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Effects of microbiota composition on emergence of depressions and behavioural disorders in animals
Bartková, Nikola ; Vinkler, Michal (advisor) ; Kubovčiak, Jan (referee)
The aim of this study is to summarize the current knowledge on the influence of gut microbiota composition on behavioural disorders in selected mammals and birds. Current research focuses on the influence of gut microbiota on the development of mental illnesses in humans and the potential therapeutic use of manipulating its composition. This paper briefly summarizes the main mechanisms of microbiota influence on the development of mental illnesses. The gut microbiota may also influence the development of behavioural disorders in animals. The literature suggests that changes in gut microbiota composition in humans with mental illnesses and animals with behavioural disorders share some similarities. In general, they are related mainly to a reduced abundance of selected genera of short-chain fatty acid producing bacteria and an increased abundance of gram-negative bacteria. The exceptions are destructive behavioural disorders in animals, which are associated with increased abundance of the Clostridia class and decreased abundance of the Lactobacillus genus. To prevent their development under stress, the thesis proposes the probiotic use of Lactobacillus rhamnosus. To manipulate the composition of the gut microbiota in the treatment of depressive disorders in humans, the administration of probiotics,...
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The role of intestinal microbiota in the development of Alzheimer's dementia
Hakenová, Kristina ; Valeš, Karel (advisor) ; Vodička, Martin (referee)
Preserving health at a higher age depends on the function of biological homeostatic systems (neural endocrine and immune activities), where the biological interaction between these systems and the intestinal microflora plays a key role. One of the most serious diseases associated with aging is Alzheimer's dementia (AD) and it is the most common cause of dementia in the world. This disease is accompanied by cognitive impairment associated with accumulation of amyloid plaques and neurofibrillary fibres in brain tissue. Naturally, biological changes occur during the process of aging, resulting in reduced functional capacity of the organism, accompanied by an increased risk of inflammatoryprocesses involved in the etiology of several chronic, pathologies, including neurodegenerative processes. These modulatory processes are associated with oxidative stress and intestinal dysbiosis. It is already well documented in the scientific literature that significant changes in the composition of intestinal microbiota occur in aging. These changes can lead to several biological changes, including increased permeability of the intestinal barrier, thereby causing the increased penetration of many biologically active substances into the body. This may be a risk factor for the development of inflammation in both...
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Variability in selected haematological traits related to gastrointestinal microbiota in parrots (Psittaciformes)
Dlugošová, Sylvie ; Vinkler, Michal (advisor) ; Volf, Jiří (referee)
Thousands of parrots all over the world suffer from illnesses and medical complications that can result from interactions between their immune system and bacteria in their digestive tract. The aim of this master's thesis is to understand the link between symptoms of these medical issues, the composition of blood and gastrointestinal microbiota in parrots. Using the hematological methods, 198 blood samples representing 53 parrot species were analyzed. The composition of microbiome was defined by combination of a molecular approach using bacterial 16S rRNA gene sequencing in 132 fecal samples, 12 intestine samples, 228 cloacal swabs and 236 beak swabs representing in total 61 parrot species and a diagnostic approach by psittacine fecal Gram's stain method. Significant association of hematological parameters with individual, environmental and clinical factors was observed, as well as its considerable interspecific variability. Absolute heterophile and lymphocyte counts have been shown more useful for infectious and autoimmune disease monitoring than H/L ratio. Relative numbers of basophiles were the best indicator for behavioral disorders. In relation to hematological parameters, the effect of the bacterial family Flavobacteriaceae, as part of the oral microbiota, and the bacteria Escherichia or...
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Novel mechanisms of T cell-mediated intestinal autoimmunity to Paneth cells
Brabec, Tomáš ; Filipp, Dominik (advisor) ; Janečková, Lucie (referee)
(En) Paneth cells are one of the major player in the maintenance of the homeostatic relationship between intestinal microbiota and the immune system. This function is largely achieved by their production of bactericidal enteric α-defensins (ED) and other antimicrobials. Disruption of Paneth cell functions is associated with severe human disorders such as Crohn's disease (CD) and Autoimmune Polyendocrinopathy- Candidiasis-Ectodermal Dystrophy (APECED). However, there is only a very limited information regarding the interactions and regulatory circuits operating between Paneth cells and intestinal immune system in either health or under pathological conditions. The previous study conducted in our laboratory described a new mechanism for the initiation and maintenance of Paneth cells targeted autoimmunity. The suggested model was that ED-specific T cells escape the selection in the thymus, infiltrate the intestine and diminish Paneth cell numbers through autoimmune destruction. This process also lead to the accumulation of inflammation- inducing bacteria, which were implied to exacerbate the inflammatory autoimmunity. Since this model of intestinal autoimmunity is of correlative nature, its intrinsic mechanism and functional relationships between immune system, Paneth cells and microbiota are largely...
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Role of bacteria and mucosal immune system and their interaction in the pathogenesis of inflammatory bowel disease
Du, Zhengyu ; Hudcovic, Tomáš (advisor) ; Prokešová, Ludmila (referee) ; Kamanová, Jana (referee)
Although the etiology and pathogenesis of inflammatory bowel disease (IBD) is not fully understood, it is generally accepted that the inflammation results from aberrant immune responses to antigens of gut microbiota in genetically susceptible individuals (Sartor et al., 2006). Alteration in intestinal microbiota has been found in IBD patients with increased abundance of certain bacteria and decreased abundance of others. Due to the complexity of the disease, multifaceted interactions between genetic factors, host immune response, gut microbiota and environment factors need to be taken into account. In this thesis, the pathogenesis of IBD was first reviewed in respect with the four factors mentioned above. Then we concentrated on the interaction between IBD-associated bacteria and mucosal immune system. We investigated the ability of mucosal-associated bacteria (MAB) from IBD patients to induce spontaneous colitis in germ-free (GF) mice and the impact of those bacteria on the development of dextran sulfate sodium (DSS)-colitis. Together with the analysis of the composition of gut microbiota of MAB colonized mice, we demonstrated the potential deleterious microbes were able to increase the susceptibility to DSS-colitis once they found a suitable niche. We revealed the mechanism of an E.coli strain...
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Mechanisms of microbiota regulation during the estrous cycle of the house mouse.
Dodoková, Alica ; Stopková, Romana (advisor) ; Janotová, Kateřina (referee)
There is a very few papers to provide an overview of the characteristics of the estrous cycle, the relationship of the estrous cycle to physiological manifestations such as the pH of the vaginal environment, as well as the dynamics of the vaginal microbiota in wild mice. The aim of this thesis is to contribute to the understanding of the dynamic relationship between external influences and the physiology of the female reproductive system, to develop a reliable methodology for measuring the pH of the vaginal microenvironment in mice as well as to quantify the overall abundance of some bacterial taxons by comparing sequencing and qPCR methods. The results suggest that the physical presence of the male in the cage has the most significant effect on the prolongation of the estrus phase, in contrast to non-significant olfactory stimulation of the urine. Fluctuation in the pH of the vaginal environment have also been shown to be cyclic, and the qPCR method shows that the composition of the vaginal microbiota, during the estrus phase, differs significantly from other phases of the estrous cycle, as we confirmed by 16S rRNA sequencing. Thus, these results provide a comprehensive view of the variability of the estrous cycle with an emphasis on the variability of the vaginal microbiota and the change in the...
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Influence of intestinal microbiota on development of neurodegenerative diseases
Hakenová, Kristina ; Valeš, Karel (advisor) ; Vodička, Martin (referee)
Aging is associated with natural biological changes, which result in a decrease in the functional capacity of the body, which is also accompanied by an increased incidence of inflammatory processes that contribute to the development of neurodegeneration. The intestinal microbiota and its interaction with the intestine and the central nervous system play a key role in maintaining the function of biological homeostatic systems at an older age. This opens the possibility of influencing or modifying human microbiota for the development of therapeutic strategies. Based on the analysis of stool samples by HPLC MS / MS, the study confirmed the effect of selected probiotics on the modification of metabolic pathways and the proper functioning of the microbiota per se. The greatest effects were observed on tyrosine metabolism, tryptophan metabolism, arachidonic acid metabolism and bile acid biosynthesis metabolism. A positive effect of selected probiotic bacteria was found in the memory component of cognitive functions. Significant improvements were observed in verbal learning and verbal memory. In subjects with mild cognitive impairment, the progression of cognitive deficit has been slowed. Significant improvement was also observed for executive functions. These findings were not followed by a subjective...
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