Virus and microbiota relationships in humans and other mammals: An evolutionary view

Effects of Dietary Supplementation with Carrot-Derived Rhamnogalacturonan-I (cRG-I) on Accelerated Protective Immune Responses and Quality of Life in Healthy Volunteers Challenged with Rhinovirus in a Randomized Trial

An adequate and balanced supply of nutrients is essential for maintaining health, and an optimal immune response is fast, contained and properly controlled, curbing infections quickly while minimizing damage. Several micronutrients contribute to normal immune function and certain dietary fibers, for example pectic polysaccharides, can play an important role in educating and regulating immune cell responses. The aim of this paper is to elaborate on our initial findings that dietary supplementation with carrot-derived rhamnogalacturonan-I (cRG-I) accelerates and augments local innate immune and anti-viral interferon response to a rhinovirus-16 (RV16) infection and reduces the severity and duration of symptoms in humans. Dietary intake of cRG-I also enhanced immune responses to this respiratory viral infection as measured by ex vivo stimulation of whole blood with the Toll-like receptor 3 (TLR3) ligand polyinosinic:polycytidylic acid and NK cell function. Consumption of cRG-I also reduced the negative effects of this common cold infection on quality of life as assessed by individual symptom scores. RG-I from carrot is a safe, sustainable, and economically viable solution that could easily be integrated into food products and dietary supplements aiming to support immune fitness and wellbeing.

An Update on the Mutual Impact between SARS-CoV-2 Infection and Gut Microbiota

The gut microbiota is essential for good health. It has also been demonstrated that the gut microbiota can regulate immune responses against respiratory tract infections. Since the outbreak of the COVID-19 pandemic, accumulating evidence suggests that there is a link between the severity of COVID-19 and the alteration of one's gut microbiota. The composition of gut microbiota can be profoundly affected by COVID-19 and vice versa. Here, we summarize the observations of the mutual impact between SARS-CoV-2 infection and gut microbiota composition. We discuss the consequences and mechanisms of the bi-directional interaction. Moreover, we also discuss the immune cross-reactivity between SARS-CoV-2 and commensal bacteria, which represents a previously overlooked connection between COVID-19 and commensal gut bacteria. Finally, we summarize the progress in managing COVID-19 by utilizing microbial interventions.

Promising diagnostic biomarkers of nonalcoholic fatty liver disease and nonalcoholic steatohepatitis: From clinical proteomics to microbiome

Fatty liver has been present in the lives of patients and physicians for almost two centuries. Vast knowledge has been generated regarding its etiology and consequences, although a long path seeking novel and innovative diagnostic biomarkers for nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) is still envisioned. On the one hand, proteomics and lipidomics have emerged as potential noninvasive resources for NAFLD diagnosis. In contrast, metabolomics has been able to distinguish between NAFLD and NASH, even detecting degrees of fibrosis. On the other hand, genetic and epigenetic markers have been useful in monitoring disease progression, eventually functioning as target therapies. Other markers involved in immune dysregulation, oxidative stress, and inflammation are involved in the instauration and evolution of the disease. Finally, the fascinating gut microbiome is significantly involved in NAFLD and NASH. This review presents state-of-the-art biomarkers related to NAFLD and NASH and new promises that could eventually be positioned as diagnostic resources for this disease. As is evident, despite great advances in studying these biomarkers, there is still a long path before they translate into clinical benefits.

Microbiota and their Influence in the Human Body

Scientists have invested considerable resources in the study of the microbiota of the human body. These microorganisms play pivotal roles in immunity and disease. Of which, probiotics are live beneficial microorganisms that keep your intestinal or lung microbiota healthy, and occupy a special role in combating the infections. Thus, it is critical to understand their contributions to these processes. Technology can facilitate advanced studies of the microbiota, including how it develops and its positive and negatives effects on the immune system. This paper investigates how several factors (e.g. birth delivery mode, metabolic activities, types of microorganisms, and immune system interactions) affect the microbiota, particularly in early life. The paper also discusses how gastrointestinal microbes in particular may be associated with certain disease processes, such as those related to schizophrenia, autism, and diabetes. Clinical studies show that certain probiotic strains, like Lactobacillus rhamnosus GG and Bifidobacterium animalis ssp. lactis help to prevent infection of pathogenic organisms (both bacterial and viral). This research may yield crucial contributions to disease prevention and public health. The dysbiosis may result in changes in the acquired immunity later on. The probiotic strains can prevent viral replication during SARS-CoV-2 or COVID-19 infection by reducing proinflammatory cytokines. There has been much interest into the intestinal flora as proposed by the diversity, volume, and proposed role in disease. Future research in the field of microbiome should be done in order to uncover their association to gut virome by noting both their influence on each other and relevant health and disease.

Dual and mutual interaction between microbiota and viral infections: a possible treat for COVID-19

All of humans and other mammalian species are colonized by some types of microorganisms such as bacteria, archaea, unicellular eukaryotes like fungi and protozoa, multicellular eukaryotes like helminths, and viruses, which in whole are called microbiota. These microorganisms have multiple different types of interaction with each other. A plethora of evidence suggests that they can regulate immune and digestive systems and also play roles in various diseases, such as mental, cardiovascular, metabolic and some skin diseases. In addition, they take-part in some current health problems like diabetes mellitus, obesity, cancers and infections. Viral infection is one of the most common and problematic health care issues, particularly in recent years that pandemics like SARS and COVID-19 caused a lot of financial and physical damage to the world. There are plenty of articles investigating the interaction between microbiota and infectious diseases. We focused on stimulatory to suppressive effects of microbiota on viral infections, hoping to find a solution to overcome this current pandemic. Then we reviewed mechanistically the effects of both microbiota and probiotics on most of the viruses. But unlike previous studies which concentrated on intestinal microbiota and infection, our focus is on respiratory system's microbiota and respiratory viral infection, bearing in mind that respiratory system is a proper entry site and residence for viruses, and whereby infection, can lead to asymptomatic, mild, self-limiting, severe or even fatal infection. Finally, we overgeneralize the effects of microbiota on COVID-19 infection. In addition, we reviewed the articles about effects of the microbiota on coronaviruses and suggest some new therapeutic measures.

Put Some Guts into It: Intestinal Organoid Models to Study Viral Infection

The knowledge about enteric viral infection has vastly increased over the last eight years due to the development of intestinal organoids and enteroids that suppose a step forward from conventional studies using cell lines. Intestinal organoids and enteroids are three-dimensional (3D) models that closely mimic intestinal cellular heterogeneity and organization. The barrier function within these models has been adapted to facilitate viral studies. In this review, several adaptations (such as organoid-derived two-dimensional (2D) monolayers) and original intestinal 3D models are discussed. The specific advantages and applications, as well as improvements of each model are analyzed and an insight into the possible path for the field is given.

Hypertransaminasemia in the course of infection with SARS-CoV-2: Incidence and pathogenetic hypothesis

In patients infected with severe acute respiratory syndrome coronavirus 2, the respiratory symptoms, such as fever, cough and dyspnea, are the most frequent clinical manifestations. These patients may also present with less well-defined symptoms like diarrhea, nausea, vomiting and/or abdominal discomfort both at the time of diagnosis and during the clinical course. In a few cases, these symptoms may also present before the appearance of respiratory symptoms. To penetrate the body, Severe acute respiratory syndrome coronavirus 2 uses ACE2 receptors, which are present not only in respiratory epithelium but also in gastrointestinal mucosa and liver cholangiocytes. In several cases, viral RNA is detectable in the stool of patients with coronavirus disease 2019 (COVID-19). The liver damage seems to show a multifactorial origin. About 2%-11% of patients with COVID-19 have known underlying hepatic pathologies. In 14%-53% of COVID-19 cases, there is an alteration of the indices of liver cytolysis and is more frequently observed in severe forms of COVID-19, especially during hospitalization.