Prevalence and Natural History of Segmental Colitis Associated With Diverticulosis.

INTRODUCTION: We assessed the prevalence and clinical outcomes of segmental colitis associated with diverticulosis (SCAD) in patients with newly diagnosed diverticulosis. METHODS: A 3-year international, multicenter, prospective cohort study was conducted involving 2,215 patients. RESULTS: SCAD diagnosis was posed in 44 patients (30 male patients; median age: 64.5 years; prevalence of 1.99%, 95% confidence interval, 1.45%-2.66%). Patients with SCAD types D and B showed worse symptoms, higher fecal calprotectin values, needed more steroids, and reached less likely complete remission. DISCUSSION: Although SCAD generally had a benign outcome, types B and D were associated with more severe symptoms and worse clinical course.

Vitamin D and malabsorptive gastrointestinal conditions: A bidirectional relationship?

This paper is one of the outcomes of the 5th International Conference "Controversies in Vitamin D" held in Stresa, Italy from 15 to 18 September 2021 as part of a series of annual meetings which was started in 2017. The scope of these meetings is to discuss controversial issues about vitamin D. Publication of the outcomes of the meeting in international journals allows a wide sharing of the most recent data with the medical and academic community. Vitamin D and malabsorptive gastrointestinal conditions was one of the topics discussed at the meeting and focus of this paper. Participants to the meeting were invited to review available literature on selected issues related to vitamin D and gastrointestinal system and to present their topic to all participants with the aim to initiate a discussion on the main outcomes of which are reported in this document. The presentations were focused on the possible bidirectional relationship between vitamin D and gastrointestinal malabsorptive conditions such as celiac disease, inflammatory bowel diseases (IBDs) and bariatric surgery. In fact, on one hand the impact of these conditions on vitamin D status was examined and on the other hand the possible role of hypovitaminosis D on pathophysiology and clinical course of these conditions was also evaluated. All examined malabsorptive conditions severely impair vitamin D status. Since vitamin D has known positive effects on bone this in turn may contribute to negative skeletal outcomes including reduced bone mineral density, and increased risk of fracture which may be mitigated by vitamin D supplementation. Due to the immune and metabolic extra-skeletal effects there is the possibility that low levels of vitamin D may negatively impact on the underlying gastrointestinal conditions worsening its clinical course or counteracting the effect of treatment. Therefore, vitamin D status assessment and supplementation should be routinely considered in all patients affected by these conditions. This concept is strengthened by the existence of a possible bidirectional relationship through which poor vitamin D status may negatively impact on clinical course of underlying disease. Sufficient elements are available to estimate the desired threshold vitamin D level above which a favourable impact on the skeleton in these conditions may be obtained. On the other hand, ad hoc controlled clinical trials are needed to better define this threshold for obtaining a positive effect of vitamin D supplementation on occurrence and clinical course of malabsorptive gastrointestinal diseases.

Vitamin D status and supplementation before and after Bariatric Surgery: Recommendations based on a systematic review and meta-analysis.

Bariatric surgery is associated with a postoperative reduction of 25(OH) vitamin D levels (25(OH)D) and with skeletal complications. Currently, guidelines for 25(OH)D assessment and vitamin D supplementation in bariatric patients, pre- and post-surgery, are still lacking. The aim of this work is to analyse systematically the published experience on 25(OH)D status and vitamin D supplementation, pre- and post-surgery, and to propose, on this basis, recommendations for management. Preoperatively, 18 studies including 2,869 patients were evaluated. Prevalence of vitamin D insufficiency as defined by 25(OH)D < 30 ng/mL (75 nmol/L) was 85%, whereas when defined by 25(OH)D < 20 ng/mL (50 nmol/L) was 57%. The median preoperative 25(OH)D level was 19.75 ng/mL. After surgery, 39 studies including 5,296 patients were analysed and among those undergoing either malabsorptive or restrictive procedures, a lower rate of vitamin D insufficiency and higher 25(OH)D levels postoperatively were observed in patients treated with high-dose oral vitamin D supplementation, defined as ≥ 2,000 IU/daily (mostly D3-formulation), compared with low-doses (< 2,000 IU/daily). Our recommendations based on this systematic review and meta-analysis should help clinical practice in the assessment and management of vitamin D status before and after bariatric surgery. Assessment of vitamin D should be performed pre- and postoperatively in all patients undergoing bariatric surgery. Regardless of the type of procedure, high-dose supplementation is recommended in patients after bariatric surgery.

Adsorptive cytapheresis in ulcerative colitis: A non-pharmacological therapeutic approach revisited.

Adsorptive cytapheresis proves effective in a proportion of patients affected by ulcerative colitis. Relatively high cost and the need for apheresis facilities, prevented the widespread use of this therapeutic approach. More so following the introduction of anti-TNFα biosimilars which proved both effective and inexpensive. Anti-TNFα agents, however, are burdened by high rate of primary and secondary non-response and prompt switching to new, high-cost biologics, and small molecules. The present review analyzes advantages and disadvantages of adsorptive cytapheresis in the present clinical scenario and suggests its repositioning in the therapeutic workup of selected subgroups of ulcerative colitis patients. The extremely favorable safety profile makes adsorptive cytapheresis a viable therapeutic option in elderly and high-risk UC patients, as well as potential second-line treatment in corticosteroid-dependent patients and poor responders to first-line biologics.

PPAR-Gamma Orchestrates EMT, AGE, and Cellular Senescence Pathways in Colonic Epithelium and Restrains the Progression of IBDs.

Intestinal fibrosis, the most common complication of inflammatory bowel disease (IBD), is characterized by an uncontrolled deposition of extracellular matrix proteins leading to complications resolvable only with surgery. Transforming growth factor is the key player in the epithelial-mesenchymal transition (EMT) and fibrogenesis process, and some molecules modulating its activity, including peroxisome proliferator-activated receptor (PPAR)-γ and its agonists, exert a promising antifibrotic action. The purpose of this study is to evaluate the contribution of signaling other than EMT, such as the AGE/RAGE (advanced glycation end products/receptor of AGEs) and the senescence pathways, in the etiopathogenesis of IBD. We used human biopsies from control and IBD patients, and we used a mouse model of colitis induced by dextran-sodium-sulfate (DSS), without/with treatments with GED (PPAR-gamma-agonist), or 5-aminosalicylic acid (5-ASA), a reference drug for IBD treatment. In patients, we found an increase in EMT markers, AGE/RAGE, and senescence signaling activation compared to controls. Consistently, we found the overexpression of the same pathways in DSS-treated mice. Surprisingly, the GED reduced all the pro-fibrotic pathways, in some circumstances more efficiently than 5-ASA. Results suggest that IBD patients could benefit from a combined pharmacological treatment targeting simultaneously different pathways involved in pro-fibrotic signals. In this scenario, PPAR-gamma activation could be a suitable strategy to alleviate the signs and symptoms of IBD and also its progression.

Old and New Adjunctive Therapies in Celiac Disease and Refractory Celiac Disease: A Review.

Celiac disease (CD) is a chronic enteropathy caused by the ingestion of gluten in a genetically susceptible individual. Currently, a gluten-free diet (GFD) is the only recommended treatment. However, unintentional gluten ingestion or a persistent villous atrophy with malabsorption (regardless of a strict GFD) as in the case of Refractory Celiac Disease (RCD) represents a major issue. In this review, we have analysed and discussed data from both randomized controlled trials and observational studies concerning adjunctive therapies as well as novel therapies for the treatment of CD and RCD. The literature search was carried out through Medline and Scopus. In total, 2268 articles have been identified and 49 were included in this review (36 studies resulting from the search strategy and 13 from other sources). Today, GFD remains the only effective treatment, although steroids, mesalamine, and more recently biological therapies have found space in the complex management of RCD. Currently, studies evaluating the effectiveness of novel therapies are still limited and preliminary results have been controversial.

Bacterial Lysate from the Multi-Strain Probiotic SLAB51 Triggers Adaptative Responses to Hypoxia in Human Caco-2 Intestinal Epithelial Cells under Normoxic Conditions and Attenuates LPS-Induced Inflammatory Response.

Hypoxia-inducible factor-1α (HIF-1α), a central player in maintaining gut-microbiota homeostasis, plays a pivotal role in inducing adaptive mechanisms to hypoxia and is negatively regulated by prolyl hydroxylase 2 (PHD2). HIF-1α is stabilized through PI3K/AKT signaling regardless of oxygen levels. Considering the crucial role of the HIF pathway in intestinal mucosal physiology and its relationships with gut microbiota, this study aimed to evaluate the ability of the lysate from the multi-strain probiotic formulation SLAB51 to affect the HIF pathway in a model of in vitro human intestinal epithelium (intestinal epithelial cells, IECs) and to protect from lipopolysaccharide (LPS) challenge. The exposure of IECs to SLAB51 lysate under normoxic conditions led to a dose-dependent increase in HIF-1α protein levels, which was associated with higher glycolytic metabolism and L-lactate production. Probiotic lysate significantly reduced PHD2 levels and HIF-1α hydroxylation, thus leading to HIF-1α stabilization. The ability of SLAB51 lysate to increase HIF-1α levels was also associated with the activation of the PI3K/AKT pathway and with the inhibition of NF-κB, nitric oxide synthase 2 (NOS2), and IL-1ß increase elicited by LPS treatment. Our results suggest that the probiotic treatment, by stabilizing HIF-1α, can protect from an LPS-induced inflammatory response through a mechanism involving PI3K/AKT signaling.

Immunoglobulin G4-Related Disease of the Intestine: A Clinicopathological Entity to Be Considered.

Background and Objectives: Immunoglobulin G4-related disease (IgG4-RD) is a recently recognized immune-mediated, systemic condition of unknown etiology, associated with fibroinflammatory lesions. Diagnosis is set in the presence of IgG4-positive plasma cell infiltration of the involved tissue and elevated serum IgG4 levels. However, approximately 30% of patients have normal serum IgG4 levels. IgG4-RD may affect several organs, including the pancreas, bile ducts, mesentery, retroperitoneum, and salivary glands, but the involvement of the gastrointestinal tract is uncommon. Materials and Methods: The case series of 4 patients with IgG4-RD involving the intestinal tract was observed in the period of 2017-2022. Colorectal and ileal biopsy specimens were stained with hematoxylin and eosin and immunohistochemical techniques using monoclonal antihuman IgG4 primary antibody. Diagnosis of IgG4-RD was based on the presence of >50 cells/ HPF and IgG4/IgG ratio >40 confirmed by two pathologists. Results: IgG4-RD was set in patients previously diagnosed as affected by Crohn's disease. Conclusions: Systematic IgG4 immunohistochemical staining should be considered in the diagnostic workup of patients with gastrointestinal strictures, mimicking Crohn's disease. The exact prevalence of the condition is likely more frequent than reported and should be defined by a large series of consecutive patients.

COVID-19 and Gastrointestinal Tract: From Pathophysiology to Clinical Manifestations.

Background: Since its first report in Wuhan, China, in December 2019, COVID-19 has become a pandemic, affecting millions of people worldwide. Although the virus primarily affects the respiratory tract, gastrointestinal symptoms are also common. The aim of this narrative review is to provide an overview of the pathophysiology and clinical manifestations of gastrointestinal COVID-19. Methods: We conducted a systematic electronic search of English literature up to January 2023 using Medline, Scopus, and the Cochrane Library, focusing on papers that analyzed the role of SARS-CoV-2 in the gastrointestinal tract. Results: Our review highlights that SARS-CoV-2 directly infects the gastrointestinal tract and can cause symptoms such as diarrhea, nausea/vomiting, abdominal pain, anorexia, loss of taste, and increased liver enzymes. These symptoms result from mucosal barrier damage, inflammation, and changes in the microbiota composition. The exact mechanism of how the virus overcomes the acid gastric environment and leads to the intestinal damage is still being studied. Conclusions: Although vaccination has increased the prevalence of less severe symptoms, the long-term interaction with SARS-CoV-2 remains a concern. Understanding the interplay between SARS-CoV-2 and the gastrointestinal tract is essential for future management of the virus.

Prognostic performance of the 'DICA' endoscopic classification and the 'CODA' score in predicting clinical outcomes of diverticular disease: an international, multicentre, prospective cohort study.

OBJECTIVE: To investigate the predictive value of the Diverticular Inflammation and Complication Assessment (DICA) classification and to develop and validate a combined endoscopic-clinical score predicting clinical outcomes of diverticulosis, named Combined Overview on Diverticular Assessment (CODA). DESIGN: A multicentre, prospective, international cohort study. SETTING: 43 gastroenterology and endoscopy centres located in Europe and South America. PARTICIPANTS: 2215 patients (2198 completing the study) at the first diagnosis of diverticulosis/diverticular disease were enrolled. Patients were scored according to DICA classifications. INTERVENTIONS: A 3-year follow-up was performed. MAIN OUTCOME MEASURES: To predict the acute diverticulitis and the surgery according to DICA classification. Survival methods for censored observation were used to develop and validate a novel combined endoscopic-clinical score for predicting diverticulitis and surgery (CODA score). RESULTS: The 3-year cumulative probability of diverticulitis and surgery was of 3.3% (95% CI 2.5% to 4.5%) in DICA 1, 11.6% (95% CI 9.2% to 14.5%) in DICA 2 and 22.0% (95% CI 17.2% to 28.0%) in DICA 3 (p<0.001), and 0.15% (95% CI 0.04% to 0.59%) in DICA 1, 3.0% (95% CI 1.9% to 4.7%) in DICA 2 and 11.0% (95% CI 7.5% to 16.0%) in DICA 3 (p<0.001), respectively. The 3-year cumulative probability of diverticulitis and surgery was ≤4%, and ≤0.7% in CODA A; <10% and <2.5% in CODA B; >10% and >2.5% in CODA C, respectively. The CODA score showed optimal discrimination capacity in predicting the risk of surgery in the development (c-statistic: 0.829; 95% CI 0.811 to 0.846) and validation cohort (c-statistic: 0.943; 95% CI 0.905 to 0.981). CONCLUSIONS: DICA classification has a significant role in predicting the risk of diverticulitis and surgery in patients with diverticulosis, which is significantly enhanced by the CODA score. TRIAL REGISTRATION NUMBER: NCT02758860.

Systematic review and meta-analysis: the advantage of endoscopic Mayo score 0 over 1 in patients with ulcerative colitis.

BACKGROUND: Mucosal healing (MH) evaluated by endoscopy is a novel target of therapy in UC as it is associated with improved long-term outcomes. It is defined based on the Mayo endoscopic score (MES), but it is still to define whether a value of MES 0 or 1 should be the target. The purpose of this paper is to present the results of a systematic review with meta-analysis which compares long-term outcomes of patients in steroid-free clinical remission with MES 0 with those with MES 1. METHODS: A systematic electronic search of the literature was performed using Medline, Scopus, and CENTRAL through December 2020 (PROSPERO n:CRD42020179333). The studies concerned UC patients, in steroid-free clinical remission, with MES of 0 or 1, and with at least 12-months of follow-up. RESULTS: Out of 4611 citations, 15 eligible studies were identified. Increases in clinical relapse among patients with MES 1 were observed in all the studies included in this review, suggesting that MES of 1 have a higher risk of relapse than a score of 0. MES 0 patients displayed a lower risk of clinical relapse (OR 0.33; 95% CI 0.26-0.43; I2 13%) irrespective of the follow-up time (12-months or longer). On the other hand, no differences were found comparing MES 0 versus MES 1 about the risk of hospitalization or colectomy. CONCLUSIONS: MES 0 is associated with a lower rate of clinical relapse than is MES 1. For this reason, MES 0, rather than MES 0-1, should be considered the therapeutic target for patients with UC.

Non-steroidal anti-inflammatory drugs and acetylsalicylic acid increase the risk of complications of diverticular disease: a meta-analysis of case-control and cohort studies.

BACKGROUND: The role of non-steroidal anti-inflammatory drugs (NSAIDs) and acetylsalicylic acid in the occurrence of diverticular bleeding (DB), complicated diverticulitis (CD), and acute diverticulitis (AD) is not yet defined. AIM: Update a systematic review and meta-analyses of case-control and cohort studies to evaluate the association between NSAIDs or acetylsalicylic acid with DB, CD, or AD. METHODS: The study included were identified through MEDLINE, Scopus, Web of Science, and Cochrane Library databases. Sizes were pooled across studies to obtain the overall effect size. A random-effects model was used to account for different sources of variation among studies. Odds ratio (OR) with 95% confidence interval (CI) was used as a measure of effect size. RESULTS: Thirteen studies were included in the systematic review and meta-analysis. NSAIDs and acetylsalicylic acid use were associated with an increased risk of DB (OR: 6.90, 95% CI 3.86 to 12.35, P ˂ 0.00001, and OR 2.84, 95% CI 2.19 to 3.67, P < 0.00001, respectively). NSAIDs and acetylsalicylic acid use were also associated with increased risk of CD occurrence (OR 3.13, 95% CI 1.73 to 5.68, P = 0.0002, and OR 1.49, 95% CI 1.02 to 2.17, P = 0.04, respectively). The only study found about AD occurrence showed that NSAIDs use was not associated with AD and acetylsalicylic acid use had a low risk of AD. CONCLUSION: NSAIDs and acetylsalicylic acid significantly increase the risk of DB and CD. Further studies are needed to clarify the role of NSAIDs and acetylsalicylic acid in AD. However, increasing evidence suggests caution in the use of such medications in patients with colonic diverticula.

Risk of colonoscopic post-polypectomy bleeding in patients on single antiplatelet therapy: systematic review with meta-analysis.

BACKGROUND: It was not yet fully established whether the use of antiplatelet agents (APAs) is associated with an increased risk of colorectal post-polypectomy bleeding (PPB). Temporarily, discontinuation of APAs could reduce the risk of PPB, but at the same time, it could increase the risk of cardiovascular disease recurrence. This study aimed to assess the PPB risk in patients using APAs compared to patients without APAs or anticoagulant therapy who had undergone colonoscopy with polypectomy. METHODS: A systematic electronic search of the literature was performed using PubMed/MEDLINE, Scopus, and CENTRAL, to assess the risk of bleeding in patients who do not interrupt single antiplatelet therapy (P2Y12 inhibitors or aspirin) and undergone colonoscopy with polypectomy. RESULTS: Of 2417 identified articles, 8 articles (all of them were non-randomized studies of interventions (NRSI); no randomized controlled trials (RCT) were available on this topic) were selected for the meta-analysis, including 1620 patients on antiplatelet therapy and 13,321 controls. Uninterrupted APAs single therapy was associated with an increased risk of PPB compared to the control group (OR 2.31; CI 1.37-3.91). Patients on P2Y12i single therapy had a higher risk of both immediate (OR 4.43; CI 1.40-14.00) and delayed PPB (OR 10.80; CI 4.63-25.16) compared to the control group, while patients on aspirin single therapy may have a little to no difference increase in the number of both immediate and delayed PPB events. CONCLUSIONS: Uninterrupted single antiplatelet therapy may increase the risk of PPB, but the evidence is very uncertain. The risk may be higher in delayed PPB. However, in deciding to discontinue APAs before colonoscopy with polypectomy, the potential higher risk of major adverse cardiovascular events should always be assessed.

Prognostic Role of Mismatch Repair Status, Histotype and High-Risk Pathologic Features in Stage II Small Bowel Adenocarcinomas.

BACKGROUND: Small bowel adenocarcinoma is a relatively rare cancer, often diagnosed in an advanced stage. In localized and resectable disease, surgery alone or in combination with adjuvant chemotherapy is the mainstay of treatment. In the recently published National Comprehensive Cancer Network Clinical Practice guidelines, criteria for selecting patients with stage II small bowel adenocarcinoma to receive adjuvant chemotherapy are provided, and they are mainly extrapolated from studies on colorectal cancer. PATIENTS AND METHODS: In the present study, we aimed to verify whether mismatch repair deficiency phenotype, high-risk pathologic features (including T4, positive resection margins and a low number of lymph nodes harvested), as well as tumor histologic subtype, were associated with cancer-specific survival in 66 stage II non-ampullary small bowel adenocarcinoma patients, collected through the Small Bowel Cancer Italian Consortium. A central histopathology review was performed. Mismatch repair deficiency was tested by immunohistochemistry for MLH1, MSH2, MSH6 and PMS2, and confirmed by polymerase chain reaction for microsatellite instability. RESULTS: We identified mismatch repair deficiency, glandular/medullary histologic subtype, and celiac disease as significant predictors of favorable cancer-specific survival using univariable analysis with retained significance in bivariable models adjusted for pT stage. Among the high-risk features, only T4 showed a significant association with an increased risk of death; however, its prognostic value was not independent of mismatch repair status. CONCLUSIONS: Mismatch repair protein expression, histologic subtype, association with celiac disease, and, in the mismatch repair proficient subset only, T stage, may help identify patients who may benefit from adjuvant chemotherapy.

Fecal Lactoferrin and Other Putative Fecal Biomarkers in Crohn's Disease: Do They Still Have a Potential Clinical Role?

INTRODUCTION: The need for noninvasive markers of disease activity is mandatory in the assessment of Crohn's disease (CD). The most widely fecal biomarker in CD, despite several limits, is fecal calprotectin. This review aims to elucidate the role, if any, of all other fecal biomarkers, as alternative tools for assessing clinical and endoscopic disease activity, and predict capsule endoscopy findings, response to therapy, disease relapse, and postoperative recurrence. These fecal biomarkers included lactoferrin, S100A12, high mobility group box 1, neopterin, polymorphonuclear neutrophil elastase, fecal hemoglobin, alpha1-antitrypsin, lysozyme, human beta-defensin-2, neutrophil gelatinase-associated lipocalin, matrix metalloproteinase-9, chitinase 3-like-1, M2-pyruvate kinase, myeloperoxidase, and eosinophil proteins. METHODS: A systematic electronic search in the medical literature was performed up to April 2020. Seventy eligible studies were identified out of 859 citations. Data were grouped according to the assessment of clinical and endoscopic disease activity, capsule endoscopy findings, response to therapy, prediction of relapse, and postoperative recurrence. RESULTS: The overall correlation between lactoferrin and clinical indexes is poor, while performance is good with endoscopic scores. Lactoferrin seems to represent a reasonably good surrogate marker of response to therapy and to be potentially useful in identifying patients at high risk for endoscopic relapse or postoperative recurrence. The evaluation of the performance of all other fecal markers is limited by the lack of adequate data. CONCLUSIONS: None of the fecal markers so far represents an acceptable alternative to calprotectin in clinical practice. Fecal lactoferrin is the only possible exception, but a more extensive investigation is still required.

Sleep disorders related to nutrition and digestive diseases: a neglected clinical condition.

Sleep disturbances often result from inappropriate lifestyles, incorrect dietary habits, and/or digestive diseases. This clinical condition, however, has not been sufficiently explored in this area. Several studies have linked the circadian timing system to the physiology of metabolism control mechanisms, energy balance regulation, and nutrition. Sleep disturbances supposedly trigger digestive disorders or conversely represent specific clinical manifestation of gastrointestinal (GI) diseases. Poor sleep may worsen the symptoms of GI disorders, affecting the quality of life. Conversely, short sleep may influence dietary choices, as well as meal timing, and the circadian system drives temporal changes in metabolic patterns. Emerging evidence suggests that patients with inappropriate dietary habits and chronic digestive disorders often sleep less and show lower sleep efficiency, compared with healthy individuals. Sleep disturbances may thus represent a primary symptom of digestive diseases. Further controlled trials are needed to fully understand the relationship between sleep disturbances, dietary habits, and GI disorders. It may be also anticipated that the evaluation of sleep quality may prove useful to drive positive interventions and improve the quality of life in a proportion of patients. This review summarizes data linking sleep disorders with diet and a series of disease including gastro-esophageal reflux disease, peptic disease, functional gastrointestinal disorders, inflammatory bowel diseases, gut microbiota alterations, liver and pancreatic diseases, and obesity. The evidence supporting the complex interplay between sleep dysfunction, nutrition, and digestive diseases is discussed.

Lymphocytic gastritis and celiac disease.

We read with great interest the review article "Lymphocytic gastritis" by Puderecki et al., which was recently published in your journal [1]. The article describes the features of lymphocytic gastritis (LG), a rare form of gastritis with unclear pathogenesis. The diagnosis of LG is based on histology which reveals intraepithelial lymphocytosis (> 25 intraepithelial lymphocytes per 100 gastric surface and foveolar epithelial cells). The endoscopic appearance of LG can vary from normal mucosa to aphthous erosions, nodularity, local spots, polyps, and ulcers. The most common locations of the lesions are the body and the antrum. With regard to etiology, Celiac disease (CD) is the main reported cause of LG, followed by Helicobacter pylori infection. After a careful review of the argument, Puderecki et al. conclude that there is no one exact cause of LG, and rather than being a separate disease, LG is more likely a sign of the disease with which it is associated [1]. We wrote to remark on the strong connection between LG and CD. Such a connection may allow some etiopathogenetic and clinical speculations.

Prolonged Chronic Consumption of a High Fat with Sucrose Diet Alters the Morphology of the Small Intestine.

(1) The high-fat diet (HFD) of western countries has dramatic effect on the health of several organs, including the digestive tract, leading to the accumulation of fats that can also trigger a chronic inflammatory process, such as that which occurs in non-alcohol steatohepatitis. The effects of a HFD on the small intestine, the organ involved in the absorption of this class of nutrients, are still poorly investigated. (2) To address this aspect, we administered a combined HFD with sucrose (HFD w/Suc, fat: 58% Kcal) regimen (18 months) to mice and investigated the morphological and molecular changes that occurred in the wall of proximal tract of the small intestine compared to the intestine of mice fed with a standard diet (SD) (fat: 18% Kcal). (3) We found an accumulation of lipid droplets in the mucosa of HFD w/Suc-fed mice that led to a disarrangement of mucosa architecture. Furthermore, we assessed the expression of several key players involved in lipid metabolism and inflammation, such as perilipin, leptin, leptin receptor, PI3K, p-mTOR, p-Akt, and TNF-α. All these molecules were increased in HFD mice compared to the SD group. We also evaluated anti-inflammatory molecules like adiponectin, adiponectin receptor, and PPAR-γ, and observed their significant reduction in the HFD w/Suc group compared to the control. Our data are in line with the knowledge that improper eating habits present a primary harmful assault on the bowel and the entire body's health. (4) These results represent a promising starting point for future studies, helping to better understand the complex and not fully elucidated spectrum of intestinal alterations induced by the overconsumption of fat.

Inflammatory Bowel Disease: New Insights into the Interplay between Environmental Factors and PPARγ.

The pathophysiological processes of inflammatory bowel diseases (IBDs), i.e., Crohn's disease (CD) and ulcerative colitis (UC), are still not completely understood. The exact etiology remains unknown, but it is well established that the pathogenesis of the inflammatory lesions is due to a dysregulation of the gut immune system resulting in over-production of pro-inflammatory cytokines. Increasing evidence underlines the involvement of both environmental and genetic factors. Regarding the environment, the microbiota seems to play a crucial role. Peroxisome proliferator-activated receptors (PPARs) are nuclear receptors that exert pleiotropic effects on glucose homeostasis, lipid metabolism, inflammatory/immune processes, cell proliferation, and fibrosis. Furthermore, PPARs modulate interactions with several environmental factors, including microbiota. A significantly impaired PPARγ expression was observed in UC patients' colonic epithelial cells, suggesting that the disruption of PPARγ signaling may represent a critical step of the IBD pathogenesis. This paper will focus on the role of PPARγ in the interaction between environmental factors and IBD, and it will analyze the most suitable in vitro and in vivo models available to better study these relationships.

Effectiveness and safety of switching to adalimumab biosimilar ABP 501 in Crohn's disease.

We read with great interest the article "Effectiveness and safety of adalimumab biosimilar ABP 501 in Crohn's disease: an observational study" by Ribaldone et al., which was recently published in your journal. The authors report the first real-life study of the adalimumab biosimilar ABP 501 in Crohn's disease (CD). The study investigated the short-term effectiveness and safety of ABP 501 in 87 patients with CD, 25 patients naïve to adalimumab and 62 switched from the adalimumab originator. A meaningful proportion of CD patients treated with ABP 501 showed clinical benefit with a satisfactory safety profile until the end of follow-up.