The gut microbiota is a complex community of microorganisms that inhabit the digestive tracts of humans, living in symbiosis with the host. Dysbiosis, characterized by an imbalance between the beneficial and opportunistic gut microbiota, is associated with several gastrointestinal disorders, such as irritable bowel syndrome (IBS); inflammatory bowel disease (IBD), represented by ulcerative colitis and Crohn’s disease; and colorectal cancer (CRC). Dysbiosis can disrupt the mucosal barrier, resulting in perpetuation of inflammation and carcinogenesis. The increase in some specific groups of harmful bacteria, such as Escherichia coli ( E. coli ) and enterotoxigenic Bacteroides fragilis (ETBF), has been associated with chronic tissue inflammation and the release of pro-inflammatory and carcinogenic mediators, increasing the chance of developing CRC, following the inflammation-dysplasia-cancer sequence in IBD patients. Therefore, the aim of the present review was to analyze the correlation between changes in the gut microbiota and the development and maintenance of IBD, CRC, and IBD-associated CRC. Patients with IBD and CRC have shown reduced bacterial diversity and abundance compared to healthy individuals, with enrichment of Firmicute s and Bacteroidetes . Specific bacteria are also associated with the onset and progression of CRC, such as Fusobacterium nucleatum , E. coli , Enterococcus faecalis , Streptococcus gallolyticus , and ETBF. Future research can evaluate the advantages of modulating the gut microbiota as preventive measures in CRC high-risk patients, directly affecting the prognosis of the disease and the quality of life of patients.

BACKGROUND Anti-tumor necrosis factor agents were the first biologic therapy approved for the management of Crohn's disease (CD). Heart failure (HF) is a rare but potential adverse effect of these medications. The objective of this report is to describe a patient with CD who developed HF after the use of infliximab. CASE SUMMARY A 50-year-old woman with a history of hypertension and diabetes presented with abdominal pain, diarrhea, and weight loss. Colonoscopy and enterotomography showed ulcerations, areas of stenosis and dilation in the terminal ileum, and thickening of the intestinal wall. The patient underwent ileocolectomy and the surgical specimen confirmed the diagnosis of stenosing CD. The patient started infliximab and azathioprine treatment to prevent post-surgical recurrence. At 6 mo after initiating infliximab therapy, the patient complained of dyspnea, orthopnea, and paroxysmal nocturnal dyspnea that gradually worsened. Echocardiography revealed biventricular dysfunction, moderate cardiac insufficiency, an ejection fraction of 36%, and moderate pericardial effusion, consistent with HF. The cardiac disease was considered an infliximab adverse effect and the drug was discontinued. The patient received treatment with diuretics for HF and showed improvement of symptoms and cardiac function. Currently, the patient is using anti-interleukin for CD and is asymptomatic. CONCLUSION This reported case supports the need to investigate risk factors for HF in inflammatory bowel disease patients and to consider the risk-benefit of introducing infliximab therapy in such patients presenting with HF risk factors.

Microscopic colitis (MC) refers to chronic inflammation of the colon which is characterized by histologic changes at the level of a radiologically and endoscopically normal mucosa. It is a common cause of chronic non-bloody diarrhea that occurs primarily in older individuals; however, there are few studies in the literature with strong scientific evidence compared to other inflammatory bowel diseases (IBD), which limits the knowledge of physicians and pathologists. This article aims to review the information on MC, describing diagnostic methods and drugs available for treatment. We conducted a search of the Pubmed database and CAPES Portal using the keywords "microscopic colitis", "collagenous colitis", "lymphocytic colitis", and "review" for selection of articles published between 1996 and 2015 related to the topic. Based on the studies discussed in this review, we conclude that MC is a relatively new gastrointestinal disorder, most studies are incipient particularly with respect to pathophysiology and immunology, and budesonide is the best documented short-term treatment. However, further studies are needed to elucidate the best strategy for treatment in the long term.

MicroRNAs (miRNAs) are non-coding RNA molecules composed of 19–25 nucleotides that regulate gene expression and play a central role in the regulation of several immune-mediated disorders, including inflammatory bowel diseases (IBD). IBD, represented by ulcerative colitis and Crohn’s disease, is characterized by chronic intestinal inflammation associated with an increased risk of colorectal cancer (CRC). CRC is one of the most prevalent tumors in the world, and its main risk factors are obesity, physical inactivity, smoking, alcoholism, advanced age, and some eating habits, in addition to chronic intestinal inflammatory processes and the use of immunosuppressants administered to IBD patients. Recent studies have identified miRNAs associated with an increased risk of developing CRC in this population. The identification of miRNAs involved in this tumorigenic process could be useful to stratify cancer risk development for patients with IBD and to monitor and assess prognosis. Thus, the present review aimed to summarize the role of miRNAs as biomarkers for the diagnosis and prognosis of IBD-associated CRC. In the future, therapies based on miRNA modulation could be used both in clinical practice to achieve remission of the disease and restore the quality of life for patients with IBD, and to identify the patients with IBD at high risk for tumor development.

Patient: Male, 51-year-old Final Diagnosis: COVID-19 • Klebsiella pneumoniae infection Symptoms: Ascites • cough • fatigue • feve Medication: — Clinical Procedure: Antibiotics • oxygen therapy • paracentesis Specialty: Gastroenterology and Hepatology • Medicine, General and Internal • Pulmonology Objective: Unusual clinical course Background: The severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2), which manifests mainly as a respiratory condition, has become a global pandemic that causes coronavirus disease-2019 (COVID-19). Although the symptoms remain mild in most patients, the elderly and patients with previous comorbidities have higher rates of morbidity and mortality. Patients with liver cirrhosis, especially after decompensation, may be more susceptible to SARS-CoV-2 infection due to systemic immune dysfunction. Case Report: The patient was a 51-year-old man who was hypertensive, an ex-alcoholic abstinent for 6 months, and a smoker. He was diagnosed with alcoholic liver cirrhosis in July 2019, and was using norfloxacin at home for secondary prophylaxis of bacterial peritonitis. He was also using furosemide and spironolactone to control ascites and propranolol for primary prophylaxis of esophageal varices. The patient entered our hospital in July 2020 with cough, dyspnea, runny nose, diarrhea, and fever. During hospitalization, we confirmed infection by COVID-19 and secondary nosocomial pulmonary infection. Chest tomography compatible with ground-glass standard was performed. The patient developed the need for auxiliary oxygen but without invasive mechanical ventilation. The patient received dexamethasone 6 mg/day and broad-spectrum antibiotic therapy (he was started on cefepime but switched to meropenem). At the end of the 14-day isolation period, he was discharged with improved respiratory status. Conclusions: Despite high mortality rates in patients with advanced cirrhosis who become infected with COVID-19, we report a case with a favorable outcome. Success has been achieved with the use of medications in studies of broad-spectrum antibiotics and the rapid detection of complications caused by the virus. Further studies in SARS-CoV-2 patients with chronic liver disease are needed.