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THE HORSE HOLOBIONT IN A STRESSFUL WORLD FROM MICROBES TO ECOSYSTEMS
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Exercise-induced stress behavior, gut-microbiota-brain axis and diet: a systematic review for athletes
No full textFatigue, mood disturbances, under performance and gastrointestinal distress are common among athletes during training and competition. The psychosocial and physical demands during intense exercise can initiate a stress response activating the sympathetic-adrenomedullary and hypothalamus-pituitary-adrenal (HPA) axes, resulting in the release of stress and catabolic hormones, inflammatory cytokines and microbial molecules. The gut is home to trillions of microorganisms that have fundamental roles in many aspects of human biology, including metabolism, endocrine, neuronal and immune function. The gut microbiome and its influence on host behavior, intestinal barrier and immune function are believed to be a critical aspect of the brain-gut axis. Recent evidence in murine models shows that there is a high correlation between physical and emotional stress during exercise and changes in gastrointestinal microbiota composition. For instance, induced exercise-stress decreased cecal levels of Turicibacter spp and increased Ruminococcus gnavus, which have well defined roles in intestinal mucus degradation and immune function. Diet is known to dramatically modulate the composition of the gut microbiota. Due to the considerable complexity of stress responses in elite athletes (from leaky gut to increased catabolism and depression), defining standard diet regimes is difficult. However, some preliminary experimental data obtained from studies using probiotics and prebiotics studies show some interesting results, indicating that the microbiota acts like an endocrine organ (e.g. secreting serotonin, dopamine or other neurotransmitters) and may control the HPA axis in athletes. What is troubling is that dietary recommendations for elite athletes are primarily based on a low consumption of plant polysaccharides, which is associated with reduced microbiota diversity and functionality (e.g. less synthesis of byproducts such as short chain fatty acids and neurotransmitters). As more elite athletes suffer from psychological and gastrointestinal conditions that can be linked to the gut, targeting the microbiota therapeutically may need to be incorporated in athletes' diets that take into consideration dietary fiber as well as microbial taxa not currently present in athlete's gut
The Crosstalk between the Gut Microbiota and Mitochondria during Exercise
No full textMany physiological changes occur in response to endurance exercise in order to adapt to the increasing energy needs, mitochondria biogenesis, increased reactive oxygen species (ROS) production and acute inflammatory responses. Mitochondria are organelles within each cell that are crucial for ATP production and are also a major producer of ROS and reactive nitrogen species during intense exercise. Recent evidence shows there is a bidirectional interaction between mitochondria and microbiota. The gut microbiota have been shown to regulate key transcriptional co-activators, transcription factors and enzymes involved in mitochondrial biogenesis such as PGC-1 alpha, SIRT1, and AMPK genes. Furthermore, the gut microbiota and its metabolites, such as short chain fatty acids and secondary bile acids, also contribute to host energy production, ROS modulation and inflammation in the gut by attenuating TNF alpha- mediated immune responses and inflammasomes such as NLRP3. On the other hand, mitochondria, particularly mitochondrial ROS production, have a crucial role in regulating the gut microbiota via modulating intestinal barrier function and mucosal immune responses. Recently, it has also been shown that genetic variants within the mitochondrial genome, could affect mitochondrial function and therefore the intestinal microbiota composition and activity. Diet is also known to dramatically modulate the composition of the gut microbiota. Therefore, studies targeting the gut microbiota can be useful for managing mitochondrial related ROS production, pro-inflammatory signals and metabolic limits in endurance athletes
Microbial spoilage and quality of marinated dark, firm, dry meat
No full textEstudi elaborat a partir d’una estada al Royal Veterinary and Agricultural University of Denmark entre els mesos de Març a Juny del 2006. S’ha investigat l’efecte dels envasats amb atmosferes modificades (MAP), així com la marinació amb vi tint, sobre l’evolució de la contaminació bacteriològica de carns fosques, dures i seques (DFD). Les carns DFD es troben a les canals d’animals que, abans del sacrifici, han estat exposades a activitats musculars prolongades o estrès. Les carns DFD impliquen importants pèrdues econòmiques degut a la contaminació bacteriològica i als problemes tecnològics relacionats amb la alta capacitat de retenció d’aigua. A més a més, és crític per la indústria investigar la diversitat de la contaminació bacteriana, identificar les espècies bacterianes i controlar-les. Però és difícil degut a la inhabilitat per detectar algunes bactèries en medis coneguts, les interaccions entre elles, la complexitat dels tipus de contaminació com són aigua, terra, femtes i l’ambient. La Polymerasa chain reaction- Denaturating Electrophoresis Gel (PCR-DGEE ) pot sobrepassar aquests problemes reflectint la diversitat microbial i les espècies bacterianes. Els resultants han indicat que la varietat bacteriana de la carn incrementava amb els dies d’envasat independentment del mètode d’envasat, però decreixia significativament amb el tractament de marinació amb vi tint. La DGEE ha mostrat diferències en les espècies trobades, indicant canvis en la contaminació bacteriana i les seves característiques en la carn DFD sota els diferents tractaments. Tot i que la marinació és una bona alternativa i solució a la comercialització de carn DFD , estudis de seqüenciació són necessaris per identificar les diferents tipus de bactèries.Report for the scientific sojourn at the Royal Veterinary and Agricultural University of Denmark from March until June 2006. The effects of modified atmosphere packaging (MAP), as well as red wine marination on evolution of bacteriological spoilage in dark, firm and dry beef meat (DFD) have been investigated. The DFD meat is found in carcasses from animals which, before slaughter, have undergone prolonged muscular activity or stress. The DFD implicates important economic losses due to the bacteriological spoilage and technological problems related to high water-holding capacity. Moreover, it is critical for meat industry to investigate contaminating bacteria diversity and identify the bacterium species and then control them. But it is very difficult to do this due to inability to detect some bacteria on the know media, the interactions between bacterium species, the complexity of sources contamination such as water, soil, feces and environment. The Polymerasa chain reaction- Denaturating Electrophoresis Gel (PCR- DGEE ) can overcome these problems by reflecting the microbial diversity and bacteria species. The results indicated that the bacterial diversity of meat increased with storage time regardless of packaging method, but decreased significantly with red wine marination treatment. The DGEE technique indicated differences in the species found, indicating changes of the contaminating bacteria and their characteristics in DFD meat under different treatment. Although marination is a good alternative and solution for DFD meat commercialization, sequence studies are necessary to identify the different types of bacteria
Role of Vitamin D in the hygiene hypothesis: the interplay between vitamin D, vitamin D receptors, gut microbiota, and immune response
No full textThe hygiene hypothesis postulates that higher levels of cleanliness and improper exposure to microorganisms early in childhood could disturb the intestinal microbiome resulting in abnormal immune responses. Recently, more attention has been put on how a lack of sun exposure and consequently vitamin D deficiency could lead to less immune tolerance and aberrant immune responses. Moreover, vitamin D receptor (VDR) function has been positioned to be a critical aspect of immune response and gut homeostasis. Therefore, this review focuses on the role that the interaction between vitamin D, VDR function, and gut microbiome might have on autoimmune diseases in the context of the hygiene hypothesis. Literature shows that there is a high correlation between vitamin D deficiency, VDR dysfunction, gut microbiota composition, and autoimmune diseases. The biologically active form of vitamin D, 1,25(OH)(2)D-3, serves as the primary ligand for VDRs, which have been shown to play a fundamental role in reducing autoimmune disease symptoms. Although the biological functions of VDR, the effects of its genetic variants, and the effects of epigenetic profiles in its promoter region are largely unknown in humans, studies in murine models are increasingly demonstrating that VDRs play a crucial role in attenuating autoimmune disease symptoms by regulating autophagy and the production of antimicrobial peptides, such cathelicidin and beta-defensin, which are responsible for modifying the intestinal microbiota to a healthier composition. Remarkably, evidence shows that hormonal compounds and byproducts of the microbiota such as secondary bile acids might also activate VDR. Therefore, understanding the interaction between VDR and gut microbiota is of the utmost importance toward understanding the rise in autoimmune diseases in Western countries. We have gained insights on how the VDR functions affects inflammation, autophagy, and microbiota composition that could lead to the development of pathogenesis of autoimmune diseases, while confirming the role vitamin D and VDRs have in the context of hygiene hypothesis
Effects of wine polyphenols on cancer prevention
No full textIntroduction: Cancer has become in the recent decades one of the leading causes of death worldwide. The search for effective prevention has become a priority for the basic and clinical science. Wine polyphenols have been proposed as alternative therapy for induction and on maintaining remission of cancer. Objective: To review current scientific evidence of cancer and the efficacy of dietary supplement therapy (especially wine polyphenols). Materials and Methods: Extensive search of scientific publications was performed in specialized electronic databases: NBCI, Elsevier, Scielo, Scirus and Science Direct. Results and discussion: Results from in vitro and laboratory animals experiments demonstrate that wine polyphenols controls the cell apoptosis of different type of cancers through out the increase of reactive oxygen species, and decrease of cell growth. Different studies have shown that regular and moderate wine consumption (one or two glasses for day) is associated with decreased incidence of cardiovascular disease, hypertension, diabetes, and certain cancers, such as colon, breast, lung, or prostate. However, more scientific evidences are needed to strength the effect of resveratrol in controlling cancer. Conclusions: A better knowledge and understanding of the wine polyphenol role in cancer disease patients is possible with the current published results. The wine polyphenols plays a significant role as antioxidant and prooxidant in cancer, although more extensive studies are required to determine the clinical significance in humans
El ácido alfa lipoico y su poder antioxidante frente al cáncer y las patologías de sensibilización central
No full textIntroduction: The alpha lipoic acid (ALA) may control and limit the production of free radicals, influencing the development of pathologies such cancer or central sensitization diseases. However, the molecular mechanisms are still not elucidated.[br/]
Objective: The objective of the present review is to contrast the antioxidant properties of ALA in the prevention and development of pathologies related to the oxidative stress.[br/]
Materials and methods: In this work, more than 100 articles published during the last 20 years that relate ALA consumption and pathologies related to the oxidative stress have been analysed. The articles have been obtained from different specialized databases (PubMed central, Web of science, Elsevier Journal, Science Direct) and included experiments in animals, cells, and humans. Domains evaluated included ALA, central sensitization diseases, free radicals, and ALA.[br/]
Results and discussion: Results from in vitro and laboratory animals experiments demonstrate that ALA controls the cell apoptosis of different type of cancers through out the increase of reactive oxygen species, and decrease of cell growth. Moreover, results demonstrated that ALA presents an antioxidant capacity and the ability to regenerate other antioxidants, which is essential to treat the central sensitization diseases.[br/]
Conclusions: The ALA plays a significant role as antioxidant and prooxidant in cancer and central sensitization diseases, although more extensive studies are required to determine the clinical significance in humans
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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