anti-inflammatory activities.

Gut microbiota: Role in pathogen colonization, immune responses, and inflammatory disease

The intestinal tract of mammals is colonized by a large number of microorganisms including trillions of bacteria that are referred to collectively as the gut microbiota. These indigenous microorganisms have co-evolved with the host in a symbiotic relationship. In addition to metabolic benefits, symbiotic bacteria provide the host with several functions that promote immune homeostasis, immune responses, and protection against pathogen colonization. The ability of symbiotic bacteria to inhibit pathogen colonization is mediated via several mechanisms including direct killing, competition for limited nutrients, and enhancement of immune responses. Pathogens have evolved strategies to promote their replication in the presence of the gut microbiota. Perturbation of the gut microbiota structure by environmental and genetic factors increases the risk of pathogen infection, promotes the overgrowth of harmful pathobionts, and the development of inflammatory disease. Understanding the interaction of the microbiota with pathogens and the immune system will provide critical insight into the pathogenesis of disease and the development of strategies to prevent and treat inflammatory disease.

Antibiotics in IBD: Still a Role in the Biological Era?

Despite compelling evidence pointing to a critical role of gut microflora in inflammatory bowel disease (IBD) pathogenesis, the role of antibiotics in clinical practice remains limited, largely due to heterogeneous trials with often conflicting evidence. In this review, we revisit previous randomized controlled trials and high-quality uncontrolled studies in an effort to better elucidate the role of antibiotics in contemporary treatment algorithms. The most established role of antibiotics is in perianal Crohn's disease (CD), utilizing ciprofloxacin with or without metronidazole often as an adjunct to biological therapy. Evidence also points to a likely modest role of various antibiotic classes in mild to moderate luminal CD, including ciprofloxacin, metronidazole, azithromycin, and rifaximin. The benefit of metronidazole in preventing postoperative recurrence in CD is well reported; however, the long-term benefit of this intervention remains uncertain. The use of antibiotics in ulcerative colitis (UC) is even more controversial, but studies using broad-spectrum oral antibiotic cocktails have reported a possible role in acute severe colitis and chronic persistent UC. Similarly, the role of oral vancomycin and gentamicin in very early-onset IBD has interesting preliminary results. Adverse events of antibiotics, the resulting alterations in the microbiome with its associated unknown long-term sequela, and the emergence of antibiotic-resistant strains must be carefully balanced. Therefore, although antibiotics may be underused in the treatment of IBD, their integration into clinical practice must be approached judiciously and individually.