Probiotics and COVID-19: is there any link?

Association Between Altered Microbiota Composition and Immune System-Related Genes in COVID-19 Infection

Microbiota and immunity affect the host's susceptibility to SARS-CoV-2 infection and the severity of COVID-19. This study aimed to identify significant alterations in the microbiota composition, immune signaling pathways, their potential association, and candidate microRNA in COVID-19 patients using an in silico study model. Enrichment online databases and Python programming were utilized to analyze GSE164805, GSE180594, and GSE182279, as well as NGS data of microbiota composition (PRJNA650244 and PRJNA660302) associated with COVID-19, employing amplicon-based/marker gene sequencing methods. C1, TNF, C2, IL1, and CFH genes were found to have a significant impact on immune signaling pathways. Additionally, we observed a notable decrease in Bacteroides spp. and Faecalibacterium sp., while Escherichia coli, Streptococcus spp., and Akkermansia muciniphila showed increased abundance in COVID-19. Notably, A. muciniphila demonstrated an association with immunity through C1 and TNF, while Faecalibacterium sp. was linked to C2 and IL1. The correlation between E. coli and CFH, as well as IL1 and Streptococcus spp. with C2, was identified. hsa-let-7b-5p was identified as a potential candidate that may be involved in the interaction between the microbiota composition, immune response, and COVID-19. In conclusion, integrative in silico analysis shows that these microbiota members are potentially crucial in the immune responses against COVID-19.

Evaluation of Four Multispecies Probiotic Cocktails in a Human Colonic Fermentation Model

Bacteriotherapy represents an attractive approach for both prophylaxis and treatment of human diseases. However, combining probiotic bacteria in "cocktails" is underexplored, despite its potential as an alternative multi-target therapy. Herein, three-strain probiotic mixtures containing different combinations of Bacillus (Bc.) coagulans [ATB-BCS-042], Levilactobacillus (Lv.) brevis [THT 0303101], Lacticaseibacillus (Lc.) paracasei [THT 031901], Bacillus subtilis subsp. natto [ATB-BSN-049], Enterococcus faecium [ATB-EFM-030], and Bifidobacterium (Bf.) animalis subsp. lactis [THT 010802] were prepared. Four cocktails (PA: Bc. coagulans + Lv. brevis + Lc. paracasei, PB: Bc. subtilis subsp. natto + Lv. brevis + Lc. paracasei, PC: E. faecium + Lv. brevis + Lc. paracasei, PD: Bc. coagulans + Lv. brevis + Bf. animalis subsp. lactis) were tested using a short-term (72 h) simulation of the human colonic microbiota in a final dose of 6 × 109 CFU. All these probiotic mixtures significantly increased butyrate production compared to the parallel control experiment. PA and PB promoted a bifidogenic effect and facilitated lactobacilli colonization. Furthermore, reporter gene assays using the AhR_HT29-Lucia cell line revealed that fermentation supernatants from PA and PB notably induced AhR transactivity. Subsequent examination of the metabolic outputs of PA and PB in intestinal epithelial models using cell culture inserts suggested no significant impact on the transepithelial electrical resistance (TEER). Assessment of the expression of proinflammatory and anti-inflammatory cytokines, as well as AhR-related target genes in the Caco-2 cell monolayers indicated that PB's metabolic output upregulated most of the measured endpoints. This in vitro investigation evaluated the potential impact of four multispecies probiotic mixtures in the human colonic microbiota and identified a promising formulation comprising a combination of Bc. subtilis subsp. natto, Lv. brevis, and Lc. paracasei as a promising formulation for further study.

Gut Microbiota Dysbiosis in COVID-19: Modulation and Approaches for Prevention and Therapy

Inflammation and oxidative stress are critical underlying mechanisms associated with COVID-19 that contribute to the complications and clinical deterioration of patients. Additionally, COVID-19 has the potential to alter the composition of patients' gut microbiota, characterized by a decreased abundance of bacteria with probiotic effects. Interestingly, certain strains of these bacteria produce metabolites that can target the S protein of other coronaviruses, thereby preventing their transmission and harmful effects. At the same time, the presence of gut dysbiosis can exacerbate inflammation and oxidative stress, creating a vicious cycle that perpetuates the disease. Furthermore, it is widely recognized that the gut microbiota can metabolize various foods and drugs, producing by-products that may have either beneficial or detrimental effects. In this regard, a decrease in short-chain fatty acid (SCFA), such as acetate, propionate, and butyrate, can influence the overall inflammatory and oxidative state, affecting the prevention, treatment, or worsening of COVID-19. This review aims to explore the current evidence regarding gut dysbiosis in patients with COVID-19, its association with inflammation and oxidative stress, the molecular mechanisms involved, and the potential of gut microbiota modulation in preventing and treating SARS-CoV-2 infection. Given that gut microbiota has demonstrated high adaptability, exploring ways and strategies to maintain good intestinal health, as well as an appropriate diversity and composition of the gut microbiome, becomes crucial in the battle against COVID-19.

The effects of functional foods mixture on inflammatory cytokines and biochemical findings in hospitalized patients with COVID-19: a randomized double-blind controlled trial

BACKGROUND

The coronavirus disease 2019 (COVID-19) pandemic has been shown to affect nutritional recommendations. Some functional foods have been demonstrated to be useful in the treatment of people with COVID-19. However, little is known about the impact of combining functional foods on disease control. This study aimed to investigate the effects of functional foods mixture on serum levels of inflammatory cytokines and biochemical findings in patients with COVID-19.

METHODS

A randomized double-blind controlled trial was conducted in Baqiyatallah Al-Azam hospital in Tehran, Iran. Sixty patients were randomly assigned to receive either a soup containing functional foods (n = 30) or a usual soup (control group) (n = 30). Participants' sociodemographic information was gathered using a general questionnaire. Blood levels of inflammatory markers and biochemical findings were assessed using standard protocols.

RESULTS

The results showed that soup containing functional foods was more effective in controlling serum levels of D-dimer, blood urea nitrogen, and creatinine than the control group (P < 0.05). Also, more significant improvement was found in the intervention group vs control group in terms of interleukin (IL)-1β, IL-6, IL-17, IL-10, and tumor necrose factor-α (P < 0.05). In contrast, the control intervention more efficiently controlled potassium levels and reduced quantitative C-reactive protein than the intervention group (P < 0.05).

CONCLUSIONS

This study indicates a soup containing functional foods could alleviate biomarkers of inflammation in patients with COVID-19. However, its effectiveness on biochemical findings remained inconclusive which warranted further research.

TRIAL REGISTRATION

IRCT, IRCT20180201038585N11. Registered 23 August 2021, https://www.irct.ir/trial/57338.

Ongoing Treatment with a Spore-Based Probiotic Containing Five Strains of Bacillus Improves Outcomes of Mild COVID-19

Spore-based Bacillus probiotic treatment improves intestinal health. The intestinal microbiota influences both the innate and adaptive immune responses. As such, the influence of ongoing spore-based probiotic treatment (five probiotic strains of Bacillus) on the clinical outcomes of mild COVID-19 was evaluated in this retrospective, observational study. Demographics, medical history, probiotic use, and COVID-19 symptom information were collected. The study included 120 patients with a PCR-confirmed SARS-CoV-2 infection and mild COVID-19 symptoms. The probiotic group (n = 60) comprised patients with ongoing probiotic treatment (≥1 month); the control group comprised patients not taking probiotics (n = 60). The primary outcome was time to symptom resolution; secondary outcomes included time to fever resolution and presence of digestive symptoms. The probiotic group had a significantly shorter time to symptom resolution (mean (95% confidence interval) days: control group, 8.48 (6.56, 10.05); probiotic group, 6.63 (5.56; 6.63); p = 0.003) and resolution of fever (control group, 2.67 (1.58, 3.61); probiotic group, 1.48 (1.21, 2.03); p < 0.001). More patients in the probiotic group (n = 53) than in the control group (n = 34) did not have digestive symptoms (p < 0.001). Among adults with mild COVID-19, participants receiving ongoing probiotic treatment had a shorter clinical course, and fewer had digestive symptoms compared with those not taking probiotics.

Effect of a Multi-Strain Probiotic Supplementation to Manage Stress during the COVID-19 Pandemic: A Randomized, Double-Blind, Placebo-Controlled, Cross-Over Clinical Trial

INTRODUCTION

The COVID-19 pandemic strongly affected every aspect of the modern society, from health to socioeconomics, leading people to experience high levels of stress.

METHODS

A double-blind, cross-over, placebo-controlled clinical study was performed to investigate the ability of a food supplement containing two probiotic strains, Limosilactobacillus reuteri PBS072 and Bifidobacterium breve BB077, in supporting 33 healthy adults, working at a university, in stress management. The efficacy of the tested strains in influencing the stress response, in terms of mood and sleep behavior, was assessed using the following validated questionnaires: Profile of Mood State (POMS) and Pittsburgh Sleep Quality Index (PSQI).

RESULTS

Outcomes of the POMS and the PSQI demonstrated a significant reduction of the questionnaire's scores both versus baseline and placebo after 30 days of probiotic intake.

CONCLUSIONS

According to the results, the probiotic food supplement investigated showed a remarkable effect on stress management by improving the quality of sleep and the mood.

Bioactive metabolites in functional and fermented foods and their role as immunity booster and anti-viral innate mechanisms

Live microorganisms in the fermented foods termed probiotics and their secondary metabolites with bioactive potential were considered as potential anti-viral capabilities through various mechanisms. Given the importance of functional and fermented foods in disease prevention, there is a need to discuss the contextualization and deep understanding of the mechanism of action of these foods, particularly considering the appearance of coronavirus (COVID-19) pandemic, which is causing health concerns and increased social services globally. The mechanism of probiotic strains or their bioactive metabolites is due to stimulation of immune response through boosting T-lymphocytes, cytokines, and cell toxicity of natural killer cells. Proper consumption of these functional and fermented foods may provide additional antiviral approaches for public benefit by modulating the immune functions in the hosts.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-022-05528-8.

Can nutraceuticals assist treatment and improve covid-19 symptoms?

Viral diseases have always played an important role in public and individual health. Since December 2019, the world is facing a pandemic of SARS-CoV-2, a coronavirus that results in a syndrome known as COVID-19. Several studies were conducted to implement antiviral drug therapy, until the arrival of SARS-CoV-2 vaccines. Numerous scientific investigations have considered some nutraceuticals as an additional treatment of COVID-19 patients to improve their clinical picture. In this review, we would like to emphasize the studies conducted to date about this issue and try to understand whether the use of nutraceuticals as a supplementary therapy to COVID-19 may be a valid and viable avenue. Based on the results obtained so far, quercetin, astaxanthin, luteolin, glycyrrhizin, lactoferrin, hesperidin and curcumin have shown encouraging data suggesting their use to prevent and counteract the symptoms of this pandemic infection.

Plant Polysaccharides Modulate Immune Function via the Gut Microbiome and May Have Potential in COVID-19 Therapy

Plant polysaccharides can increase the number and variety of beneficial bacteria in the gut and produce a variety of active substances, including short-chain fatty acids (SCFAs). Gut microbes and their specific metabolites have the effects of promoting anti-inflammatory activity, enhancing the intestinal barrier, and activating and regulating immune cells, which are beneficial for improving immunity. A strong immune system reduces inflammation caused by external viruses and other pathogens. Coronavirus disease 2019 (COVID-19) is still spreading globally, and patients with COVID-19 often have intestinal disease and weakened immune systems. This article mainly evaluates how polysaccharides in plants can improve the immune system barrier by improving the intestinal microecological balance, which may have potential in the prevention and treatment of COVID-19.

Nutrition as a key to boost immunity against COVID-19

The Coronavirus-disease 2019 (COVID-19) was declared as a global pandemic on March 11, 2020 by the World Health Organization. Since then, the scientific community has been actively engaged in developing a vaccine against the dreaded disease. Considerable research has also been performed for drugs that can directly interfere with the viral replication pathway. However, the production of these vaccines and drugs demands a lot of time and effort which is undesirable considering the pace at which the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is spreading across the continents. For this reason, the possible role of dietary nutrients in reducing the risk of SARS-CoV-2 infection as well as mitigating the symptoms, may be explored. These natural substances are readily available, have negligible side effects and confer several benefits to the immune system. Macronutrients like proteins are vital for antibody production. Dietary constituents such as omega-3-fatty acids, vitamin C, vitamin E, phytochemicals such as carotenoids and polyphenols exhibit anti-inflammatory and antioxidant properties. This review highlights the significance of relevant nutrients in boosting the immune system.

Reply to Cafiero et al. Comment on "Kopańska et al. Disorders of the Cholinergic System in COVID-19 Era-A Review of the Latest Research. Int. J. Mol. Sci. 2022, 23, 672"

We have carefully read the Letter to the Editor by Concetta Cafiero, Alessandra Micera, Agnese Re, Beniamino Schiavone, Giulio Benincasa, and Raffaele Palmirotta related to our paper entitled "Disorders of the Cholinergic System in COVID-19 Era-A Review of the Latest Research" [...].

Herbal Remedies, Nutraceuticals, and Dietary Supplements for COVID-19 Management: An Update

Currently, the world is facing a Coronavirus pandemic with a grave deficiency of specific therapy for Coronavirus Disease (COVID-19). Moreover, scientists attempt to discover the most refined approach to prevent this condition. Regarding COVID-19 infection, herbal medicines with immunomodulatory effects may offer patients a promising preventive treatment option. Several ayurvedic and Traditional Chinese Medicine (TCM) are effective during this worrisome Coronavirus pandemic i.e. Tinospora cordifolia (Willd.) Miers, Withania somnifera (L.) Dunal, Scutellaria baicalensis Georgi, Curcuma longa L. etc. TCM was shown to be utilized with over 90% efficacy when the COVID-19 pandemic broke out in early 2020. In addition to herbal treatments and nutraceutical drugs, dietary supplements such as vitamins and amino acid derivatives also play a significant part in COVID-19 management. Diet can assist in regulating inflammation, while nutraceuticals can aid in the prevention of viral invasion. Functional amino acids (e.g., arginine, cysteine, glutamate, glutamine, glycine, taurine, and tryptophan) and glutathione, which are all abundant in animal-sourced foodstuffs, are crucial for optimum immunity and health in humans and animals. The goal of this article is to thoroughly evaluate recent statistics on the effectiveness of herbal medicines in COVID-19, the antiviral activity of nutraceuticals, and the significance of these results in creating dietary supplements that would enhance innate immunity and contribute as preventive measures against severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2).

Therapeutic mechanisms and impact of traditional Chinese medicine on COVID-19 and other influenza diseases

Coronavirus disease 2019 (COVID-19), first reported in Wuhan, China, has rapidly spread worldwide. Traditional Chinese medicine (TCM) has been used to prevent and treat viral epidemics and plagues for over 2,500 years. In the guidelines on fighting against COVID-19, the National Health Commission of the People's Republic of China has recommended certain TCM formulas, namely Jinhua Qinggan granule (JHQGG), Lianhua Qingwen granule (LHQWG), Qingfei Paidu decoction (QFPDD), Xuanfei Baidu granule (XFBD), Xuebijing injection (XBJ), and Huashi Baidu granule (HSBD) for treating COVID-19 infected individuals. Among these six TCM formulas, JHQGG and LHQWG effectively treated mild/moderate and severe COVID-19 infections. XFBD therapy is recommended for mild COVID-19 infections, while XBJ and HSBD effectively treat severe COVID-19 infections. The internationalization of TCM faces many challenges due to the absence of a clinical efficacy evaluation system, insufficient research evidence, and a lack of customer trust across the globe. Therefore, evidence-based research is crucial in battling this infectious disease. This review summarizes SARS-CoV-2 pathogenesis and the history of TCM used to treat various viral epidemics, with a focus on six TCM formulas. Based on the evidence, we also discuss the composition of various TCM formulas, their underlying therapeutic mechanisms, and their role in curing COVID-19 infections. In addition, we evaluated the roles of six TCM formulas in the treatment and prevention of other influenza diseases, such as influenza A (H1N1), severe acute respiratory syndrome (SARS), and Middle East respiratory syndrome (MERS). Furthermore, we highlighted the efficacy and side effects of single prescriptions used in TCM formulas.

Evidences and perspectives of the use of probiotics, prebiotics, synbiotics, and postbiotics as adjuvants for prevention and treatment of COVID-19: A bibliometric analysis and systematic review

BACKGROUND

Coronavirus disease-19 (COVID-19) is an infectious disease transmitted by the virus responsible for the severe acute respiratory syndrome 2 (SARS-CoV-2), which exhibit several clinical manifestations including gastrointestinal symptoms.

SCOPE AND APPROACH

This review aimed to provide insights and perspectives for the use of probiotics, prebiotics, synbiotics, and postbiotics as adjuvants for prevention/treatment and/or modulation of the microbiota in COVID-19 patients. Eighty-four studies published in the Scopus database from the onset of the pandemic until December 2021 were assessed and submitted to a bibliometric analysis adapted from VOSviewer software.

KEY FINDINGS AND CONCLUSIONS

Through bibliometric analysis, it might be suggested that the modulation of the gut/lung microbiome is promising as an adjuvant for the prevention/treatment of COVID-19 patients, due to immunomodulation properties related to probiotics and prebiotics. So far, few clinical studies involving the application of probiotics in COVID-19 patients have been completed, but reduction in the duration of the disease and the severity of symptoms as fatigue, olfactory dysfunction and breathlessness, nausea and vomiting and other gastrointestinal symptoms were some of the main findings. However, probiotics are not recommended to immunocompromised patients in corticosteroid therapy. The future perspectives point to the modulation of the intestinal microbiota by probiotics, prebiotics, synbiotics, and postbiotics represent a promising adjuvant approach for improving the health of patients with COVID-19.

Role of Probiotics in the Management of COVID-19: A Computational Perspective

Coronavirus disease 2019 (COVID-19) was declared a pandemic at the beginning of 2020, causing millions of deaths worldwide. Millions of vaccine doses have been administered worldwide; however, outbreaks continue. Probiotics are known to restore a stable gut microbiota by regulating innate and adaptive immunity within the gut, demonstrating the possibility that they may be used to combat COVID-19 because of several pieces of evidence suggesting that COVID-19 has an adverse impact on gut microbiota dysbiosis. Thus, probiotics and their metabolites with known antiviral properties may be used as an adjunctive treatment to combat COVID-19. Several clinical trials have revealed the efficacy of probiotics and their metabolites in treating patients with SARS-CoV-2. However, its molecular mechanism has not been unraveled. The availability of abundant data resources and computational methods has significantly changed research finding molecular insights between probiotics and COVID-19. This review highlights computational approaches involving microbiome-based approaches and ensemble-driven docking approaches, as well as a case study proving the effects of probiotic metabolites on SARS-CoV-2.

Impact of COVID-19 on the Intestinal Microbiome

PURPOSE OF REVIEW

This review article aims to explore the GI changes induced by SARS-CoV-2 and how gut microbial homeostasis can influence these changes and affect the lung-gut axis and its relationship with the induction of the cytokine release syndrome in severe COVID-19 patients.

RECENT FINDINGS

Coronavirus disease 2019 (COVID-19) affects not only the respiratory system but can produce multi-systemic damage. The expression of angiotensin-converting enzyme 2 (ACE-2) receptors in the gastrointestinal (GI) tract, the high prevalence of GI symptoms in severely ill COVID-19 patients, and the abnormalities described in the gut microbiome in these patients have raised concerns about the influence of GI tract as a risk factor or as a potential modulator to reduce the severity of COVID-19. Understanding the mechanisms by which gut dysbiosis may influence viral transmission and disease progression in COVID-19 may help in shaping how accessible therapies, like diet modulation, can potentially help beat the devastating consequences of COVID-19.

Japanese newspaper advertisements for dietary supplements before and after COVID-19: a content analysis

OBJECTIVES

Public health institutions have alerted consumers about advertising for dietary supplements with false claims of preventing or treating COVID-19. We quantitatively and qualitatively examined newspaper advertisements for dietary supplements before and after the COVID-19 spread.

DESIGN

Content analysis.

PARTICIPANTS

We analysed advertisements for dietary supplements in two major Japanese newspapers in February-July 2019 and February-July 2020. Our analysis covered 2167 advertisements.

RESULTS

The number of advertisements for dietary supplements that claimed to be effective in infection prevention (p=0.009) and improving joint (p=0.002) and digestive functions (p=0.002) significantly increased after the spread of COVID-19 compared with before. Dietary supplements that claimed to be effective in preventing infection were advertised in combination with recommendations for gargling and handwashing. Such terms as 'defence' and 'prevent' were used to promote the preventive effect.

CONCLUSIONS

False and misleading claims in advertising for dietary supplements may result in consumer harm, such as overdosing and failure to take preventive behaviour. While the pandemic continues, there will be an increasing need for disseminating accessible information about the appropriate use of dietary supplements, consumer education and warnings to manufacturers.

Role of Probiotic for Prevention and Management of COVID-19: A Literature Review

Backgrounds: Coronavirus brought about by SARS-CoV-2 is a continuous worldwide pandemic. SARS-CoV-2 influences the human respiratory tracts’ epithelial cells, prompting a proinflammatory cytokine storm and ongoing lung inflammation. With various patients kicking the bucket day by day, an immunization and explicit antiviral medication regimens are being investigated. The choice to utilize this medication during the COVID-19 pandemic should be founded on cautious thought of the likely as preventive and curative in such context. Methods: A literature review changed into carried out through the PubMed, Science Direct, Medline, and Google Scholar search engines consist of probiotics preventive and management possibility in COVID-19. Results: The probiotics significantly affects the host insusceptible reaction, foundationally, and on invulnerable responses at close by mucosal locales, like the lung. Certain strains of probiotics have improved interferon type I levels, hoisting the number and capacity of antigen-introducing cells, regular executioner cells, and T cells, just as expanding the degree of specific antibodies at the fundamental and mucosal destinations. Conclusion: Probiotics have various advantages and potential in preventing and as the treatment of COVID-19, adjusting the arrangement of human gut microflora, reinforcing gut obstruction work, and defensive invulnerable reactions.

A comprehensive review of the analysis and integration of omics data for SARS-CoV-2 and COVID-19

Since the first report of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in December 2019, over 100 million people have been infected by COVID-19, millions of whom have died. In the latest year, a large number of omics data have sprung up and helped researchers broadly study the sequence, chemical structure and function of SARS-CoV-2, as well as molecular abnormal mechanisms of COVID-19 patients. Though some successes have been achieved in these areas, it is necessary to analyze and mine omics data for comprehensively understanding SARS-CoV-2 and COVID-19. Hence, we reviewed the current advantages and limitations of the integration of omics data herein. Firstly, we sorted out the sequence resources and database resources of SARS-CoV-2, including protein chemical structure, potential drug information and research literature resources. Next, we collected omics data of the COVID-19 hosts, including genomics, transcriptomics, microbiology and potential drug information data. And subsequently, based on the integration of omics data, we summarized the existing data analysis methods and the related research results of COVID-19 multi-omics data in recent years. Finally, we put forward SARS-CoV-2 (COVID-19) multi-omics data integration research direction and gave a case study to mine deeper for the disease mechanisms of COVID-19.

Patient Nutrition and Probiotic Therapy in COVID-19: What Do We Know in 2021?

BACKGROUND

The main nutritional consequences of COVID-19 include reduced food intake, hypercatabolism, and rapid muscle wasting. Some studies showed that malnutrition is a significant problem among patients hospitalized due to COVID-19 infection, and the outcome of patients with SARS-CoV-2 is strongly associated with their nutritional status. The purpose of this study was to collect useful information about the possible elements of nutritional and probiotic therapy in patients infected with the SARS-CoV-2 virus.

METHODS

A narrative review of the literature, including studies published up to 13 September 2021.

RESULTS

Probiotics may support patients by inhibiting the ACE2 receptor, i.e., the passage of the virus into the cell, and may also be effective in suppressing the immune response caused by the proinflammatory cytokine cascade. In patients' diet, it is crucial to ensure an adequate intake of micronutrients, such as omega-3 fatty acids (at 2-4 g/d), selenium (300-450 μg/d) and zinc (30-50 mg/d), and vitamins A (900-700 µg/d), E (135 mg/d), D (20,000-50,000 IU), C (1-2 g/d), B6, and B12. Moreover, the daily calorie intake should amount to ≥1500-2000 with 75-100 g of protein.

CONCLUSION

In conclusion, the treatment of gut dysbiosis involving an adequate intake of prebiotic dietary fiber and probiotics could turn out to be an immensely helpful instrument for immunomodulation, both in COVID-19 patients and prophylactically in individuals with no history of infection.

Synbiotics Containing Nanoprebiotics: A Novel Therapeutic Strategy to Restore Gut Dysbiosis

A new formulation, nanoprebiotics [e.g., phthalyl pullulan nanoparticles (PPNs)], was demonstrated to enhance the antimicrobial activity of probiotics [e.g., Lactobacillus plantarum (LP)] in vitro through intracellular stimulation better than that by backbone prebiotics, which are commonly used. In this study, we aimed to investigate whether this combination would exert distinct effects as synbiotics in vivo. Synbiotics combinations of LP, pullulan, and PPNs were used as experimental treatments in a dysbiosis-induced murine model, and their restorative effect was assessed using pathogen Escherichia coli K99 challenge. Our results showed that the E. coli infection was suppressed markedly in the experimental group fed with synbiotics containing PPNs. In addition, the decrease in serum endotoxin level after synbiotics treatment suggested the reinforcement of the gut barrier. Comparison of treatment groups, including a normal control group, showed that synbiotics containing PPNs increased microbial diversity, which is a representative parameter of healthy status. Furthermore, distinct from probiotics treatment alone, synbiotics showed additive effects of enrichment of several well-known beneficial bacteria such as Lactobacillus, Bifidobacterium, and other butyrate-producing bacteria including Faecalibacterium. Collectively, our results indicate that synbiotics containing PPNs are effective at restoring gut dysbiosis, suppressing pathogenic infection, and increasing microbial diversity, suggesting that synbiotics with nanoprebiotics have the potential to be a novel strategy for ameliorating gut dysbiosis and infectious diseases.

The microbiota-related coinfections in COVID-19 patients: a real challenge

BACKGROUND

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the cause of ongoing global pandemic of coronavirus disease 2019 (COVID-19), has infected millions of people around the world, especially the elderly and immunocompromised individuals. The infection transmission rate is considered more rapid than other deadly pandemics and severe epidemics encountered earlier, such as Ebola, Zika, Influenza, Marburg, SARS, and MERS. The public health situation therefore is really at a challenging crossroads.

MAIN BODY

The internal and external and resident microbiota community is crucial in human health and is essential for immune responses. This community tends to be altered due to pathogenic infections which would lead to severity of the disease as it progresses. Few of these resident microflora become negatively active during infectious diseases leading to coinfection, especially the opportunistic pathogens. Once such a condition sets in, it is difficult to diagnose, treat, and manage COVID-19 in a patient.

CONCLUSION

This review highlights the various reported possible coinfections that arise in COVID-19 patients vis-à-vis other serious pathological conditions. The local immunity in lungs, nasal passages, oral cavity, and salivary glands are involved with different aspects of COVID-19 transmission and pathology. Also, the role of adaptive immune system is discussed at the site of infection to control the infection along with the proinflammatory cytokine therapy.

Microbiota-Gut-Brain Communication in the SARS-CoV-2 Infection

The coronavirus disease of 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome 2 (SARS-CoV-2). In addition to pneumonia, individuals affected by the disease have neurological symptoms. Indeed, SARS-CoV-2 has a neuroinvasive capacity. It is known that the infection caused by SARS-CoV-2 leads to a cytokine storm. An exacerbated inflammatory state can lead to the blood-brain barrier (BBB) damage as well as to intestinal dysbiosis. These changes, in turn, are associated with microglial activation and reactivity of astrocytes that can promote the degeneration of neurons and be associated with the development of psychiatric disorders and neurodegenerative diseases. Studies also have been shown that SARS-CoV-2 alters the composition and functional activity of the gut microbiota. The microbiota-gut-brain axis provides a bidirectional homeostatic communication pathway. Thus, this review focuses on studies that show the relationship between inflammation and the gut microbiota-brain axis in SARS-CoV-2 infection.

Double-Barrel Shotgun: Probiotic Lactic Acid Bacteria with Antiviral Properties Modified to Serve as Vaccines

Contrary to the general belief that the sole function of probiotics is to keep intestinal microbiota in a balanced state and stimulate the host’s immune response, several studies have shown that certain strains of lactic acid bacteria (LAB) have direct and/or indirect antiviral properties. LAB can stimulate the innate antiviral immune defence system in their host, produce antiviral peptides, and release metabolites that prevent either viral replication or adhesion to cell surfaces. The SARS-CoV (COVID-19) pandemic shifted the world’s interest towards the development of vaccines against viral infections. It is hypothesised that the adherence of SARS-CoV spike proteins to the surface of Bifidobacterium breve could elicit an immune response in its host and trigger the production of antibodies. The question now remains as to whether probiotic LAB could be genetically modified to synthesize viral antigens and serve as vaccines—this concept and the role that LAB play in viral infection are explored in this review.

Gut probiotic Lactobacillus rhamnosus attenuates PDE4B-mediated interleukin-6 induced by SARS-CoV-2 membrane glycoprotein

Membrane glycoprotein is the most abundant protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), but its role in coronavirus disease 2019 (COVID-19) has not been fully characterized. Mice intranasally inoculated with membrane glycoprotein substantially increased the interleukin (IL)-6, a hallmark of the cytokine storm, in bronchoalveolar lavage fluid (BALF), compared to mice inoculated with green fluorescent protein (GFP). The high level of IL-6 induced by membrane glycoprotein was significantly diminished in phosphodiesterase 4 (PDE4B) knockout mice, demonstrating the essential role of PDE4B in IL-6 signaling. Mycelium fermentation of Lactobacillus rhamnosus (L. rhamnosus) EH8 strain yielded butyric acid, which can down-regulate the PDE4B expression and IL-6 secretion in macrophages. Feeding mice with mycelia increased the relative abundance of commensal L. rhamnosus. Two-week supplementation of mice with L. rhamnosus plus mycelia considerably decreased membrane glycoprotein-induced PDE4B expression and IL-6 secretion. The probiotic activity of L. rhamnosus plus mycelia against membrane glycoprotein was abolished in mice treated with GLPG-0974, an antagonist of free fatty acid receptor 2 (Ffar2). Activation of Ffar2 in the gut-lung axis for down-regulation of the PDE4B-IL-6 signalling may provide targets for development of modalities including probiotics for treatment of the cytokine storm in COVID-19.

Recent advance of ACE2 and microbiota dysfunction in COVID-19 pathogenesis

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused the coronavirus disease 2019 (COVID-19) and has become the world's most pressing public health threat. Although not as common as respiratory symptoms, a substantial proportion of patients with COVID-19 presented the gastrointestinal symptoms. ACE2, as the receptor of SARS-CoV and SARS-CoV-2, is highly expressed in the epithelia of the epithelium cells in lung and intestine. In addition, ACE2 is essential for the innate immunity, amino acid transportation and the homeostasis of intestinal microecology. The composition of gut microbiota in COVID-19 patients was altered and concordant with inflammatory, which may explain the gastrointestinal symptoms in patients. Here we reviewed and discussed the evolving role for ACE2 and gut microbiota in SARS-CoV-2 infection which might provide innovative approaches to targeting ACE2 and gut microbiota for the COVID-19 therapy.

COVID-19 and gastroenteric manifestations

Coronavirus disease 2019 (COVID-19), caused by the infection of a novel coronavirus [severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)], has become a pandemic. The infection has resulted in about one hundred million COVID-19 cases and millions of deaths. Although SARS-CoV-2 mainly spreads through the air and impairs the function of the respiratory system, it also attacks the gastrointestinal epithelial cells through the same receptor, angiotensin converting enzyme 2 receptor, which results in gastroenteric symptoms and potential fecal-oral transmission. Besides the infection of SARS-CoV-2, the treatments of COVID-19 also contribute to the gastroenteric manifestations due to the adverse drug reactions of anti-COVID-19 drugs. In this review, we update the clinical features, basic studies, and clinical practices of COVID-19-associated gastroenteric manifestations.

Probiotics as Adjunctive Treatment for Patients Contracted COVID-19: Current Understanding and Future Needs

The coronavirus disease 2019 (COVID-19) is caused by a novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which rages all over the world and seriously threatens human life and health. Currently, there is no optimal treatment for COVID-19, and emerging evidence found that COVID-19 infection results in gut microbiota dysbiosis. The intestinal microbial richness of patients of COVID-19 does not return to normal levels even six months after recovery, but probiotic adjunctive treatment has been found to restore gut homeostasis. An updated PubMed search returned four finished clinical trials that supported the use of probiotics as adjunctive treatment for COVID-19, while at least six clinical trials aiming to investigate beneficial effects of probiotic intake in managing COVID-19 are currently in progress worldwide. Here in we tentatively summarized the understanding of the actions and potential mechanisms of probiotics in the management of COVID-19. We also highlighted some future needs for probiotic researchers in the field. The success in using probiotics as adjunctive treatment for COVID-19 has expanded the scope of application of probiotics, meanwhile deepening our knowledge in the physiological function of probiotics in modulating the gut-lung axis.

Probiotics for the Prevention of Acute Respiratory-Tract Infections in Older People: Systematic Review

The aim of this systematic review was to present the indirect influence of probiotics on the incidence and duration of acute upper respiratory-tract infections in older people, by regulating the immune system. Eight randomized, placebo-controlled clinical trials met the inclusion criteria, considering the threshold of older people being 60 years and over. Single strain probiotics were used in all studies, including three probiotic strains used in fermented foods: Lactobacillus delbrueckii subsp. bulgaricus OLL1073R-1, Lacticaseibacillus paracasei subsp. paracasei CNCM I-1518 and Lacticaseibacillusparacasei Shirota, and three probiotic strains used as food supplements: Loigolactobacillus coryniformis K8 CECT5711, Bacillus subtilis CU1 and Lacticaseibacillus rhamnosus GG. Current evidence showed that certain probiotic strains were better than a placebo in lowering the incidence or number of older people experiencing acute upper respiratory tract infections; however, not all probiotic strains were efficient, and not all studies reported statistically significant outcomes. More high quality large-scale properly controlled clinical studies focusing on older people are warranted.

The potential for Lactoferrin to reduce SARS-CoV-2 induced cytokine storm

The COVID-19 pandemic is a serious global health threat caused by severe acute respiratory syndrome of coronavirus 2 (SARS-CoV-2). Symptoms of COVID-19 are highly variable with common hyperactivity of immune responses known as a "cytokine storm". In fact, this massive release of inflammatory cytokines into in the pulmonary alveolar structure is a main cause of mortality during COVID-19 infection. Current management of COVID-19 is supportive and there is no common clinical protocol applied to suppress this pathological state. Lactoferrin (LF), an iron binding protein, is a first line defense protein that is present in neutrophils and excretory fluids of all mammals, and is well recognized for its role in maturation and regulation of immune system function. Also, due to its ability to sequester free iron, LF is known to protect against insult-induced oxidative stress and subsequent "cytokine storm" that results in dramatic necrosis within the affected tissue. Review of the literature strongly suggests utility of LF to silence the "cytokine storm", giving credence to both prophylactic and therapeutic approaches towards combating COVID-19 infection.

COVID-19: pathogenesis, advances in treatment and vaccine development and environmental impact-an updated review

Diseases negatively impact the environment, causing many health risks and the spread of pollution and hazards. A novel coronavirus, severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) has led to a recent respiratory syndrome epidemic in humans. In December 2019, the sudden emergence of this new coronavirus and the subsequent severe disease it causes created a serious global health threat and hazards. This is in contrast to the two aforementioned coronaviruses, SARS-CoV-2 (in 2002) and middle east respiratory syndrome coronavirus MERS-CoV (in 2012), which were much more easily contained. The World Health Organization (WHO) dubbed this contagious respiratory disease an "epidemic outbreak" in March 2020. More than 80 companies and research institutions worldwide are working together, in cooperation with many governmental agencies, to develop an effective vaccine. To date, six authorized vaccines have been registered. Up till now, no approved drugs and drug scientists are racing from development to clinical trials to find new drugs for COVID-19. Wild animals, such as snakes, bats, and pangolins are the main sources of coronaviruses, as determined by the sequence homology between MERS-CoV and viruses in these animals. Human infection is caused by inhalation of respiratory droplets. To date, the only available treatment protocol for COVID-19 is based on the prevalent clinical signs. This review aims to summarize the current information regarding the origin, evolution, genomic organization, epidemiology, and molecular and cellular characteristics of SARS-CoV-2 as well as the diagnostic and treatment approaches for COVID-19 and its impact on global health, environment, and economy.

Potential Role of Gut Microbiota in Traditional Chinese Medicine against COVID-19

The coronavirus disease 2019 (COVID-19) spreads and rages around the world and threatens human life. It is disappointing that there are no specific drugs until now. The combination of traditional Chinese medicine (TCM) and western medication seems to be the current more effective treatment strategy for COVID-19 patients in China. In this review, we mainly discussed the relationship between COVID-19 and gut microbiota (GM), as well as the possible impact of TCM combined with western medication on GM in the treatment of COVID-19 patients, aiming to provide references for the possible role of GM in TCM against COVID-19. The available data suggest that GM dysbiosis did occur in COVID-19 patients, and the intervention of GM could ameliorate the clinical condition of COVID-19 patients. In addition, TCMs (e.g., Jinhua Qinggan granule, Lianhua Qingwen capsule, Qingfei Paidu decoction, Shufeng Jiedu capsule, Qingjin Jianghuo decoction, Toujie Quwen granules, and MaxingShigan) have been proven to be safe and effective for the treatment of COVID-19 in Chinese clinic. Among them, Ephedra sinica, Glycyrrhiza uralensis, Bupleurum chinense, Lonicera japonica,Scutellaria baicalensi, and Astragalus membranaceus are common herbs and have a certain regulation on GM, immunity, and angiotensin converting enzyme 2 (ACE2). Notably, Qingfei Paidu decoction and MaxingShigan have been demonstrated to modulate GM. Finally, the hypothesis of GM-mediated TCM treatment of COVID-19 is proposed, and more clinical trials and basic experiments need to be initiated to confirm this hypothesis.

Potential Roles for Probiotics in the Treatment of COVID-19 Patients and Prevention of Complications Associated with Increased Antibiotic Use

Medical care for patients hospitalized with COVID-19 is an evolving process. Most COVID-19 inpatients (58-95%) received empiric antibiotics to prevent the increased mortality due to ventilator-associated pneumonia and other secondary infections observed in COVID-19 patients. The expected consequences of increased antibiotic use include antibiotic-associated diarrhea (AAD) and Clostridioides difficile infections (CDI). We reviewed the literature (January 2020-March 2021) to explore strategies to reduce these consequences. Antimicrobial stewardship programs were effective in controlling antibiotic use during past influenza epidemics and have also been shown to reduce healthcare-associated rates of CDI. Another potential strategy is the use of specific strains of probiotics shown to be effective for the prevention of AAD and CDI prior to the pandemic. During 2020, there was a paucity of published trials using these two strategies in COVID-19 patients, but trials are currently ongoing. A multi-strain probiotic mixture was found to be effective in reducing COVID-19-associated diarrhea in one trial. These strategies are promising but need further evidence from trials in COVID-19 patients.

COVID-19: Role of Nutrition and Supplementation

At the end of 2019, a new coronavirus (COVID-19) appeared on the world scene, which mainly affects the respiratory system, causing pneumonia and multi-organ failure, and, although it starts with common symptoms such as shortness of breath and fever, in about 2-3% of cases it leads to death. Unfortunately, to date, no specific treatments have been found for the cure of this virus and, therefore, it is advisable to implement all possible strategies in order to prevent infection. In this context, it is important to better define the role of all behaviors, in particular nutrition, in order to establish whether these can both prevent infection and improve the outcome of the disease in patients with COVID-19. In the literature, it is widely shown that states of malnutrition, overweight, and obesity negatively affect the immune system, leading to viral infections, and several studies have shown that nutritional interventions can act as immunostimulators, helping to prevent viral infections. Even if several measures, such as the assumption of a specific diet regimen, the use of dietary supplements, and other similar interventions, are promising for the prevention, management, and recovery of COVID-19 patients, it is important to highlight that strong data from randomized clinical trials are needed to support any such assumption. Considering this particular scenario, we present a literature review addressing several important aspects related to diet and SARS-CoV-2 infection, in order to highlight the importance of diet and supplementation in prevention and management of, as well as recovery from COVID-19.

Probiotic lactobacilli: Can be a remediating supplement for pandemic COVID-19. A review

In recent years increased attention is focussed on microorganisms inhabiting the digestive system that provides prophylactic and therapeutic benefits to the host. After Metchnikoff exposed the secret behind Bulgarian peasants' extended longevity, a graze to incorporate the responsible microbes in functional food emerged. Then interest towards microbe-rich food went to the vegetative phase for some time, but now a renaissance to engage these wonder microbes in the healthcare sector is increasing. With a new definition, probiotics, these good microbes have been widely applied in different types of products, either as pharmaceuticals, nutritional supplements, or foods. Probiotics, a significant source in functional dairy products, claims diverse roles such as improving intestinal tract health, enhancing the immune system, synthesizing and enhancing the bioavailability of nutrients, reducing symptoms of lactose intolerance, decreasing the prevalence of allergy in susceptible individuals, and reducing the risk of certain cancers. In the recent COVID-19 issue, searches are going fast to use probiotics as vaccine carriers, dysbiosis balancer, and immunity booster. The high expectation from probiotics expanded the development of bioengineered probiotics as new-generation probiotics. From the animal model and in vitro studies, the probiotic intervention is extrapolated to innate and adaptive immunity inducer against SARS viral infections. The possibility of using it as prophylactic and therapeutic agents in COVID-19 is explored. However, its significant activity against corona virus-induced respiratory syndromes is questioned by a few researchers also. The emerging citations on the research approach and meta-analysis of probiotic intervention against the re-emerging pandemic viral attack on the respiratory and gastrointestinal domains need to be analyzed in this context. As it is essential to understand the reality of recent experimental outcomes in the probiotic approach towards SARS-CoV-2 prevention, management, and control, the recent publications were focused on this review.

Probiotics, prebiotics, and COVID-19 infection: A review article

The beneficial live microbes of humans and animals are termed probiotics, and the chemical compounds that improve the growth of probiotics are known as prebiotics. Paraprobiotics and postbiotics refer to dead or inactivated living cells of probiotics and healthful metabolic products that are produced by the living cells of probiotics, respectively. Although the healthful, functional, nutritional, and immune benefits of probiotics and prebiotics are scientifically well established beyond a reasonable doubt, their potential biological roles against COVID-19 infection still warrant further clinical and laboratory investigation.

Systematic Network and Meta-analysis on the Antiviral Mechanisms of Probiotics: A Preventive and Treatment Strategy to Mitigate SARS-CoV-2 Infection

With the alarming rise of infected cases and deaths, COVID-19 is a pandemic, affecting 220 countries worldwide. Until now, no specific treatment is available against SARS-CoV-2. The causal virus SARS-CoV-2 primarily infects lung cells, leading to respiratory illness ranging in severity from the common cold to deadly pneumonia. This, with comorbidities, worsens the clinical outcome, particularly for immunosuppressed individuals with COVID-19. Interestingly, the commensal gut microbiota has been shown to improve lung infections by modulating the immune system. Therefore, fine-tuning of the gut microbiome with probiotics could be an alternative strategy for boosting immunity and treating COVID-19. Here, we present a systematic biological network and meta-analysis to provide a rationale for the implementation of probiotics in preventing and/or treating COVID-19. We have identified 90 training genes from the literature analysis (according to PRISMA guidelines) and generated an association network concerning the candidate genes linked with COVID-19 and probiotic treatment. The functional modules and pathway enrichment analysis of the association network clearly show that the application of probiotics could have therapeutic effects on ACE2-mediated virus entry, activation of the systemic immune response, nlrp3-mediated immunomodulatory pathways, immune cell migration resulting in lung tissue damage and cardiovascular difficulties, and altered glucose/lipid metabolic pathways in the disease prognosis. We also demonstrate the potential mechanistic domains as molecular targets for probiotic applications to combat the viral infection. Our study, therefore, offers probiotics-mediated novel preventive and therapeutic strategies for COVID-19 warfare.

Gut microbiota in antiviral strategy from bats to humans: a missing link in COVID-19

Bats are a potential natural reservoir for SARS-CoV-2 virus and other viruses detrimental to humans. Accumulated evidence has shown that, in their adaptation to a flight-based lifestyle, remodeling of the gut microbiota in bats may have contributed to immune tolerance to viruses. This evidence from bats provides profound insights into the potential influence of gut microbiota in COVID-19 disease in humans. Here, we highlight recent advances in our understanding of the mechanisms by which the gut microbiota helps bats tolerate deadly viruses, and summarize the current clinical evidence on the influence of gut microbiota on the susceptibility to SARS-CoV-2 infection and risk of COVID-19 leading to a fatal outcome. In addition, we discuss the implications of gut microbiota-targeted approaches for preventing infection and reducing disease severity in COVID-19 patients.

The Role of Mucosal Immunity and Recombinant Probiotics in SARS-CoV2 Vaccine Development

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV2), causing the 2019 novel coronavirus disease (COVID-19), was introduced by WHO (World Health Organization) as "pandemic" in March 2020. According to WHO, thus far (23 November 2020) 58,425,681 infected cases including 1,385,218 deaths have been reported worldwide. In order to reduce transmission and spread of this lethal virus, attempts are globally being made to develop an appropriate vaccine. Intending to neutralize pathogens at their initial entrance site, protective mucosal immunity is inevitably required. In SARS-CoV2 infection and transmission, respiratory mucosa plays a key role; hence, apparently mucosal vaccination could be a superior approach to elicit mucosal and systemic immune responses simultaneously. In this review, the advantages of mucosal vaccination to control COVID-19 infection, limitations, and outcomes of mucosal vaccines have been highlighted. Considering the gut microbiota dysregulation in COVID-19, we further provide evidences on utilization of recombinant probiotics, particularly lactic acid bacteria (LAB) as vaccine carrier. Their intrinsic immunomodulatory features, natural adjuvanticity, and feasible expression of relevant antigen in the mucosal surface make them more appealing as live cell factory. Among all available platforms, bioengineered probiotics are considered as the most affordable, most practical, and safest vaccination approach to halt this emerging virus.

The Microbiota/Host Immune System Interaction in the Nose to Protect from COVID-19

Coronavirus disease 2019 (COVID-19) is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and is characterized by variable clinical presentation that ranges from asymptomatic to fatal multi-organ damage. The site of entry and the response of the host to the infection affect the outcomes. The role of the upper airways and the nasal barrier in the prevention of infection is increasingly being recognized. Besides the epithelial lining and the local immune system, the upper airways harbor a community of microorganisms, or microbiota, that takes an active part in mucosal homeostasis and in resistance to infection. However, the role of the upper airway microbiota in COVID-19 is not yet completely understood and likely goes beyond protection from viral entry to include the regulation of the immune response to the infection. Herein, we discuss the hypothesis that restoring endogenous barriers and anti-inflammatory pathways that are defective in COVID-19 patients might represent a valid strategy to reduce infectivity and ameliorate clinical symptomatology.

Ozone as adjuvant support in the treatment of COVID-19: A preliminary report of probiozovid trial

The evaluation of new therapeutic resources against coronavirus disease 2019 (COVID-19) represents a priority in clinical research considering the minimal options currently available. To evaluate the adjuvant use of systemic oxygen-ozone administration in the early control of disease progression in patients with COVID-19 pneumonia. PROBIOZOVID is an ongoing, interventional, randomized, prospective, and double-arm trial enrolling patient with COVID-19 pneumonia. From a total of 85 patients screened, 28 were recruited. Patients were randomly divided into ozone-autohemotherapy group (14) and control group (14). The procedure consisted in a daily double-treatment with systemic Oxygen-ozone administration for 7 days. All patients were treated with ad interim best available therapy. The primary outcome was delta in the number of patients requiring orotracheal-intubation despite treatment. Secondary outcome was the difference of mortality between the two groups. Moreover, hematological parameters were compared before and after treatment. No differences in the characteristics between groups were observed at baseline. As a preliminary report we have observed that one patient for each group needed intubation and was transferred to ITU. No deaths were observed at 7-14 days of follow up. Thirty-day mortality was 8.3% for ozone group and 10% for controls. Ozone therapy did not significantly influence inflammation markers, hematology profile, and lymphocyte subpopulations of patients treated. Ozone therapy had an impact on the need for the ventilatory support, although did not reach statistical significance. Finally, no adverse events related to the use of ozone-autohemotherapy were reported. Preliminary results, although not showing statistically significant benefits of ozone on COVID-19, did not report any toxicity.

Intestinal Barrier Function in Health and Disease-Any role of SARS-CoV-2?

Alterations in the structure and function of the intestinal barrier play a role in the pathogenesis of a multitude of diseases. During the recent and ongoing coronavirus disease (COVID-19) pandemic, it has become clear that the gastrointestinal system and the gut barrier may be affected by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus, and disruption of barrier functions or intestinal microbial dysbiosis may have an impact on the progression and severity of this new disease. In this review, we aim to provide an overview of current evidence on the involvement of gut alterations in human disease including COVID-19, with a prospective outlook on supportive therapeutic strategies that may be investigated to rescue intestinal barrier functions and possibly facilitate clinical improvement in these patients.

Food policy, nutrition and nutraceuticals in the prevention and management of COVID-19: Advice for healthcare professionals

BACKGROUND

The 2019 novel coronavirus (2019-nCoV) represents an ongoing major global health crisis with a potentially unprecedented death toll and socio-economic impact in the modern era. Measures taken to reduce the rate of transmission are too unprecedented, but are deemed necessary. The extensive strain on public health services has meant that individual agency is increasingly called for. To support this, there is a need to review policy and procedure governing the food and commerce industries in particular. Additionally, it is necessary to convey a more comprehensive and nuanced understanding of relevant diet and lifestyle factors to both healthcare practitioners and the general public.

SCOPE AND APPROACH

To our knowledge, a review of possible additional measures for healthcare proffesionals, which includes the possible nutritional management COVID-19 pandemic does not yet exist.Key Findings and Conclusions: This review identifies i) changing trends in consumer awareness and purchasing patterns in response to COVID-19, and their potential future implications for the food and food-commerce industry ii) problematic elements of policy relevant to the outbreak of COVID-19, including the handling of wild-life and food-commerce, ii) newly emergent technologies in food science which represent viable and cost-effective means to reduce the risk of transmission of coronavirus, such as anti-microbial packaging, iii) important nutritional considerations with regard to coronavirus disease prevention and management, including nutrition in early infancy, and the role of select micronutrients (vitamins and minerals), phytochemicals and probiotics in conferring protection against both viral infection and pathogenicity.

Gut Microbiota Dysbiosis-Immune Hyperresponse-Inflammation Triad in Coronavirus Disease 2019 (COVID-19): Impact of Pharmacological and Nutraceutical Approaches

Coronavirus Disease 2019 (COVID-19) is a pandemic infection caused by a novel coronavirus named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Patients present a complex clinical picture that, in severe cases, evolves to respiratory, hepatic, gastrointestinal, and neurological complications, and eventually death. The underlying pathophysiological mechanisms are complex and multifactorial and have been summarized as a hyperresponse of the immune system that originates an inflammatory/cytokine storm. In elderly patients, particularly in those with pre-existing cardiovascular, metabolic, renal, and pulmonary disorders, the disease is particularly severe, causing prolonged hospitalization at intensive care units (ICU) and an increased mortality rate. Curiously, the same populations have been described as more prone to a gut microbiota (GM) dysbiosis profile. Intestinal microflora plays a major role in many metabolic and immune functions of the host, including to educate and strengthen the immune system to fight infections, namely of viral origin. Notably, recent studies suggest the existence of GM dysbiosis in COVID-19 patients. This review article highlights the interplay between the triad GM dysbiosis-immune hyperresponse-inflammation in the individual resilience/fragility to SARS-CoV-2 infection and presents the putative impact of pharmacological and nutraceutical approaches on the triumvirate, with focus on GM.

Reflections on treatment of COVID-19 with traditional Chinese medicine

Coronavirus disease 2019 (COVID-19) pandemic is spreading rapidly around the globe. By the establishment of an integrative system combining both traditional Chinese medicine (TCM) and western medicine, China has achieved good clinical efficacy in the prevention and control of the pandemic. The advantages of TCM in the treatment of COVID-19 include effective relief of symptoms, retarding the development from mild and moderate to severe, improvement of cure rate, reducing death rates, and promotion of rehabilitation. Besides, according to the different severity levels of individual cases, the National Health Commission of the People's Republic of China issued treatment guidelines that provide corresponding prescriptions for patients. From the perspective of TCM, this review aims to analyze the role of a variety of TCM prescriptions in the treatment of COVID-19, focusing on the analysis of the "Three TCM prescriptions and three medicines" recommended by the Chinese authorities during the pandemic. We expect that this review will provide insights into the prevention and treatment of COVID-19 with TCM.

ACE2 imbalance as a key player for the poor outcomes in COVID-19 patients with age-related comorbidities - Role of gut microbiota dysbiosis

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COVID-19 patients with pre-existing age-related comorbidities have poor outcomes.

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Gut microbiota dysbiosis is associated with ageing and age-related diseases.

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Viral-mediated ACE2 shedding favors poor outcomes by RAS-dependent mechanisms.

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Viral-mediated ACE2 shedding favors poor outcomes by RAS-independent gut dysbiosis.

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Potential of ACE2 and gut microbiota-based therapeutic opportunities for COVID-19.

Coronavirus disease 19 (COVID-19) is a pandemic condition caused by the new coronavirus SARS-CoV-2. The typical symptoms are fever, cough, shortness of breath, evolving to a clinical picture of pneumonia and, ultimately, death. Nausea and diarrhea are equally frequent, suggesting viral infection or transmission via the gastrointestinal-enteric system. SARS-CoV-2 infects human cells by using angiotensin converting enzyme 2 (ACE2) as a receptor, which is cleaved by transmembrane proteases during host cells infection, thus reducing its activities. ACE2 is a relevant player in the renin-angiotensin system (RAS), counterbalancing the deleterious effects of angiotensin II. Furthermore, intestinal ACE2 functions as a chaperone for the aminoacid transporter B⁰AT1. It has been suggested that B⁰AT1/ACE2 complex in the intestinal epithelium regulates gut microbiota (GM) composition and function, with important repercussions on local and systemic immune responses against pathogenic agents, namely virus. Notably, productive infection of SARS-CoV-2 in ACE2⁺ mature human enterocytes and patients’ GM dysbiosis was recently demonstrated. This review outlines the evidence linking abnormal ACE2 functions with the poor outcomes (higher disease severity and mortality rate) in COVID-19 patients with pre-existing age-related comorbidities and addresses a possible role for GM dysbiosis. The article culminates with the therapeutics opportunities based on these pathways.

Probiotics at War Against Viruses: What Is Missing From the Picture?

Our world is now facing a multitude of novel infectious diseases. Bacterial infections are treated with antibiotics, albeit with increasing difficulty as many of the more common causes of infection have now developed broad spectrum antimicrobial resistance. However, there is now an even greater challenge from both old and new viruses capable of causing respiratory, enteric, and urogenital infections. Reports of viruses resistant to frontline therapeutic drugs are steadily increasing and there is an urgent need to develop novel antiviral agents. Although this all makes sense, it seems rather strange that relatively little attention has been given to the antiviral capabilities of probiotics. Over the years, beneficial strains of lactic acid bacteria (LAB) have been successfully used to treat gastrointestinal, oral, and vaginal infections, and some can also effect a reduction in serum cholesterol levels. Some probiotics prevent gastrointestinal dysbiosis and, by doing so, reduce the risk of developing secondary infections. Other probiotics exhibit anti-tumor and immunomodulating properties, and in some studies, antiviral activities have been reported for probiotic bacteria and/or their metabolites. Unfortunately, the mechanistic basis of the observed beneficial effects of probiotics in countering viral infections is sometimes unclear. Interestingly, in COVID-19 patients, a clear decrease has been observed in cell numbers of Lactobacillus and Bifidobacterium spp., both of which are common sources of intestinal probiotics. The present review, specifically motivated by the need to implement effective new counters to SARS-CoV-2, focusses attention on viruses capable of co-infecting humans and other animals and specifically explores the potential of probiotic bacteria and their metabolites to intervene with the process of virus infection. The goal is to help to provide a more informed background for the planning of future probiotic-based antiviral research.