Changes in the gut microbiota of rats after exposure to the fungicide Mancozeb.

Mancozeb is a fungicide commonly used in pest control programs, especially to protect vineyards. Its toxicity has already been evidenced in several studies. However, its influence on the composition and diversity of the gut microbiota remains unknown. In this work, the adverse impact of Mancozeb on the intestinal microbiota was investigated using a rodent model. Adult male Sprague Dawley rats were randomized into three groups: Control (standard diet), MZ1 (Mancozeb dose: 250 mg/kg bw/day), and MZ2 (Mancozeb dose: 500 mg/kg bw/day). After 12 weeks of experiment, animals were euthanized, and feces present in the intestine were collected. After fecal DNA extraction, the V4 region of the 16S rRNA gene was amplified followed by sequencing in an Ion S5™ System. Alpha and beta diversity analysis showed significant differences between Control and Mancozeb groups (MZ1 e MZ2), but no difference between MZ1 and MZ2 was observed. Seven genera significantly increased in abundance following Mancozeb exposure, while five genera decreased. Co-occurrence analyses revealed that the topological properties of the microbial networks, which can be used to infer co-occurrence interaction patterns among microorganisms, were significantly lower in both groups exposed to Mancozeb when compared to Control. In addition, 23 differentially abundant microbial metabolic pathways were identified in Mancozeb-treated groups mainly related to a change in energy metabolism, LPS biosynthesis, and nucleotide biosynthesis. In conclusion, the exposure to Mancozeb presented side effects by changing the composition of the microbiota in rats, increasing bacterial diversity regardless of the dose used, reducing the interaction patterns of the microbial communities, and changing microbial metabolic pathways.

Oxidative Stress and Antioxidant Defense in the Brain of Bat Species with Different Feeding Habits.

Assessing the levels of oxidative stress markers and antioxidant enzymes in the brain is crucial in evaluating its antioxidant capacity and understanding the influence of various dietary patterns on brain well-being. This study aimed to investigate the antioxidant status and oxidative damage in the brain of bat species with different feeding habits to gain insights into their protective mechanisms against oxidative stress and their interspecific variation. The levels of oxidative damage markers and the activities of antioxidants were measured in the brain of four bat species with different feeding habits, namely insectivorous, frugivorous, nectarivorous, and hematophagous. Insectivorous bats showed higher levels of SOD and fumarase compared to the other groups, while hematophagous bats showed lower levels of these enzymes. On the other hand, the activities of glutathione peroxidase and glutathione S-transferase were higher in hematophagous bats and lower in insectivorous bats. The carbonyl groups and malondialdehyde levels were lower in frugivores, while they were similar in the other feeding guilds. Nitrite and nitrate levels were higher in the hematophagous group and relatively lower in all other groups. The GSSG/GSH ratio was higher in the hematophagous group and lower in frugivores. Overall, our results indicate that the levels of oxidative stress markers and the activities of antioxidant enzymes in the brain vary significantly among bat species with different feeding habitats. The findings suggest that the antioxidant status of the brain is influenced by diet and feeding habits.

Oxidative Stress and Antioxidant Defense in the Heart, Liver, and Kidney of Bat Species with Different Feeding Habits.

The aim of this study was to compare the oxidative metabolism of four neotropical bat species with different feeding habits and investigate the relationship between their feeding habits and oxidative status. In terms of oxidative damage, our findings revealed major differences among the four bat species. In particular, hematophagous bats had lower levels of oxidative damage in the heart but higher levels in the liver. Nectarivorous bats had lower levels of carbonyl groups in the kidneys compared to insectivorous and hematophagous bats. The activity of various antioxidant and non-antioxidant enzymes in the heart, liver, and kidney also showed significant differences among the bat species. H2O2 consumption was lower in the heart of hematophagous bats, while insectivorous bats exhibited the highest enzymatic activity in the kidney. SOD activity was lower in the heart of hematophagous bats and lower in nectarivorous bats in the liver. Fumarase activity was higher in the heart of frugivorous/insectivorous and lower in nectarivorous/hematophagous bats. GPx activity was higher in the heart of nectarivorous/insectivorous and higher in the kidney of insectivorous bats. GST activity was higher in the heart of nectarivorous and lower in hematophagous bats. The correlation analysis between oxidative markers and enzymatic/non-enzymatic antioxidants in the heart, liver, and kidney exhibited distinct patterns of correlations due to variations in antioxidant defense mechanisms and oxidative stress responses in different organs. The observed differences in oxidative damage, antioxidant enzyme activities, and correlations between oxidative markers and antioxidants highlight the adaptability and complexity of the antioxidant defense systems in these bats. Each organ appears to have specific demands and adaptations to cope with oxidative stress based on its physiological functions and exposure to dietary components. Our results have major significance for the conservation and management of bats, which are threatened species despite being crucial components of ecosystems. Our study's implications go beyond bat biology and offer valuable insights into comparative oxidative physiology.

Distribution and interaction patterns of bacterial communities in an ornithogenic soil of Seymour Island, Antarctica.

Next-generation, culture-independent sequencing offers an excellent opportunity to examine network interactions among different microbial species. In this study, soil bacterial communities from a penguin rookery site at Seymour Island were analyzed for abundance, structure, diversity, and interaction networks to identify interaction patterns among the various taxa at three soil depths. The analysis revealed the presence of eight phyla distributed in different proportions among the surface layer (0-8 cm), middle layer (20-25 cm), and bottom (35-40 cm). The bottom layer presented the highest values of bacterial richness, diversity, and evenness when compared to surface and middle layers. The network analysis revealed the existence of a unique pattern of interactions in which the soil microbial network formed a clustered topology, rather than a modular structure as is usually found in biological communities. In addition, specific taxa were identified as important players in microbial community structure. Furthermore, simulation analyses indicated that the loss of potential keystone groups of microorganisms might alter the patterns of interactions within the microbial community. These findings provide new insights for assessing the consequences of environmental disturbances at the whole-community level in Antarctica.

Platelets: still a therapeutical target for haemostatic disorders.

Platelets are cytoplasmatic fragments from bone marrow megakaryocytes present in blood. In this work, we review the basis of platelet mechanisms, their participation in syndromes and in arterial thrombosis, and their potential as a target for designing new antithrombotic agents. The option of new biotechnological sources is also explored.

Advancing Microbiology through the Discovery of New Microbial Species and Strains.

In our pursuit of understanding the intricacies of microbial life, the isolation and characterization of new microbial species and strains play a pivotal role [...].

Extremophiles and Extreme Environments: A Decade of Progress and Challenges.

It is with great enthusiasm that we embark on a retrospective journey to the landmark work "Extremophiles and Extreme Environments" (1 in Appendix A), published 10 years ago as part of its Special Issue (2 in Appendix A) [...].

The Impact of Probiotic Bifidobacterium on Liver Diseases and the Microbiota.

Recent studies have shown the promising potential of probiotics, especially the bacterial genus Bifidobacterium, in the treatment of liver diseases. In this work, a systematic review was conducted, with a focus on studies that employed advanced Next Generation Sequencing (NGS) technologies to explore the potential of Bifidobacterium as a probiotic for treating liver pathologies such as Non-Alcoholic Fatty Liver Disease (NAFLD), Non-Alcoholic Steatohepatitis (NASH), Alcoholic Liver Disease (ALD), Cirrhosis, and Hepatocelullar Carcinoma (HCC) and its impact on the microbiota. Our results indicate that Bifidobacterium is a safe and effective probiotic for treating liver lesions. It successfully restored balance to the intestinal microbiota and improved biochemical and clinical parameters in NAFLD, ALD, and Cirrhosis. No significant adverse effects were identified. While more research is needed to establish its efficacy in treating NASH and HCC, the evidence suggests that Bifidobacterium is a promising probiotic for managing liver lesions.

Lactobacilli in COVID-19: A Systematic Review Based on Next-Generation Sequencing Studies.

The global pandemic was caused by the SARS-CoV-2 virus, known as COVID-19, which primarily affects the respiratory and intestinal systems and impacts the microbial communities of patients. This systematic review involved a comprehensive search across the major literature databases to explore the relationship between lactobacilli and COVID-19. Our emphasis was on investigations employing NGS technologies to explore this connection. Our analysis of nine selected studies revealed that lactobacilli have a reduced abundance in the disease and an association with disease severity. The protective mechanisms of lactobacilli in COVID-19 and other viral infections are likely to be multifaceted, involving complex interactions between the microbiota, the host immune system, and the virus itself. Moreover, upon closely examining the NGS methodologies and associated statistical analyses in each research study, we have noted concerns regarding the approach used to delineate the varying abundance of lactobacilli, which involves potential biases and the exclusion of pertinent data elements. These findings provide new insight into the relationship between COVID-19 and lactobacilli, highlighting the potential for microbiota modulation in COVID-19 treatment.

The Influence of Probiotic Lactobacilli on COVID-19 and the Microbiota.

This comprehensive review explores the potential of using lactobacilli as a probiotic in the management of COVID-19. Our findings suggest that lactobacilli show promise in reducing the risk of death, gastrointestinal and overall symptoms, and respiratory failure, as well as in lowering cytokines and inflammatory markers associated with the disease. The molecular mechanisms by which lactobacilli protect against COVID-19 and other viral infections may be related to the reduction in inflammation, modulation of the immune response, and direct interaction with viruses to produce antiviral substances. However, the selected studies demonstrate the presence of mixed findings for various clinical, biochemical, hematological, and immunological parameters, which may be attributed to methodological differences among studies. We highlight the importance of clearly describing randomization processes to minimize bias and caution against small sample sizes and inappropriate statistical tests that could lead to errors. This review offers valuable insights into the therapeutic potential of lactobacilli in the context of COVID-19 and identifies avenues for further research and applications. These findings hold promise for the development of novel approaches to managing COVID-19 and warrant further investigation into the potential benefits of lactobacilli in combating the disease.

Microbial composition and diversity in intraradicular biofilm formed in situ: New concepts based on next-generation sequencing.

This study aimed to characterize the taxonomic composition of intraradicular multispecies biofilms (IMBs) formed in situ in a model to reproduce clinical conditions. Twelve palatal roots of maxillary molars had its canals prepared. Two roots were randomly selected to sterility control. Ten intraoral prosthetic appliances with lateral slots were fabricated. The roots were positioned in the slots with the canal access open to the oral cavity. Eight volunteers wore the appliance for 21 days, and two wore it at two different time points. One root from each appliance was removed and stored at -20°C until DNA extraction and sequencing (n = 10). Biofilm was analyzed using next-generation sequencing and bioinformatics. The V4 hyper-variable region of the 16SrRNA gene was amplified and sequenced. For data analyses, the mothur pipeline was used for 16SrRNA processing, and subsequent analyses of the sequence dataset were performed in R using the MicrobiomeAnalyst R package. The taxonomy-based analysis of bacterial communities identified 562 operational taxonomic units (OTUs), which belonged to 93 genera, 44 families, and 8 phyla. Bacterial colonization was different for each biofilm, and samples did not have the same group of bacteria. Alpha and beta diversity analysis revealed some general patterns of sample clustering. A core microbiome of prevalent OTUs and genera was identified. IMBs were heterogeneous when analyzed individually, but some diversity patterns were found after sample clustering. The experimental model seemed to reproduce the actual biofilm composition in endodontic infections, which suggests that it may be used to evaluate disinfection protocols.

Distribution and Utilization of Vitamin E in Different Organs of Wild Bats from Different Food Groups.

In this work, we examined the levels of vitamin E in the heart, liver, and kidneys of four species of adult male bats with distinct feeding habits. Our results indicate consistent vitamin E levels in the heart across all four bat species, suggesting the presence of regulatory mechanisms. Additionally, the liver displayed notably higher vitamin E levels in nectarivorous and frugivorous bats, while hematophagous bats exhibited lower levels, indicating a link between dietary intake and liver vitamin E levels. Furthermore, correlation analysis provided additional insights into the relationships between vitamin E and key antioxidant parameters in the livers of bats. On the other hand, no correlation was observed between vitamin E and key antioxidant parameters in the heart. Intriguingly, vitamin E was not detected in the kidneys, likely due to physiological factors and the prioritization of vitamin E mobilization in the heart, where it serves critical physiological functions. This unexpected absence of vitamin E in bat kidneys highlights the unique metabolic demands and prioritization of vitamin mobilization in wild animals like bats, compared to conventional animal models. These findings provide insight into the intricate distribution and utilization of vitamin E in bats, emphasizing the influence of dietary intake and metabolic adaptations on vitamin E levels in different organs.

Microbial composition and diversity in intraradicular biofilm formed in situ: New concepts based on next-generation sequencing.

This study aimed to characterize the taxonomic composition of intraradicular multispecies biofilms (IMB) formed in situ in a model to reproduce clinical conditions. Twelve palatal roots of maxillary molars had its canals prepared. Two roots were randomly selected to sterility control. Ten intraoral prosthetic appliances with lateral slots were fabricated. The roots were positioned in the slots with the canal access open to the oral cavity. Eight volunteers wore the appliance for 21 days, and two wore it at two different time points. One root from each appliance was removed and stored at -20°C until DNA extraction and sequencing (n = 10). Biofilm was analyzed using next-generation sequencing and bioinformatics. The V4 hyper-variable region of the 16SrRNA gene was amplified and sequenced. For data analyses, the mothur pipeline was used for 16SrRNA processing, and subsequent analyses of the sequence dataset were performed in R using the Microbiome Analyst R package. The taxonomy-based analysis of bacterial communities identified 562 operational taxonomic units (OTUs), which belonged to 93 genera, 44 families, and 8 phyla. Bacterial colonization was different for each biofilm, and samples did not have the same group of bacteria. Alpha and beta diversity analysis revealed some general patterns of sample clustering. A core microbiome of prevalent OTUs and genera was identified. IMBs were heterogeneous when analyzed individually, but some diversity patterns were found after sample clustering. The experimental model seemed to reproduce the actual biofilm composition in endodontic infections, which suggests that it may be used to evaluate disinfection protocols.

Ornithine aspartate effects on bacterial composition and metabolic pathways in a rat model of steatotic liver disease.

BACKGROUND: Metabolic-dysfunction associated steatotic liver disease (MASLD) is a hepatic manifestation of metabolic syndrome. Studies suggest ornithine aspartate (LOLA) as drug therapy. AIM: To analyze the influence of LOLA intake on gut microbiota using a nutritional model of MASLD. METHODS: Adult male Sprague Dawley rats were randomized into three groups: Control (10 rats fed with a standard diet), MASLD (10 rats fed with a high-fat and choline-deficient diet), and LOLA (10 rats receiving 200 mg/kg/d LOLA, after the 16th week receiving high-fat and choline-deficient diet). After 28 wk of the experiment, animals were euthanized, and feces present in the intestine were collected. Following fecal DNA extraction, the V4 region of the 16S rRNA gene was amplified followed by sequencing in an Ion S5™ system. RESULTS: Alpha and beta diversity metrics were comparable between MASLD and LOLA. 3 OTUs were differentially abundant between MASLD and LOLA, which belong to the species Helicobacter rodentium, Parabacteroides goldsteinii, and Parabacteroides distasonis. The functional prediction provided two different metabolic profiles between MASLD and LOLA. The 9 pathways differentially abundant in MASLD are related to a change in energy source, adenosine/purine nucleotides degradation as well as guanosine and adenosine deoxyribonucleotides biosynthesis. The 14 pathways differentially abundant in LOLA are associated with four major metabolic functions primarily influenced by L-aspartate, including tricarboxylic acid cycle pathways, purine/guanosine nucleotides biosynthesis, pyrimidine ribonucleotides biosynthesis and salvage as well as lipid IVA biosynthesis. CONCLUSION: Although LOLA had no influence on alpha and beta diversity in this nutritional model of MASLD, it was associated with changes in specific gut microbes and their related metabolic pathways.

Sodium propionate oral supplementation ameliorates depressive-like behavior through gut microbiome and histone 3 epigenetic regulation.

Major depressive disorder (MDD) is a global health concern, affecting over 250 million individuals worldwide. In recent years, the gut-brain axis has emerged as a promising field for understanding the pathophysiology of MDD. Microbial metabolites, such as short-chain fatty acids (SCFAs)-acetate, butyrate, and propionate-, have gained attention for their potential to influence epigenetic modifications within the host brain. However, the precise mechanisms through which these metabolites participate in MDD pathophysiology remain elusive. This study was designed to investigate the effects of oral SCFA supplementation in adult male Wistar rats subjected to chronic unpredictable mild stress (CUMS). A subset of control and CUMS-exposed rats received different supplementations: sodium acetate (NaOAc) at a concentration of 60 mM, sodium butyrate (NaB) at 40 mM, sodium propionate (NaP) at 50 mM, or a mixture of these SCFAs. The gut microbiome was assessed through 16S rRNA sequencing, and epigenetic profiling was performed using Western blot analysis. Results demonstrated that NaP supplementation significantly alleviated anhedonia in stressed animals, as evidenced by improved performance in the sucrose consumption test. This ameliorative effect was potentially associated with the modulation of gut bacterial communities, accompanied by the attenuation of the region-specific epigenetic dysregulation in the brain of the animals exposed to chronic stress. These findings suggest a potential association between gut dysbiosis and stress response, and NaP could be a promising target for future MDD interventions. However, further studies are needed to fully elucidate the underlying mechanisms of these effects.

Comparative Analysis of the Gut Microbiota of Bat Species with Different Feeding Habits.

Bats are a diverse and ecologically important group of mammals that exhibit remarkable diversity in their feeding habits. These diverse feeding habits are thought to be reflected in the composition and function of their gut microbiota, which plays important roles in nutrient acquisition, immune function, and overall health. Despite the rich biodiversity of bat species in South America, there is a lack of microbiome studies focusing on bats from this region. Such studies could offer major insights into conservation efforts and the preservation of biodiversity in South America. In this work, we aimed to compare the gut microbiota of four bat species with different feeding habits from Southern Brazil, including nectarivorous, frugivorous, insectivorous, and hematophagous bats. Our findings demonstrate that feeding habits can have a significant impact on the diversity and composition of bat gut microbiotas, with each species exhibiting unique metabolic potentials related to their dietary niches. In addition, the identification of potentially pathogenic bacteria suggests that the carriage of microbial pathogens by bats may vary, depending on feeding habits and host-specific factors. These findings provide novel insights into the relationship between bat feeding habits and gut microbiota composition, highlighting the need to promote diverse habitats and food sources to support these ecologically important species.

Changes in diversity, abundance, and structure of soil bacterial communities in Brazilian Savanna under different land use systems.

The Brazilian Savanna, also known as "Cerrado", is the richest and most diverse savanna in the world and has been ranked as one of the main hotspots of biodiversity. The Cerrado is a representative biome in Central Brazil and the second largest biome in species diversity of South America. Nevertheless, large areas of native vegetation have been converted to agricultural land including grain production, livestock, and forestry. In this view, understanding how land use affects microbial communities is fundamental for the sustainable management of agricultural ecosystems. The aim of this work was to analyze and compare the soil bacterial communities from the Brazilian Cerrado associated with different land use systems using high throughput pyrosequencing of 16S rRNA genes. Relevant differences were observed in the abundance and structure of bacterial communities in soils under different land use systems. On the other hand, the diversity of bacterial communities was not relevantly changed among the sites studied. Land use systems had also an important impact on specific bacterial groups in soil, which might change the soil function and the ecological processes. Acidobacteria, Proteobacteria, and Actinobacteria were the most abundant groups in the Brazilian Cerrado. These findings suggest that more important than analyzing the general diversity is to analyze the composition of the communities. Since soil type was the same among the sites, we might assume that land use was the main factor defining the abundance and structure of bacterial communities.

A Critical Assessment of the Peer Review Process in Life: From Submission to Final Decision.

In the world of academic research and scientific publishing, the process of peer review plays a pivotal role [...].

The Role of Bifidobacterium in COVID-19: A Systematic Review.

The COVID-19 pandemic, caused by the SARS-CoV-2 virus, mainly causes respiratory and intestinal symptoms and changes in the microbiota of patients. We performed a systematic search in major databases using "Bifidobacterium" and "COVID-19" or "SARS-CoV-2" as key terms to assess the relationship of the genus to COVID-19. After the selection steps, 25 articles were analyzed. Of these, eighteen were observational, and seven were interventional articles that evaluated the use of Bifidobacterium alone or in mix as probiotics for additional treatment of patients with COVID-19. All stages and severities were contemplated, including post-COVID-19 patients. Overall, Bifidobacterium was associated with both protective effects and reduced abundance in relation to the disease. The genus has been found to be abundant in some cases and linked to disease severity. The studies evaluating the use of Bifidobacterium as probiotics have demonstrated the potential of this genus in reducing symptoms, improving pulmonary function, reducing inflammatory markers, alleviating gastrointestinal symptoms, and even contributing to better control of mortality. In summary, Bifidobacterium may offer protection against COVID-19 through its ability to modulate the immune response, reduce inflammation, compete with pathogenic microbes, and maintain gut barrier function. The findings provide valuable insights into the relationship between the disease and the genus Bifidobacterium, highlighting the potential of microbiota modulation in the treatment of COVID-19.