Dagmar Srutkova

• PhD
• Complex of Biomedical Institutes at Krč

Background The dual allergen exposure hypothesis states that sensitization to food antigens occurs through a damaged skin barrier in individuals with no previous oral tolerance to certain foods. However, the resulting allergic reaction could depend on factors such as the host’s genetic predisposition as well as the skin and gut microbiota. Methods...

Escherichia coli A0 34/86 (EcO83) is a probiotic strain used in newborns to prevent nosocomial infections and diarrhoea. This bacterium stimulates both pro‐ and anti‐inflammatory cytokine production and its intranasal administration reduces allergic airway inflammation in mice. Despite its benefits, there are concerns about the use of live probioti...

Allergies have become a growing problem and the number of cases is increasing yearly. Administration of postbiotics, well-defined bacterial molecules, is gaining attention as a novel and promising strategy to ameliorate the allergic burden. The BAP1 polysaccharide (PS) of Bifidobacterium adolescentis CCDM 368, was previously characterized by us reg...

The alarming prevalence of inflammatory bowel disease (IBD) in early childhood is associated with imbalances in the microbiome, the immune response, and environmental factors. Some pathogenic Escherichia coli (E. coli) strains have been found in IBD patients, where they may influence disease progression. Therefore, the discovery of new harmful bact...

Butyrate, a metabolite produced by gut bacteria, has demonstrated beneficial effects in the colon and has been used to treat inflammatory bowel diseases. However, the mechanism by which butyrate operates remains incompletely understood. Given that oral butyrate can exert either a direct impact on the gut mucosa or an indirect influence through its...

Microbiota plays a role in shaping the HPA-axis response to psychological stressors. To examine the role of microbiota in response to acute immune stressor, we stimulated the adaptive immune system by anti-CD3 antibody injection and investigated the expression of adrenal steroidogenic enzymes and profiling of plasma corticosteroids and their metabo...

Intestinal epithelial cells have the capacity to upregulate MHCII molecules in response to certain epithelial-adhesive microbes, such as segmented filamentous bacteria (SFB). However, the mechanism regulating MHCII expression as well as the impact of epithelial MHCII–mediated antigen presentation on T cell responses targeting those microbes remains...

The currently observed high prevalence of allergic diseases has been associated with changes in microbial exposure in industrialized countries. Defined bacterial components represent a new strategy for modulating the allergic immune response. We show that intranasal administration of exopolysaccharide isolated from Lacticaseibacillus (L.) rhamnosus...

PRRSV is capable of evading the effective immune response, thus persisting in piglets and throughout the swine herd. We show here that PRRSV invades the thymus and causes depletion of T-cell precursors and alteration of the TCR repertoire. Developing thymocytes are affected during negative selection when they transit from the triple-negative to tri...

Bifidobacteria are among the most common bacteria used for their probiotic properties and their impact on the maturation and function of the immune system has been well-described. Recently, scientific interest is shifting from live bacteria to defined bacteria-derived biologically active molecules. Their greatest advantage over probiotics is the de...

The ability of hyaluronan as a dietary supplement to increase skin moisture and relieve knee pain has been demonstrated in several clinical studies. To understand the mechanism of action, determining hyaluronan's bioavailability and in vivo fate is crucial. Here, we used 13C-hyaluronan combined with LC–MS analysis to compare the absorption and meta...

The intestinal microbiota is known to influence postnatal growth. We previously found that a strain of Lactiplantibacillus plantarum (strain LpWJL) buffers the adverse effects of chronic undernutrition on the growth of juvenile germ-free mice. Here, we report that LpWJL sustains the postnatal growth of malnourished conventional animals and supports...

IL-17 protects epithelial barriers by inducing the secretion of antimicrobial peptides (AMPs). However, the effect of IL-17 on Paneth cells (PCs), the major producers of AMPs in the small intestine, is unclear. Here, we show that targeted ablation of the IL-17 receptor (IL-17R) in PCs disrupts their antimicrobial functions and decreases the frequen...

Background Animals form complex symbiotic associations with their gut microbes, whose evolution is determined by an intricate network of host and environmental factors. In many insects, such as Drosophila melanogaster , the microbiome is flexible, environmentally determined, and less diverse than in mammals. In contrast, mammals maintain complex mu...

Background: Nearly 45% of deaths among children under 5 years of age are related to undernutrition. Protein-energy malnutrition (PEM) is accompanied by underweight (low weight for age), stunting (low height for age), and wasting (low weight for height). Bacteriotherapy is considered as a promising complementary therapy to refeeding for ameliorating...

Several studies have indicated the beneficial anti-inflammatory effect of butyrate in inflammatory bowel disease (IBD) therapy implying attempts to increase butyrate production in the gut through orally administered dietary supplementation. Through the gut–liver axis, however, butyrate may reach directly the liver and influence the drug-metabolizin...

Bifidobacteria are gram-positive, anaerobic or microaerophilic bacteria, which also include strains with proven probiotic activity. The positive effect of probiotic bacteria on the host is well known. Probiotic strains of Bifidobacteria have the ability to modulate the immune system through components of the cell wall, such as peptidoglycan, polysa...

The expression of MHCII by intestinal epithelial cells (IEC) determines the severity of intestinal immunopathological reactions. However, the function of MHCII on IEC under homeostatic conditions remains elusive. Here we report that MHCII expression on IECs is a hallmark of an adaptive wave of homeostatic intestinal immune responses to commensal se...

The development of inflammatory bowel disease (IBD) is associated with alterations in the gut microbiota. There is currently no universal treatment for this disease, thus emphasizing the importance of developing innovative therapeutic approaches. Gut microbiome-derived metabolite butyrate with its well-known anti-inflammatory effect in the gut is a...

INTRODUCTION Due to their health-promoting properties, bacteria of the Bifidobacterium genus are commonly used as probiotics. Not only do they impact the general well-being of the host, but they are also crucial for the maturation of the immune system and the creation of immune system responses. However, the use of the whole bacteria causes the bod...

Bifidobacterium strains are well known for their health-promoting properties. However, the exact effect on the host results from the composition and metabolic activity of the studied bacteria. Moreover, the immunomodulatory properties of the Bifidobacterium molecules may differ between antigens. This is why thorough studies are needed to reveal a b...

Animals form complex symbiotic associations with their gut microbes, whose evolution is determined by an intricate network of host and environmental factors. In many insects, such as Drosophila melanogaster , the microbiome is flexible, environmentally determined and less diverse than in mammals. In contrast, mammals maintain complex multispecies c...

In pigs (Sus scrofa), the initial immunoglobulin rearrangement of the κ light chain is replaced by λ before the heavy chains rearrange, and the light chains may rearrange even later. This study investigates whether these developmental differences are reflected in the usage of IGK and IGL genes. We found large differences between peripheral B cells...

Mus musculus is the classic mammalian model for biomedical research. Despite global efforts to standardize breeding and experimental procedures, the undefined composition and interindividual diversity of the microbiota of laboratory mice remains a limitation. In an attempt to standardize the gut microbiome in preclinical mouse studies, here we repo...

The classical definition of probiotics states that bacteria must be alive to be beneficial for human organism. However, recent reports show that inactivated bacteria or their effector molecules can also possess such properties. In this study, we investigated the physical and immunomodulatory properties of four Bifidobacterium strains in the heat-tr...

Glucocorticoids (GCs) are hormones that are released in response to stressors and exhibit many activities, including immunomodulatory and anti-inflammatory activities. They are primarily synthesized in the adrenal gland but are also produced in peripheral tissues via regeneration of adrenal 11-oxo metabolites or by de novo synthesis from cholestero...

A steady rise in the number of poly-sensitized patients has increased the demand for effective prophylactic strategies against multi-sensitivities. Probiotic bacteria have been successfully used in clinics and experimental models to prevent allergic mono-sensitization. In the present study, we have investigated whether probiotic bacteria could prev...

The use of probiotics is now widely practiced due to their beneficial effect on health and their relative safety status. Research shows that oral administration of probiotics such as Bifidobacterium to allergy sufferers can alleviate symptoms and prevent relapse in patients with allergic rhinitis (1). Recently, intranasal administration of probioti...

Numerous studies indicate the beneficial effect of the human gut microbiota on the health and proper functioning of the host (O'Callaghan A., van Sinderen D.; 2016). One of the main representatives of the gastrointestinal tract belongs to the gram-positive, anaerobic Bifidobacterium genus, whose immunomodulatory properties have already been confirm...

Mucosal surfaces are colonized by highly diverse commensal microbiota. Coating with secretory IgA (SIgA) promotes the survival of commensal bacteria while it inhibits the invasion by pathogens. Bacterial coating could be mediated by antigen-specific SIgA recognition, polyreactivity, and/or by the SIgA-associated glycans. In contrast to many in vitr...

A variety of health benefits has been documented to be associated with the consumption of probiotic bacteria, namely bifidobacteria and lactobacilli. Thanks to the scientific advances in recent years we are beginning to understand the molecular mechanisms by which bacteria in general and probiotic bacteria in particular act as host physiology and i...

The Oligo-Mouse-Microbiota (OMM¹²) is a recently developed synthetic bacterial community for functional microbiome research in mouse models (Brugiroux et al., 2016). To date, the OMM¹² model has been established in several germ-free mouse facilities world-wide and is employed to address a growing variety of research questions related to infection b...

Epidermal growth factor receptor (EGFR)-targeted anticancer therapy induces stigmatizing skin toxicities affecting patients' quality of life and therapy adherence. The lack of mechanistic details underlying these adverse events hampers their management. We found that EGFR/ERK signaling is required in LRIG1-positive stem cells during de novo hair er...

The gut microbiota play an important role in shaping brain functions and behavior, including the activity of the hypothalamus-pituitary-adrenocortical (HPA) axis. However, little is known about the effect of the microbiota on the distinct structures (hypothalamus, pituitary, and adrenals) of the HPA axis. In the present study, we analyzed the influ...

Psoriatic patients have altered microbiota, both in the intestine and on the skin. It is not clear, however, whether this is a cause or consequence of the disease. In this study, using an experimental mouse model of psoriasis induced by imiquimod (IMQ), we show that oral treatment with a broad spectrum of antibiotics (MIX) or metronidazole (MET) al...

Background: Mucosal mast cells (MC) are key players in IgE-mediated food allergy (FA). The evidence on the interaction between gut microbiota, MC and susceptibility to FA is contradictory. Objective: We tested the hypothesis that commensal bacteria are essential for MC migration to the gut and their maturation impacting the susceptibility to FA. Me...

Background: Mucosal mast cells (MC) are key players in IgE-mediated food allergy (FA). The evidence on the interaction between gut microbiota, MC and susceptibility to FA is contradictory. Objective: We tested the hypothesis that commensal bacteria are essential for MC migration to the gut and their maturation impacting the susceptibility to FA. Me...

Fig. S1. Foxp3 expression in the mesenteric lymph nodes and spleens of OVA‐treated mice.

Here, we compared the abilities of polysaccharides L900/2 and L900/3, which were previously isolated from Lactobacillus rhamnosus LOCK 0900, to modulate the immune response to bystander antigens in a mouse model of ovalbumin (OVA) sensitization. In vivo, both polysaccharides reduced the levels of OVA-specific IgE, IgE-dependent basophil degranulati...

Germ-free animals have been used to define the vital role of commensal bacteria on the maturation of the host immune system. However, the role of bacterial residues in diet in this setting is poorly understood. Here we investigated the effect of bacterial contamination in sterile diet on the level of allergic sensitization in germ-free mice. Steril...

Composition of the feed mixture ST1. (DOCX)

Flow cytometry analyses of maturation of bone marrow-derived DC. Mouse bone marrow-derived DC (BM-DC) were prepared and stimulated as described in the manuscript. BM-DC were labelled with monoclonal antibodies for CD11c (FITC), MHC II (APC), CD40, CD80 or CD86 (PE) (eBioscience, USA). Appropriate isotype antibodies were used as controls to determin...

The Bifidobacteria show great diversity in the cell surface architecture which may influence the physicochemical properties of the bacterial cell and strain specific properties. The immunomodulatory role of bifidobacteria has been extensively studied, however studies on the immunoreactivity of their protein molecules are very limited. Here, we comp...

The Lactobacillus casei strain, LOCK 0919, is intended for the dietary management of food allergies and atopic dermatitis (LATOPIC® BIOMED). The use of a probiotic to modulate immune responses is an interesting strategy for solving imbalance problems of gut microflora that may lead to various disorders. However, the exact bacterial signaling mechan...

Increasing numbers of clinical trials and animal experiments have shown that probiotic bacteria are promising tools for allergy prevention. Here, we analyzed the immunomodulatory properties of three selected lactobacillus strains and the impact of their mixture on allergic sensitization to Bet v 1 using a gnotobiotic mouse model. We showed that Lac...

Microbiota and infant development Malnutrition in children is a persistent challenge that is not always remedied by improvements in nutrition. This is because a characteristic community of gut microbes seems to mediate some of the pathology. Human gut microbes can be transplanted effectively into germ-free mice to recapitulate their associated phen...

The genus Lactobacillus belongs to a large heterogeneous group of low G + C Gram-positive anaerobic bacteria, which are frequently used as probiotics. The health-beneficial effects, in particular the immunomodulation effect, of probiotics depend on the strain and dose used. Strain variations may be related to diversity of the cell surface architect...

Disturbances in the intestinal microbial community (i.e. dysbiosis) or presence of the microbes with deleterious effects on colonic mucosa has been linked to the pathogenesis of inflammatory bowel diseases. However the role of microbiota in induction and progression of ulcerative colitis (UC) has not yet been fully elucidated. Three lines of human...

In the present study, phenotypic and genotypic methods and MALDI-TOF mass spectrometry were applied for the species identification of 29 out of 30 strains of the genus Lactobacillus isolated from faecal samples of 30 breastfed infants. All strains were tested for growth in milk and/or reconstituted skimmed milk supplemented with 0.5 % yeast extract...

Background: Reduced microbial diversity has been associated with inflammatory bowel disease (IBD) and probiotic bacteria have been proposed for its prevention and/or treatment. Nevertheless, comparative studies of strains of the same subspecies for specific health benefits are scarce. Here we compared two Bifidobacterium longum ssp. longum strains...

A decrease in the abundance and biodiversity of intestinal bacteria within the Firmicutes phylum has been associated with inflammatory bowel disease (IBD). In particular, the anti-inflammatory bacterium Faecalibacterium prausnitzii, member of the Firmicutes phylum and one of the most abundant species in healthy human colon, is underrepresented in t...

The structures of polysaccharides (PS) isolated from Lactobacillus rhamnosus LOCK 0900 and results from stimulation of mouse bone marrow-derived dendritic cells (BM-DC) and human embryonal kidney (HEK293) cells stably transfected with Toll-like receptors (TLR) upon exposure to these antigens were studied. L. rhamnosus LOCK 0900 produces PS that dif...

Increasing numbers of clinical trials and animal experiments have shown that probiotic bacteria are promising tools for allergy prevention. Here, we analyzed the immunomodulatory properties of three selected lactobacillus strains and the impact of their mixture on allergic sensitization to Bet v 1 using a gnotobiotic mouse model. We showed that Lac...

[This corrects the article on p. e37156 in vol. 7.].

The egg protein ovalbumin (OVA) belongs to six most frequent food allergens. We investigated how thermal processing influences its ability to induce allergic symptoms and immune responses in mouse model of food allergy. Effect of increased temperature (70°C and 95°C) on OVA secondary structure was characterized by circular dichroism and by the kine...

Cross-reactivity of anti-OVA specific antibodies. At the end of the experiment we determined the levels of OVA-specific antibodies in OVA and heated (h)-OVA treated mice against OVA, h-OVA (70°C) and boiled (b)-OVA (95°C). The levels were retained for IgE, IgG2a and IgA (a, c, d) when we used OVA as coating antigen for h-OVA-treated mice or h-OVA a...

One of the promising approaches in the therapy of ulcerative colitis is administration of butyrate, an energy source for colonocytes, into the lumen of the colon. This study investigates the effect of butyrate producing bacterium Clostridium tyrobutyricum on dextran sodium sulphate (DSS)-induced colitis in mice. Immunocompetent BALB/c and immunodef...

Probiotic bacteria can be used for the prevention and treatment of human inflammatory diseases including inflammatory bowel diseases (IBD). However, the nature of active components and exact mechanisms of this beneficial effects have not been fully elucidated. Our aim was to investigate if lysate of probiotic bacterium L. casei DN-114 001 (Lc) coul...

Metagenomic approaches are currently being used to decipher the genome of the microbiota (microbiome), and, in parallel, functional studies are being performed to analyze the effects of the microbiota on the host. Gnotobiological methods are an indispensable tool for studying the consequences of bacterial colonization. Animals used as models of hum...