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

Probiotic supplementation in healthy pre-school-aged children: What, why, how and when?

AIM

We previously published the prevalence and predictors of probiotic use among a cohort of healthy 4 and 5-year-old children. Here we explore the species and strains most commonly used, the reasons probiotics are used, perceptions of the impact on children's health and parental behaviours around probiotic supplementation in children.

METHODS

Parents of 4 and 5-year-old children living in the Australian Capital Territory were invited to participate in an observational, cross-sectional study by completing a web-based survey between February and May 2020. Data concerning 481 children were eligible for analysis. Results are presented as simple proportions, with odds ratios and 95% confidence intervals where appropriate.

RESULTS

Lacticaseibacillus rhamnosus and Bifidobacterium animalis subsp. lactis were the most frequently reported species, and Lacticaseibacillus rhamnosus GG was the most frequently reported strain. The most common reason for administering probiotics to the 228 (47.4%) of 481 children ever exposed was to promote general health (54%). Half (51%) of parents perceived probiotics had improved their child's general health, although this was more likely for children who had recently (odds ratio (OR): 2.69, 95% confidence intervals (CI): 1.47-4.93) or regularly (OR: 2.92, CI: 1.46-5.85) used probiotics or whose parent had recently used probiotics (OR: 2.47, CI: 1.34-4.55). Initial exposure to probiotics occurred before the age of 2 years in 65% of the cohort.

CONCLUSION

This community-based study suggests that parents use probiotics primarily to improve children's general health and with modest perceived effect. The long-term effects of early and prolonged exposure to probiotics are not well understood.

Long COVID: The latest manifestations, mechanisms, and potential therapeutic interventions

COVID-19 caused by SARS-CoV-2 infection affects humans not only during the acute phase of the infection, but also several weeks to 2 years after the recovery. SARS-CoV-2 infects a variety of cells in the human body, including lung cells, intestinal cells, vascular endothelial cells, olfactory epithelial cells, etc. The damages caused by the infections of these cells and enduring immune response are the basis of long COVID. Notably, the changes in gene expression caused by viral infection can also indirectly contribute to long COVID. We summarized the occurrences of both common and uncommon long COVID, including damages to lung and respiratory system, olfactory and taste deficiency, damages to myocardial, renal, muscle, and enduring inflammation. Moreover, we provided potential treatments for long COVID symptoms manifested in different organs and systems, which were based on the pathogenesis and the associations between symptoms in different organs. Importantly, we compared the differences in symptoms and frequency of long COVID caused by breakthrough infection after vaccination and infection with different variants of concern, in order to provide a comprehensive understanding of the characteristics of long COVID and propose improvement for tackling COVID-19.

Characterization of antifungal cyclic dipeptides of Lacticaseibacillus paracasei ZX1231 and active packaging film prepared with its cell-free supernatant and bacterial nanocellulose

Fungal infection and/or spoilage are major concerns of crop and food security worldwide, prompting the developments and application of various antimicrobial agents. In this study, nine strains of lactic acid bacteria (LAB) with antifungal activities were isolated from the traditional Chinese fermented wort of Meigui rice vinegar, where fungi coexist. The cell-free supernatant (CFS) of Lacticaseibacillus paracasei ZX1231 exhibited significant inhibitory activities against Aspergillus niger, Penicillium citrinum, Penicillium polonicum, Zygosaccharomyces rouxii, Talaromyces rubrifaciens, and Candida albicans. Among the four cyclic dipeptides (CDPs) uncovered from the CFS, cyclo(Phe-Leu) and cyclo(Anthranily-Pro) were found in the family Lactobacillaceae for the first time, which inhibited the C. albicans filamentation by targeting upon RAS1-cAMP-PKA pathway. CFS antifungal activities were optimally combined with a bacterial nanocellulose (BNC) matrix to prepare the active quality packaging CFS-BNC films. The challenge tests confirmed that CFS-BNC films significantly inhibited the fungi growth and thus prolonged the shelf life of bread, beef, cheese and soy sauce. L. paracasei ZX1231, its CFS, and the CFS-BNC film may have extensive applications in food preservation and food packaging.

Intestinal microbiota analysis and network pharmacology reveal the mechanism by which Lianhua Qingwen capsule improves the immune function of mice infected with influenza A virus

Objective

Lianhua Qingwen capsule (LHQW) can attenuate lung injury caused by influenza virus infection. However, it is unclear whether the intestinal microbiota plays a role in LHQW activity in ameliorating viral infectious pneumonia. This study aimed to investigate the role of intestinal microbiota in LHQW activity in ameliorating viral infectious pneumonia and its possible mechanisms.

Research design and methods

A mouse model of influenza A viral pneumonia was established by intranasal administration in BALB/c mice. Detection of influenza virus in the lungs, pathological examination of the lungs and small intestine, and biochemical detection of inflammatory indices were performed. The effects of LHQW on intestinal microbiota were evaluated by 16S rRNA gene sequencing. The key components and targets of LHQW were screened via network pharmacology and verified through molecular docking, molecular dynamics simulation, and free binding energy calculations.

Results

Body weight decreased, inflammatory factor levels were disturbed, and the lung and intestinal mucosal barriers were significantly injured in the infected group. The alpha diversity of the intestinal microbiota decreased, and the abundance of Bacteroidetes, Muribaculaceae_unclassified, and Streptococcus decreased significantly. LHQW treatment reduced the viral load in the lungs, rescued body weight and survival, alleviated lung and intestinal mucosal barrier injury, reversed the reduction in the intestinal microbiota alpha diversity, and significantly increased the abundance of Bacteroidetes and Muribaculaceae. Network pharmacological analysis showed that six active herbal medicinal compounds from LHQW could regulate the intestinal microbiota and inhibit the immune-inflammatory response through the Toll-like receptor (TLR) and nuclear factor-κB (NF-κB) signalling pathways in the lungs.

Conclusion

These results suggest that LHQW is effective for treating influenza A virus infectious pneumonia, and the mechanism is associated with the regulation of the TLR4/NF-κB signalling pathway in the lungs by restoring intestinal microbiota and repairing the intestinal wall.

Mapping trends and hotspot regarding gastrointestinal microbiome and neuroscience: A bibliometric analysis of global research (2002-2022)

BACKGROUND

Scholars have long understood that gastrointestinal microorganisms are intimately related to human disorders. The literature on research involving the gut microbiome and neuroscience is emerging. This study exposed the connections between gut microbiota and neuroscience methodically and intuitively using bibliometrics and visualization. This study's objectives were to summarize the knowledge structure and identify emerging trends and potential hotspots in this field.

MATERIALS AND METHODS

On October 18, 2022, a literature search was conducted utilizing the Web of Science Core Collection (WoSCC) database for studies on gut microbiota and neuroscience studies from 2002 to 2022 (August 20, 2022). VOSviewer and CiteSpace V software was used to conduct the bibliometrics and visualization analysis.

RESULTS

From 2002 to 2022 (August 20, 2022), 2,275 publications in the WoSCC database satisfied the criteria. The annual volume of publications has rapidly emerged in recent years (2016-2022). The most productive nation (n = 732, 32.18%) and the hub of inter-country cooperation (links: 38) were the United States. University College Cork had the most research papers published in this area, followed by McMaster University and Harvard Medical School. Cryan JF, Dinan TG, and Clarke G were key researchers with considerable academic influence. The journals with the most publications are "Neurogastroenterology and Motility" and "Brain Behavior and Immunity." The most cited article and co-cited reference was Cryan JF's 2012 article on the impact of gut microbiota on the brain and behavior. The current research hotspot includes gastrointestinal microbiome, inflammation, gut-brain axis, Parkinson's disease (PD), and Alzheimer's disease (AD). The research focus would be on the "gastrointestinal microbiome, inflammation: a link between obesity, insulin resistance, and cognition" and "the role of two important theories of the gut-brain axis and microbial-gut-brain axis in diseases." Burst detection analysis showed that schizophrenia, pathology, and psychiatric disorder may continue to be the research frontiers.

CONCLUSION

Research on "gastrointestinal microbiome, inflammation: a link between obesity, insulin resistance, and cognition" and "the role of two important theories of the gut-brain axis and microbial-gut-brain axis in diseases" will continue to be the hotspot. Schizophrenia and psychiatric disorder will be the key research diseases in the field of gut microbiota and neuroscience, and pathology is the key research content, which is worthy of scholars' attention.

The published trend of studies on COVID-19 and dietary supplements: Bibliometric analysis

BACKGROUND

There are no guidelines on dietary supplements for the prevention or treatment of COVID-19. Therefore, we would like to analyze and discuss the above confusion through the bibliometric analysis.

METHODS

On 3 September 2022, we conducted a search of all relevant literature retrieved from the WOS core collection database from 2019 to 2022. CiteSpace software is used to build the visual co-occurrence network.

RESULTS

In the study of "COVID-19 and Dietary Supplements", the total of 170 authors published 855 articles in 451 journals. Several distinct core author groups were formed by Wang, Grant, Singh, Zhu, and other authors with numerous publications. The majority of the publications came from the Shahid Beheshti University of Medical Sciences. The United States of America had the highest number of publications. By analyzing keyword clusters, we found that the research focus was dietary supplements (vitamin D, vitamin K, vitamin C), mechanisms (ferritin, specialized pro-resolving mediators (SPMs), oxidative stress), research methods (clinical trials), and the prevention and treatment strategies (lockdown) of COVID-19.

CONCLUSIONS

vitamin D is the mainstream dietary supplement for COVID-19. There are still numerous controversies that deserve further discussion. Such as whether the use of vitamin D or TCM offers benefits, and whether the addition of dietary supplements during the lockdown measures can help prevent COVID-19 infection.

Are Nutraceuticals Effective in COVID-19 and Post-COVID Prevention and Treatment?

The beginning of the end or the end of the beginning? After two years mastered by coronavirus disease 19 (COVID-19) pandemic, we are now witnessing a turnaround. The reduction of severe cases and deaths from COVID-19 led to increasing importance of a new disease called post-COVID syndrome. The term post-COVID is used to indicate permanency of symptoms in patients who have recovered from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Immune, antiviral, antimicrobial therapies, as well as ozone therapy have been used to treat COVID-19 disease. Vaccines have then become available and administered worldwide to prevent the insurgence of the disease. However, the pandemic is not over yet at all given the emergence of new omicron variants. New therapeutic strategies are urgently needed. In this view, great interest was found in nutraceutical products, including vitamins (C, D, and E), minerals (zinc), melatonin, probiotics, flavonoids (quercetin), and curcumin. This review summarizes the role of nutraceuticals in the prevention and/or treatment of COVID-19 disease and post-COVID syndrome.

Probiotics in the Management of Mental and Gastrointestinal Post-COVID Symptomes

Patients with “post-COVID” syndrome manifest with a variety of signs and symptoms that continue/develop after acute COVID-19. Among the most common are gastrointestinal (GI) and mental symptoms. The reason for symptom occurrence lies in the SARS-CoV-2 capability of binding to exact receptors, among other angiotensin converting enzyme 2 (ACE2) receptors in gastrointestinal lining and neuropilin-1 (NRP-1) in the nervous system, which leads to loss of gastrointestinal and blood-brain barriers integrity and function. The data are mounting that SARS-CoV-2 can trigger systemic inflammation and lead to disruption of gut-brain axis (GBA) and the development of disorders of gut brain interaction (DGBIs). Functional dyspepsia (FD) and irritable bowel syndrome (IBS) are the most common DGBIs syndromes. On the other hand, emotional disorders have also been demonstrated as DGBIs. Currently, there are no official recommendations or recommended procedures for the use of probiotics in patients with COVID-19. However, it can be assumed that many doctors, pharmacists, and patients will want to use a probiotic in the treatment of this disease. In such cases, strains with documented activity should be used. There is a constant need to plan and conduct new trials on the role of probiotics and verify their clinical efficacy for counteracting the negative consequences of COVID-19 pandemic. Quality control is another important but often neglected aspect in trials utilizing probiotics in various clinical entities. It determines the safety and efficacy of probiotics, which is of utmost importance in patients with post-acute COVID-19 syndrome.

Hotspots and future directions in rheumatoid arthritis-related cardiovascular disease: A scientometric and visualization study from 2001 to 2021 based on Web of Science

Background

The morbidity and mortality of cardiovascular diseases (CVD) in patients with rheumatoid arthritis (RA) is significantly higher than those in the general population, leading to RA-related CVD has attracted broad attention and numerous articles have been published. However, no study has systematically examined this area from a scientometric perspective. This study aimed to visualize the knowledge structure and identify emerging research trends and potential hotspots in this field.

Materials and methods

Articles and reviews on RA-CVD published from 2001 to 2021 were extracted from the Web of Science Core Collection database. CiteSpace and VOSviewer software were used to visualize the knowledge network of countries, institutions, authors, references and keywords in this field. SPSS and Microsoft Excel software were used for curve fitting and correlation analysis.

Results

A total of 2,618 articles and reviews were included. The number of publications about RA-related CVD significantly increased yearly. Publications were mainly concentrated in North America, Europe and East Asia. The United States contributed most with 699 publications, followed by the United Kingdom and Italy. Gross Domestic Product was an important factor affecting scientific output. University of Manchester and Professor Kitas George D. were the most prolific institutions and influential authors, respectively. Journal of Rheumatology was the most productive journal for RA-related CVD research. The research hotspots switched in the order of clinical features (cardiovascular events), mechanism exploration, anti-tumor necrosis factor therapy, risk factors, and antirheumatic drug safety, which can be observed from the keyword analysis and co-cited reference cluster analysis.

Conclusions

This study found that research on RA-related CVD is flourishing. The safety and cardiovascular pharmacological mechanisms of anti-rheumatoid drugs, especially targeted synthetic DMARDs, would be the focus of current research and developmental trends in future research.

Cardiopulmonary exercise test: A 20-year (2002-2021) bibliometric analysis

Background

The clinical application value of cardiopulmonary exercise test (CPET) has increasingly attracted attention, and related research has been increasing yearly. However, there is no summary analysis of the existing CPET literature. This is the first bibliometric analysis of publications in the CPET.

Methods

CPET-related articles published between 2002 and 2021 were retrieved from the Web of Science Core Collection database. The search was limited to Articles and Reviews in English. CiteSpace software was used to conduct collaborative network analysis of countries/regions, institutions, authors, the co-occurrence of subject categories and keywords, and co-citation analysis of authors, journals, and references.

Results

A total of 4,426 publications were identified. During the study period, the number of published articles increased yearly. Developed countries from the Americas and Europe led the field. The University of Milan was the most prolific institution, with Ross Arena and Wasserman K being the most prolific and co-cited authors in the field, respectively. Cardiovascular System & Cardiology and Respiratory System were the main areas involved. Moreover, heart failure, oxygen uptake, and prognostic value were the central themes.

Conclusions

CPET had attracted widespread attention, and the number of publications will increase substantially according to the current growth trends. In the future, CPET is expected to be further adopted in large-scale clinical studies as a means of assessing the functional ability of patients to verify the efficacy of related interventions. High-quality evidence-based medical CPET-related indicators is expected to be used in clinical diseases risk prediction.

Microbiota and COVID-19: Long-term and complex influencing factors

The coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). According to the World Health Organization statistics, more than 500 million individuals have been infected and more than 6 million deaths have resulted worldwide. Although COVID-19 mainly affects the respiratory system, considerable evidence shows that the digestive, cardiovascular, nervous, and reproductive systems can all be involved. Angiotensin-converting enzyme 2 (AEC2), the target of SARS-CoV-2 invasion of the host is mainly distributed in the respiratory and gastrointestinal tract. Studies found that microbiota contributes to the onset and progression of many diseases, including COVID-19. Here, we firstly conclude the characterization of respiratory, gut, and oral microbial dysbiosis, including bacteria, fungi, and viruses. Then we explore the potential mechanisms of microbial involvement in COVID-19. Microbial dysbiosis could influence COVID-19 by complex interactions with SARS-CoV-2 and host immunity. Moreover, microbiota may have an impact on COVID-19 through their metabolites or modulation of ACE2 expression. Subsequently, we generalize the potential of microbiota as diagnostic markers for COVID-19 patients and its possible association with post-acute COVID-19 syndrome (PACS) and relapse after recovery. Finally, we proposed directed microbiota-targeted treatments from the perspective of gut microecology such as probiotics and prebiotics, fecal transplantation and antibiotics, and other interventions such as traditional Chinese medicine, COVID-19 vaccines, and ACE2-based treatments.

Mapping Knowledge Structure and Global Research Trends in Gout: A Bibliometric Analysis From 2001 to 2021

Background

The incidence and prevalence of gout have been steadily increasing globally, which has resulted in gout research attracting consistently increased attention. This study aimed to visualize the knowledge structure and research trends in gout research through bibliometrics to help understand the future development of basic and clinical research.

Methods

Articles and reviews on gout from 2001 to 2021 were extracted from the Web of Science Core Collection database. CiteSpace and VOSviewer software were used to visualize the knowledge network of countries, institutions, authors, references, and keywords in this field. SPSS and Microsoft Excel software were used for curve fitting and correlation analysis.

Results

A total of 3,259 articles and reviews were included. The number of publications about gout significantly increased yearly. Publications were mainly concentrated in North America, Europe, Oceania, and East Asia. The USA contributed most with 1,025 publications, followed by China and New Zealand. After adjusting for publications by population size and Gross Domestic Product (GDP), New Zealand ranked in the first place. GDP and international collaboration were significantly correlated with scientific productivity for gout research. University of Auckland and Professor Dalbeth Nicola were the most prolific institutions and influential authors, respectively. Rheumatology was the most productive journal for gout research. Gout research hotspots have shifted over time in the following order: clinical features, pathological mechanisms, complications, gouty arthritis, epidemiology, and dual-energy computed tomography to drug clinical trials, which can be observed from the keyword analysis and co-cited reference cluster analysis.

Conclusions

This study found that research on gout is flourishing. The development and experimentation of drugs for the prevention and treatment of gouty arthritis would be the focus of current research and developmental trends in future research.

Mapping the global research landscape on nutrition and the gut microbiota: Visualization and bibliometric analysis

BACKGROUND

Nutrition is a significant modifiable element that influences the composition of the gastrointestinal microbiota, implying the possibility of therapeutic diet methods that manipulate the composition and diversity of the microbial.

AIM

To overview research papers on nutrition and gut microbiota and determines the hotspots in this field at the global level.

METHODS

Scopus and Reference Citation Analysis were used to construct a bibliometric technique. It was decided to create bibliometric indicators and mapping as in most previous studies. 2012 through 2021 served as the study's timeframe.

RESULTS

A total of 5378 documents from the Scopus database were selected for analysis. Of all retrieved studies, 78.52% were research papers (n = 4223), followed by reviews (n = 820; 15.25%). China ranked first with a total number of articles of 1634 (30.38%), followed by the United States in second place with a total number of articles of 1307 (24.3%). In the last decade, emerging hotspots for gut microbiota and nutrition research included "gut microbiota metabolism and interaction with dietary components", "connection between the gut microbiota and weight gain", and "the influence of high-fat diet and gut microbiota on metabolic disorders".

CONCLUSION

This is the first thorough bibliometric analysis of nutrition and gut microbiota publications conducted on a global level. Investigation of the association between nutrition/diet and the gut microbiota is still in its infancy and will be expanded in the future. However, according to recent trends, the "effect of gut microbiota and high-fat diet on metabolic disorders" will be an increasing concern in the future.

SARS CoV-2-Induced Viral Sepsis: The Role of Gut Barrier Dysfunction

A considerable proportion of patients with severe COVID-19 meet Sepsis-3 criteria and share common pathophysiological mechanisms of multiorgan injury with bacterial sepsis, in absence of secondary bacterial infections, a process characterized as “viral sepsis”. The intestinal barrier exerts a central role in the pathophysiological sequence of events that lead from SARS-CoV-2 infection to severe systemic complications. Accumulating evidence suggests that SARS-CoV-2 disrupts the integrity of the biological, mechanical and immunological gut barrier. Specifically, microbiota diversity and beneficial bacteria population are reduced, concurrently with overgrowth of pathogenic bacteria (dysbiosis). Enterocytes’ tight junctions (TJs) are disrupted, and the apoptotic death of intestinal epithelial cells is increased leading to increased gut permeability. In addition, mucosal CD4(+) and CD8(+) T cells, Th17 cells, neutrophils, dendritic cells and macrophages are activated, and T-regulatory cells are decreased, thus promoting an overactivated immune response, which further injures the intestinal epithelium. This dysfunctional gut barrier in SARS-CoV-2 infection permits the escape of luminal bacteria, fungi and endotoxin to normally sterile extraintestinal sites and the systemic circulation. Pre-existing gut barrier dysfunction and endotoxemia in patients with comorbidities including cardiovascular disease, obesity, diabetes and immunosuppression predisposes to aggravated endotoxemia. Bacterial and endotoxin translocation promote the systemic inflammation and immune activation, which characterize the SARS-CoV-2 induced “viral sepsis” syndrome associated with multisystemic complications of severe COVID-19.

Disorders of intestinal microbiocenosis: expanding the application of probiotics

The problem of interaction between a person and the intestinal microbiome is surrounded by many secrets and mysteries. The bacterial flora of the gastrointestinal tract has a local and systemic effect not only on the digestive system, but also on  the entire body as a whole. Numerous studies have proved the pathogenetic relationship of the state of the intestinal biocenosis not only with diseases of the gastrointestinal tract, but also with pathological processes from other organs and systems of the body. In terms of its role in maintaining homeostasis, the intestinal microflora is not inferior to any other vital organ. In the presented review, the current aspects of the terminology and clinic of disorders of intestinal microbiocenosis are considered. Probiotics occupy an important place in the complex therapy of intestinal microbiocenosis disorders and the corresponding clinical manifestations. The review considers the main mechanisms of probiotic / host interaction, non-immunological and immunological effects of probiotics and the requirements for them, the main directions of use of representatives of the normal microflora Bifidobacterium and Lactobacillus. The data of meta-analyzes and systematic reviews, testifying to the expansion of indications for the appointment of probiotics, are considered the possibilities of probiotics in the complex therapy of Helicobacter pylori infection, syndrome of increased epithelial intestinal permeability, and the prevention of respiratory infections.

The review concludes with the results of a search in the PubMed database on the possibility of using probiotics in the prevention and treatment of a new coronavirus infection COVID-19. The availability of modern, effective and safe probiotics in the arsenal of a practical doctor (primarily a general practitioner and general practitioner), and their use, contributes to the optimization of drug therapy not only in gastroenterological patients, but also in patients with other somatic pathologies, including those with new coronavirus infection COVID-19.

Microbiota and the Response to Vaccines Against Respiratory Virus

This mini review describes the role of gut and lung microbiota during respiratory viral infection and discusses the implication of the microbiota composition on the immune responses generated by the vaccines designed to protect against these pathogens. This is a growing field and recent evidence supports that the composition and function of the microbiota can modulate the immune response of vaccination against respiratory viruses such as influenza and SARS-CoV-2. Recent studies have highlighted that molecules derived from the microbiome can have systemic effects, acting in distant organs. These molecules are recognized by the immune cells from the host and can trigger or modulate different responses, interfering with vaccination protection. Modulating the microbiota composition has been suggested as an approach to achieving more efficient protective immune responses. Studies in humans have reported associations between a better vaccine response and specific bacterial taxa. These associations vary among different vaccine strategies and are likely to be context-dependent. The use of prebiotics and probiotics in conjunction with vaccination demonstrated that bacterial components could act as adjuvants. Future microbiota-based interventions may potentially improve and optimize the responses of respiratory virus vaccines.