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How to boost the immune defence prior to respiratory virus infections with the special focus on coronavirus infections

DOI:10.1186/s13099-020-00385-2
Authors:
Samir Jawhara at Université de Lille
Samir Jawhara
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Abstract

The emergence of the novel coronavirus SARS-CoV-2, which causes severe respiratory tract infections in humans (COVID-19), has become a global health concern. One of the most worrying features of COVID-19 is a phenomenon known as the "cytokine storm", which is a rapid overreaction of the immune system. Additionally, coagulation abnormalities, thrombocytopenia and digestive symptoms, including anorexia, vomiting, and diarrhea, are often observed in critically ill patients with COVID-19. Baker's yeast β-glucan, a natural immunomodulatory component derived from Saccharomyces cerevisiae, primes the immune system to respond better to any microbial infection. Our previous studies have shown that oral administration of yeast β-glucans decreased the diarrhoea, modulated cytokine expression, and reduced the intestinal inflammation. Additionally, we showed that β-glucan fractions decreased coagulation in plasma and reduced the activation of platelets. During the period of home confinement facing individuals during the COVID-19 pandemic, our immune defence could be weakened by different factors, including stress, anxiety and poor nutrition, while a healthy diet rich in vitamins C and D can reinforce the immune defence and reduce the risk of microbial infections. Additionally, β-glucan can be used to strengthen the immune defence in healthy individuals prior to any possible viral infections. This short review focuses on the role of baker's yeast β-glucan, with a healthy diet rich in natural vitamins C and D, in addition to a healthy gut microbiota can provide synergistic immune system support, helping the body to naturally defend prior to respiratory virus infections, until stronger options such as vaccines are available.
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... By increasing circulating monocytes and neutrophils and increasing neutrophil oxidative microbicidal activity without generating harmful inflammatory responses, b-glucans enhanced the clearance of antibiotic-resistant S. aureus in a rat intra-abdominal infection model (30,34). Daily dietary supplementation with b-glucan improved the vaccination response to Newcastle disease virus in chickens (35). A combination of b-glucan and vitamin C also improved healing in the treatment of infection by M. corti (35). ...
... Daily dietary supplementation with b-glucan improved the vaccination response to Newcastle disease virus in chickens (35). A combination of b-glucan and vitamin C also improved healing in the treatment of infection by M. corti (35). Yeast-based glucans have been applied in clinical studies of bacterial and viral infections. ...
... Another yeast-derived b-glucan was able to protect mice infected with a lethal titer of the A/Puerto Rico/8/34 (PR8; H1N1) strain of influenza virus (38). In pigs infected with swine influenza virus, administration of S. cerevisiae yeast b-glucan decreased pulmonary lesion score and viral replication along with an increase in IFN-g and NO levels (35). ...
Beneficial Immune Regulation by Biological Response Modifier Glucans in COVID-19 and Their Envisaged Potentials in the Management of Sepsis
Article
Full-text available
  • Jun 2022
Sepsis is a life-threatening condition caused by an abnormal immune response induced by infection with no approved or specific therapeutic options. We present our perspectives for the therapeutic management of sepsis through a four-way approach: (1) infection control through immune enhancement; (2) immune suppression during the initial hyper-inflammatory phase; (3) balanced immune-modulation to counter the later immune-paralysis phase; and (4) advantageous effects on metabolic and coagulation parameters throughout. COVID-19 is a virus-triggered, accelerated sepsis-like reaction that is associated with the rapid progress of an inflammatory cascade involving a cytokine storm and multiorgan failure. Here, we discuss the potential of the biological response modifiers, β-glucans (BRMGs), in the management of sepsis based on their beneficial effects on inflammatory-immune events in COVID-19 clinical studies. In COVID-19 patients, apart from metabolic regulation, BRMGs, derived from a black yeast, Aureobasidium pullulans strain AFO-202, have been reported to stimulate immune responses. BRMGs, produced by another strain (N-163) of A. pullulans, have been implicated in the beneficial regulation of inflammatory markers and immunity, namely IL-6, C-reactive protein (CRP), D-Dimer, ferritin, neutrophil-to-lymphocyte ratio (NLR), lymphocyte-to-C-reactive protein ratio (LCR), leucocyte-to-C-reactive protein ratio (LeCR), and leukocyte-to-IL-6 ratio (LeIR). Agents such as these β-glucans, which are safe as they have been widely consumed by humans for decades, have potential as adjuncts for the prevention and management of sepsis as they exert their beneficial effects across the spectrum of processes and factors involved in sepsis pathology, including, but not limited to, metabolism, infection, inflammation, immune modulation, immune enhancement, and gut microbiota.
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... The 1,3-1,6-beta-glucans are considered to be the best biological response modifiers and have immunogenic properties [176]. Most glucans with this chain structure are derived from macrofungi (mushrooms) or yeast [172,177]. The hypothesis posed by Galler and Yan [172] was corroborated by other authors, who found that β-glucans from mushrooms demonstrated the potential for the treatment of lung injury [178]. ...
... [ 169,177,191] The promising results of studies on mushroom β-glucan from Agaricus bisporus and Lentinula edodes [14,175] allow us to assume a beneficial effect of these compounds in the prevention, course, and counteracting complications of COVID-19 in the era of the pandemic caused by SARS-CoV-2. Still, there are only a few studies on the promising function of mushroom β-glucans in the context of COVID-19; such research needs to be continued due to the easy availability and significant amounts of beta-glucans in mushrooms [35], as well as the safety and ease of administration without significant side effects, even in the case of insufficient purification [14,186,187]. ...
Beta-Glucans from Fungi: Biological and Health-Promoting Potential in the COVID-19 Pandemic Era
Article
Full-text available
  • Nov 2021
Beta-glucans comprise a group of polysaccharides of natural origin found in bacteria, algae, and plants, e.g., cereal seeds, as well as microfungi and macrofungi (mushrooms), which are characterized by diverse structures and functions. They are known for their metabolic and im-munomodulatory properties, including anticancer, antibacterial, and antiviral. Recent reports suggest a potential of beta-glucans in the prevention and treatment of COVID-19. In contrast to β-glucans from other sources, β-glucans from mushrooms are characterized by β-1,3-glucans with short β-1,6-side chains. This structure is recognized by receptors located on the surface of immune cells; thus, mushroom β-glucans have specific immunomodulatory properties and gained BRM (biological response modifier) status. Moreover, mushroom beta-glucans also owe their properties to the formation of triple helix conformation, which is one of the key factors influencing the bioac-tivity of mushroom beta-glucans. This review summarizes the latest findings on biological and health-promoting potential of mushroom beta-glucans for the treatment of civilization and viral diseases, with particular emphasis on COVID-19.
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... Results of five studies with 1506 participants included in a metaanalysis showed that zinc supplementation led to a significantly lower risk of mortality in COVID-19 patients when it was compared with non-supplemented controls [24]. On the other hand, β-glucan is a polysaccharide that is abundantly found in the cell wall of S. cerevisiae and primes the immune system to respond better to any viral infection [25]. Additionally, the use of oral β-glucan has been hypothesized to boost immune responses and abrogate symptoms in viral infection [26,27]. ...
Anti-Inflammatory Effects, Protection of Gut Barrier Integrity and Stimulation of Phagocytosis of Postbiotic Combination ABB C1
Article
Full-text available
  • Feb 2023
This study evaluated the anti-inflammatory effects, the protection of gut barrier integrity, and the stimulation of phagocytosis in peripheral cells of a nutritional supplement based on a synergistic combination of yeast-based ingredients with a unique 1,3/1,6-glucan complex and a consortium of postbiotic Saccharomyces cerevisiae rich in selenium and zinc. The anti-inflammatory effect in caco-2 cells in the presence and absence of a pro-inflammatory challenge (tumour necrosis factor alpha [TNF-α]/interferon gamma [IFN-ɣ]) showed statistically significant reductions in IFN-ɣ induced protein-10 (IP-10), and monocyte chemoattractant protein-1 (MCP-1) levels vs. controls (p < 0.001). Disruption of the gut integrity in the presence or absence of Escherichia coli (ETEC H10407) showed transepithelial electrical resistance (TEER) values higher in the ABB C1® group after 6 h of testing. Spontaneous build-up of the gut epithelium monolayer over 22 days was also greater in the ABB C1® condition vs. a negative control. ABB C1® showed a significantly higher capacity to stimulate phagocytosis as compared with controls of algae β-1,3-glucan and yeast β-1,3/1,6 glucan (p < 0.001). This study supports the mechanism of action by which ABB C1® may improve the immune response and be useful to prevent infection and allergy in clinical practice.
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... Results of five studies with 1506 participants included in a meta-analysis showed that zinc supplementation led to a significant lower risk of mortality in COVID-19 patients when it was compared with non-supplemented controls [24]. On the other hand, β-glucan is a polysaccharide that is abundantly found in the cell wall of S. cerevisiae and primes the immune system to respond better to any viral infection [25]. Also, the use of oral β-glucan has been hypothesized to boost immune responses and abrogate symptoms in viral infection [26,27]..Therefore, it was considered of interest to assess the anti-inflammatory effect of ABB C1 ® on intestinal cells, preservation of the gut barrier integrity, and activity in stimulating phagocytosis of peripheral cells. ...
Anti-Inflammatory Effects, Protection of Gut Barrier Integrity and Stimulation of Phagocytosis of postbiotic combination ABB C1®
Preprint
  • Jan 2023
This study evaluated the anti-inflammatory effects, protection of gut barrier integrity, and stimulation of phagocytosis in peripheral cells of a nutritional supplement based on a synergistic combination of yeast-based ingredients with a unique 1,3/1,6-glucan complex and a consortium of postbiotic Saccharomyces cerevisiae rich in selenium and zinc. The anti-inflammatory effect in Caco-2 cells in the presence and absence of a pro-inflammatory challenge (tumour necrosis factor alpha [TNF-α]/interferon gamma [IFN-ɣ]) showed statistically significant reductions of IFN-ɣ induced protein-10 (IP-10), and monocyte chemoattractant protein-1 (MCP-1) levels vs. controls (p < 0.001). Disruption of the gut integrity in the presence or absence of Escherichia coli (ETEC H10407) showed transepithelial electrical resistance (TEER) values higher in the ABB C1® group after 6 hours of testing. Spontaneous build-up of the gut epithelium monolayer over 22 days was also greater in the ABB C1® condition vs. a negative control. ABB C1® showed a significantly higher capacity to stimulate phagocytosis as compared with controls of algae β-1,3-glucan and yeast β-1,3/1,6 glucan (p < 0.001). This study supports the mechanism of action by which ABB C1® may improve the immune response and be useful to prevent infection and allergy in clinical practice.
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... Nutrition intervention securing an adequate supply of zinc and selenium, as well as vitamin D, has been recommended for rising antiviral resistance against progressive COVID-19 [19]. On the other hand, β-glucan is a polysaccharide that is abundantly found in the cell wall of S. cerevisiae and primes the immune system to respond better to any viral infection [20]. Also, the use of oral β-glucan has been hypothesized to boost immune responses and abrogate symptoms in COVID-19 [21], as well in other viral attacks [22]. ...
In Vitro and in Vivo Anti-Inflammatory Effects, Protection of Gut Barrier Integrity and Stimulation of Phagocytosis of ABB C1®, a Synergistic Combination of β-Glucans and Selenium- and Zinc-Enriched Saccharomyces cerevisiae
Preprint
  • Dec 2022
This study evaluated the anti-inflammatory effects, protection of gut barrier integrity, and stimulation of phagocytosis in peripheral cells of a nutritional supplement based on a synergistic combination of yeast-based ingredients with a unique 1,3/1,6-glucan complex and a consortium of postbiotic Saccharomyces cerevisiae rich in selenium and zinc. The anti-inflammatory effect in Caco-2 cells in the presence and absence of a pro-inflammatory challenge (tumour necrosis factor alpha [TNF-α]/interferon gamma [IFN-ɣ]) showed statistically significant reductions of IFN-ɣ induced protein-10 (IP-10), and monocyte chemoattractant protein-1 (MCP-1) levels vs. controls (p < 0.001). Disruption of the gut integrity in the presence or absence of Escherichia coli (ETEC H10407) showed transepithelial electrical resistance (TEER) values higher in the ABB C1® group after 6 hours of testing. Spontaneous build-up of the gut epithelium monolayer over 22 days was also greater in the ABB C1® condition vs. a negative control. ABB C1® showed a significantly higher capacity to stimulate phagocytosis as compared with controls of algae β-1,3-glucan and yeast β-1,3/1,6 glucan (p < 0.001). This study supports the mechanism of action by which ABB C1® may improve the immune response and be useful to prevent infection and allergy in clinical practice.
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... We hypothesized that when ASCA are produced by the immune system, they could neutralize S. cerevisiae which is a beneficial yeast for our health [28,29]. Beta-glucan, derived from S. cerevisiae, primes the immune system to respond better to any viral infection [30]. Additionally, the use of oral beta-glucan was hypothesized to boost immune responses and abrogate symptoms in COVID-19 [31]. ...
Anti-Saccharomyces cerevisiae antibodies in patients with COVID-19
Article
Full-text available
  • Jul 2022
Background and study aim: Anti-Saccharomyces cerevisiae antibodies (ASCA) have been described in many autoimmune diseases (AIDs). Coronavirus disease 2019 (COVID-19) could trigger AIDs. This study aimed to determine the frequency of ASCA in patients with COVID-19. Patients and methods This study included 88 adult patients with severe COVID-19, 51 mild COVID-19, and 160 healthy blood donors. ASCA of isotype immunoglobulin (Ig)G and IgA were detected by enzyme-linked immunosorbent assay. Results The frequency of ASCA (IgG or IgA) was significantly higher in patients with severe COVID-19 (21.6% vs. 3.7%, p < 10⁻⁻³) and in patients with mild COVID-19 than in the healthy controls (13.7% vs. 3.7%, p = 0.03). ASCA-IgA was significantly more frequent in patients with severe COVID-19 than in healthy controls (15.9% vs. 0.6%, p < 10⁻³). ASCA-IgG was significantly more frequent in patients with mild COVID-19 than in healthy controls (13.7% vs. 3.1%, p = 0.02). ASCA (IgG or IgA) were more frequent in severe than in mild COVID-19, but the difference was not statistically significant (21.6% vs. 13.7%). ASCA-IgA was significantly more frequent in patients with severe than those with mild COVID-19 (15.9% vs. 0%, p = 0.003). The mean ASCA-IgG and ASCA-IgA levels were significantly higher in patients with severe COVID-19 than in healthy controls (5.8 U/mL ± 11.8 vs. 2.3 U/mL ± 2.8, p < 10⁻³ and 9.2 U/mL ± 21.5 vs. 3.4 U/mL ± 1.7, respectively, p < 10⁻³). The mean ASCA-IgG levels were significantly higher in patients with mild COVID-19 than in healthy controls (6.2 U/mL ± 12.9 vs. 2.3 U/mL ± 2.8, p < 10⁻³). The mean ASCA-IgA levels were significantly higher in patients with severe than in those with mild COVID-19 (9.2 U/mL ± 21.5 vs. 2.6 U/mL ± 1.2, p = 0.03). Conclusion ASCA was more frequent in patients with COVID-19 than in healthy controls.
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... BCG vaccination (178,179) or the administration of mucosal immunotherapies such as Trained Immunity-based Vaccines (TIbV) (180) have been shown to confer protection against SARS-CoV-2 infection. Along this line, prophylactic treatments based on b-glucans (181) or their incorporation through the diet (182) have been proposed to serve as a defense against COVID-19, but experimental data are still scarce in this topic. ...
Dectin-1 Signaling Update: New Perspectives for Trained Immunity
Article
Full-text available
  • Feb 2022
The C-type lectin receptor Dectin-1 was originally described as the β-glucan receptor expressed in myeloid cells, with crucial functions in antifungal responses. However, over time, different ligands both of microbial-derived and endogenous origin have been shown to be recognized by Dectin-1. The outcomes of this recognition are diverse, including pro-inflammatory responses such as cytokine production, reactive oxygen species generation and phagocytosis. Nonetheless, tolerant responses have been also attributed to Dectin-1, depending on the specific ligand engaged. Dectin-1 recognition of their ligands triggers a plethora of downstream signaling pathways, with complex interrelationships. These signaling routes can be modulated by diverse factors such as phosphatases or tetraspanins, resulting either in pro-inflammatory or regulatory responses. Since its first depiction, Dectin-1 has recently gained a renewed attention due to its role in the induction of trained immunity. This process of long-term memory of innate immune cells can be triggered by β-glucans, and Dectin-1 is crucial for its initiation. The main signaling pathways involved in this process have been described, although the understanding of the above-mentioned complexity in the β-glucan-induced trained immunity is still scarce. In here, we have reviewed and updated all these factors related to the biology of Dectin-1, highlighting the gaps that deserve further research. We believe on the relevance to fully understand how this receptor works, and therefore, how we could harness it in different pathological conditions as diverse as fungal infections, autoimmunity, or cancer.
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... Gram staining of Clostridium will show large gram-positive rods, with a paucity of leukocytes (as is typical of anaerobic infections) [2], while Escherichia coli shows gram-negative rods, and Enterococcus faecium shows gram-positive cocci [20,21]. In this case, the medical group did not perform Gram staining due to the clinical laboratory chaos caused by the coronavirus disease 2019 (COVID-19) outbreak at the beginning of last year [22,23]. However, because cellular morphology and arrangement are insufficient for differentiating the species directly, Gram strains, although efficient and compensatory, are sometimes the only distinguishing characteristic while cultures and subsequent drug sensitivity experiments are still the conventional critical tests for early and accurate pathogen diagnosis. ...
Coinfection of Clostridium perfringens and Escherichia coli in gas-producing perianal abscess diagnosed by 16S rDNA sequencing: a case report
Article
Full-text available
  • Oct 2021
Background Gas-producing perianal abscess raises the possibility of clostridial infection, with Clostridium perfringens being the most common causative agent, which is highly lethal if untreated timely. As the treatment of clostridial infections often differs from that of non-clostridial infections, which they may closely resemble, the importance of accurate pathogenic organism identification cannot be overemphasized. The 16S rDNA of bacteria is highly conserved within a species and among species of the same genus but demonstrates substantial variation between different species, thus making it a suitable genomic candidate for bacterial detection and identification. Case presentation Here, we report the case of a 53-year-old patient who was admitted to the hospital for a gas-producing perianal abscess. The patient was managed with ceftizoxime and ornidazole and then received debridement and drainage at the lesion on the second day after admission. The bacterial cultures of the patient isolates from the debridement showed a coinfection of Escherichia coli and Enterococcus faecium. Although perianal redness and swelling subsided obviously after the surgery, the patient was febrile to 38.3℃ with his left upper thigh red and swollen, aggravated with tenderness and crepitus. Considering insufficient debridement and the risk of incorrect identification of pathogens, a second debridement and drainage were performed 4 days after the primary operation, and 16S rDNA sequencing of the isolates implicated Clostridium perfringens infection. Given the discrepancies in diagnostic results and the treatment outcomes, Enterococcus faecium was identified as sample contamination, and a diagnosis of coinfection of Clostridium perfringens and Escherichia coli in gas-producing perianal abscess was confirmed. The patient was then successfully treated with meropenem and vancomycin and was discharged at 27 days of admission. Conclusions This case represents the first report of coinfection of both clostridial and non-clostridial organisms in gas-producing perianal abscess and the first case reporting the use of 16S rDNA sequencing in the diagnosis of perianal abscess. Timely pathogen identification is critical for treating gas-producing perianal abscess and an antibiotic regimen covering both aerobic and anaerobic organisms is recommended before true pathogens are identified.
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Creating Logical Flow When Writing Scientific Articles
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Full-text available
  • Oct 2021
Numerous guidelines on how to write a scientific article have been published. Many books and articles giving detailed instructions on how to develop a research question, perform a literature search, or design a study protocol are widely available. However, there are few guidelines on how to create logical flow when writing a scientific article. Logical flow is the key to achieving a smooth and orderly progression of ideas, sentences, paragraphs, and content towards a convincing conclusion. This article provides guidelines for creating logical flow when writing the text and main sections of a scientific article. The first step is creating a draft outline of the whole article. Once completed, the draft outline is developed into a single, coherent article that logically explains the study. Logical flow in the text is created by using precise and concise words, composing clear sentences, and connecting well-structured paragraphs. The use of transitions connects sentences and paragraphs, ensuring clarity and coherence when presenting academic arguments and conclusions. Logical flow in the main sections of a scientific article is achieved by presenting the whole story of the article sequentially in the introduction, methods, results, and discussion, focusing attention on the most important points in each section, and connecting all of these to the main purpose of the study.
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Alternative Wound Management: Translating Science into Practice
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On the origin and continuing evolution of SARS-CoV-2
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Full-text available
  • Mar 2020
The SARS-CoV-2 epidemic started in late December 2019 in Wuhan, China, and has since impacted a large portion of China and raised major global concern. Herein, we investigated the extent of molecular divergence between SARS-CoV-2 and other related coronaviruses. Although we found only 4% variability in genomic nucleotides between SARS-CoV-2 and a bat SARS-related coronavirus (SARSr-CoV; RaTG13), the difference at neutral sites was 17%, suggesting the divergence between the two viruses is much larger than previously estimated. Our results suggest that the development of new variations in functional sites in the receptor-binding domain (RBD) of the spike seen in SARS-CoV-2 and viruses from pangolin SARSr-CoVs are likely caused by natural selection besides recombination. Population genetic analyses of 103 SARS-CoV-2 genomes indicated that these viruses had two major lineages (designated L and S), that are well defined by two different SNPs that show nearly complete linkage across the viral strains sequenced to date. We found that L lineage was more prevalent than the S lineage within the limited patient samples we examined. The implication of these evolutionary changes on disease etiology remains unclear. These findings strongly underscores the urgent need for further comprehensive studies that combine viral genomic data, with epidemiological studies of coronavirus disease 2019 (COVID-19).
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Single-cell analysis of two severe COVID-19 patients reveals a monocyte-associated and tocilizumab-responding cytokine storm
Article
Full-text available
  • Aug 2020
Several studies show that the immunosuppressive drugs targeting the interleukin-6 (IL-6) receptor, including tocilizumab, ameliorate lethal inflammatory responses in COVID-19 patients infected with SARS-CoV-2. Here, by employing single-cell analysis of the immune cell composition of two severe-stage COVID-19 patients prior to and following tocilizumab-induced remission, we identify a monocyte subpopulation that contributes to the inflammatory cytokine storms. Furthermore, although tocilizumab treatment attenuates the inflammation, immune cells, including plasma B cells and CD8⁺ T cells, still exhibit robust humoral and cellular antiviral immune responses. Thus, in addition to providing a high-dimensional dataset on the immune cell distribution at multiple stages of the COVID-19, our work also provides insights into the therapeutic effects of tocilizumab, and identifies potential target cell populations for treating COVID-19-related cytokine storms.
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Can Drinking Microfiltered Raw Immune Milk From Cows Immunized Against SARS-CoV-2 Provide Short-Term Protection Against COVID-19?
Article
Full-text available
  • Jul 2020
The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes severe respiratory tract infections in humans (COVID-19), has become a global health concern. Currently, several vaccine candidates against SARS-CoV-2 are in clinical trials but approval of these vaccines is likely to take a long time before they are available for public use. In a previous report, the importance of passive immunity and how immunoglobulin (Ig)G collected from recovered coronavirus patients could help in the protection against COVID-19 and boost the immune system of new patients was reported. Passive immunity by immunoglobulin transfer is a concept employed by most mammals and bovine IgG has a role to play in human therapy. IgG is one of the major components of the immunological activity found in cow's milk and colostrum. Heterologous transfer of passive immunity associated with the consumption of bovine immune milk by humans has been investigated for decades for its immunological activity against infections. This short review focuses on passive immunity and how microfiltered raw immune milk or colostrum collected from cows vaccinated against SARS-CoV-2 could provide short-term protection against SARS-CoV-2 infection in humans and could be used as an option until a vaccine becomes commercially available.
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Article
Full-text available
  • Jul 2020
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How Fungal Glycans Modulate Platelet Activation via Toll-Like Receptors Contributing to the Escape of Candida albicans from the Immune Response
Article
Full-text available
  • Jul 2020
Platelets are essential for vascular repair and for the maintenance of blood homeostasis. They contribute to the immune defence of the host against many infections caused by bacteria, viruses and fungi. Following infection, platelet function is modified, and these cells form aggregates with microorganisms leading, to a decrease in the level of circulating platelets. During candidaemia, mannans, β-glucans and chitin, exposed on the cell wall of Candida albicans, an opportunistic pathogenic yeast of humans, play an important role in modulation of the host response. These fungal polysaccharides are released into the circulation during infection and their detection allows the early diagnosis of invasive fungal infections. However, their role in the modulation of the immune response and, in particular, that of platelets, is not well understood. The structure and solubility of glycans play an important role in the orientation of the immune response of the host. This short review focuses on the effect of fungal β-glucans and chitin on platelet activation and how these glycans modulate platelet activity via Toll-like receptors, contributing to the escape of C. albicans from the immune response.
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Roles of flavonoids against coronavirus infection
Article
In terms of public health, the 21st century has been characterized by coronavirus pandemics: in 2002-03 the virus SARS-CoV caused SARS; in 2012 MERS-CoV emerged and in 2019 a new human betacoronavirus strain, called SARS-CoV-2, caused the unprecedented COVID-19 outbreak. During the course of the current epidemic, medical challenges to save lives and scientific research aimed to reveal the genetic evolution and the biochemistry of the vital cycle of the new pathogen could lead to new preventive and therapeutic strategies against SARS-CoV-2. Up to now, there is no cure for COVID-19 and waiting for an efficacious vaccine, the development of “savage” protocols, based on “old” anti-inflammatory and anti-viral drugs represents a valid and alternative therapeutic approach. As an alternative or additional therapeutic/preventive option, different in silico and in vitro studies demonstrated that small natural molecules, belonging to polyphenols family, can interfere with various stages of coronavirus entry and replication cycle. Here, we reviewed the capacity of well-known (e.g. quercetin, baicalin, luteolin, hesperetin, gallocatechin gallate, epigallocatechin gallate) and uncommon (e.g. scutellarein, amentoflavone, papyriflavonol A) flavonoids, secondary metabolites widely present in plant tissues with antioxidant and anti-microbial functions, to inhibit key proteins involved in coronavirus infective cycle, such as PLpro, 3CLpro, NTPase/helicase. Due to their pleiotropic activities and lack of systemic toxicity, flavonoids and their derivative may represent target compounds to be tested in future clinical trials to enrich the drug arsenal against coronavirus infections.
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Digestive Symptoms in COVID-19 Patients With Mild Disease Severity: Clinical Presentation, Stool Viral RNA Testing, and Outcomes
Article
  • Apr 2020
Objectives: Coronavirus disease 2019 (COVID-19) most commonly presents with respiratory symptoms, including cough, shortness of breath, and sore throat. However, digestive symptoms also occur in patients with COVID-19 and are often described in outpatients with less severe disease. In this study, we sought to describe the clinical characteristics of COVID-19 patients with digestive symptoms and mild disease severity. Methods: We identified COVID-19 patients with mild disease and one or more digestive symptoms (diarrhea, nausea, and vomiting), with or without respiratory symptoms, and compared them with a group presenting solely with respiratory symptoms. We followed up patients clinically until they tested negative for COVID-19 on at least 2 sequential respiratory tract specimens collected ≥24 hours apart. We then compared the clinical features between those with digestive symptoms and those with respiratory symptoms. Results: There were 206 patients with low severity COVID-19, including 48 presenting with a digestive symptom alone, 69 with both digestive and respiratory symptoms, and 89 with respiratory symptoms alone. Between the 2 groups with digestive symptoms, 67 presented with diarrhea, of whom 19.4% experienced diarrhea as the first symptom in their illness course. The diarrhea lasted from 1 to 14 days, with an average duration of 5.4 ± 3.1 days and a frequency of 4.3 ± 2.2 bowel movements per day. Concurrent fever was found in 62.4% of patients with a digestive symptom. Patients with digestive symptoms presented for care later than those with respiratory symptoms (16.0 ± 7.7 vs 11.6 ± 5.1 days, P < 0.001). Nevertheless, patients with digestive symptoms had a longer duration between symptom onset and viral clearance (P < 0.001) and were more likely to be fecal virus positive (73.3% vs 14.3%, P = 0.033) than those with respiratory symptoms. Discussion: We describe a unique subgroup of COVID-19 patients with mild disease severity marked by the presence of digestive symptoms. These patients are more likely to test positive for viral RNA in stool, to have a longer delay before viral clearance, and to experience delayed diagnosis compared with patients with only respiratory symptoms.
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Early nutritional supplementation in non-critically ill patients hospitalized for the 2019 novel coronavirus disease (COVID-19): Rationale and feasibility of a shared pragmatic protocol
Article
Objectives Beginning in December 2019, the 2019 novel coronavirus disease (COVID-19) has caused a pneumonia epidemic that began in Wuhan, China, and is rapidly spreading throughout the whole world. Italy is the hardest hit country after China. Considering the deleterious consequences of malnutrition, which certainly can affect patients with COVID-19, the aim of this study is to present a pragmatic protocol for early nutritional supplementation of non-critically ill patients hospitalized for COVID-19 disease. It is based on the observation that most patients present at admission with severe inflammation and anorexia leading to a drastic reduction of food intake, and that a substantial percentage develops respiratory failure requiring non-invasive ventilation or even continuous positive airway pressure. Methods High-calorie dense diets in a variety of different consistencies with highly digestible foods and snacks are available for all patients. Oral supplementation of whey proteins as well as intravenous infusion of multivitamin, multimineral trace elements solutions are implemented at admission. In the presence of 25-hydroxyvitamin D deficit, cholecalciferol is promptly supplied. If nutritional risk is detected, two to three bottles of protein-calorie oral nutritional supplements (ONS) are provided. If <2 bottles/d of ONS are consumed for 2 consecutive days and/or respiratory conditions are worsening, supplemental/total parenteral nutrition is prescribed. Conclusion We are aware that our straight approach may be debatable. However, to cope with the current emergency crisis, its aim is to promptly and pragmatically implement nutritional care in patients with COVID-19, which might be overlooked despite being potentially beneficial to clinical outcomes and effective in preventing the consequences of malnutrition in this patient population.
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