Probiotics and immune health

Are We What We Eat? Impact of Diet on the Gut-Brain Axis in Parkinson's Disease

Parkinson’s disease is characterized by motor and non-motor symptoms, such as defects in the gut function, which may occur before the motor symptoms. To date, there are therapies that can improve these symptoms, but there is no cure to avoid the development or exacerbation of this disorder. Dysbiosis of gut microbiota could have a crucial role in the gut–brain axis, which is a bidirectional communication between the central nervous system and the enteric nervous system. Diet can affect the microbiota composition, impacting gut–brain axis functionality. Gut microbiome restoration through probiotics, prebiotics, synbiotics or other dietary means could have the potential to slow PD progression. In this review, we will discuss the influence of diet on the bidirectional communication between gut and brain, thus supporting the hypothesis that this disorder could begin in the gut. We also focus on how food-based therapies might then have an influence on PD and could ameliorate non-motor as well as motor symptoms.

Mining for Active Molecules in Probiotic Supernatant by Combining Non-Targeted Metabolomics and Immunoregulation Testing

Chronic respiratory diseases such as asthma are highly prevalent in industrialized countries. As cases are expected to rise, there is a growing demand for alternative therapies. Our recent research on the potential benefits of probiotics suggests that they could prevent and reduce the symptoms of many diseases by modulating the host immune system with secreted metabolites. This article presents the first steps of the research that led us to identify the immunoregulatory bioactivity of the amino acid d-Trp reported in our previous study. Here we analyzed the cell culture metabolic footprinting of 25 commercially available probiotic strains to associate metabolic pathway activity information with their respective immune modulatory activity observed in vitro. Crude probiotic supernatant samples were processed in three different ways prior to untargeted analysis in positive and negative ionization mode by direct infusion ESI-FT-ICR-MS: protein precipitation and solid phase extraction (SPE) using HLB and CN-E sorbent cartridges. The data obtained were submitted to multivariate statistical analyses to distinguish supernatant samples into the bioactive and non-bioactive group. Pathway analysis using discriminant molecular features showed an overrepresentation of the tryptophan metabolic pathway for the bioactive supernatant class, suggesting that molecules taking part in that pathway may be involved in the immunomodulatory activity observed in vitro. This work showcases the potential of metabolomics to drive product development and novel bioactive compound discovery out of complex biological samples in a top-down manner.

Probiotics, prebiotics and synbiotics improved the functionality of aquafeed: Upgrading growth, reproduction, immunity and disease resistance in fish

Aquaculture plays an increasingly significant role in improving the sustainability of global fish production. This sector has been intensified with the advent of new husbandry practices and the development of new technology. However, the increasing intensification and indiscriminate commercialized farming has enhanced the vulnerability of cultivated aquatic species to damage from pathogens. In efforts to confront these various diseases, frequent use of drugs, antibiotics, chemotherapeutics, and agents for sterilization have unintentionally added to the risk of transmission of pathogens and harmful chemical compounds to consumers. Some natural dietary supplements are believed to have the potential to offset this setback in aquaculture. Application of bio-friendly feed additives such as probiotics, prebiotics and synbiotics are becoming popular dietary supplements with the potential to not only improve growth performance, but in some cases can also enhance immune competence and the overall well-being of fish and crustaceans. The present review discusses and summarizes the effects of probiotics, prebiotics and synbiotics application on growth, stress mitigation, microbial composition of intestine, immune system and health condition of aquatic animals in association with existing constraints and future perspectives in aquaculture.

A novel probiotic strain exerts therapeutic effects on mouse model of multiple sclerosis by altering the expression of inflammasome and IDO genes and modulation of T helper cytokine profile

Multiple sclerosis is an inflammatory demyelinating disease that commences to neuronal cell destruction. Recently, a promising evidence of synergic effects of combined supplementation with vitamin D and probiotics in modulating the gut microbiota and metabolome is emerging. Bacillus Coagulans IBRC-M10791 as a novel strain was chosen, prevention and treatment impacts of regular administered were studied in Cuprizone-induced C57bl/6 mouse of demyelination. The mice were divided into six groups and received a daily dose of cuprizone or probiotics. To investigate the effect of probiotic, the IDO-1, CYP27B1, NLRP1, NLRP3, and AIM2 expression were estimated by Real-Time PCR, and IL-4, IL-17, IFN-gamma, and TGF-beta cytokines were measured by ELISA. The results showed that there was significant decrease in IL-17 and IFN-γ and modulatory effects on IL-4 and TGF-β. On the other hand, we demonstrated that there are significant decrease for expression of IDO-1, CYP27b1, NLRP1, NLRP3 and AIM2 genes in prevention and treatment groups compared to cuprizone group. Also, a significant enhancement in rate of remyelination and alternations proved by LFB staining and Y-Maze test. In conclusion, our study provides insight into how the therapeutic effect of the chosen strain of probiotic was correlated with the modulation of the level of inflammatory and anti-inflammatory cytokines. Further, we demonstrated that the expression of genes related to Tryptophan, Vitamin D and Inflammasome pathways could be affected by B.coagulans. Our study could be beneficial to provide a novel Co-therapeutic strategy for Multiple sclerosis.

Role of NRF2 and Sirtuin activators in COVID-19

COVID-19 is a pandemic requiring immediate solution for treatment because of its complex pathophysiology. Exploration of novel targets and thus treatment will be life savers which is the need of the hour. 2 host factors- TMPRSS2 and ACE2 are responsible for the way the virus will enter and replicate in the host. Also NRF2 is an important protein responsible for its anti-inflammatory role by multiple mechanisms of action like inhibition of NF-kB, suppression of pro-inflammatory genes, etc. NRF2 is deacetylated by Sirtuins and therefore both have a direct association. Absence of SIRT indicates inhibition of NRF2 expression and thus no anti-oxidative and anti-inflammatory protection for the cell. Therefore, we propose that NRF2 activators and/or SIRT activators can be evaluated to check their efficacy in ameliorating the symptoms of COVID-19.

Mechanism of Lactobacillus reuteri Probiotic in Increasing Intestinal Mucosal Immune System

Probiotics are defined as live microorganisms which, when consumed in adequate quantities as food ingredients, provide health benefits to the host. Lactobacillus, Bifidobacterium, and Saccharomyces, are three probiotics that are intensively used as probiotics in humans and animals. Probiotics have beneficial effects on health when given adequate amounts. The concept of probiotics on human health, namely modulating the gut microbiota and its effect on the host. Probiotics play an important role in maintaining intestinal integrity through a number of different interactions, including changes in cytokine expression in the mucosa. Probiotics compete with intestinal pathogens for mucosal receptors, thereby increasing interepithelial resistance. Probiotics such as Lactobacillus casei sp GG strain was used as a prophylaxis that could increase the expression of epithelial mucin, thereby reducing the translocation of pathogenic bacteria. Abnormal local immune response is characterized by decreased secretion of IgA, thus allowing enterocyte attachment and local translocation of bacterial antigens, which are the main stimulation of pathological events. Colonic stasis can promote the growth of pathogenic bacteria which allows malignant porin bacterial strains to thrive. The gut microbiota has a major influence on human health. The microbial population has an important role in the host, such as the metabolic activity of probiotics producing energy and nutrient absorption, developing the host immune system, and preventing colonization and infection of pathogens. Lactobacillus reuteri is a hetero-fermentative bacterium that lives in the digestive tract of humans. L. reuteri has been used to treat infant necrotizing pseudomembrane. In this paper, the mechanism of L reuteri to increase host immunological response will be reviewed.

Microbiota, probiotics and respiratory infections: the three musketeers can tip off potential management of COVID-19

Rapid infectivity of SARS-CoV2 with recent viral variants is posing a challenge in the development of robust therapeutic strategies. On the other hand, microbiota is debated for its involvement in SARS-CoV2 infection with varied opinions. Although ample data about the role of microbiota and probiotics in respiratory viral infections are available, their role in COVID-19 is limited albeit emerging rapidly. The utilization of probiotics for the management of COVID-19 is still under investigation in many clinical trials. Existing information coupled with recent COVID-19 related studies can suggest various ways to use microbiota modulation and probiotics for managing this pandemic. Present article indicates the role of microbiota modulation and probiotics in respiratory infections. In addition, scattered evidence was gathered to understand the potential of microbiota and probiotics in the management of SARS-CoV2. Gut-airway microbiota connection is already apparent in respiratory tract viral infections, including SARS-CoV2. Though few clinical trials are evaluating microbiota and probiotics for COVID-19 management, the safety evaluation must be given more serious consideration because of the possibility of opportunistic infections among COVID-19 patients. Nevertheless, the information about microbiota modulation using probiotics and prebiotics can be helpful to manage this outbreak and this review presents different aspects of this idea.

Probiotic, Lactobacillus pentosus BD6 boost the growth and health status of white shrimp, Litopenaeus vannamei via oral administration

This study aims to assess and determine the oral-administration of probiotic, Lactobacillus pentosus BD6 on growth performance, immunity and disease resistance of white shrimp, Litopenaeus vannamei. Lac. pentosus BD6 effectively inhibited the growth of aquatic pathogens, which was used in the test. Shrimp were fed with the control diet (without probiotic supplement) for 60 days and the probiotic-containing diets at 10⁷, 10⁸, 10⁹, and 10¹⁰ cfu kg^-1, respectively. Shrimp fed with the diet containing probiotic at the doses of 10^9-10 cfu kg^-1 showed significant increase in growth performance as well as feed efficiency than that of the control. After a challenge test with Vibrio alginolyticus, shrimp fed with a probiotic diet at a dose of 10¹⁰ cfu kg^-1 showed a significantly lower mortality as compared to the control and that of shrimp fed the diet containing probiotic at the levels up to 10^7-8 cfu kg^-1. In addition, a therapeutic potential of Lac. pentosus BD6 was discovered because the cumulative mortalities of shrimp fed with probiotic and pathogen V. parahaemolyticus simultaneously were significantly lower when compared to control shrimp. Probiotic in diet at a dose of 10^9-10 cfu kg^-1 significantly increased PO activity of shrimp, while shrimp receiving probiotic at the doses of 10^8-10 cfu kg^-1 showed significant increase in lysozyme activity and phagocytic activity. Shrimp fed with the diet containing probiotic at the level of 10¹⁰ cfu kg^-1 also indicated higher gene expression of prophenoloxidase (proPO) I, but not proPO II, lipopolysaccharide and β-1,3-glucan-binding protein and penaeidin 4. Analysis of the bacterial microbiota of the shrimp intestine revealed that oral administration of probiotic increased the relative abundance of beneficial bacteria and reduced the abundance of harmful pathogenic bacteria in the gut flora of shrimp. Despite no statistically significant difference, an analysis of microbial diversity recorded higher species richness, Shannon-Weaver diversity index and evenness in the probiotic group, compared to the control group. It was concluded that Lac. pentosus BD6 has great antibacterial ability against a wide range of pathogens and has therapeutic potential to reduce the mortality of shrimp infected with V. parahaemolyticus. Additionally, dietary Lac. pentosus BD6 at the level of 10¹⁰ cfu kg^-1 was recommended to improve growth performance, immunity and disease resistance of shrimp against V. alginolyticus.

Sex-Dependent Effects of Intestinal Microbiome Manipulation in a Mouse Model of Alzheimer's Disease

Mechanisms linking intestinal bacteria and neurodegenerative diseases such as Alzheimer's disease (AD) are still unclear. We hypothesized that intestinal dysbiosis might potentiate AD, and manipulating the microbiome to promote intestinal eubiosis and immune homeostasis may improve AD-related brain changes. This study assessed sex differences in the effects of oral probiotic, antibiotics, and synbiotic treatments in the AppNL-G-F mouse model of AD. The fecal microbiome demonstrated significant correlations between bacterial genera in AppNL-G-F mice and Aβ plaque load, gliosis, and memory performance. Female and not male AppNL-G-F mice fed probiotic but not synbiotic exhibited a decrease in Aβ plaques, microgliosis, brain TNF-α, and memory improvement compared to no treatment controls. Although antibiotics treatment did not produce these multiple changes in brain cytokines, memory, or gliosis, it did decrease Aβ plaque load and colon cytokines in AppNL-G-F males. The intestinal cytokine milieu and splenocyte phenotype of female but not male AppNL-G-F mice indicated a modest proinflammatory innate response following probiotic treatment compared to controls, with an adaptive response following antibiotics treatment in male AppNL-G-F mice. Overall, these results demonstrate the beneficial effects of probiotic only in AppNL-G-F females, with minimal benefits of antibiotics or synbiotic feeding in male or female mice.

Overview on the Prevalence of Fungal Infections, Immune Response, and Microbiome Role in COVID-19 Patients

Patients with severe COVID-19, such as individuals in intensive care units (ICU), are exceptionally susceptible to bacterial and fungal infections. The most prevalent fungal infections are aspergillosis and candidemia. Nonetheless, other fungal species (for instance, Histoplasma spp., Rhizopus spp., Mucor spp., Cryptococcus spp.) have recently been increasingly linked to opportunistic fungal diseases in COVID-19 patients. These fungal co-infections are described with rising incidence, severe illness, and death that is associated with host immune response. Awareness of the high risks of the occurrence of fungal co-infections is crucial to downgrade any arrear in diagnosis and treatment to support the prevention of severe illness and death directly related to these infections. This review analyses the fungal infections, treatments, outcome, and immune response, considering the possible role of the microbiome in these patients. The search was performed in Medline (PubMed), using the words "fungal infections COVID-19", between 2020-2021.

A Microbiome-Driven Approach to Combating Depression During the COVID-19 Pandemic

The significant stressors brought about and exacerbated by COVID-19 are associated with startling surges in mental health illnesses, specifically those related to depressive disorders. Given the huge impact of depression on society, and an incomplete understanding of impactful therapeutics, we have examined the current literature surrounding the microbiome and gut-brain axis to advance a potential complementary approach to address depression and depressive disorders that have increased during the COVID-19 pandemic. While we understand that the impact of the human gut microbiome on emotional health is a newly emerging field and more research needs to be conducted, the current evidence is extremely promising and suggests at least part of the answer to understanding depression in more depth may lie within the microbiome. As a result of these findings, we propose that a microbiome-based holistic approach, which involves carefully annotating the microbiome and potential modification through diet, probiotics, and lifestyle changes, may address depression. This paper's primary purpose is to shed light on the link between the gut microbiome and depression, including the gut-brain axis and propose a holistic approach to microbiome modification, with the ultimate goal of assisting individuals to manage their battle with depression through diet, probiotics, and lifestyle changes, in addition to offering a semblance of hope during these challenging times.

Response of the yellow mealworm (Tenebrio molitor) gut microbiome to diet shifts during polystyrene and polyethylene biodegradation

Plastic biodegradation by mealworm is regarded as an emerging strategy for plastic disposal. In this study, the polystyrene (PS) and low density polyethylene (LDPE) degradation efficiency by yellow mealworms (Tenebrio molitor larvae) supplemented with bran and the effects of plastics on the gut core microbiome were explored to construct a circular and continuous reactor for plastic biodegradation in the future. The gut microbiome was also investigated with dietary shift to explore the relationship between specific diets and gut microbes. The bran plus plastic (7:1 ratio, w/w) co-diet contributed to the mealworm survival and growth. The formation of -C˭O-/-C-O- groups in the plastic-fed mealworms frass represented the oxidation process of plastic biodegradation in the mealworm gut. The changes in molecular weights (M_w, M_n and M_z) of residual PS and LDPE in mealworms frass compared with that of PS and PE feedstock confirmed the plastic depolymerization and biodegradation. Lactobacillus and Mucispirillum were significantly associated with PE + bran diet compared to bran diet and PE diet, representing the response of mealworm gut microbiome to the bran and plastic mixture was distinguished from either bran or plastics alone. The gut microbiome changed substantially with the diet shift, indicating that microbial community assembly was a stochastic process and diverse plastic-degrading bacteria might occur in the mealworm gut.

The Improving Effect and Safety of Probiotic Supplements on Patients with Osteoporosis and Osteopenia: A Systematic Review and Meta-Analysis of 10 Randomized Controlled Trials

AIM

Probiotics are considered to be bone metabolism regulators, and their efficacy as an adjuvant treatment option for osteoporosis is still controversial. The purpose of this study is to compare the available data from randomized controlled trials (RCT) of probiotics in the treatment of osteoporosis and osteopenia.

METHODS

As of June 2021, databases such as Medline, Embase, Web of Science, and Central Cochrane Library have been used for English-language literature searches and CNKI and China Biomedical Database have been used for Chinese-language literature searches. RevMan 5.3 was used for bias risk assessment, heterogeneity detection, and meta-analysis. This research has been registered in PROSPERO (CRD42020085934).

RESULTS

This systematic review and meta-analysis included 10 RCTs involving 1156. Compared with the placebo, the absolute value of lumbar spine's BMD was not statistically significant (WMD 0.04 (-0.00, 0.09), P=0.07, random effect model), while the percentage of lumbar spine's BMD was higher (SMD 1.16 (0.21, 2.12), P=0.02, random effect model). Compared with the control group, the percentage of total hip's BMD was not statistically significant (SMD 0.52 (-0.69, 1.73), P=0.40, random effect model). The safety analysis showed that, compared with control group, the adverse events in the experimental group were not statistically significant (RR 1.02 (0.92, 1.12), P=0.70, fixed effect model).

CONCLUSION

Probiotics may be safety supplements to improve the lumbar spine's BMD of patients with osteoporosis and osteopenia. More large-sample, random-controlled, high-quality RCTs are needed to further verify the effectiveness and safety of probiotics in intervening osteoporosis or osteopenia.

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.

Immunonutrition effects on coping with COVID-19

COVID-19 implications are still a threat to global health. In the face of this pandemic, food and nutrition are key issues that can boost the immune system. The bioactivity of functional foods and nutrients (probiotics, prebiotics, water- and fat-soluble vitamins, minerals, flavonoids, glutamine, arginine, nucleotides, and PUFAs) contributes to immune system modulation, which establishes the status of nutrients as a factor of immune competence. These foods can contribute, especially during a pandemic, to the minimization of complications of SARS-CoV-2 infection. Therefore, it is important to support the nutritional strategies for strengthening the immune status, associated with good eating habits, as a way to confront COVID-19.

The emerging role of probiotics as a mitigation strategy against coronavirus disease 2019 (COVID-19)

COVID-19 is an acute respiratory infection accompanied by pneumonia caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which has affected millions of people globally. To date, there are no highly efficient therapies for this infection. Probiotic bacteria can interact with the gut microbiome to strengthen the immune system, enhance immune responses, and induce appropriate immune signaling pathways. Several probiotics have been confirmed to reduce the duration of bacterial or viral infections. Immune fitness may be one of the approaches by which protection against viral infections can be reinforced. In general, prevention is more efficient than therapy in fighting viral infections. Thus, probiotics have emerged as suitable candidates for controlling these infections. During the COVID-19 pandemic, any approach with the capacity to induce mucosal and systemic reactions could potentially be useful. Here, we summarize findings regarding the effectiveness of various probiotics for preventing virus-induced respiratory infectious diseases, especially those that could be employed for COVID-19 patients. However, the benefits of probiotics are strain-specific, and it is necessary to identify the bacterial strains that are scientifically established to be beneficial.

Cell-free culture supernatant of Lactobacillus curvatus Wikim38 inhibits RANKL-induced osteoclast differentiation and ameliorates bone loss in ovariectomized mice

This study was conducted to investigate the inhibitory effects of the cell-free culture supernatant of Lactobacillus curvatus Wikim 38 (LC38-CS) on RANKL-induced osteoclast differentiation and bone loss in a mice model of ovariectomy-induced post-menopausal osteoporosis. LC38-CS inhibited the RANKL-induced differentiation of bone marrow-derived macrophages (BMDMs) into osteoclasts in a dose-dependent manner. F-actin ring formation and bone resorption were also reduced by LC38-CS treatment of RANKL-treated BMDMs. In addition, LC38-CS decreased the RANKL-induced activation of the TRAF6/NF-κB/MAPKs axis at the early stage and the expression of osteoclastogenesis-related genes in BMDMs treated with RANKL. PRMT1 and ADMA levels, new biomarkers for osteoclastogenesis, were decreased by LC38-CS treatment. The administration of LC38-CS increased bone volume and bone mineral density in ovariectomized mice in μ-CT analysis. These findings suggest that LC38-CS inhibited RANKL-induced osteoclast differentiation by the downregulation of molecular mechanisms and exerted anti-osteoporotic effects.

Genomics as a Clinical Decision Support Tool: Successful Proof of Concept for Improved ASD Outcomes

Considerable evidence is emerging that Autism Spectrum Disorder (ASD) is most often triggered by a range of different genetic variants that interact with environmental factors such as exposures to toxicants and changes to the food supply. Up to 80% of genetic variations that contribute to ASD found to date are neither extremely rare nor classified as pathogenic. Rather, they are less common single nucleotide polymorphisms (SNPs), found in 1-15% or more of the population, that by themselves are not disease-causing. These genomic variants contribute to ASD by interacting with each other, along with nutritional and environmental factors. Examples of pathways affected or triggered include those related to brain inflammation, mitochondrial dysfunction, neuronal connectivity, synapse formation, impaired detoxification, methylation, and neurotransmitter-related effects. This article presents information on four case study patients that are part of a larger ongoing pilot study. A genomic clinical decision support (CDS) tool that specifically focuses on variants and pathways that have been associated with neurodevelopmental disorders was used in this pilot study to help develop a targeted, personalized prevention and intervention strategy for each child. In addition to an individual's genetic makeup, each patient's personal history, diet, and environmental factors were considered. The CDS tool also looked at genomic SNPs associated with secondary comorbid ASD conditions including attention deficit hyperactivity disorder (ADHD), obsessive-compulsive disorder (OCD), anxiety, and pediatric autoimmune neuropsychiatric disorder associated with streptococcal infections/pediatric acute-onset neuropsychiatric syndrome (PANDAS/PANS). The interpreted genomics tool helped the treating clinician identify and develop personalized, genomically targeted treatment plans. Utilization of this treatment approach was associated with significant improvements in socialization and verbal skills, academic milestones and intelligence quotient (IQ), and overall increased ability to function in these children, as measured by autism treatment evaluation checklist (ATEC) scores and parent interviews.

Probiotics: an Antibiotic Replacement Strategy for Healthy Broilers and Productive Rearing

Pathogens develop resistance to antibiotics at a rate much faster than the discovery of new antimicrobial compounds. Reports of multidrug-resistant bacteria isolated from broilers, and the possibility that these strains may spread diseases amongst humans, prompted many European countries to ban the inclusion of antibiotics in feed. Probiotics added to broiler feed controlled a number of bacterial infections. A combination of Enterococcus faecium, Pediococcus acidilactici, Bacillus animalis, Lactobacillus salivarius and Lactobacillus reuteri decreased the colonisation of Campylobacter jejuni and Salmonella Enteritidis in the gastro-intestinal tract (GIT) of broilers, whereas Bacillus subtilis improved feed conversion, intestinal morphology, stimulated the immune system and inhibited the colonisation of Campylobacter jejuni, Escherichia coli and Salmonella Minnesota. Lactobacillus salivarius and Pediococcus parvulus improved weight gain, bone characteristics, intestinal morphology and immune response, and decreased the colonisation of S. Enteritidis. Lactobacillus crispatus, L. salivarius, Lactobacillus gallinarum, Lactobacillus johnsonii, Enterococcus faecalis and Bacillus amyloliquefaciens decreased the Salmonella count and led to an increase in lysozyme and T lymphocytes. Probiotics may also improve feed digestion through production of phytases, lipases, amylases and proteases or stimulate the GIT to secrete digestive enzymes. Some strains increase the nutritional value of feed by production of vitamins, exopolysaccharides and antioxidants. Bacteriocins, if produced, regulate pathogen numbers in the GIT and keep pro-inflammatory and anti-inflammatory reactions in balance.

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 as a biological detoxification tool of food chemical contamination: A review

Nowadays, people are exposed to diverse environmental and chemical pollutants produced by industry and agriculture. Food contaminations such as persistent organic pollutants (POPs), heavy metals, and mycotoxins are a serious concern for global food safety with economic and public health implications especially in the newly industrialized countries (NIC). Mounting evidence indicates that chronic exposure to food contaminants referred to as xenobiotics exert a negative effect on human health such as inflammation, oxidative stress, and intestinal disorders linked with perturbation of the composition and metabolic profile of the gut microflora. Although the physicochemical technologies for food decontamination are utilized in many cases but require adequate conditions which are often not feasible to be met in many industrial sectors. At present, one promising approach to reduce the risk related to the presence of xenobiotics in foodstuffs is a biological detoxification done by probiotic strains and their enzymes. Many studies confirmed that probiotics are an effective, feasible, and inexpensive tool for preventing xenobiotic-induced dysbiosis and alleviating their toxicity. This review aims to summarize the current knowledge of the direct mechanisms by which probiotics can influence the detoxification of xenobiotics. Moreover, probiotic-xenobiotic interactions with the gut microbiota and the host response were also discussed.

Gut microbiota in mental health and depression: role of pre/pro/synbiotics in their modulation

The microbiome residing in the human gut performs a wide range of biological functions. Recently, it has been elucidated that a change in dietary habits is associated with alteration in the gut microflora which results in increased health risks and vulnerability towards various diseases. Falling in line with the same concept, depression has also been shown to increase its prevalence around the globe, especially in the western world. Various research studies have suggested that changes in the gut microbiome profile further result in decreased tolerance of stress. Although currently available medications help in relieving the symptoms of depressive disorders briefly, these drugs are not able to completely reverse the multifactorial pathology of depression. The discovery of the communication pathway between gut microbes and the brain, i.e. the Gut-Brain Axis, has led to new areas of research to find more effective and safer alternatives to current antidepressants. The use of probiotics and prebiotics has been suggested as being effective in various preclinical studies and clinical trials for depression. Therefore, in the present review, we address the new antidepressant mechanisms via gut microbe alterations and provide insight into how these can provide an alternative to antidepressant therapy without the side effects and risk of adverse drug reactions.

In vivo evidence: Repression of mucosal immune responses in mice with colon cancer following sustained administration of Streptococcus thermophiles

Probiotics have attracted considerable attention because of their ability to ameliorate disease and prevent cancer. In this study, we examined the immunomodulatory effects of a Streptococcus thermophilus probiotic on the intestinal mucosa azoxymethane-induced colon cancer. Sixty female mice were divided into four groups (n = 15 each). One group of untreated mice was used as a control (C group). Another mouse group was injected with azoxymethane once weekly for 8 weeks to induce colon cancer (CC group). Finally, two groups of mice were continuously treated twice per week from week 2 to 16 with either the Lactobacillus plantarum (Lac CC group) or S. thermophilus (Strep CC group) bacterial strain pre-and post-treatment as performed for the CC group. Remarkably, Tlr2, Ifng, Il4, Il13, Il10, and Tp53 transcription were significantly downregulated in the Strep CC intestinal mucosa group. Additionally, IL2 expression was decreased significantly in the Strep CC mouse serum, whereas TNFα was remarkably elevated compared to that in the CC, Lac CC, and untreated groups. This study suggested that Streptococcus thermophilus did not interrupt or hinder colon cancer development in mice when administered as a prophylactic.

The impact of prenatal use of oral Clostridium butyricum on maternal group B Streptococcus colonization: A retrospective study

OBJECTIVE

The aim of this study is to examine the effect of taking Clostridium butyricum (Miyarisan BM) orally for 4 weeks since the 32⁺⁰ weeks of gestation on preventing Group B Streptococcus colonization.

MATERIALS AND METHODS

We retrospectively collected data on the pregnancy outcomes of 1602 women between October 2017 and August 2019. The control group received standard antenatal care, and the intervention group received standard antenatal care with a daily oral dose of probiotics since the 32⁺⁰ weeks of gestation. The daily dose was one pack of C. butyricum (Miyarisan BM) once or twice a day. A vaginal Group B Streptococcus swab was collected between 36⁺⁰ and 36⁺⁶ weeks of gestation.

RESULTS

After applying the designated exclusion criteria, the total number of participants was 1576. The Group B Streptococcus colonization rate was significantly decreased in the intervention group (P = 0.0338; adjusted OR: 0.66 (0.45-0.97)).

CONCLUSION

Probiotics can reduce the colonization rate of Group B Streptococcus in the vagina and rectum under three conditions: (1) intervention of adequate length, (2) sufficient probiotic dose, and (3) effective probiotics.

Probiotics/ prebiotics in viral respiratory infections: implication for emerging pathogens

BACKGROUND

Viral respiratory infections could result in perturbation of the gut microbiota due to a probable cross-talk between lungs and gut microbiota. This can affect the pulmonary health and the gastrointestinal system.

OBJECTIVE

This review aimed to discuss the impact of probiotics/ prebiotics and supplements on the prevention and treatment of respiratory infections, especially emerging pathogens.

METHODS

The data were searched were searched in PubMed, Scopus, Google Scholar, Google Patents, and The Lens-Patent using keywords of probiotics and viral respiratory infections in the title, abstract, and keywords.

RESULT

Probiotics consumption could decrease the susceptibility to viral respiratory infections, such as COVID-19 and simultaneously enhance vaccine efficiency in infectious disease prevention through the immune system enhancement. Probiotics improve the gut microbiota and the immune system via regulating the innate system response and production of anti-inflammatory cytokines. Moreover, treatment with probiotics contributes to the intestinal homeostasis restitution under antibiotic pressure and decreasing the risk of secondary infections due to viral respiratory infections. Probiotics present varied performances in different conditions; thus, promoting their efficacy through combining with supplements (prebiotics, postbiotics, nutraceuticals, berberine, curcumin, lactoferrin, minerals, and vitamins) is important. Several supplements reported to enhance the probiotics' efficacy and their mechanisms as well as probiotics related patents are summarized in this review. Using nanotechnology and microencapsulation techniques can also improve probiotics efficiency.

CONCLUSION

Given the global challenge of COVID-19, probiotic/prebiotic and following nutritional guidelines should be regarded seriously. Additionally, their role as an adjuvant in vaccination for immune response augmentation needs attention.

Role of Probiotic Bacilli in Developing Synbiotic Food: Challenges and Opportunities

The human body is inhabited by a vast diversity of probiotic microorganisms that could positively affect human physiology. Besides, prebiotic food substances may induce symbiotic relationship among probiotic species through the successful establishment of commensal microbiota, whose connections with the host are multifaceted and multidirectional. As deliberated throughout this review, prebiotic and synbiotic foods contain the capability to stimulate numerous health characteristics in host organisms through various means. Predominantly, the normal microbiota fosters the digestion of food and may boost the innate and adaptive immune system’s functionalities. Therefore, live probiotic bacteria, for instance, probiotic Bacilli obtained together with prebiotic food, can help stimulate healthiness in humans. Thus, we discuss how certain dietary fibers may preserve the probiotic efficacy by serving as the scaffold for probiotic Bacilli to colonize them through forming symbiotic interactions. The fibers can essentially promote protection by encapsulating probiotic Bacilli against various environmental and physical stresses that might kill the free-living bacterial cells. Besides, these fibers would serve as prebiotic substances that would eventually be utilized for the proliferation of probiotic cells. It is believed that applying this conceptual idea will provide a novel platform toward developing probiotic and synbiotic foods, as discussed in this review.

The Role of Nutrition in the COVID-19 Pandemic

SARS-CoV-2, the cause of the COVID-19 disease, is posing unprecedent challenges. In the literature, increasing evidence highlights how malnutrition negatively affects the immune system functionality, impairing protection from infections. The current review aims to summarize the complex relationship between SARS-CoV-2 infection and nutritional status and the effects of malnutrition in terms of disease severity, patients' recovery time, incidence of complications and mortality rate. Current studies evaluating the possibility of modulating nutrition and supplementation in combination with pharmacological treatments in the clinical setting to prevent, support, and overcome infection are also described. The discussion of the most recent pertinent literature aims to lay the foundations for making reasonable assumptions and evaluations for a nutritional "best practice" against COVID-19 pandemic and for the definition of sound cost-effective strategies to assist healthcare systems in managing patients and individuals in their recovery from COVID-19.

The Kynurenine Pathway Is Upregulated by Methyl-deficient Diet and Changes Are Averted by Probiotics

SCOPE

Probiotics exert immunomodulatory effects and may influence tryptophan metabolism in the host. Deficiency of nutrients related to C1 metabolism might stimulate inflammation by enhancing the kynurenine pathway. This study used Sprague Dawley rats to investigate whether a methyl-deficient diet (MDD) may influence tryptophan/kynurenine pathways and cytokines and whether probiotics can mitigate these effects.

METHODS AND RESULTS

Rats are fed a control or MDD diet. Animals on the MDD diet received vehicle, probiotics (L. helveticus R0052 and B. longum R0175), choline, or probiotics + choline for 10 weeks (n = 10 per group). Concentrations of plasma kynurenine metabolites and the methylation and inflammatory markers in plasma and liver are measured.

RESULTS

MDD animals (vs controls) show upregulation of plasma kynurenine, kynurenic acid, xanthurenic acid, 3-hydroxyxanthranilic acid, quinolinic acid, nicotinic acid, and nicotinamide (all p < 0.05). In the MDD rats, the probiotics (vs vehicle) cause lower anthranilic acid and a trend towards lower kynurenic acid and picolinic acid. Compared to probiotics alone, probiotics + choline is associated with a reduced enrichment of the bacterial strains in cecum. The interventions have no effect on inflammatory markers.

CONCLUSIONS

Probiotics counterbalance the effect of MDD diet and downregulate downstream metabolites of the kynurenine pathway.

Lozenges with probiotic strains enhance oral immune response and health

OBJECTIVE

Probiotics participate in regulating oral microbiota and reducing the prevalence of oral diseases; however, clinical research on probiotics is insufficient. Therefore, in this study, we performed in vitro screening of potential oral protective probiotic strains and then evaluated the clinical efficacy of the selected strains on maintaining oral health.

MATERIALS AND METHODS

Fifty healthy individuals were recruited and randomly assigned into the placebo group and probiotics group, which included three strains of probiotics, Lactobacillus salivarius subs. salicinius AP-32, Lactobacillus paracasei ET-66, and Lactobacillus plantarum LPL28. Each group was blindly administered placebo or probiotics for four weeks.

RESULTS

Next-generation sequencing results showed that the oral microbiota of Lactobacillus salivarius in the oral cavity were significantly increased in subjects supplemented with mixed probiotic lozenges. The anti-bacterial activities of viable probiotics were observed within two weeks. Both IgA levels and Lactobacillus and Bifidobacterium abundances in the oral cavity were significantly increased in the experimental groups, along with a reduced formation of plaque. Most participants reported that their oral health conditions and intestinal symptoms had improved.

CONCLUSIONS

Overall, our clinical study suggests that oral probiotic lozenges may enhance oral immunity, modulate oral microbiota, and improve oral health.

Lactobacillus reuteri in Its Biofilm State Improves Protection from Experimental Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) is a devastating disease predominately found in premature infants that is associated with significant morbidity and mortality. Despite decades of research, medical management with broad spectrum antibiotics and bowel rest has remained relatively unchanged, with no significant improvement in patient outcomes. The etiology of NEC is multi-factorial; however, gastrointestinal dysbiosis plays a prominent role in a neonate's vulnerability to and development of NEC. Probiotics have recently emerged as a new avenue for NEC therapy. However, current delivery methods are associated with potential limitations, including the need for at least daily administration in order to obtain any improvement in outcomes. We present a novel formulation of enterally delivered probiotics that addresses the current limitations. A single enteral dose of Lactobacillus reuteri delivered in a biofilm formulation increases probiotic survival in acidic gastric conditions, increases probiotic adherence to gastrointestinal epithelial cells, and reduces the incidence, severity, and neurocognitive sequelae of NEC in experimental models.

Bioactive compounds and probiotics-a ray of hope in COVID-19 management

The use of bioactive compounds and probiotic bacteria against the viral diseases in human is known for a long time. Anti-viral, anti-inflammatory and anti-allergic properties of bioactive compounds and bacteria with probiotic properties in respiratory viral diseases may have significance to enhance immunity. This review highlights some of the important bioactive compounds and probiotic bacteria, suggesting them as a ray of hope in the milieu of the COVID-19 management.

Weather Conditions and COVID-19 Incidence in a Cold Climate: A Time-Series Study in Finland

Background: The current coronavirus disease 2019 (COVID-19) is spreading globally at an accelerated rate. There is some previous evidence that weather may influence the incidence of COVID-19 infection. We assessed the role of meteorological factors including temperature (T) and relative humidity (RH) considering the concentrations of two air pollutants, inhalable coarse particles (PM10) and nitrogen dioxide (NO2) in the incidence of COVID-19 infections in Finland, located in arctic-subarctic climatic zone. Methods: We retrieved daily counts of COVID-19 in Finland from Jan 1 to May 31, 2020, nationwide and separately for all 21 hospital districts across the country. The meteorological and air quality data were from the monitoring stations nearest to the central district hospital. A quasi-Poisson generalized additional model (GAM) was fitted to estimate the associations between district-specific meteorological factors and the daily counts of COVID-19 during the study period. Sensitivity analyses were conducted to test the robustness of the results. Results: The incidence rate of COVID-19 gradually increased until a peak around April 6 and then decreased. There were no associations between daily temperature and incidence rate of COVID-19. Daily average RH was negatively associated with daily incidence rate of COVID-19 in two hospital districts located inland. No such association was found nationwide. Conclusions: Weather conditions, such as air temperature and relative humidity, were not related to the COVID-19 incidence during the first wave in the arctic and subarctic winter and spring. The inference is based on a relatively small number of cases and a restricted time period.

The issue of the correct use of probiotics in the absence of recommendations

Antibiotics are important for saving both human health and life. Antibiotics destroy all bacteria within their spectrum, because they do not distinguish between good and bad bacteria. Even if an antibiotic therapy lasts only a few days, it may cause diarrhoea and mycosis. Antibiotics destroy most bacterial species in the intestines. These changes may affect one’s whole life. Today it is a challenge for medicine to be able to manipulate the microbiome so as to restore normal relations between microorganisms. At present, when antibiotics are abused, probiotics are very often applied. However, as there are no recommendations, a lot of mistakes can be made when using them. Both drugs and dietary supplements can be classified as probiotics. Medicinal probiotics are subject to very strict registration requirements and their use is associated with a specific disease or ailment. Probiotic microorganisms must be classified according to their genus, species and strain. These preparations may contain one or more probiotic strains depending on its application. At present there are no established schemes or rules concerning the dosage of probiotic preparations. This issue arouses numerous controversies. It is assumed that the probiotic should be applied at a dose which proved to have a beneficial effect in tests conducted on humans. Patients usually make decisions on the choice and dosage of preparations themselves. Individualised probiotic therapy is the key to success. There is no universal preparation – a specific probiotic should be used in a particular clinical case.

Supercooling as a potentially improved storage option for commercial kimchi

The supercooling degree (SD), which refers to the difference between the ice nucleation temperature and freezing point of kimchi, varies depending on the type of kimchi, manufacturer, recipe, and manufacturing season. The aim of this study is to investigate the major influencing factors for the supercooled storage of kimchi and to analyze the possibility of supercooled storage for commercial kimchi. Pearson correlation analysis determined that, in commercial kimchi manufactured between March and July 2018, the SD of kimchi correlated to the number of aerobic bacteria (P < 0.01), however, was not associated with lactic acid bacteria. Moreover, the ice nucleation temperature of saline solution inoculated with aerobic bacteria was reduced from -3.03 ± 0.04 to -6.18 ± 0.11 °C by 10 kGy gamma ray sterilization. Meanwhile, the ice nucleation temperatures of 1.8 kg of commercial red cabbage kimchi and 500 g of white cabbage kimchi manufactured in February 2020 were -3.93 ± 0.06 °C and -3.57 ± 0.06 °C, respectively, and they could be stored at -2.5 °C for 12 weeks without freezing. Additionally, supercooled storage of kimchi at -2.5 °C caused a fermentation delay effect compared to control storage at 1 °C, considering the acidity and amount of lactic acid bacteria. Therefore, if the number of aerobic bacteria is controlled during the manufacturing process of kimchi, supercooled storage at temperatures below -2.5 °C may extend the shelf life of kimchi. PRACTICAL APPLICATION: We have shown that aerobic bacteria are the key influencing factor for ice nucleation of kimchi during supercooled storage. Aside from the initial sterilization process, fermentation of kimchi can also be delayed by lowering the storage temperature below -2.5 °C. Moreover, the method of direct cool refrigeration may have an industrial-level application.

Yogurt Consumption Is Associated with Lower Levels of Chronic Inflammation in the Framingham Offspring Study

Some studies suggest that dairy foods may be linked with less chronic inflammation. However, few studies have investigated the separate effects of different types of dairy on inflammation. Therefore, the current study aims to examine the separate prospective impacts of milk, yogurt and cheese on biomarkers of chronic inflammation in 1753 community-dwelling participants of the Framingham Offspring Study (FOS). Mean intakes of dairy foods were derived from two sets of three-day diet records. Six inflammatory biomarkers were assessed approximately seven years later at exam 7. Results showed that those who consumed yogurt (vs. those who did not) had statistically significantly lower levels of interleukin-6 (IL-6) (mean log-transformed levels of 1.31 and 1.26 in consumers/non-consumers, respectively, p = 0.02) and fibrin (mean log-transformed levels of 5.91 and 5.89 in consumers/non-consumers, respectively, p = 0.03). The inverse association between IL-6 and yogurt consumption was similar in participants who were of normal weight and those who were overweight. For fibrin, the effects were stronger in overweight individuals. No statistically significant associations were observed between any of these inflammation biomarkers and milk or cheese intakes. Overall, our study compared the separate impacts of three types of dairy foods on chronic inflammation and found that only yogurt intake was linked with lower levels of chronic inflammation.

The Strategy of Boosting the Immune System Under the COVID-19 Pandemic

The novel coronavirus (SARS-CoV-2) infection (COVID-19) has raised considerable concern on the entire planet. On March 11, 2020, COVID-19 was categorized by the World Health Organization (WHO) as a pandemic infection, and by March 18, 2020, it has spread to 146 countries. The first internal defense line against numerous diseases is personalized immunity. Although it cannot be claimed that personalized nutrition will have an immediate impact on a global pandemic, as the nutritional interventions required a long time to induce beneficial outcomes on immunity development, nutritional strategies are still able to clarify and have a beneficial influence on the interplay between physiology and diet, which could make a positive contribution to the condition in the next period. As such, a specific goal for every practitioner is to evaluate different tests to perceive the status of the patient, such as markers of inflammation, insulin regulation, and nutrient status, and to detect possible imbalances or deficiencies. During the process of disease development, the supplementation and addition of different nutrients and nutraceuticals can influence not only the viral replication but also the cellular mechanisms. It is essential to understand that every patient has its individual needs. Even though many nutrients, nutraceuticals, and drugs have beneficial effects on the immune response and can prevent or ameliorate viral infections, it is essential to detect at what stage in COVID-19 progression the patient is at the moment and decide what kind of nutrition intervention is necessary. Furthermore, understanding the pathogenesis of coronavirus infection is critical to make proper recommendations.

Oral probiotics in coronavirus disease 2019: connecting the gut-lung axis to viral pathogenesis, inflammation, secondary infection and clinical trials

Defined as helpful live bacteria that can provide medical advantages to the host when administered in tolerable amounts, oral probiotics might be worth considering as a possible preventive or therapeutic modality to mitigate coronavirus disease 2019 (COVID-19) symptom severity. This hypothesis stems from an emerging understanding of the gut-lung axis wherein probiotic microbial species in the digestive tract can influence systemic immunity, lung immunity, and possibly viral pathogenesis and secondary infection co-morbidities. We review the principles underlying the gut-lung axis, examples of probiotic-associated antiviral activities, and current clinical trials in COVID-19 based on oral probiotics.

The relevance of nutrition as a step forward to combat COVID-19

A new type of single-stranded RNA virus that belongs to the coronavirus’s family named SARS-CoV-2 has recently appeared, with fast-growing human to human transmissions. This virus has posed an important global health threat. Many nutrients can support the immune system and help in preventing or in ameliorating the response to viral infections. In the case of COVID-19, the unique pathophysiology of the coronavirus needs to be understood, in order to determine whether any potential nutrition intervention is indicated. A literature survey that comprised of ongoing research was conducted to evaluate the benefits of the bioactives present in food, such as: plant-derived extracts, vitamins, minerals, probiotics, and prebiotics, against the mechanisms of the COVID-19 infection. Although no food is yet confirmed to help in the prevention or in the treatment of the coronavirus transmission alone, exploring the possible implications of nutrition-infection interrelationships is of utmost importance. Well-designed and controlled clinical studies are emerging to explain whether the higher consumption of fruits, vegetables, protein-rich foods, unsaturated fatty acids, and other natural functional foods may aid in combating the COVID-19 infection. Meanwhile, a healthy and balanced diet is traditionally practised in viral infections that support the healthy gut microbiota profile. The human immune system function should be a vital prophylactic measure, along with adequate physical activities and sleeping habits. The consumption of immune-supportive nutrients is also encouraged in the elderly, comorbid, and in the immune-compromised as well as in malnourished individuals, in order to minimise the complications and the negative outcomes that are associated with the COVID-19 disease. Keywords: COVID-19 nutrition, mаcronutrients, micronutrients, bioactive compounds, malnutrition

Integrative role of traditional and modern technologies to combat COVID-19

INTRODUCTION

With the development of various branches of sciences, we will be able to resolve different clinical aspects of various diseases better. The convergence of these sciences can potentially tackle the new corona crisis.

AREAS COVERED

In this review, we attempted to explore and describe various scientific branches studying COVID-19. We have reviewed the literature focusing on the prevention, diagnosis, and treatment of COVID-19. The primary databases targeted were Science Direct, Scopus and PubMed. The most relevant reports from the recent two decades were collected utilizing keywords including SARS-CoV, MERS-CoV, COVID-19, epidemiology, therapeutics and diagnosis.

EXPERT OPINION

Based on this literature review, both traditional and emerging approaches are vital for the prevention, diagnosis and treatment of COVID-19. The traditional sciences play an essential role in the preventive and supportive care of corona infection, and modern technologies appear to be useful in the development of precise diagnosis and powerful treatment approaches for this disease. Indeed, the integration of these sciences will help us to fight COVID-19 disease more efficiently.

Kidney diseases and COVID-19 infection: causes and effect, supportive therapeutics and nutritional perspectives

Recently, the novel coronavirus disease 2019 (COVID-19), has attracted the attention of scientists where it has a high mortality rate among older adults and individuals suffering from chronic diseases, such as chronic kidney diseases (CKD). It is important to elucidate molecular mechanisms by which COVID-19 affects the kidneys and accordingly develop proper nutritional and pharmacological strategies. Although numerous studies have recently recommended several approaches for the management of COVID-19 in CKD, its impact on patients with renal diseases remains the biggest challenge worldwide. In this paper, we review the most recent evidence regarding causality, potential nutritional supplements, therapeutic options, and management of COVID-19 infection in vulnerable individuals and patients with CKD. To date, there is no effective treatment for COVID-19-induced kidney dysfunction, and current treatments are yet limited to anti-inflammatory (e.g. ibuprofen) and anti-viral medications (e.g. Remdesivir, and Chloroquine/Hydroxychloroquine) that may increase the chance of treatment. In conclusion, the knowledge about kidney damage in COVID-19 is very limited, and this review improves our ability to introduce novel approaches for future clinical trials for this contiguous disease.

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.

Dysbiosis, Small Intestinal Bacterial Overgrowth, and Chronic Diseases

Dysbiosis is characterized by an alteration in quantity and quality of intestinal microbiota composition. In the presence of dysbiosis, enterocytes will have difficulty in maintaining the integrity of the mucosal barrier, leading to increased intestinal permeability. These events are recognised to be linked to several chronic diseases. One of the consequences of dysbiosis is the manifestation of small intestinal bacterial overgrowth (SIBO), which is associated to a variety of chronic diseases. Single food nutrients and bioactive molecules, food additives, pre- and probiotics, and different dietary patterns may change the composition of the intestinal microbiota. Low FODMAPs diet has been a reference in SIBO treatment. This chapter intends to describe how the intestinal microbiota, dysbiosis, and SIBO can be related; to define dysbiosis food and nutrients influence; and to offer some nutritional therapy strategies for applying the low FODMAPs protocol, enabling better adherence by patients in order to increase their wellbeing.

Gut microbiota in Celiac Disease: microbes, metabolites, pathways and therapeutics

INTRODUCTION

Current evidence supports a vital role of the microbiota on health outcomes, with alterations in an otherwise healthy balance linked to chronic medical conditions like celiac disease (CD). Recent advances in microbiome analysis allow for unparalleled profiling of the microbes and metabolites. With the growing volume of data available, trends are emerging that support a role for the gut microbiota in CD pathogenesis.

AREAS COVERED

In this article, the authors review the relationship between factors such as genes and antibiotic exposure on CD onset and the intestinal microbiota. The authors also review other microbiota within the human body (like the oropharynx) that may play a role in CD pathogenesis. Finally, the authors discuss implications for disease modification and the ultimate goal of prevention. The authors reviewed literature from PubMed, EMBASE, and Web of Science.

EXPERT OPINION

CD serves as a unique opportunity to explore the role of the intestinal microbiota on the development of chronic autoimmune disease. While research to date provides a solid foundation, most studies have been case-control and thus do not have capacity to explore the mechanistic role of the microbiota in CD onset. Further longitudinal studies and integrated multi-omics are necessary for investigating CD pathogenesis.

Probiotic Lactobacillus fermentum strain JDFM216 improves cognitive behavior and modulates immune response with gut microbiota

Increasing evidence indicates that alterations in gut microbiota are associated with mammalian development and physiology. The gut microbiota has been proposed as an essential player in metabolic diseases including brain health. This study aimed to determine the impact of probiotics on degenerative changes in the gut microbiota and cognitive behavior. Assessment of various behavioral and physiological functions was performed using Y-maze tests, wheel running tests, accelerated rotarod tests, balance beam tests, and forced swimming tests (FSTs), using adult mice after 50 weeks of administering living probiotic bacterium Lactobacillus fermentum strain JDFM216 or a vehicle. Immunomodulatory function was investigated using immune organs, immune cells and immune molecules in the mice, and gut microbiota was also evaluated in their feces. Notably, the L. fermentum JDFM216-treated group showed significantly better performance in the behavior tests (P < 0.05) as well as improved phagocytic activity of macrophages, enhanced sIgA production, and stimulated immune cells (P < 0.05). In aged mice, we observed decreases in species belonging to the Porphyromonadaceae family and the Lactobacillus genus when compared to young mice. While administering the supplementation of L. fermentum JDFM216 to aged mice did not shift the whole gut microbiota, the abundance of Lactobacillus species was significantly increased (P < 0.05). Our findings suggested that L. fermentum JDFM216 also provided beneficial effects on the regulation of immune responses, which has promising implications for functional foods. Taken together, L. fermentum JDFM216 could confer the benefit of improving health with enhanced cognition, physiological behavior, and immunity by modulating the gut microbiota.

Potential Inhibitors for SARS-CoV-2 and Functional Food Components as Nutritional Supplement for COVID-19: A Review

The severe acute respiratory syndrome is a viral respiratory infection and commonly called as COVID-19, caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). It widely transmitted through direct or indirect contact. Currently, no specific treatment against SARS-CoV-2 are available; only prevention and supportive strategy are the preventive measures. The present review emphasizes the latest research related to COVID-19 and SARS-CoV-2 virus as well as the current status of potential inhibitors identified. Recent interest in SARS-CoV-2 has focused on transmission, symptoms, structure, and its structural proteins that exhibit promising therapeutics targets for rapid identification of potential inhibitors. The quick identification of potential inhibitors and immune-boosting functional food ingredients are crucial to combat this pandemic disease. We also tried to give an overview of the functional food components as a nutritional supplement, which helps in boosting our immune system and could be useful in preventing the COVID-19 and/or to improve the outcome during therapy.

Molecular insights into probiotic mechanisms of action employed against intestinal pathogenic bacteria

Gastrointestinal (GI) diseases, and in particular those caused by bacterial infections, are a major cause of morbidity and mortality worldwide. Treatment is becoming increasingly difficult due to the increase in number of species that have developed resistance to antibiotics. Probiotic lactic acid bacteria (LAB) have considerable potential as alternatives to antibiotics, both in prophylactic and therapeutic applications. Several studies have documented a reduction, or prevention, of GI diseases by probiotic bacteria. Since the activities of probiotic bacteria are closely linked with conditions in the host's GI-tract (GIT) and changes in the population of enteric microorganisms, a deeper understanding of gut-microbial interactions is required in the selection of the most suitable probiotic. This necessitates a deeper understanding of the molecular capabilities of probiotic bacteria. In this review, we explore how probiotic microorganisms interact with enteric pathogens in the GIT. The significance of probiotic colonization and persistence in the GIT is also addressed.

The immunomodulatory effects of probiotics on respiratory viral infections: A hint for COVID-19 treatment?

Respiratory virus infections are among the most prevalent diseases in humans and contribute to morbidity and mortality in all age groups. Moreover, since they can evolve fast and cross the species barrier, some of these viruses, such as influenza A and coronaviruses, have sometimes caused epidemics or pandemics and were associated with more serious clinical diseases and even mortality. The recently identified Coronavirus Disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a Public Health Emergency of International concern and has been associated with rapidly progressive pneumonia. To ensure protection against emerging respiratory tract infections, the development of new strategies based on modulating the immune responses is essential. The use of probiotic components has substantially increased due to their effects on immune responses, in particular on those that occur in the upper/lower respiratory tract. Superinduction of inflammatory reaction, known as a cytokine storm, has been correlated directly with viral pneumonia and serious complications of respiratory infections. In this review, probiotics, as potential immunomodulatory agents, have been proposed to improve the host's response to respiratory viral infections. In addition, the effects of probiotics on different aspects of immune responses and their antiviral properties in both pre-clinical and clinical contexts have been described in detail.

Effects of Mannan Oligosaccharides and/or Bifidobacterium on Growth and Immunity in Domestic Pigeon (Columba livia domestica)

The goal of this study was to evaluate the influences of mannan oligosaccharides (MOSs) and/or Bifidobacterium on the growth and immunity of pigeons over a 56-day period. One hundred paired adult pigeons were randomly divided into four groups of five paired pigeons. Paired pigeons with two young squabs were housed in a man-made aviary. Parent pigeons in the control group received a basal diet (C), while the other three groups were fed with the basal diet supplemented with 20 g of MOSs/kg of feed (M), 10 g Bifidobacterium (1×1010 CFU/g)/kg of feed (B), or a combination of M and B (MB). We found higher body weights (BW) in pigeons of the B group than in the C, M, and MB groups. None of the treatments exerted significant effects involving spleen and thymus indices, whereas M birds tended to improve the bursa of Fabricius index. Pigeons fed with the M-supplemented diet exhibited improved serum immunoglobulin M (IgM) concentrations compared with those fed with C and the B- and MB-supplemented diets. In addition, M treatment increased immunoglobulin A (IgA) levels compared with MB treatment. MB treatment improved serum immunoglobulin G (IgG) concentrations compared to that by the C treatment. The concentration of secretory immunoglobulin A (sIgA) was significantly reduced in the duodenum and increased in the ileum in pigeons fed with the MB-supplemented diet. This study indicated that dietary supplementation with Bifidobacterium increased the growth performance. Dietary supplementation with MOSs or in combination with Bifidobacterium was able to improve immune function in pigeons but exerted no apparent effect on weight gain. Accordingly, in terms of economic benefits, the findings suggested that supplementation with Bifidobacterium alone may improve production performance, and that supplementation with MOSs alone may improve immune function in pigeons.