Editorial of the Special Issue "Dietary Fiber and Inflammatory Bowel Disease".

Inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis, is a chronic disease of the gastrointestinal (GI) tract; its burden has significantly increased in recent decades, with 6.8 million cases of IBD reported in 2017 according to the Global Burden of Disease study [...].

Translational Potential of Metabolomics on Animal Models of Inflammatory Bowel Disease-A Systematic Critical Review.

In the development of inflammatory bowel disease (IBD), the gut microbiota has been established as a key factor. Recently, metabolomics has become important for understanding the functional relevance of gut microbial changes in disease. Animal models for IBD enable the study of factors involved in disease development. However, results from animal studies may not represent the human situation. The aim of this study was to investigate whether results from metabolomics studies on animal models for IBD were similar to those from studies on IBD patients. Medline and Embase were searched for relevant studies up to May 2017. The Covidence systematic review software was used for study screening, and quality assessment was conducted for all included studies. Data showed a convergence of ~17% for metabolites differentiated between IBD and controls in human and animal studies with amino acids being the most differentiated metabolite subclass. The acute dextran sodium sulfate model appeared as a good model for analysis of systemic metabolites in IBD, but analytical platform, age, and biological sample type did not show clear correlations with any significant metabolites. In conclusion, this systematic review highlights the variation in metabolomics results, and emphasizes the importance of expanding the applied detection methods to ensure greater coverage and convergence between the various different patient phenotypes and animal models of inflammatory bowel disease.

Effects of Intestinal Fungi and Viruses on Immune Responses and Inflammatory Bowel Diseases.

The intestinal microbiota comprises diverse fungal and viral components, in addition to bacteria. These microbes interact with the immune system and affect human physiology. Advances in metagenomics have associated inflammatory and autoimmune diseases with alterations in fungal and viral species in the gut. Studies of animal models have found that commensal fungi and viruses can activate host-protective immune pathways related to epithelial barrier integrity, but can also induce reactions that contribute to events associated with inflammatory bowel disease. Changes in our environment associated with modernization and the COVID-19 pandemic have exposed humans to new fungi and viruses, with unknown consequences. We review the lessons learned from studies of animal viruses and fungi commonly detected in the human gut and how these might affect health and intestinal disease.

Aspects of inflammatory bowel disease during the COVID-19 pandemic and general considerations. / Aspectos y consideraciones generales en la enfermedad inflamatoria intestinal durante la pandemia por COVID-19.

So far, available evidence suggests that patients with inflammatory bowel disease (IBD) are not at greater risk for developing COVID-19 infection. In regard to patients with IBD remission: 5-aminosalycylates (5-ASAs) do not increase the risk for infection and should be continued. There is no need to suspend them or lower the dose. Immunomodulating drugs, such as thiopurines and methotrexate, should be continued, without modifying doses (even in patients with positive SARS-CoV-2 infection). No type of biologic therapy should be suspended, unless there are signs of COVID-19. Regarding patients with IBD activity: the oral and/or topical 5-ASA dose should be optimized in cases of disease relapse. Budesonide MMX should be considered in cases of mild-to-moderate activity, to avoid systemic steroid use. Systemic steroids should be avoided whenever possible because doses above 20mg per day have an immunosuppressive effect, which could increase susceptibility to any type of infection, including COVID-19. The combined use of thiopurines with steroids and/or tumor necrosis factor (TNF) monoclonal antibodies should also be avoided because those combinations can increase the risk for infections, including COVID-19. Finally, biologic treatment with anti-TNF-alpha agents or any other mechanism of action, such as anti-integrins or anti-interleukins, should be suspended if patients become infected with SARS-CoV-2. The drugs can be restarted once the infectious process is resolved.