Mechanisms of gastrointestinal barrier dysfunction in COVID-19 patients

Comparative analysis of COVID-19 responses in Japan and Africa: diet, phytochemicals, vitamin D, and gut microbiota in reducing mortality-A systematic review and meta-analysis

Background

As the novel coronavirus disease 2019 (COVID-19) pandemic subsides, the clinical sequelae are becoming more problematic. Interestingly, the statistical data indicate that Africa has experienced the lowest number of cases and deaths, with an unexpected phenomenon where the number of deaths from COVID-19 has not increased significantly. Several studies have investigated the relationship between diet and coronavirus. However, no systematic review/meta-analysis has conclusively linked diet (phytochemicals and vitamin D) and the gut microbiota in the context of COVID-19.

Methods

This study examined the responses to COVID-19 in Japan and Africa, formulating the following hypotheses: (1) a healthy diet is effective against COVID-19, (2) blood vitamin D levels are associated with COVID-19 mortality, and (3) COVID-19 is associated with the gut microbiota. To investigate these hypotheses, a keyword search and meta-analysis were conducted using PubMed, and each hypothesis was tested.

Results

This study found that a healthy diet, particularly rich in phytochemicals such as polyphenols and flavonoids, is effective against COVID-19. An association was detected between blood vitamin D levels and COVID-19 mortality. The gut microbiota was linked to COVID-19 and its amelioration. These findings may have significant implications for not only understanding COVID-19 but also future prevention of pneumonia.

Editor-in-Chief articles of choice and comments at the year-end of 2023

As the Editor-in-Chief of World Journal of Gastroenterology, every week prior to a new issue's online publication, I perform a careful review of all encompassed articles, including the title, clinical and/or research importance, originality, novelty, and ratings by the peer reviewers. Based on this review, I select the papers of choice and suggest pertinent changes (e.g., in the title) to the Company Editors responsible for publication. This process, while time-consuming, is very important for assuring the quality of publications and highlighting important articles that Readers may revisit.

Repurposing TAK875 as a novel STAT3 inhibitor for treating inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic immune-mediated disease associated with a high recurrence rate and an elevated risk of colon cancer. In this study, we screened a bioactive compound library using a luciferase reporter assay and identified the compound TAK875 as a novel inhibitor of signal transducer and activator of transcription 3 (STAT3). Surface plasmon resonance analysis, differential scanning fluorimetry, and isothermal titration calorimetry demonstrated that TAK875 directly bound to recombinant STAT3. TAK875 suppressed the lipopolysaccharide (LPS)-induced release of nitric oxide, inducible nitric oxide synthase, and inflammatory factors in RAW264.7 cells, likely by inhibiting STAT3 phosphorylation. In addition, TAK875 inhibited the differentiation of CD4+ T cells into T-helper 17 cells, which may partially account for its anti-inflammatory effect. TAK875 also alleviated the LPS-induced accumulation of intracellular reactive oxygen species, thus displaying its antioxidant effects. Finally, we demonstrated its satisfactory anti-inflammatory effect in a dextran sulfate sodium-induced mouse model of ulcerative colitis. In conclusion, this study presented TAK875 as a novel STAT3 inhibitor and demonstrated its anti-inflammatory and antioxidant effects both in vitro and in vivo.

Eliminating COVID-19 as the immediate culprit for igniting pancreatitis

The impact of severe acute respiratory syndrome coronavirus 2 infection on the potential development of pancreatitis is a subject of ongoing debate within academic discourse. Establishing a causal link between COVID-19 and pancreatitis may not be fully supported by relying only on retrospective studies or case reports. This study examined the relationship between COVID-19 phenotypes and pancreatitis by Mendelian randomization (MR) method. The identification of instrumental variables (single nucleotide polymorphisms) that exhibit a robust association with the COVID-19 phenotypes was accomplished through a meticulous process of rigorous screening procedures. We included acute pancreatitis and chronic pancreatitis (CP) as the outcomes in the MR analysis, even though no definitive studies exist between COVID-19 and CP. A direct causal relationship between genetically predicted COVID-19 phenotypes and pancreatitis risk cannot be established. There is an ongoing debate over the designation of COVID-19 as a definitive cause of pancreatitis.