The role of angiotensin converting enzyme 2 has expanded from regulating the renin angiotensin system to regulating intestinal amino acid homeostasis and the gut microbiome. Recently, angiotensin converting enzyme 2 was identified as a primary receptor for severe acute respiratory syndrome coronaviruses 1 and 2 being expressed in multiple tissues including the luminal surface of the gut. In this brief perspective, we examine the role of angiotensin converting enzyme 2 as the receptor for severe acute respiratory syndrome coronavirus 2 and the impact of coronavirus disease 19 infection on the gut microbiome and on the gut epithelium.

Immune checkpoint inhibitors have limited efficacy in many tumors. We investigated mechanisms of tumor resistance to inhibitors of programmed cell death-1 (PDCD1, also called PD-1) in mice with gastric cancer, and the role of its ligand, PD-L1.

The Hippo pathway and its downstream effectors YAP and TAZ (YAP/TAZ) are heralded as important regulators of organ growth and regeneration. However, different studies provided contradictory conclusions about their role during regeneration of different organs, ranging from promoting proliferation to inhibiting it. Here we resolve the function of YAP/TAZ during regeneration of the liver, where Hippo's role in growth control has been studied most intensely.

Chronic colonic inflammation leads to dysplasia and cancer in patients with inflammatory bowel disease. We have described the critical role of innate immune signaling via Toll-like receptor 4 (TLR4) in the pathogenesis of dysplasia and cancer. In the current study, we interrogate the intersection of TLR4 signaling, epithelial redox activity, and the microbiota in colitis-associated neoplasia.

Destroying visceral sensory nerves impacts pancreatic islet function, glucose metabolism, and diabetes onset, but how islet endocrine cells interact with sensory neurons has not been studied.

Gastroesophageal reflux disease (GERD) is a chronic common disorder for which patients often refer to specialists. In the last decades, numerous studies helped to clarify the pathophysiology and the natural history of this disease. Currently, in the clinical setting, GERD is defined by the presence of symptoms that, when endoscopic investigation is required, permit to distinguish between cases with or without associated esophageal mucosal injuries. These conditions are called erosive reflux disease and non-erosive reflux disease (NERD), respectively. The latter is the most common manifestation of GERD. Symptoms are defined typical, as heartburn and regurgitation, and atypical (also called extra-esophageal), as coughing and/or wheezing, hoarseness, sore throat, otitis media, and dental manifestations. In this context, it is crucial for clinicians to investigate the presence of features of suspected malignancy, as unexplained weight loss, anemia, dysphagia, persistent vomiting, familiar history of cancer, long history of GERD, and beginning of GERD symptoms after the age of 50 years. The presence of these risk factors should induce to perform an endoscopic examination. Particular attention should be given to functional conditions that can mimic GERD, such as functional heartburn and hypersensitive esophagus as well as, more rarely, eosinophilic esophagitis. The former ones have different pathophysiology and this explains the frequent non-response to proton pump inhibitor drugs. This narrative review provides to clinicians a useful and practical overview of the state-of-the-art on advancements in the knowledge of GERD.

The largest cause of mortality in patients with inflammatory bowel disease (IBD) remains thromboembolic disease (TED). Recent reports have demonstrated that both monogenic and polygenic factors contribute to TED and 10% of healthy subjects are genetically at high risk for TED. Our aim was to utilize whole-exome sequencing and genome-wide genotyping to determine the proportion of IBD patients genetically at risk for TED and investigate the effect of genetic risk of TED in IBD.

Although Crohn's disease (CD) and ulcerative colitis (UC) have been considered as disorders that affect individuals of European ancestry, the epidemiology of the inflammatory bowel diseases (IBDs) is changing. Coupled with the increasing incidence of IBD in previously low-incidence areas, the population demographics of IBD in the United States are also changing, with increases among non-White races and ethnicities. It is therefore important to fully understand the epidemiology and progression of IBD in different racial and ethnic groups, and the effects of race and ethnicity on access to care, use of resources, and disease-related outcomes. We review differences in IBD development and progression among patients of different races and ethnicities, discussing the effects of factors such as access to care, delays in diagnosis, and health and disease perception on disparities in IBD care and outcomes. We identify research priorities for improving health equity among minority patients with IBD.

Endoscopic disease activity scoring in ulcerative colitis (UC) is useful in clinical practice but done infrequently. It is required in clinical trials, where it is expensive and slow because human central readers are needed. A machine learning algorithm automating the process could elevate clinical care and facilitate clinical research. Prior work using single-institution databases and endoscopic still images has been promising.