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The last discovered organ of the human body is microbiome which is present at different sites in it. Gut microbiome consists of about 1000–1500 bacterial species and as regulated by genetic makeup, lifestyle, and environmental conditions, the gut microbiota of a healthy individual can comprise approximately 160 species of bacteria. Majority of gut microbiome consists of Firmicutes, Actinobacteria, Bacteroidetes, and to a lesser extent Proteobacteria, Euryarchaeota, Fusobacteria, and Verrucomicrobia. The gut-lung axis is involved in the migration of immune cells from gut to respiratory tract through circulation and encourages the host's ability to fight infections. The gut regulates the responses in lungs via host-acquired inflammatory mediators in the circulation. Dendritic cells located in the Peyer's patches of the intestine, macrophages, and Langerhans cells are the major antigen-presenting cells that play a vital role in the modulation and development of innate immune response. Gut microbiota interacts via the regulation and development of adaptive immune response. B and T lymphocytes are the key players of adaptive immunity. CD4 + T cells after activation differentiate into four major kinds of cell classes: (1) regulatory T cells (Treg), (2) Th2, (3) Th1, and (4) Th17 cells. Gut microbial interactions can induce the production of various types of immune cells as demonstrated by various studies. For instance, Clostridia induces the formation of Treg cells. Likewise, Bacteroides fragilis inhabiting the gut can incite the production of Th1 cells and production of T17 cells is stimulated by segmental filamentous bacteria. Gut microbiota also plays a vital role in the physiology and metabolism leading to the synthesis of various immunoregulatory metabolites such as SCFAs, antimicrobial peptides (AMPs), amino acids, and polyamines. SARS-CoV-2 virus entry to the cell is via ACE2 receptor present in respiratory epithelium and gut epithelium. This receptor is highly expressed (100 times more than in the lung) in the epithelial cells of the stomach, duodenum, ileum, and rectum as well as cholangiocytes and hepatocytes. High level of ACE2 receptor expressing in the gastrointestinal epithelial cells along with high-level co-expression of TMPRSS2 (cellular serine peptidase) causes coronavirus to infect gastrointestinal tract along with lungs leading to altered intestinal permeability and enterocyte malabsorption with symptoms of diarrhea in patients of COVID-19. Hence, COVID-19 patients with gastrointestinal symptoms have significantly longer duration of illness and viral clearance time than patients without any gastrointestinal symptoms. Obese patients with gut dysbiosis have decreased population of Bacteroides species. COVID-19 patients with type 2 diabetics have increased population of Fusobacterium, Ruminococcus, and Blautia with decreased population of Bacteroides, Bifidobacterium, Faecalibacterium, Akkermansia, and Roseburia. Diet with low fiber, high fat, and high carbohydrate causes gut dysbiosis. Intake of high-fiber diet consisting of whole grains, vegetables, and fruits induces growth of Bifidobacterium, Bacteroides, and Lactobacilli. Probiotics are nonpathogenic live organisms which are safe to be taken as dietary supplements. The major genera of probiotics are Lactobacillus, Bifidobacterium, and Saccharomyces. These probiotics increase the activity of T cells, NK cell, and polymorphonuclear cells. Prebiotics in the form of maize fiber, inulin, and polydextrose improves digestion and immunity. Hence, healthy gut microbiome with its strong immune intervention may bring recovery in COVID-19 patients. However, so far no published studies have reported that probiotics can be used as an adjunctive therapy in our fight against the SARS-CoV-2 infection. A far-reaching approach should consist of randomized, multicenter, controlled trials to explore the potential benefits of gut microbiome and how changes in dietary habits can be used as an add-on strategy against the COVID-19 pandemic. © The Author(s), under exc us ve licence to Springer Nature Singapore Pte Ltd. 2021.
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Patients suffering severe COVID-19 show an aggressive and excessive immune response against the SARS-CoV-2 coronavirus, known as a cytokine storm. If left untreated these patients face the risk of tissue damage, multi-organ failure and death. A high relative abundance of Prevotella copri has been reported in patients with newly diagnosed rheumatoid arthritis (RA). On the other hand, it has been observed that Prevotella histicola can modulate the inflammatory manifestations of autoimmune diseases like multiple sclerosis, and it is now being evaluated as a monoclonal microbial treatment in COVID-19. We observed that pre-treatment with P. histicola decreased NF-kB activation, while pre-treatment with P. histicola and P. copri decreased IRF activation in monocytes upon SARS-CoV-2 glycoprotein. Our findings suggest that exposure of blood immune cells, such as monocytes, to commensal species of Prevotella may reduce the inflammatory response to SARS-CoV-2 glycoprotein. Besides treatments targeting the viral infection, other treatments such as immunomodulation by bacteria aiming to reduce or regulate the inflammatory process in COVID-19 to avoid the development of related complications may be considered.
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Background: SARS-CoV-2 infection induces disturbed airway microbiota during the acute phase of infection that may contribute to persistence of long-term pulmonary sequelae. To date it is unclear if the presence of a disrupted microbiota following severe disease is linked to long-term pulmonary function impairment. This one-year follow-up study investigated the association between airway microbiota and lung function after severe COVID-19. Method(s): In the Swiss COVID Lung study (NCT04581135), we conducted 16S rRNA sequencing on upper respiratory tract specimen obtained by oropharyngeal swabs 3 to 12 months after hospitalisation from 72 subjects (total samples n = 169) with severe COVID-19. Subjects underwent 1 - 3 follow-up visits during which lung function testing was performed to investigate correlation with the richness and composition of airway microbiota. Result(s): Total lung capacity (TLC) was negatively correlated with bacterial richness (p = 0.0081). Recovered COVID-19 subjects with ongoing respiratory impairment (TLC < 80%) showed low phylum heterogeneity with a majority of the dominant taxa being Bacteroidetes (64% of the 50 most abundant taxa in the group). In contrast, the phylum with the largest number of dominant taxa in subjects with TLC >= 80% was Firmicutes (48% of the 50 most abundant taxa in the group). Conclusion(s): Patients with impaired total lung capacity between 3 and 12 months after severe COVID-19 have a distinct oropharyngeal microbiota from those with restored total lung capacity. Future studies need to assess the contribution of microbiota to lung function impairment after severe COVID-19, as airway microbiota analysis may assist monitoring of sequelae and recovery.
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This article highlights information on the beneficial and pathogenic microorganisms of the oral cavity of dogs, effects of grass consumption, and the breeding and care of dogs.
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Introduction: Increased inflammatory cytokines has been observed in COVID-19 patients and there is evidence showing an alteration in gut-microbiota composition. SARS-CoV-2 can cause gastrointestinal symptoms, such as diarrhea. Evidence of an altered gut-microbiota composition and cytokines levels in COVID-19 diarrhea patients is lacking. Objectives: To compare serum cytokine levels and gut microbiota between COVID-19 diarrhea (D-COVID- 19) and non-diarrhea (NonD-COVID-19) patients and non- COVID-19 controls (HC). Material and methods: We included 143 hospitalized COVID-19 patients (positive quantitative reverse transcription PCR) in a single University Hospital, and 53 ambulatory HC (negative rapid serological test) were included. Blood and stool samples were collected at hospital admission in COVID-19 patients and at the time of HC recruitment. 27- pro and anti-inflammatory cytokines (Bio-Plex Pro™, Bio- Rad) were measured. Gut microbiota composition and diversity profiles were characterized by sequencing the 16S rRNA gene V3-V4 region amplified using DNA extracted from stool samples. Bioinformatics analysis was performed with QIIME2 software. First, we compare cytokine levels between COVID- 19 and HC and then COVID-19 with and without diarrhea. All comparisons were adjusted for age, sex, and BMI with linear regression. Results: The mean age in COVID-19 patients was 54 +/- 15 years (F=50%) and 52 +/- 8 (F=62%) for HC. Diarrhea was present in 19 (13.29%) of COVID-19 patients. COVID-19 patients had significative higher levels of: IL- 1ra, IL-2, IL-6, IL-7, IL-8, IL-13, IP-10 and PDGF-bb. Significant lower values of: IL-9, FGF -basic, MIP-1β, TNF-α were observed in D-COVID-19 compared to NonD-COVID-19. COVID-19 patients had a significant reduction of bacterial species (p=0.0001), and diversity and complexity of the bacterial community (Shannon's index) (p=0.0001) compared to the HC. There was no difference between D-COVID-19 and NonD-COVID-19. There were also changes in the composition of the microbiota associated with COVID-19. At the phylum level, COVID-19 patients showed a significant decrease in Actinobacteria and Firmicutes, and an increase in Bacteroidetes. At species level, an increase of 4 species of the genus Bacteroides was observed in COVID-19 patients. 31 very diverse bacterial species were found, all decreased in D-COVID-19. Conclusions: An alteration in serum cytokine levels was observed between COVID-19 and HC. D-COVID-19 had a decrease in some proinflammatory cytokines. A significant decrease in richness and species diversity of gutmicrobiota was observed in COVID-19 patients compared to HC, but no significant differences were observed between D-COVID-19 and NonD-COVID-19. However, in D-COVID- 19, a decrease in some bacterial species was observed.(Table Presented)(Figure Presented)
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There is an increasing universal awareness of environmental problems arising as a result of COVID- 19 pandemic and pollution especially in Nigeria. Among the source of this problem is effluent discharge from industries, particularly hospitals in arable farmlands and environs. Two outstanding hospital were purposively selected;Madonna Catholic Hospital and Abia Specialist Hospital in Umuahia, Abia State. Their wastewater samples were collected from three different wards;maternity, general private, and general out-patients department (GOPD) wards. Results obtained show significant variation in physiochemical properties in some wards and heavy metals across all wards. Seven bacteria species;Staphylococcus aureus, Escherichia coli, Klesbsiella pneumonia, Pseudomonas aeruginosa, Proteus vulgaris, Bacteriod sp and Streptococcus pyogenes and one fungi specie- Candida albican were recorded from the samples. The bacterial load in Madonna ranged from 209.04 to 232.95cfu/ml in January, February, and March each and was statistically the same in the three wards (p>0.05). Fungi load ranged from 1.58 to 2.35cfu/ml in January, February, and March each and also significantly different at (p>0.05). The frequency of microbial characteristics isolated in the two hospital wastewater ranged from 33 to 100% with 100% of Staphylococcus aureus and Escherichia coli in all the wards, while other species varied significantly between 67 and 33% each. The results of the isolated bacteria from hospital wastewater showed resistivity to the tested antibiotics, and as therapeutic agents. Therefore, results call for need for urgent attention to be given to the discharge of wastewater from hospitals to ensure that food production around the environment is not contaminated.
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This experiment was conducted to investigate the effects of recombinant porcine Lactobacillus reuteri secreting bovine lactoferrin peptide (LFCA) on growth performance of newborn piglets and the protective effect on porcine transmissible gastroenteritis virus (TGEV)infection which caused piglet diarrhea. Experiment 1:thirty-six one-day-old newborn piglets with an average body weight of about 1.5 kg were randomly divided into 3 groups, which were pPG-LFCA/LR-CO21 group, pPG/LR-CO21 group and control group, each group with 12 piglets. Piglets in each group were orally administered recombinant porcine Lactobacillus reuteri expressing LFCA pPG-LFCA/LR-CO21, containing empty vector plasmid PPG/LR-CO21 and equal volume phosphate buffer (PBS);oral administration continued for 3 days, and the observation time after oral administration was 14 d. During the period, piglets were fed freely, and the changes of body weight and diarrhea were recorded. Experiment 2:thirty one-day-old newborn piglets with an average body weight of about 1.5 kg were randomly divided into 5 groups and given TGEV with a half tissue culture infection dose (TCID50) of 10-7.50/mL by oral administration of 1, 3, 6, 9 and 12 mL, respectively. The observation period of 7 d was set to analyze the conditions of half lethal dose. Experiment 3:another thirty-two newborn piglets with an average body weight of about 1.5 kg were selected as experimental animals and randomly divided into 4 groups, with 8 piglets in each group. The groups were pPG-LFCA/LR-CO21 group, pPG/LR-CO21 group, control group and TGEV infect group. There were 8 replicates in each group and 1 piglet in each replicate. Each head of the experimental group was orally fed ppG-LFCA/LR-CO21, pPG/LR-CO21 and equal volume of PBS at a dose of 2..1010 CFU per day for 1 consecutive week. At 8 days of age, TGEV was infected by oral administration at half lethal dose, and samples were collected after 7 days of infection. The weight change and diarrhea of each group of piglets were recorded;hematoxylin-eosin staining was used to detect the length of intestinal villi and the depth of crypts;enzyme linked immunosorbent assay (ELISA) was used to determine total serum total immunoglobulin G (IgG) and total secretory immunoglobulin A (sIgA) antibody contents. RT-qPCR was used to detect the mRNA relative expression levels of Claudin-1, Occludin, tight junction protein-1 (ZO-1), inflammatory cytokines interleukin-6 (IL-6), interleukin-8 (IL-8), interferon-P (IFN-P), tumor necrosis factor-a (TNF-a) and Toll-like receptor 2 (TLR2). The flora structure of the contents of the piglet's cecum was analyzed. After oral recombinant porcine Lactobacillusreuteri, compared with the control group, the average daily gain of newborn piglets in the pPG-LFCA/LR-CO21 group was significantly increased (P < 0.01), while the diarrhea rate was significantly decreased (P < 0.01). Compared with TGEV infection group, the average daily gain of piglets in pPG-LFCA/LR-CO21 group was increased and diarrhea rate was decreased, and the differences were significant (P < 0.05). Villus height and the ratio of villus height to crypt depth in jejunum and ileum were significantly increased (P < 0.05). The contents of total IgG and intestinal mucosal total sIgA antibody in serum of piglets were significantly increased (P < 0.05);the mRNA relative expression levels of tight junction protein-related genes Claudin-1, Occludin and ZO-1 in intestinal mucosal tissue were extremely significantly increased (P < 0.01), and the serum TNF-a content was extremely significantly decreased (P < 0.01). Serum IFN-P, IL-6, IL-8 and TLR2 contents were significantly increased (P < 0.01), and the survival rate of piglets was improved. The analysis of the bacterial diversity in the contents of the piglets' cecum showed that the proportion of normal intestinal flora of piglets decreased after TGEV infection. Compared with the TGEV infect group, the proportion of pathogenic bacteria Bacteroides in piglet's intestinal flora decreased by o
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Background: Gut microbiota is a complex ecosystem of bacteria, viruses, archaea, protozoa and yeasts in our intestine. It has several functions, including maintaining human body equilibrium. Microbial “dysbiosis” can be responsible for outbreak of local and systemic infections, especially in critically ill patients. Methods: to build a narrative review, we performed a Pubmed, Medline and EMBASE search for English language papers, reviews, meta-analyses, case series and randomized controlled trials (RCTs) by keywords and their associations: critically ill patient;nutrition;gut microbiota;probiotics;gut virome;SARS-COV 2. Results: Over the antibiotic-based “selective decontamination”, potentially responsible for drug-resistant microorganisms development, there is growing interest of scientists and the pharmaceutical industry for pre-, probiotics and their associations as safe and reliable remedies restoring gut microbial “eubiosis”. Very first encouraging evidences link different gut microbiota profiles with SARS-COV 2 disease stage and gravity. Thus, there is frame for a probiotic therapeutic approach of COVID-19. Conclusions: gut microbiota remodulation seems to be a promising and safe therapeutic approach to prevent local and systemic multi-resistant bug infections in the intensive care unit (ICU) patients. This approach deserves more and more attention at the time of SARS-COV 2 pandemic.
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Regular exercise can upgrade the efficiency of the immune system and beneficially alter the composition of the gastro-intestinal microbiome. We tested the hypothesis that active athletes have a more diverse microbiome than sedentary subjects, which could provide better protection against COVID-19 during infection. Twenty active competing athletes (CA) (16 male and 4 females of the national first and second leagues), aged 24.15 ± 4.7 years, and 20 sedentary subjects (SED) (15 male and 5 females), aged 27.75 ± 7.5 years, who had been diagnosed as positive for COVID-19 by a PCR test, served as subjects for the study. Fecal samples collected five to eight days after diagnosis and three weeks after a negative COVID-19 PCR test were used for microbiome analysis. Except for two individuals, all subjects reported very mild and/or mild symptoms of COVID-19 and stayed at home under quarantine. Significant differences were not found in the bacterial flora of trained and untrained subjects. On the other hand, during COVID-19 infection, at the phylum level, the relative abundance of Bacteroidetes was elevated during COVID-19 compared to the level measured three weeks after a negative PCR test (p < 0.05) when all subjects were included in the statistical analysis. Since it is known that Bacteroidetes can suppress toll-like receptor 4 and ACE2-dependent signaling, thus enhancing resistance against pro-inflammatory cytokines, it is suggested that Bacteroidetes provide protection against severe COVID-19 infection. There is no difference in the microbiome bacterial flora of trained and untrained subjects during and after a mild level of COVID-19 infection.