Third-line rescue therapy for Helicobacter pylori infection

H pylori gastric infection is one of the most prevalent infectious diseases worldwide. The discovery that most upper gastrointestinal diseases are related to Hpylori infection and therefore can be treated with antibiotics is an important medical advance. Currently, a first-line triple therapy based on proton pump inhibitor （PPI） or ranitidine bismuth citrate （RBC） plus two antibiotics （darithromycin and amoxicillin or nitroimidazole） is recommended by all consensus conferences and guidelines. Even with the correct use of this drug combination, infection can not be eradicated in up to 23% of patients. Therefore, several second line therapies have been recommended. A 7 d quadruple therapy based on PPI, bismuth, tetracycline and metronidazole is the more frequently accepted. However, with second-line therapy, bacterial eradication may fail in up to 40% of cases. When Hpylori eradication is striclly indicated the choice of further treatment is controversial. Currently, a standard third-line therapy is lacking and various protocols have been proposed. Even after two consecutive failures, the most recent literature data have demonsbated that Hpylori eradication can be achieved in almost all patients, even when antibiotic susceptibility is not tested. Different possibilities of empirical treatment exist and the available third-line strategies are herein reviewed.

Role and mechanisms of action of escherichia coli nissle 1917 in the maintenance of remission in ulcerative colitis patients: an update

Ulcerative colitis (UC) is a chronic inflammatory disease, whose etiology is still unclear. Its pathogenesis involves an interaction between genetic factors, immune response and the “forgotten organ”, Gut Microbiota. Several studies have been conducted to assess the role of antibiotics and probiotics as additional or alternative therapies for Ulcerative Colitis. Escherichia coli Nissle (EcN) is a nonpathogenic Gram-negative strain isolated in 1917 by Alfred Nissle and it is the active component of microbial drug Mutaflor® (Ardeypharm GmbH, Herdecke, Germany and EcN, Cadigroup, In Italy) used in many gastrointestinal disorder including diarrhea, uncomplicated diverticular disease and UC. It is the only probiotic recommended in ECCO guidelines as effective alternative to mesalazine in maintenance of remission in UC patients. In this review we propose an update on the role of EcN 1917 in maintenance of remission in UC patients, including data about efficacy and safety. Further studies may be helpful for this subject to further the full use of potential of EcN.

Management and treatment of lactose malabsorption

Lactose malabsorption is a very common condition characterized by intestinal lactase deficiency. Primary lactose malabsorption is an inherited deficit present in the majority of the world＇s population, while secondary hypolactasia can be the consequence of an intestinal disease. The presence of malabsorbed lactose in the colonic lumen causes gastrointestinal symptoms. The condition is known as lactose intolerance. In patients with lactase nonpersistence, treatment should be considered exclusively if intolerance symptoms are present. In the absence of guidelines, the common therapeutic approach tends to exclude milk and dairy products from the diet. However, this strategy may have serious nutritional disadvantages. Several studies have been carried out to find alternative approaches, such as exogenous β-galactosidase, yogurt and probiotics for their bacterial lactase activity, pharmacological and non pharmacological strategies that can prolong contact time between enzyme and substrate delaying gastrointestinal transit time, and chronic lactose ingestion to enhance colonic adaptation. In this review the usefulness of these approaches is discussed and a therapeutic management with a flow chart is proposed.

Endoscopic tools for the diagnosis and evaluation of celiac disease

Celiac disease(CD)is an autoimmune disease of the small bowel induced by ingestion of wheat,rye and barley.Current guidelines indicate histological analysis on at least four duodenal biopsies as the only way to diagnose CD.These indications are based on the conception of the inability of standard endoscopy to make diagnosis of CD and/or to drive biopsy sampling.Over the last years,technology development of endoscopic devices has greatly ameliorated the accuracy of macroscopic evaluation of duodenal villous pattern,increasing the diagnostic power of endoscopy of CD.The aim of this paper is to review the new endoscopic tools and procedures proved to be useful in the diagnosis of CD,such as chromoendoscopy,Fujinon Intelligent Chromo Endoscopy,Narrow Band Imaging,Optical Coherence Tomography,Water-Immersion Technique,confocal laser endomicroscopy,high-resolution magnification endoscopy,capsule endoscopy and I-Scan technology.

Culture-guided treatment approach for Helicobacter pylori infection:Review of the literature

The progressive loss of efficacy of standard eradication therapies has made the treatment of Helicobacter pylori (H. pylori) more challenging than ever. Endoscopic-guided antibiotic susceptibility testing had previously been suggested to guide treatment after failure of second-line therapies. However, its role has expanded over the years, in accordance with the current Maastricht Guidelines. Several authors have dealt with this topic, developing both efficacy trials and cost-effectiveness trials against resistant H. pylori infections as well as infections in naïve patients. However, results are not homogeneous enough to provide definite advice, because antibiotic resistance is not the only reason for treatment failure. Moreover, the culture-guided approach is surrounded by many practical issues, such as the availability of both endoscopy units and microbiology laboratories, and the need for a standard of quality that cannot be satisfied everywhere. Finally, pre-treatment susceptibility testing should be part - and not the only weapon - of a targeted, personalized strategy to overcome H. pylori infection.

Microscopic colitis

Microscopic colitis may be defined as a clinical syndrome, of unknown etiology, consisting of chronic watery diarrhea, with no alterations in the large bowel at the endoscopic and radiologic evaluation. Therefore, a definitive diagnosis is only possible by histological analysis. The epidemiological impact of this disease has become increasingly clear in the last years, with most data coming from Western countries. Microscopic colitis includes two histological subtypes [collagenous colitis (CC) and lymphocytic colitis (LC)] with no differences in clinical presentation and management. Collagenous colitis is characterized by a thickening of the subepithelial collagen layer that is absent in LC. The main feature of LC is an increase of the density of intra-epithelial lymphocytes in the surface epithelium. A number of pathogenetic theories have been proposed over the years, involving the role of luminal agents, autoimmunity, eosinophils, genetics (human leukocyte antigen), biliary acids, infections, alterations of pericryptal fibroblasts, and drug intake; drugs like ticlopidine, carbamazepine or ranitidine are especially associated with the development of LC, while CC is more frequently linked to cimetidine, non-steroidal antiinflammatory drugs and lansoprazole. Microscopic colitis typically presents as chronic or intermittent watery diarrhea, that may be accompanied by symptoms such as abdominal pain, weight loss and incontinence. Recent evidence has added new pharmacological options for the treatment of microscopic colitis:the role of steroidal therapy, especially oral budesonide, has gained relevance, as well as immunosuppressive agents such as azathioprine and 6-mercaptopurine. The use of anti-tumor necrosis factoragents, infliximab and adalimumab, constitutes a new, interesting tool for the treatment of microscopic colitis, but larger, adequately designed studies are needed to confirm existing data.

Glucagon-like peptide-2 analogues for Crohn’s disease patients with short bowel syndrome and intestinal failure

Short bowel syndrome(SBS)with intestinal failure(IF)is a rare but severe complication of Crohn’s disease(CD),which is the most frequent benign condition that leads to SBS after repeated surgical resections,even in the era of biologics and small molecules.Glucagon-like peptide-2 analogues have been deeply studied recently for the treatment of SBS-IF.These drugs have a significant intestinotrophic effect and the potential to reduce the chronic dependence of SBSIF patients on parenteral support or nutrition.Teduglutide has been approved for the treatment of SBS-IF,and apraglutide is currently in clinical development.The use of these drugs was examined with a focus on their use in CD patients.

Infliximab does not increase colonic cancer risk associated to murine chronic colitis

AIM To explore the influence of Infliximab(IFX) on cancer progression in a murine model of colonic cancer associated to chronic colitis.METHODS AOM/DSS model was induced in C57BL/6 mice. Mice were injected with IFX(5 mg/kg) during each DSS cycle while control mice received saline. Body weight, occult blood test and stool consistency were measured to calculate the disease activity index(DAI). Mice were sacrificed at week 10 and colons were analyzed macroscopically and microscopically for number of cancers and degree of inflammation. MTT assay was performed on CT26 to evaluate the potential IFX role on metabolic activity and proliferation. Cells were incubated with TNF-α or IFX or TNF-α plus IFX, and cell vitality was evaluated after 6, 24 and 48 h. The same setting was used after pre-incubation with TNF-α for 24 h.RESULTS IFX significantly reduced DAI and body weight loss in mice compared with controls, preserving also colon length at sacrifice. Histological score was also reduced in treated mice. At macroscopic analysis, IFX treated mice showed a lower number of tumor lesions compared to controls. This was confirmed at microscopic analysis, although differences were not statistically significant. In vitro, IFX treated CT26 maintained similar proliferation ability at MTT test, both when exposed to IFX alone and when associated to TNF-α.CONCLUSION IFX did not increase colonic cancer risk in AOM-DSS model of cancer on chronic colitis nor influence directly the proliferation of murine colon cancer epithelial cells.

COVID-19 as a trigger of irritable bowel syndrome:A review of potential mechanisms

In December 2019 a novel coronavirus disease 2019(COVID-19),caused by the severe acute respiratory syndrome coronavirus-2(SARS-CoV-2),started spreading from Wuhan city of Chinese Hubei province and rapidly became a global pandemic.Clinical symptoms of the disease range from paucisymptomatic disease to a much more severe disease.Typical symptoms of the initial phase include fever and cough,with possible progression to acute respiratory distress syndrome.Gastrointestinal manifestations such as diarrhoea,vomiting and abdominal pain are reported in a considerable number of affected individuals and may be due to the SARS-CoV-2 tropism for the peptidase angiotensin receptor 2.The intestinal homeostasis and microenvironment appear to play a major role in the pathogenesis of COVID-19 and in the enhancement of the systemic inflammatory responses.Long-term consequences of COVID-19 include respiratory disturbances and other disabling manifestations,such as fatigue and psychological impairment.To date,there is a paucity of data on the gastrointestinal sequelae of SARS-CoV-2 infection.Since COVID-19 can directly or indirectly affect the gut physiology in different ways,it is plausible that functional bowel diseases may occur after the recovery because of potential pathophysiological alterations(dysbiosis,disruption of the intestinal barrier,mucosal microinflammation,post-infectious states,immune dysregulation and psychological stress).In this review we speculate that COVID-19 can trigger irritable bowel syndrome and we discuss the potential mechanisms.

Gut microbiome beats two to zero host genome

The gut microbiota and its genomic scaffold, exceeding the human one nearly 500 times, substantially affect human health and diseases. Host-microbe interactions, exerted through microbial biochemical and immunological activities, contain pathogen burden, control neurological and endocrine signalling, enterocyte wellness, energy biosynthesis, gut dysbiosis, complement gaps of host metabolic pathways, finally contributing to human physiology and disease within the gastrointestinal district and through gut-liver and gut-brain axis (1). Regardless substantial advances in correlating microbiota modulation and perturbation with various influencers, the specific impact of internal and external stimuli need to be definitely assigned though causality relationships beyond correlative measures. Host origin or genetic background, age, sanitation, delivery mode, breast-feeding and weaning, infections, diet, drugs, but also exercise, sleep, stress have been reviewed in a wide range of recent literature (2). All external (i.e., food, pathogens) and internal (i.e., microbiota) host modulating factors, both, can be conceptually synthetized by the term "exposome" which we are exposed to in the lifetime and which drives both individual enterophenotypes and disease phenotypes (3). Integrative descriptive and functional charts of microbiota allow the description of the microbiota-host Holobionts system, relationship that can be employed in understanding personalized physiology and nutrition, thus providing patient-tailored therapies (Figure 1). To investigate microbiota unbalance and passage from healthy to disease or unhealthy status, individual baseline compositions and variations within an individual's own range are required.