Probiotics-Derived Peptides and Their Immunomodulatory Molecules Can Play a Preventive Role Against Viral Diseases Including COVID-19

Gut microbiota alteration and its association with immune function in post-COVID-19 patients

To reveal the variation of gut microbiota and its association with immune function in cured patients with coronavirus 2019 (COVID-19) disease, gut microbiota of patients discharged from hospital for 20 ~ 23 months and healthy volunteers was analyzed by high throughput 16S rRNA sequencing. The diversity and abundance were compared, and the correlation with immunity factors was investigated, and changes in the content of 6 genera microorganisms with proportion higher than 0.1% were revealed in patients with COVID-19 disease: reduced content of Subdoligranulum, Haemophilus, Coprococcus, Eubacterium vertriosum group, and Lachnospiraceae ND3007 group and increased content of Hungatella. NK cells were negatively correlated to Subdoligranulum, while CD8 cells were positively correlated to Subdoligranulum but negative to Hungatella. IL-8 concentration was negatively correlated to Subdoligranulum, Haemophilus, Coprococcus, Eubacterium vertriosum group, and Lachnospiraceae ND3007 group but positively to Hungatella, while IL-1β concentration was negatively correlated to Haemophilus and Eubacterium ventriosum group but positively to Hungatella. The variation of probiotics and potential pathogenic bacteria implies a higher risk in diseases and inflammation, and the modulation of the gut microbiota may help the healing of COVID-19 patients.

Potential role of salivary lactic acid bacteria in pathogenesis of oral lichen planus

BACKGROUND

Emerging evidence emphasized the role of oral microbiome in oral lichen planus (OLP). To date, no dominant pathogenic bacteria have been identified consistently. It is noteworthy that a decreased abundance of Streptococcus, a member of lactic acid bacteria (LAB) in OLP patients has been commonly reported, indicating its possible effect on OLP. This study aims to investigate the composition of LAB genera in OLP patients by high-throughput sequencing, and to explore the possible relationship between them.

METHODS

We collected saliva samples from patients with OLP (n = 21) and healthy controls (n = 22) and performed 16 S rRNA gene high-throughput sequencing. In addition, the abundance of LAB genera was comprehensively analyzed and compared between OLP and HC group. To verify the expression of Lactococcus lactis, real time PCR was conducted in buccal mucosa swab from another 14 patients with OLP and 10 HC. Furthermore, the correlation was conducted between clinical severity of OLP and LAB.

RESULTS

OLP and HC groups showed similar community richness and diversity. The members of LAB, Lactococcus and Lactococcus lactis significantly decreased in saliva of OLP cases and negatively associated with OLP severity. In addition, Lactococcus and Lactococcus lactis showed negative relationship with Fusobacterium and Aggregatibacter, which were considered as potential pathogens of OLP. Similarly, compared with healthy controls, the amount of Lactococcus lactis in mucosa lesion of OLP patients was significantly decreased.

CONCLUSIONS

A lower amount of Lactococcus at genus level, Lactococcus lactis at species level was observed in OLP cases and associated with disease severity. Further studies to verify the relationship between LAB and OLP, as well as to explore the precise mechanism is needed.

Exploring the Interplay between COVID-19 and Gut Health: The Potential Role of Prebiotics and Probiotics in Immune Support

The COVID-19 pandemic has profoundly impacted global health, leading to extensive research focused on developing strategies to enhance outbreak response and mitigate the disease's severity. In the aftermath of the pandemic, attention has shifted towards understanding and addressing long-term health implications, particularly in individuals experiencing persistent symptoms, known as long COVID. Research into potential interventions to alleviate long COVID symptoms has intensified, with a focus on strategies to support immune function and mitigate inflammation. One area of interest is the gut microbiota, which plays a crucial role in regulating immune responses and maintaining overall health. Prebiotics and probiotics, known for their ability to modulate the gut microbiota, have emerged as potential therapeutic agents in bolstering immune function and reducing inflammation. This review delves into the intricate relationship between long COVID, the gut microbiota, and immune function, with a specific focus on the role of prebiotics and probiotics. We examine the immune response to long COVID, emphasizing the importance of inflammation and immune regulation in the persistence of symptoms. The potential of probiotics in modulating immune responses, including their mechanisms in combating viral infections such as COVID-19, is discussed in detail. Clinical evidence supporting the use of probiotics in managing long COVID symptoms is summarized, highlighting their role as adjunctive therapy in addressing various aspects of SARS-CoV-2 infection and its aftermath.

Exploring the binding capacity of lactic acid bacteria derived bacteriocins against RBD of SARS-CoV-2 Omicron variant by molecular simulations

The changes in the SARS-CoV-2 genome have resulted in the emergence of new variants. Some of the variants have been classified as variants of concern (VOC). These strains have higher transmission rate and improved fitness. One of the prevalent were the Omicron variant. Unlike previous VOCs, the Omicron possesses fifteen mutations on the spike protein's receptor binding domain (RBD). The modifications of spike protein's key amino acid residues facilitate the virus' binding capability against ACE2, resulting in an increase in the infectiousness of Omicron variant. Consequently, investigating the prevention and treatment of the Omicron variant is crucial. In the present study, we aim to explore the binding capacity of twenty-two bacteriocins derived from Lactic Acid Bacteria (LAB) against the Omicron variant by using protein-peptidedocking and molecular dynamics (MD) simulations. The Omicron variant RBD was prepared by introducing fifteen mutations using PyMol. The protein-peptide complexes were obtained using HADDOCK v2.4 docking webserver. Top scoring complexes obtained from HADDOCK webserver were retrieved and submitted to the PRODIGY server for the prediction of binding energies. RBD-bacteriocin complexes were subjected to MD simulations. We discovered promising peptide-based therapeutic candidates for the inhibition of Omicron variant for example Salivaricin B, Pediocin PA 1, Plantaricin W, Lactococcin mmfii and Enterocin A. The lead bacteriocins, except Enterocin A, are biosynthesized by food-grade lactic acid bacteria. Our study puts forth a preliminary information regarding potential utilization of food-grade LAB-derived bacteriocins, particularly Salivaricin B and Pediocin PA 1, for Covid-19 treatment and prophylaxis.Communicated by Ramaswamy H. Sarma.

SARS-CoV-2 infection threatening intestinal health: A review of potential mechanisms and treatment strategies

The outbreak of the COVID-19 pandemic has brought great problems to mankind, including economic recession and poor health. COVID-19 patients are frequently reported with gastrointestinal symptoms such as diarrhea and vomiting in clinical diagnosis. Maintaining intestinal health is the key guarantee to maintain the normal function of multiple organs, otherwise it will be a disaster. Therefore, the purpose of this review was deeply understanded the potential mechanism of SARS-CoV-2 infection threatening intestinal health and put forward reasonable treatment strategies. Combined with the existing researches, we summarized the mechanism of SARS-CoV-2 infection threatening intestinal health, including intestinal microbiome disruption, intestinal barrier dysfunction, intestinal oxidative stress and intestinal cytokine storm. These adverse intestinal events may affect other organs through the circulatory system or aggravate the course of the disease. Typically, intestinal disadvantage may promote the progression of SARS-CoV-2 through the gut-lung axis and increase the disease degree of COVID-19 patients. In view of the lack of specific drugs to inhibit SARS-CoV-2 replication, the current review described new strategies of probiotics, prebiotics, postbiotics and nutrients to combat SARS-CoV-2 infection and maintain intestinal health. To provide new insights for the prevention and treatment of gastrointestinal symptoms and pneumonia in patients with COVID-19.

The Role of Gut Microbiome Supplementation in COVID-19 Management

COVID-19, which is caused by the RNA virus, SARS-CoV-2, mainly affects the respiratory system and has a varied clinical presentation. However, several studies have shown that COVID-19 can also affect the gastrointestinal (GI) system. Patients can experience various GI symptoms, such as vomiting and diarrhea, and the virus has been detected in the stool samples of patients hospitalized with COVID-19. There have also been rare reports of COVID-19 presenting with isolated GI symptoms and lack of respiratory symptoms, and the virus has also been detected for prolonged periods in the fecal samples of COVID-19 patients. Major alterations in the gut microbiome in the form of depletion of beneficial organisms and an abundance of pathogenic organisms have been reported in the fecal samples of hospitalized COVID-19 patients. Although the US FDA has approved several drugs to manage COVID-19, their efficacy remains modest. So, there is a constant ongoing effort to investigate novel treatment options for COVID-19. Health supplements like probiotics, prebiotics, postbiotics, and synbiotics have been popularly known for their various health benefits. In this review, we have summarized the current literature, which shows the potential benefit of these health supplements to mitigate and/or prevent the clinical presentation of COVID-19.

Immunomodulatory approaches in managing lung inflammation in COVID-19: A double-edge sword

INTRODUCTION

The novel coronavirus infectious disease 2019 (COVID-19) which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has emerged as a gigantic problem. The lung is the major target organ of SARS-CoV-2 and some of its variants like Delta and Omicron variant adapted in such a way that these variants can significantly damage this vital organ of the body. These variants raised a few eyebrows as the outbreaks have been seen in the vaccinated population. Patients develop severe respiratory illnesses which eventually prove fatal unless treated early.

MAIN BODY

Studies have shown that SARS-CoV-2 causes the release of pro-inflammatory cytokines such as interleukin (IL)-6, IL-1β and tumor necrosis factor (TNF)-α which are mediators of lung inflammation, lung damage, fever, and fibrosis. Additionally, various chemokines have been found to play an important role in the disease progression. A plethora of pro-inflammatory cytokines "cytokine storm" has been observed in severe cases of SARS-CoV-2 infection leading to acute respiratory distress syndrome (ARDS) and pneumonia that may prove fatal. To counteract cytokine storm-inducing lung inflammation, several promising immunomodulatory approaches are being investigated in numerous clinical trials. However, the benefits of using these strategies should outweigh the risks involved as the use of certain immunosuppressive approaches might lead the host susceptible to secondary bacterial infections.

CONCLUSION

The present review discusses promising immunomodulatory approaches to manage lung inflammation in COVID-19 cases which may serve as potential therapeutic options in the future and may prove lifesaving.

Laterosporulin25: A probiotically produced, novel defensin-like bacteriocin and its immunogenic properties

Although multiple vaccines have been developed against infectious diseases, the rapid emergence of new pathogens develops an urgent need for novel strategies to combat infectious diseases. Antimicrobial peptides (AMPs) are excellent agents to fight against infectious diseases having unique multiple mechanisms of action against various pathogens. Apart from the direct applications, AMPs can also be developed as subunit vaccines or could be used as a highly immunogenic carrier protein with highly antigenic but non-immunogenic antigens. Here in the present study, we have identified a novel defensin-like bacteriocin, laterosporulin25 (LS25) upon genome mining of Brevibacillus laterosporus DSM25, a probiotic bacterial strain. By using immunoinformatic tools, we have studied the immunogenic and physiochemical properties of LS25. LS25 is characterized as defensin-like bacteriocin, having 51 amino acids and a molecular weight of 5862.7 Da. The modeled tertiary structure of LS25 is docked with TLR3 and TLR4-MD2 complex to confirm the facilitation of induced immune response that is further validated using molecular dynamics simulations and In-silico immune stimulations. Overall, detailed immunoinformatics analysis suggested LS25 as a potential candidate to be used as an adjuvant or carrier protein for subunit vaccine development, however, further in-vitro and in-vivo experiments are essential to validate its potential.

Oligosaccharides as Potential Regulators of Gut Microbiota and Intestinal Health in Post-COVID-19 Management

The COVID-19 pandemic has had a profound impact worldwide, resulting in long-term health effects for many individuals. Recently, as more and more people recover from COVID-19, there is an increasing need to identify effective management strategies for post-COVID-19 syndrome, which may include diarrhea, fatigue, and chronic inflammation. Oligosaccharides derived from natural resources have been shown to have prebiotic effects, and emerging evidence suggests that they may also have immunomodulatory and anti-inflammatory effects, which could be particularly relevant in mitigating the long-term effects of COVID-19. In this review, we explore the potential of oligosaccharides as regulators of gut microbiota and intestinal health in post-COVID-19 management. We discuss the complex interactions between the gut microbiota, their functional metabolites, such as short-chain fatty acids, and the immune system, highlighting the potential of oligosaccharides to improve gut health and manage post-COVID-19 syndrome. Furthermore, we review evidence of gut microbiota with angiotensin-converting enzyme 2 expression for alleviating post-COVID-19 syndrome. Therefore, oligosaccharides offer a safe, natural, and effective approach to potentially improving gut microbiota, intestinal health, and overall health outcomes in post-COVID-19 management.

Can Probiotics, Particularly Limosilactobacillus fermentum UCO-979C and Lacticaseibacillus rhamnosus UCO-25A, Be Preventive Alternatives against SARS-CoV-2?

COVID-19, an infection produced by the SARS-CoV-2 virus in humans, has rapidly spread to become a high-mortality pandemic. SARS-CoV-2 is a single-stranded RNA virus characterized by infecting epithelial cells of the intestine and lungs, binding to the ACE2 receptor present on epithelial cells. COVID-19 treatment is based on antivirals and antibiotics against symptomatology in addition to a successful preventive strategy based on vaccination. At this point, several variants of the virus have emerged, altering the effectiveness of treatments and thereby attracting attention to several alternative therapies, including immunobiotics, to cope with the problem. This review, based on articles, patents, and an in silico analysis, aims to address our present knowledge of the COVID-19 disease, its symptomatology, and the possible beneficial effects for patients if probiotics with the characteristics of immunobiotics are used to confront this disease. Moreover, two probiotic strains, L. fermentum UCO-979C and L. rhamnosus UCO-25A, with different effects demonstrated at our laboratory, are emphasized. The point of view of this review highlights the possible benefits of probiotics, particularly those associated with immunomodulation as well as the production of secondary metabolites, and their potential targets during SARS-CoV-2 infection.

Preventing Respiratory Viral Diseases with Antimicrobial Peptide Master Regulators in the Lung Airway Habitat

The vast surface area of the respiratory system acts as an initial site of contact for microbes and foreign particles. The whole respiratory epithelium is covered with a thin layer of the airway and alveolar secretions. Respiratory secretions contain host defense peptides (HDPs), such as defensins and cathelicidins, which are the best-studied antimicrobial components expressed in the respiratory tract. HDPs have an important role in the human body's initial line of defense against pathogenic microbes. Epithelial and immunological cells produce HDPs in the surface fluids of the lungs, which act as endogenous antibiotics in the respiratory tract. The production and action of these antimicrobial peptides (AMPs) are critical in the host's defense against respiratory infections. In this study, we have described all the HDPs secreted in the respiratory tract as well as how their expression is regulated during respiratory disorders. We focused on the transcriptional expression and regulation mechanisms of respiratory tract HDPs. Understanding how HDPs are controlled throughout infections might provide an alternative to relying on the host's innate immunity to combat respiratory viral infections.

Genomic, probiotic, and metabolic potentials of Liquorilactobacillus nagelii AGA58, a novel bacteriocinogenic motile strain isolated from lactic acid-fermented shalgam

This study aimed to perform genomic, probiotic, and metabolic characterization of a novel Liquorilactobacillus nagelii AGA58 isolated from a lactic acid-fermented shalgam beverage to understand its metabolic potentials and probiotic features. AGA58 is gram-positive, motile, catalase-negative and appears as short rods under the light-microscope. The AGA58 chromosome comprises a single linear chromosome of 2,294,635 bp that is predicted to carry 2135 coding sequences, including 45 tRNA genes, 3 mRNA, and 3 rRNA operons. The genome has a G+C content of 36.9%, including 55 pseudogenes and a single intact prophage. AGA58 is micro-anaerobic due to achieving a shorter doubling time and faster growth rate than micro-aerophilic conditions. It carries flagellar biosynthesis protein-encoding genes predicting motile behavior, which was confirmed with the in vitro motility test. AGA58 is an obligatory homofermentative lactobacillus that can ferment hexose sugars such as galactose, glucose, fructose, sucrose, mannose, N-acetyl glucosamine, maltose, and trehalose to lactate through glycolysis. No acid production from pentoses implies that five-carbon sugars are being utilized for purine and pyrimidine synthesis. Putative pyruvate metabolism revealed formate, malate, oxaloacetate, acetate, acetaldehyde, acetoin, and lactate forms from pyruvate. AGA58 is predicted to encode the LuxS gene and biosynthesis of class IIa and Blp family class-II bacteriocins suggesting this bacterium's antimicrobial potential, linked to antagonism tests that AGA58 can inhibit Escherichia coli ATCC 43895, Salmonellaenterica serovar Typhimurium ATCC 14028, and Klebsiellapneumonia ATCC 13883. Moreover, AGA58 is tolerant to acid and bile concentrations simulating the human gastrointestinal conditions depicting the probiotic potential of the organism as the first report in literature within the same species.

In Silico Analysis of Bacteriocins from Lactic Acid Bacteria Against SARS-CoV-2

The COVID-19 pandemic caused by a novel coronavirus (SARS-CoV-2) is a serious health concern in the twenty-first century for scientists, health workers, and all humans. The absence of specific biotherapeutics requires new strategies to prevent the spread and prophylaxis of the novel virus and its variants. The SARS-CoV-2 virus shows pathogenesis by entering the host cells via spike protein and Angiotensin-Converting Enzyme 2 receptor protein. Thus, the present study aims to compute the binding energies between a wide range of bacteriocins with receptor-binding domain (RBD) on spike proteins of wild type (WT) and beta variant (lineage B.1.351). Molecular docking analyses were performed to evaluate binding energies. Upon achieving the best bio-peptides with the highest docking scores, further molecular dynamics (MD) simulations were performed to validate the structure and interaction stability. Protein-protein docking of the chosen 22 biopeptides with WT-RBD showed docking scores lower than -7.9 kcal/mol. Pediocin PA-1 and salivaricin P showed the lowest (best) docking scores of - 12 kcal/mol. Pediocin PA-1, salivaricin B, and salivaricin P showed a remarkable increase in the double mutant's predicted binding affinity with -13.8 kcal/mol, -13.0 kcal/mol, and -12.5 kcal/mol, respectively. Also, a better predicted binding affinity of pediocin PA-1 and salivaricin B against triple mutant was observed compared to the WT. Thus, pediocin PA-1 binds stronger to mutants of the RBD, particularly to double and triple mutants. Salivaricin B showed a better predicted binding affinity towards triple mutant compared to WT, showing that it might be another bacteriocin with potential activity against the SARS-CoV-2 beta variant. Overall, pediocin PA-1, salivaricin P, and salivaricin B are the most promising candidates for inhibiting SARS-CoV-2 (including lineage B.1.351) entrance into the human cells. These bacteriocins derived from lactic acid bacteria hold promising potential for paving an alternative way for treatment and prophylaxis of WT and beta variants.

Dietary supplements and nutraceuticals in the recovery of COVID-19: A systematic review and meta-analysis

The outbreak of nSARS-CoV2 in December 2019 turned into a global pandemic and is still underway. Infection with nSARS-CoV2 resulted in severe acute respiratory distress syndrome and was named COVID-19. COVID-19 requires the intervention of a series of therapeutics, including antiviral, anti-inflammatory, and immune-modulating molecules. Additionally, studies have demonstrated that nutraceuticals offer a promising impact in fast recovery and boosting immunity. Here, the study aimed to provide a comprehensive synthesis of the scientific evidence examining the effectiveness of nutraceuticals. A detailed search of scientific literature was conducted utilizing the most relevant scientific studies published during 2019–2022 on the intervention of nutraceuticals in the management of COVID-19. PubMed, Cochrane Central Register of Controlled Trials and Scielo databases were explored for the most relevant studies. Meta-analysis was carried out using the MedCalC tool as per PRISMA guidelines for odds ratio among the studies along with risk factor analysis and relative risk. A total of 1,308 original records were identified, where 1,268 studies were collected from different databases, and 40 additional records were obtained from non-pre-defined sources. Odds ratio, risk analysis, and risk difference analysis showed nutraceuticals intervention reported effective (P < 0.001) in COVID-19 patient over control. Nutraceuticals-based interventions had improved immunity, short-term duration, and fast recovery of COVID-19 patients.

The Beneficial Role of Probiotic Lactobacillus in Respiratory Diseases

Respiratory diseases cause a high incidence and mortality worldwide. As a natural immunobiotic, Lactobacillus has excellent immunomodulatory ability. Administration of some Lactobacillus species can alleviate the symptoms of respiratory diseases such as respiratory tract infections, asthma, lung cancer and cystic fibrosis in animal studies and clinical trials. The beneficial effect of Lactobacillus on the respiratory tract is strain dependent. Moreover, the efficacy of Lactobacillus may be affected by many factors, such as bacteria dose, timing and host background. Here, we summarized the beneficial effect of administered Lactobacillus on common respiratory diseases with a focus on the mechanism and safety of Lactobacillus in regulating respiratory immunity.

A Review on the Antiviral Activity of Functional Foods Against COVID-19 and Viral Respiratory Tract Infections

Due to the absence of successful therapy, vaccines for protection are continuously being developed. Since vaccines must be thoroughly tested, viral respiratory tract infections (VRTIs), mainly coronaviruses, have seriously affected human health worldwide in recent years. In this review, we presented the relevant data which originated from trusted publishers regarding the practical benefits of functional foods (FFs) and their dietary sources, in addition to natural plant products, in viral respiratory and COVID-19 prevention and immune-boosting activities. As a result, FFs were confirmed to be functionally active ingredients for preventing COVID-19 and VRTIs. Furthermore, the antiviral activity and immunological effects of FFs against VRTIs and COVID-19 and their potential main mechanisms of action are also being reviewed. Therefore, to prevent COVID-19 and VRTIs, it is critical to identify controlling the activities and immune-enhancing functional food constituents as early as possible. We further aimed to summarize functional food constituents as a dietary supplement that aids in immune system boosting and may effectively reduce VRTIs and COVID-19 and promote therapeutic efficacy.

Designing Anti-Microbial Peptides Against Major β-Lactamase Enzymes in Clinically Important Gram-Negative Bacterial Pathogens: An In-Silico Study

Anti-microbial resistance (AMR) creating healthcare concerns worldwide requires ardent exploration of therapeutic alternatives. Although anti-microbial peptides (AMP) are popular for broad-spectrum activity, recent evidence of increasing resistance to membrane-acting AMPs by ESKAPE pathogens has compelled us to design novel AMPs as therapeutic candidates. A library of 60 AMPs comprising natural AMPs and their mutants was constructed through in-silico methods. After physico-chemical property evaluations, each peptide in the library was subjected to flexible molecular docking against four major β-lactamases in Gram-negative ESKAPE pathogens. Among the potent AMP mutants, a Lactoferricin B-Mutant (M4) possessed uniformly high affinity with SHV1, OXA48, NDM1, and AmpC having energies -842.0Kcal/mol, -774.8Kcal/mol, -1103.3Kcal/mol, and -858.8Kcal/mol respectively. Coarse-grained clustering and flexibility analysis further accounted for the residue-level stable configurations of the protein-peptide complexes with high affinity. Highest affinity of Lactoferricin B_M4 was found with NDM1 due to H-bonds, salt-bridges, and hydrophobic interactions with the metallo-β-lactamase domain including crucial active-site residue Asp124. Molecular dynamics simulation further confirmed the stability of Lactoferricin B_M4-NDM1 complex having low residue-level root-mean square deviations (RMSD), atomic-level fluctuations, and radius of gyration (Rg). The study encourages experimental validations and similar methods to identify potential AMPs against drug-resistant pathogens.

Lactobacillus crispatus DSM25988 as novel bioactive agent to co-aggregate Streptococcus pyogenes and to exclude it by binding to human cells

Streptococcus pyogenes, a group A streptococcus, is the major bacterial pathogen responsible for acute bacterial infection of the human oropharynx and the causative agent of scarlet fever. Estimates of the global burden of S. pyogenes related diseases revealed 616 million cases of pharyngitis, and at least 517,000 deaths due to severe invasive diseases and sequelae. Here we describe Lactobacillus crispatus DSM25988 that was identified among hundreds of Lactobacillus strains (referring to all organisms that were classified as Lactobacillaceae until 2020) showing ability to prevent adhesion of S. pyogenes to Detroit 562 cells, and to exhibit a masking and co-aggregating effect on S. pyogenes in vitro. L. crispatus DSM25988 also inhibits invasion of cultured human epithelial pharyngeal cells by S. pyogenes. Competitive binding to fibronectin might be involved in the inhibition process. Antiviral activity of the L. crispatus DSM25988 cells were identified in an in vitro cell model demonstrating that L. crispatus effectively excludes viruses from epithelial cells using SARS-CoV2 proteins as a model. This finding points to the potential of DSM25988 to protect cells from virus infection. Biological activity is retained in heat treated cells. The heat-treated Lactobacillus strain was further developed into functional throat lozenges, wherein its biological activity is stably maintained in the formulation. Lozenges containing L. crispatus DSM25988 underwent testing in an uncontrolled, prospective user study in 44 subjects with symptoms of sore throat for a period of up to 14 days. The study data shows promising safety and efficacy of the medical device when used against symptoms of sore throat like scratchy feeling, hoarse voice and swallowing pain.

Gastrointestinal Microbiota Dysbiosis Associated with SARS-CoV-2 Infection in Colorectal Cancer: The Implication of Probiotics

The complexity of coronavirus disease 2019 (COVID-19)’s pathophysiology is such that microbial dysbiosis in the lung and gastrointestinal (GI) microbiota may be involved in its pathogenic process. GI microbiota dysbiosis has been associated with respiratory disorders, including COVID-19, as well as sporadic colorectal cancer (CRC) through imbalanced microbiota and compromised immune response. It is pertinent to understand the possible role of probiotics in stabilizing the microbial environment and maintaining the integrity of the respiratory and GI tracts in SARS-CoV-2 induced dysbiosis and colorectal carcinogenesis. The long-term implication of SARS-CoV-2 in GI dysbiosis via microbiota-gut-lung cross-talk could increase the risk of new CRC diagnosis or worsen the condition of previously diagnosed individuals. Recent knowledge shows that the immune-modulatory response to probiotics is shifting the beneficial use of probiotics towards the treatment of various diseases. In this review, we highlight the potential impact of probiotics on SARS-CoV-2 infection associated with CRC through microbiota imbalance in COVID-19 patients.

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.

Anti-Tuberculosis Activity of Pediococcus acidilactici Isolated from Young Radish Kimchi against Mycobacterium tuberculosis

Tuberculosis is a highly contagious disease caused by Mycobacterium tuberculosis. It affects about 10 million people each year and is still one of the leading causes of death worldwide. About 2 to 3 billion people (equivalent to 1 in 3 people in the world) are infected with latent tuberculosis. Moreover, as the number of multidrug-resistant, extensively drug-resistant, and totally drug-resistant strains of M. tuberculosis continues to increase, there is an urgent need to develop new anti-tuberculosis drugs that are different from existing drugs to combat antibiotic-resistant M. tuberculosis. Against this background, we aimed to develop new anti-tuberculosis drugs using probiotics. Here, we report the anti-tuberculosis effect of Pediococcus acidilactici PMC202 isolated from young radish kimchi, a traditional Korean fermented food. Under coculture conditions, PMC202 inhibited the growth of M. tuberculosis. In addition, PMC202 inhibited the growth of drug-sensitive and -resistant M. tuberculosis- infected macrophages at a concentration that did not show cytotoxicity and showed a synergistic effect with isoniazid. In a 2-week, repeated oral administration toxicity study using mice, PMC202 did not cause weight change or specific clinical symptoms. Furthermore, the results of 16S rRNA-based metagenomics analysis confirmed that dysbiosis was not induced in bronchoalveolar lavage fluid after oral administration of PMC202. The anti-tuberculosis effect of PMC202 was found to be related to the reduction of nitric oxide. Our findings indicate that PMC202 could be used as an anti-tuberculosis drug candidate with the potential to replace current chemicalbased drugs. However, more extensive toxicity, mechanism of action, and animal efficacy studies with clinical trials are needed.

Efficacy of a Probiotic Consisting of Lacticaseibacillus rhamnosus PDV 1705, Bifidobacterium bifidum PDV 0903, Bifidobacterium longum subsp. infantis PDV 1911, and Bifidobacterium longum subsp. longum PDV 2301 in the Treatment of Hospitalized Patients with COVID-19: a Randomized Controlled Trial

The treatment of coronavirus disease (COVID-19) and COVID-19-associated diarrhea remains challenging. This study aimed to evaluate the efficacy of a multi-strain probiotic in the treatment of COVID-19. This was a randomized, controlled, single-center, open-label trial (NCT04854941). Inpatients with confirmed COVID-19 and pneumonia were randomly assigned to a group that received a multi-strain probiotic (PRO group) or to the control group (CON group). There were 99 and 101 patients in the PRO and CON groups, respectively. No significant differences in mortality, total duration of disease and hospital stay, incidence of intensive care unit admission, need for mechanical ventilation or oxygen support, liver injury development, and changes in inflammatory biomarker levels were observed between the PRO and CON groups among all included patients as well as among subgroups delineated based on age younger or older than 65 years, and subgroups with chronic cardiovascular diseases and diabetes. Diarrhea on admission was observed in 11.5% of patients; it resolved earlier in the PRO group than in the CON group (2 [1-4] vs. 4 [3-6] days; p = 0.049). Hospital-acquired diarrhea developed less frequently in the PRO group than in the CON group among patients who received a single antibiotic (0% vs. 12.5%; p = 0.023) unlike among those who received > 1 antibiotic (10.5% vs. 13.3%; p = 0.696). The studied probiotic had no significant effect on mortality and changes in most biomarkers in COVID-19. However, it was effective in treating diarrhea associated with COVID-19 and in preventing hospital-acquired diarrhea in patients who received a single antibiotic.

Role of Exposure to Lactic Acid Bacteria from Foods of Animal Origin in Human Health

Animal products, in particular dairy and fermented products, are major natural sources of lactic acid bacteria (LAB). These are known for their antimicrobial properties, as well as for their roles in organoleptic changes, antioxidant activity, nutrient digestibility, the release of peptides and polysaccharides, amino acid decarboxylation, and biogenic amine production and degradation. Due to their antimicrobial properties, LAB are used in humans and in animals, with beneficial effects, as probiotics or in the treatment of a variety of diseases. In livestock production, LAB contribute to animal performance, health, and productivity. In the food industry, LAB are applied as bioprotective and biopreservation agents, contributing to improve food safety and quality. However, some studies have described resistance to relevant antibiotics in LAB, with the concomitant risks associated with the transfer of antibiotic resistance genes to foodborne pathogens and their potential dissemination throughout the food chain and the environment. Here, we summarize the application of LAB in livestock and animal products, as well as the health impact of LAB in animal food products. In general, the beneficial effects of LAB on the human food chain seem to outweigh the potential risks associated with their consumption as part of animal and human diets. However, further studies and continuous monitorization efforts are needed to ensure their safe application in animal products and in the control of pathogenic microorganisms, preventing the possible risks associated with antibiotic resistance and, thus, protecting public health.

Modulatory Effects of Probiotics During Pathogenic Infections With Emphasis on Immune Regulation

In order to inhibit pathogenic complications and to enhance animal and poultry growth, antibiotics have been extensively used for many years. Antibiotics applications not only affect target pathogens but also intestinal beneficially microbes, inducing long-lasting changes in intestinal microbiota associated with diseases. The application of antibiotics also has many other side effects like, intestinal barrier dysfunction, antibiotics residues in foodstuffs, nephropathy, allergy, bone marrow toxicity, mutagenicity, reproductive disorders, hepatotoxicity carcinogenicity, and antibiotic-resistant bacteria, which greatly compromise the efficacy of antibiotics. Thus, the development of new antibiotics is necessary, while the search for antibiotic alternatives continues. Probiotics are considered the ideal antibiotic substitute; in recent years, probiotic research concerning their application during pathogenic infections in humans, aquaculture, poultry, and livestock industry, with emphasis on modulating the immune system of the host, has been attracting considerable interest. Hence, the adverse effects of antibiotics and remedial effects of probiotics during infectious diseases have become central points of focus among researchers. Probiotics are live microorganisms, and when given in adequate quantities, confer good health effects to the host through different mechanisms. Among them, the regulation of host immune response during pathogenic infections is one of the most important mechanisms. A number of studies have investigated different aspects of probiotics. In this review, we mainly summarize recent discoveries and discuss two important aspects: (1) the application of probiotics during pathogenic infections; and (2) their modulatory effects on the immune response of the host during infectious and non-infectious diseases.