Micro(nano)plastics and Their Potential Impact on Human Gut Health: A Narrative Review.

Microplastics and nanoplastics (MNPs) are becoming an increasingly severe global problem due to their widespread distribution and complex impact on living organisms. Apart from their environmental impact, the effects of MNPs on living organisms have also continued to attract attention. The harmful impact of MNPs has been extensively documented in marine invertebrates and larger marine vertebrates like fish. However, the research on the toxicity of these particles on mammals is still limited, and their possible effects on humans are poorly understood. Considering that MNPs are commonly found in food or food packaging, humans are primarily exposed to them through ingestion. It would be valuable to investigate the potential harmful effects of these particles on gut health. This review focuses on recent research exploring the toxicological impacts of micro- and nanoplastics on the gut, as observed in human cell lines and mammalian models. Available data from various studies indicate that the accumulation of MNPs in mammalian models and human cells may result in adverse consequences, in terms of epithelial toxicity, immune toxicity, and the disruption of the gut microbiota. The paper also discusses the current research limitations and prospects in this field, aiming to provide a scientific basis and reference for further studies on the toxic mechanisms of micro- and nanoplastics.

Henoch-schonlein purpura following exposure to SARS-CoV2 vaccine or infection: a systematic review and a case report.

BACKGROUND: Henoch-Schonlein purpura (HSP) is an IgA-mediated systemic small-vessel vasculitis (IgAV) that typically presents with a variable tetrad of symptoms. HSP if often preceded by respiratory tract infections, vaccinations, drugs or malignancies. During the recent COVID-19 pandemic multiples cases of HSP have been described after both infection and vaccination for SARS-CoV2. This study aims to perform a systematic review of literature and describe an additional complicated case of de-novo HSP appeared after the administration of the third dose of a mRNA-SARS-CoV2 vaccination. METHODS: Electronic bibliographic research was performed to identify all the original reports describing cases of de-novo HSP or IgAV appeared after respiratory infection or vaccine administration for SARS-CoV2. We included all case series or case reports of patients who respected our inclusion and exclusion criteria. RESULTS: Thirty-eight publications met our pre-defined inclusion criteria, for an overall number of 44 patients. All patients presented with palpable purpura variable associated with arthralgia, abdominal pain or renal involvement. Increased levels of inflammation markers, mild leukocytosis and elevated D-dimer were the most common laboratory findings. Up to 50% of patients presented proteinuria and/or hematuria. Almost all skin biopsies showed leukocytoclastic vasculitis, with IgA deposits at direct immunofluorescence in more than 50% of cases. CONCLUSIONS: Our results suggest that the immune response elicited by SARS-CoV2 vaccine or infection could play a role in the development of HSP. Current research suggests a possible role of IgA in immune hyperactivation, highlighted by early seroconversion to IgA found in some COVID-19 patients who develop IgA vasculitis.

Effectiveness and Safety of Switching from Intravenous to Subcutaneous Vedolizumab Formulation in Inflammatory Bowel Disease Patients in Clinical Remission.

BACKGROUND AND AIMS: Subcutaneous vedolizumab formulation has been shown to be as effective and safe as the intravenous one in randomized control trials. Real-life data are limited especially for patients receiving long-term intravenous therapy. This study aimed to evaluate the safety and effectiveness of switching from intravenous to subcutaneous vedolizumab in a large cohort of patients with stable clinical remission. METHODS: In this prospective cohort study, we enrolled consecutive patients attending our center between September 2021 and April 2022. The baseline demographic characteristics, 12- and 24-weeks follow-up clinical activity, C-reactive protein levels, and adverse events were recorded. The primary endpoint was to assess combined steroid-free clinical remission plus biochemical remission 24-week after the switch. RESULTS: 93 patients (43 Crohn's disease, 50 ulcerative colitis), switched to subcutaneous vedolizumab after a median duration of intravenous treatment of 36 months [IQR 16-52]. At baseline, 80 patients (86%) had a combined remission. At 24-week, 89.2% (n=74) maintained combined steroid-free clinical remission plus biochemical remission. 25 adverse events were reported, mostly SARS-CoV-2 infections and injection site reactions, with a further four recurrence episodes. Twelve patients (12.9%) discontinued subcutaneous administration and restarted intravenous vedolizumab. CONCLUSIONS: Switching from intravenous to subcutaneous vedolizumab can be considered effective and safe for maintaining remission in patients with inflammatory bowel disease. In addition, this might reduce healthcare costs. However, large-scale real-life studies with long-term follow-up are necessary.

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 SBS-IF 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.

Risk Factors, Diagnosis, and Management of Clostridioides difficile Infection in Patients with Inflammatory Bowel Disease.

Clostridioides difficile infection (CDI) and inflammatory bowel disease (IBD) are two pathologies that share a bidirectional causal nexus, as CDI is known to have an aggravating effect on IBD and IBD is a known risk factor for CDI. The colonic involvement in IBD not only renders the host more prone to an initial CDI development but also to further recurrences. Furthermore, IBD flares, which are predominantly set off by a CDI, not only create a need for therapy escalation but also prolong hospital stay. For these reasons, adequate and comprehensive management of CDI is of paramount importance in patients with IBD. Microbiological diagnosis, correct evaluation of clinical status, and consideration of different treatment options (from antibiotics and fecal microbiota transplantation to monoclonal antibodies) carry pivotal importance. Thus, the aim of this article is to review the risk factors, diagnosis, and management of CDI in patients with IBD.

Intestinal Permeability and Dysbiosis in Female Patients with Recurrent Cystitis: A Pilot Study.

Recurrent cystitis (RC) is a common disease, especially in females. Anatomical, behavioral and genetic predisposing factors are associated with the ascending retrograde route, which often causes bladder infections. RC seems to be mainly caused by agents derived from the intestinal microbiota, and most frequently by Escherichia coli. Intestinal contiguity contributes to the etiopathogenesis of RC and an alteration in intestinal permeability could have a major role in RC. The aim of this pilot study is to assess gut microbiome dysbiosis and intestinal permeability in female patients with RC. Patients with RC (n = 16) were enrolled and compared with healthy female subjects (n = 15) and patients with chronic gastrointestinal (GI) disorders (n = 238). We calculated the Acute Cystitis Symptom Score/Urinary Tract Infection Symptom Assessment (ACSS/UTISA) and Gastrointestinal Symptom Rating Scale (GSRS) scores and evaluated intestinal permeability and the fecal microbiome in the first two cohorts. Patients with RC showed an increased prevalence of gastrointestinal symptoms compared with healthy controls. Of the patients with RC, 88% showed an increased intestinal permeability with reduced biodiversity of gut microbiota compared to healthy controls, and 68% of the RC patients had a final diagnosis of gastrointestinal disease. Similarly, GI patients reported a higher incidence of urinary symptoms with a diagnosis of RC in 20%. Gut barrier impairment seems to play a major role in the pathogenesis of RC. Further studies are necessary to elucidate the role of microbiota and intestinal permeability in urinary tract infections.

Impact of SARS-CoV-2 Infection on the Course of Inflammatory Bowel Disease in Patients Treated with Biological Therapeutic Agents: A Case-Control Study.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has raised concerns in patients with inflammatory bowel disease (IBD), not only due to consequences of coronavirus disease 2019 itself but also as a possible cause of IBD relapse. The main objective of this study was to assess the role of SARS-CoV-2 in IBD clinical recurrence in a cohort of patients undergoing biological therapy. Second, we evaluated the difference in C-reactive protein (CRP) levels between the start and end of the follow-up period (ΔCRP) and the rate of biological therapy discontinuation. Patients with IBD positive for SARS-CoV-2 infection were compared with non-infected patients. IBD recurrence was defined as the need for intensification of current therapy. We enrolled 95 IBD patients with SARS-CoV-2 infection and 190 non-infected patients. During follow-up, 11 of 95 (11.6%) SARS-CoV-2-infected patients experienced disease recurrence compared to 21 of 190 (11.3%) in the control group (p = 0.894). Forty-six (48.4%) SARS-CoV-2-infected patients discontinued biological therapy versus seven (3.7%) in the control group (p < 0.01). In the multivariate analysis, biological agent discontinuation (p = 0.033) and ΔCRP (p = 0.017), but not SARS-CoV-2 infection (p = 0.298), were associated with IBD recurrence. SARS-CoV-2 infection was not associated with increased IBD recurrence rates in this cohort of patients treated with biological agents.

Comparison of performances of infliximab biosimilars CT-P13 versus SB2 in the treatment of inflammatory bowel diseases: a real-life multicenter, observational study in Italy.

BACKGROUND: To compare the performances of Infliximab (IFX) biosimilar CT-P13 and SB2 in the treatment of Inflammatory Bowel Diseases (IBD) outpatients in Italy. RESEARCH DESIGN AND METHODS: Three hundred and eighty IBD outpatients were retrospectively evaluated. The primary endpoint was to compare the two IFX biosimilars in terms of reaching and maintenance of remission at any timepoint. RESULTS: 197 patients with Ulcerative Colitis (UC) and 183 patients with Crohn's Disease (CD) treated with CT-P13 or SB2 and having a median (IQR) follow-up of 12 (6-36) months were compared: 230 (60.5%) were naïve to anti-TNFα, 20 (5.26%) were switched from IFX originator or from IFX CT-P13 to IFX SB2. Clinical remission was achieved in 133 (67.5%) UC patients and in 164 (89.6%) CD patients (p < 0.000), with no differences between CT-P13 and SB2 in the rate of remission in UC (p = 0.667) and CD (p = 0.286). Clinical response, steroid-free remission, rate of surgery, mucosal healing (MH) in UC, switching from IFX originator or from other biosimilar, and safety were similar. Higher MH rate was obtained in CD patients treated with CT-P13 (p = 0.004). CONCLUSION: This first comparative study found that both IFX biosimilars CT-P13 and SB2 are effective and safe in managing IBD outpatients.

Impact of COVID-19 pandemic on the daily management of biotechnological therapy in inflammatory bowel disease patients: Reorganisational response in a high-volume Italian inflammatory bowel disease centre.

The coronavirus disease 2019 (COVID-19) pandemic is having a major clinical as well as organisational impact on the national health-care system in Italy, particularly in high-volume hospitals which are usually active for many essential clinical needs, including inflammatory bowel disease (IBD). Here, we report major clinical and organisational challenges at a high-volume Italian IBD centre one month after the start of the Italian government's restrictions due to the COVID-19 pandemic. All routine follow-up IBD visits of patients in remission were cancelled or rescheduled for 8-12 weeks' time. However, access to the hospital for therapy or for unstable/relapsing patients was not considered postponable. Everyone attending the centre (e.g. physicians, nurses, administrative personnel and patients) were advised to respect the general recommended rules for hand hygiene and social distancing, to disclose if they had a fever or cough or flu-like symptoms and to wear a surgical mask and gloves. At the entrance of the therapy area, a control station was set up in order to double-check all patients with a clinical interview and conduct thermal scanning. A total of 1451 IBD patients under biotechnological or experimental therapy actively followed in the CEMAD IBD centre were included in the study. About 65% of patients maintained their appointment schedules without major problems, while in 20% of cases planned infusions were delayed because of the patient's decision or practical issues. About 10% of patients receiving subcutaneous therapy were allowed to collect their medicine without a follow-up visit. Finally, 10% of patients living outside the Lazio region requested access to their therapy at a local centre closer to their home. At present, five patients have been found to be positive for SARS-CoV-2 infection but with minimal symptoms, 22 are in 'quarantine' for contact considered to be 'at risk' for the infection. Up to now, none of them has experienced significant symptoms. This study represents the first observational detailed report about short-term impact of the COVID-19 pandemic on patient organisation and management in a high-volume IBD centre.

Nutrition, IBD and Gut Microbiota: A Review.

Inflammatory bowel disease (IBD) is a chronic relapsing-remitting systemic disease of the gastrointestinal tract, characterized by an inflammatory process that requires lifelong treatment. The underlying causes of IBD are still unclear, as this heterogeneous disorder results from a complex interplay between genetic variability, the host immune system and environmental factors. The current knowledge recognizes diet as a risk factor for the development of IBD and attributes a substantial pathogenic role to the intestinal dysbiosis inducing an aberrant mucosal immune response in genetically predisposed individuals. This review focused on the clinical evidence available that considers the impact of some nutrients on IBD onset and the role of different diets in the management of IBD and their effects on the gut microbiota composition. The effects of the Specific Carbohydrate Diet, low fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAP) diet, gluten free diet, anti-inflammatory diet and Mediterranean diet are investigated with regard to their impact on microbiota and on the evolution of the disease. At present, no clear indications toward a specific diet are available but the assessment of dysbiosis prior to the recommendation of a specific diet should become a standard clinical approach in order to achieve a personalized therapy.

The Association of Disease Activity, BMI and Phase Angle with Vitamin D Deficiency in Patients with IBD.

Hypovitaminosis D is frequently present in inflammatory bowel disease (IBD) with a higher incidence in Crohn's disease (CD) than in Ulcerative Colitis (UC). Given the involvement of the alimentary tract, many factors can contribute to hypovitaminosis D. The aim of the study was to investigate the association of disease activity, body mass index (BMI) and phase angle with vitamin D deficiency in patients with IBD. A cross-sectional study was conducted on a cohort of 206 IBD patients (October 2016-September 2018). Of these patients, 32.6% were affected by hypovitaminosis D (CD: 38.6%; UC: 25.6%; p < 0.01). Negative and significant associations (p < 0.01) were found between BMI and vitamin D serum levels both in CD and UC patients. BMI represented a determinant of hypovitaminosis D (Odds Ratio (OR) = 1.12, p < 0.01) only in UC patients; phase angle was associated to hypovitaminosis D in both groups (CD: OR = 0.64, p < 0.05; UC: OR = 0.49, p < 0.01). Results of the present study confirm a higher incidence of hypovitaminosis D in patients with CD than in those with UC, and show that nutritional status plays a crucial role in the incidence of vitamin D deficiency in patients with IBD.

Characterization of Sarcopenia in an IBD Population Attending an Italian Gastroenterology Tertiary Center.

(1) Background: There is growing interest in the assessment of muscular mass in inflammatory bowel disease (IBD) as sarcopenia is associated with important outcomes. The aim of the study was to evaluate the percentage of sarcopenia in IBD patients, characterizing methods for assessment and clinical symptoms associated to it. (2) Methods: Consecutive IBD patients accessing the Fondazione Policlinico Agostino Gemelli Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) were enrolled. Healthy patients, elderly or elderly sarcopenic patients, were enrolled as controls. Skeletal muscle mass was evaluated by Dual Energy X-ray Absorptiometry (DEXA) or Bio-Impedensometric Analysis (BIA). Asthenia degree was assessed by subjective visual analogue scales (VAS). Quality of life was measured by the EQ-5D questionnaire. (3) Results: Patients with IBD showed a significant reduction in skeletal muscle mass than healthy controls with lower DEXA and BIA parameters. Moreover, IBD patients presented a lower perception of muscle strength with a higher incidence of asthenia and reduction in quality of life when compared with healthy controls. A significant association between loss in skeletal muscle mass and high asthenia degree was found, configuring a condition of sarcopenia in about one third of patients with IBD. (4) Conclusions: Sarcopenia is common in IBD patients and it is associated with fatigue perception as well as a reduction in quality of life. Therefore, routine assessment of nutritional status and body composition should be a cornerstone in clinical practice, bringing gastroenterologists and nutritionists closer together for a compact, defined picture.

Acute intramucosal dissection in eosinophilic esophagitis.

Acute intramucosal dissection of the esophagus (IED) is a rare complication of eosinophilic esophagitis (EoE). Only few of such IED cases have been described in the literature. We report the case of a 32-year-old man with a 4-months diagnosis of EoE who was referred to the Emergency Department complaining of dysphagia, epigastric pain and fever and who was diagnosed, after an urgent endoscopy, an IED. After careful evaluation and multidisciplinary assessment the patient was managed conservatively, with specific medical therapy-high-dose proton pump inhibitors, swallowed steroid, broad-spectrum antibiotic-and, after a period of absolute fasting, a diet regimen based on "six food elimination diet" with a stepwise increase of food consistency. The patient experienced a rapid and complete relief of symptoms, paralleled by a progressive healing of IED with no recurrence over a 6-month follow-up period. In EoE patients with a high clinical suspicion of an acute IED, we suggest an early execution of chest CT and a contrast esophagography, avoiding potentially dangerous endoscopic procedures in the acute phase that can contribute to enlargement of the dissection, or progression to perforation. Once the diagnosis of IED is confirmed, even in the presence of a contained perforation, a conservative treatment with a multidisciplinary management should always be considered.

Skeletal muscle-gut axis: emerging mechanisms of sarcopenia for intestinal and extra intestinal diseases.

In recent years, there has been an increasing interest on muscle wasting, considering the reduction of quality of life and the increase of morbidity and mortality associated. Sarcopenia and cachexia represent two conditions of reduction of muscle mass, sharing several elements involved in their pathogenesis, such as systemic inflammation, impaired muscle protein synthesis, increased muscle apoptosis, mitochondrial dysfunction in skeletal muscle tissue and insulin resistance. These features often characterize cancer, inactivity or denervation, but also inflammatory diseases, such as chronic obstructive pulmonary disease, renal failure, cardiac failure, rheumatoid arthritis, inflammatory bowel disease and aging in general. The gastrointestinal tract and gut microbiota are thought to be deeply associated with muscle function and metabolism, although the exact mechanisms that link gut with skeletal muscle are still not well known. This review summarized the potential pathways linking gut with muscle, in particular in conditions as sarcopenia and cachexia. The main emerging pathways implicated in the skeletal muscle-gut axis are: the myostatin/activin signaling pathway, the IGF1/PI3K/AKT/mTOR signaling pathway, which results suppressed, the NF-kB signaling pathway and the FOXO signaling pathway. Further researches in this field are necessary to better explain the linkage between gut microbiota and muscle wasting and the possible emerging therapies associated.

Gut microbiota and inflammatory bowel disease: so far so gut!

Major advances have occurred in the knowledge of the pathogenesis of inflammatory bowel disease (IBD) over the last decade, and perhaps the most major, and clinically advantageous of these advances has been the discovery of the microbiome as a key multifaceted component of inflammation. The gut microbiome is the largest known group of cells in the body, and is now recognized as an organ in its own right. Initial studies looking at a possible role of bacterial manipulation of the immune system in IBD, looked at identifying a specific bacterial species, and were not representative of a feasible model of inflammation in IBD overall. More recently there has been a shift towards the concept of dysbiosis, and the acceptance that a number of bacterial factors interact with the immune system in order for inflammation to occur. In the present review we will focus on past perspective of the role of microbiota in IBD, current evidences about dysbiosis in IBD and also the main therapeutic modalities to affect IBD by affecting gut microbiota: probiotics, prebiotics, fecal microbiota transplantation and emerging dietary intervention.

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.

Gastric non-secreting neuroendocrine tumor and hypochlorhydria-related hypergastrinemia: a case report.

INTRODUCTION: Zollinger-Ellison syndrome is characterized by recurrent peptic ulcers and diarrhea that result from gastrin-secreting neuroendocrine tumors of the gastrointestinal tract; nevertheless, severe hypergastrinemia may also have alternative pathogenetic explanations. CASE PRESENTATION: A 61-year-old woman of Caucasian origin presented with a history of epigastric pain and early satiety, severe hypergastrinemia (approximately 2000 pg/mL) and a neuroendocrine polyp in the corpus of her stomach. Chronic atrophic gastritis and intestinal metaplasia was present, but she denied use of acid suppressant drugs and the results of tests for Helicobacter pylori as well as gastric parietal cell and intrinsic factor antibodies were negative. She underwent a radical gastric tangential resection. Six months later, serum gastrin was still elevated despite lack of recurrence of tumor. CONCLUSION: The clinical picture was suggestive for a hypochlorhydria-related hypergastrinemia with subsequent development of a non-secreting carcinoid. We suggest a periodic endoscopic follow-up in patients with severe hypochlorhydria-related hypergastrinemia in order to earlier detect neuroendocrine polyps.

Use and indications of cholestyramine and bile acid sequestrants.

Cholestyramine is a bile acid sequestrant, like colestipol and colesevelam. These molecules are positively charged non-digestible resins that bind to bile acids in the intestine to form an insoluble complex, which is excreted in the feces. They are used mainly for the treatment of primary hypercholesterolemia and hypercholesterolemia associated with mild hypertriglyceridemia, in patients not responding to dietary treatment as well as a second line-treatment for pruritus associated with cholestatic disease, in patients with incomplete biliary obstruction. Several data indicate that modulation of bile acid homeostasis has a good clinical effect in managing diabetes mellitus and the diarrhea from bile acid malabsorption. In this review, we present the "in label" use and indication for these compounds, revisiting the other clinical applications that may benefit from the use of bile acid sequestrants in the near future.

Propionyl-L-carnitine hydrochloride for treatment of mild to moderate colonic inflammatory bowel diseases.

AIM: To assess clinical and endoscopic response to propionyl-L-carnitine hydrochloride (PLC) in colonic inflammatory bowel disease. METHODS: Patients suffering from mild to moderate ulcerative colitis (UC) or Crohn's disease (CD) colitis, with disease activity index (DAI) between 3 and 10 and under stable therapy with oral aminosalicylates, mercaptopurine or azathioprine, for at least 8 wk prior to baseline assessments, were considered suitable for enrollment. Fourteen patients were enrolled to assume PLC 2 g/d (two active tablets twice daily) orally. Clinical-endoscopic and histological activity were assessed by DAI and histological index (HI), respectively, following a colonoscopy performed immediately before and after 4 wk treatment. Clinical response was defined as a lowering of at least 3 points in DAI and clinical remission as a DAI score ≤ 2. Histological response was defined as an improvement of HI of at least 1 point. We used median values for the analysis. Differences pre- and post-treatment were analyzed by Wilcoxon signed rank test. RESULTS: All patients enrolled completed the study. One patient, despite medical advice, took deflazacort 5 d before follow-up colonoscopy examination. No side effects were reported by patients during the trial. After treatment, 71% (SE 12%) of patients achieved clinical response, while 64% (SE 13%) obtained remission. Separating UC from CD patients, we observed a clinical response in 60% (SE 16%) and 100%, respectively. Furthermore 60% (SE 16%) of UC patients and 75% (SE 25%) of CD patients were in clinical remission after therapy. The median DAI was 7 [interquartile range (IQR): 4-8] before treatment and decreased to 2 (IQR: 1-3) (P < 0.01) after treatment. Only patients with UC showed a significant reduction of DAI, from a median 6.5 (IQR: 4-9) before treatment to 2 (IQR: 1-3) after treatment (P < 0.01). Conversely, in CD patients, although displaying a clear reduction of DAI from 7 (IQR: 5.5-7.5) before therapy to 1.5 (IQR: 0.5-2.5) after therapy, differences observed were not significant (P = 0.06). Seventy-nine percent (SE 11%) of patients showed improvement of HI of at least 1 point, while only one CD and two UC patients showed HI stability; none showed HI worsening. Median HI decreased from 1 (IQR: 1-2), to 0.5 (IQR: 0-1) at the endoscopic control in the whole population (P < 0.01), while it changed from 1 (IQR: 1-2) to 0.5 (IQR: 0-1) in UC patients (P < 0.01) and from 1.5 (IQR: 1-2) to 0.5 (IQR: 0-1) in CD patients (P = not significant). The two sample tests of proportions showed no significant differences in clinical and histological response or in clinical remission between UC and CD patients. No side effects were reported during treatment or at 4 wk follow-up visit. CONCLUSION: PLC improves endoscopic and histological activity of mild to moderate UC. Further studies are required to evaluate PLC efficacy in colonic CD patients.

The gut barrier: new acquisitions and therapeutic approaches.

The intestinal barrier serves 2 critical functions for the survival of the individual: first, it allows nutrient absorption and second, it defends the body from dangerous macromolecule penetration. It is a complex multilayer system, consisting of an external "anatomic" barrier and an inner "functional" immunological barrier. The interaction of these 2 barriers enables equilibrated permeability to be maintained. Many factors can alter this balance: gut microflora modifications, mucus layer alterations, and epithelial damage can increase intestinal permeability, allowing the translocation of luminal content to the inner layer of intestinal wall. Several techniques are now available that enable us to study gut permeability: "in vitro" models (Caco-2 and HT29-MTX cells) and "in vivo" not invasive tests (sugar tests and radioisotope scanning tests) are used to estimate permeability and to suggest molecular pathophysiological mechanisms of intestinal permeability in health and diseases. Many medicinal products used in the treatment of gastrointestinal diseases have also found to play an active role in modulate intestinal permeability: corticosteroids, 5-aminosalicylic acid, anti-tumor necrosis factor, probiotics, and mucosal protectors, like gelatin tannate. This review will particularly address the role of the gut barrier in maintaining intestinal permeability (microbiota, mucus, and epithelial cells), the techniques used for estimating intestinal permeability and the therapeutic approaches able to modify it.