RESUMO

Asthma prevalence has been increasing in communities that become more urbanised. Our previous results showed that Saccharomyces cerevisiae UFMG A-905 prevented the development of asthma symptoms and characteristics in a dose-dependent manner. Perinatal programming theory proposes that early exposure to some stimuli may have a protective effect in adult life. The aim of this study was to evaluate the effects of perinatal administration of S. cerevisiae UFMG A-905 in the prevention of asthma in the offspring of mice. S. cerevisiae UFMG A-905 was cultured in YPD broth medium and administered to three groups of mice: before conception, during gestation and lactation (CGL group); during gestation and lactation (GL group); and only during lactation (L group). The offspring of these animals were sensitised and challenged with ovalbumin. Two control groups received saline in the same periods. After, in vivo measurements of airway hyperresponsiveness (AHR) were performed. Total and differential cell count in bronchoalveolar lavage (BAL); ELISA for interleukin (IL)-4, IL-5, IL-10, IL-13, and IL-17A in the lung homogenate or BAL; and ELISA for ovalbumin (OVA)-specific immunoglobulin E (IgE) were performed. The animals of the CGL, GL, and L group, when compared to the OVA group, presented a significant reduction of AHR ( P < 0.01), levels of IL-5 ( P < 0.001) in BAL, and IL-4 ( P < 0.05) and IL-13 ( P < 0.01) in the lung homogenate. Serum IgE levels were significantly higher ( P < 0.05) in CGL and GL groups when compared to the OVA group, but not in the L group. Only in the group L, there was a significant decrease in the number of total cells ( P < 0.01) and eosinophils ( P < 0.05). Perinatal administration of S. cerevisiae UFMG A-905 prevented the development of asthma-like characteristics and may be an option for asthma management. The protective effects on the offspring were more prominent when the yeast was given during lactation.

RESUMO

Allergic contact dermatitis (ACD) is a common allergic skin disease that affects individuals subjected to different antigen exposure conditions and significantly impacts the quality of life of those affected. Numerous studies have demonstrated that probiotics suppress inflammation through immunomodulatory effects. In this study, we aimed to evaluate the effect of the probiotic Bifidobacterium longum 51A as a preventive treatment for ACD using an oxazolone-induced murine model. We demonstrated that B. longum 51A exerted a prophylactic effect on oxazolone-induced ACD-like skin inflammation via reductions in ear and dermal thickness and leucocyte infiltration. The administration of inactivated B. longum 51A did not affect oxazolone-induced ACD-like skin inflammation, suggesting that the bacteria must be alive to be effective. Given that B. longum 51A is an acetate producer, we treated mice with acetate intraperitoneally, which also prevented ear and dermal thickening. Moreover, the tissue levels of the inflammatory cytokines and chemokines interleukin (IL)-10, IL-33, tumour necrosis factor-α, chemokine (C-C motif) ligand 2/monocyte chemoattractant protein-1 and chemokine (C-C motif) ligand 5/RANTES were significantly reduced after probiotic treatment, but only IL-33 and IL-10 were reduced when the mice were treated with acetate. These results show that B. longum 51A exerted a potential prophylactic effect on skin inflammation and that acetate represents one potential mechanism. However, other factors are likely involved since these two treatments do not yield the same results.

Assuntos

Bifidobacterium longum/fisiologia , Dermatite Alérgica de Contato/imunologia , Dermatite Alérgica de Contato/prevenção & controle , Probióticos/administração & dosagem , Animais , Citocinas/genética , Citocinas/imunologia , Dermatite Alérgica de Contato/etiologia , Dermatite Alérgica de Contato/genética , Feminino , Humanos , Interleucina-10/genética , Interleucina-10/imunologia , Interleucina-33/genética , Interleucina-33/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Oxazolona/efeitos adversos , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/imunologia

RESUMO

Mucositis is an inflammation of the gastrointestinal mucosa resulting from high doses of radio/chemotherapy treatment and may lead to interruption of antineoplasic therapy. Soluble fibres, like pectin, increase SCFA production, which play a role in gut homoeostasis and inflammation suppression. Due to the properties of pectin, the aim of the present study was to evaluate the effect of a high-fibre (HF) diet on chemotherapy-induced mucositis in a murine model. C57/BL6 mice received control (AIN93M), HF, low/zero fibre (LF) diets for 10 d prior to mucositis challenging with irinotecan (75 mg/kg), or they were treated with acetate added to drinking water 5 d prior to and during the mucositis induction. Mice that received the HF diet showed decreased immune cells influx and improved histopathological parameters in the intestine, compared with mice that received the normal diet. Furthermore, the HF diet decreased intestinal permeability induced in the mucositis model when compared with the control group. This effect was not observed for acetate alone, which did not improve gut permeability. For instance, mice that received the LF diet had worsened gut permeability, compared with mice that received the normal diet and mucositis. The effects of the HF and LF diets were shown to modulate the intestinal microbiota, in which the LF diet increased the levels of Enterobacteriaceae, a group associated with gut inflammation, whereas the HF diet decreased this group and increased Lactobacillus and Bifidobacterium (SCFA producers) levels. In conclusion, the results demonstrated the importance of dietary fibre intake in the modulation of gut microbiota composition and homoeostasis maintenance during mucositis in this model.

Assuntos

Antineoplásicos , Fibras na Dieta/administração & dosagem , Mucosite , Animais , Antineoplásicos/efeitos adversos , Modelos Animais de Doenças , Inflamação , Camundongos , Mucosite/induzido quimicamente , Pectinas

RESUMO

Inflammatory bowel diseases (IBD) are chronic processes involving a deregulated immune response against intestinal microbiota in genetically susceptible individuals. Ulcerative colitis (UC) is an IBD restricted to colonic mucosa and its chronicity is a predisposing factor for colorectal cancer (CRC). Probiotics have been investigated as an adjuvant treatment for UC, and Escherichia coli Nissle 1917 (EcN) was the focus of our investigation. The aim of this study was to investigate the preventive effect of the EcN probiotic in an experimental model of chronic colitis in germ-free (GF) and conventional (CV) mice. CV female mice were used for clinical, immunological and permeability experiments. GF mice were used for a faecal microbiota transplantation assay. To induce colitis, three cycles of 3.0% dextran sulphate sodium (DSS) were administered to the animals. For probiotic treatment, the mice received a daily intragastric gavage of 9.0 log10 cfu of EcN, beginning 10 days before colitis induction and continuing until the end of the experiment. EcN presented beneficial effects when administered preventively. Daily Disease Activity Index (DAI) evolution demonstrated significant difference in remission periods after the first two DSS cycles and during the third one. Reduction in bacterial translocation after probiotic treatment indicated protection of the intestinal barrier. Associated with mucosal preservation, restoration of secretory immunoglobulin A levels and reduction of interleukin (IL)-5, IL-13, tumour necrosis factor and interferon-γ levels were observed in EcN treatment. Finally, when microbiota modification was verified, 16S rRNA-based compositional analysis showed variation of intestinal microbiota between the control and colitis groups. After faecal transplantation using GF mice, it was observed that EcN treatment in CV mice might result in modulated intestinal microbiota. This was observed indirectly in the reduced daily DAI, when colitis was compared with treated group. In conclusion, EcN presented beneficial effects in this model, suggesting its usefulness for treating UC.

Assuntos

Colite Ulcerativa/prevenção & controle , Escherichia coli/fisiologia , Transplante de Microbiota Fecal , Mucosa Intestinal/microbiologia , Probióticos/farmacologia , Animais , Colo/patologia , Sulfato de Dextrana/toxicidade , Modelos Animais de Doenças , Escherichia coli/classificação , Feminino , Microbioma Gastrointestinal/fisiologia , Vida Livre de Germes , Imunoglobulina A/análise , Interferon gama/sangue , Interleucina-13/sangue , Interleucina-5/sangue , Mucosa Intestinal/patologia , Camundongos , RNA Ribossômico 16S/genética , Fator de Necrose Tumoral alfa/sangue

RESUMO

Food allergy is triggered when there is an abnormal activation of the immune system by food allergens. Currently, there is no curative therapy for this pathological condition. Due to the immunomodulatory properties of probiotics they are potential candidates as therapeutic tools for food allergy. Therefore, the aim of this study was to evaluate the probiotic effect of Saccharomyces cerevisiae UFMG A-905 (905) in an in vivo model of food allergy. Probiotic effect was assessed by clinical, histological, immunological and microbiological parameters analysis. Furthermore, we also evaluated if 905 after inactivation has an effect, as well as if such an effect is dose dependent. Our results showed that oral administration of only viable 905 promotes a significant attenuation of tissue injury and myeloperoxidase (MPO) activity levels. Moreover, the treatment reduced interleukin 17 levels, and administration of the supernatant from the yeast culture also promoted a significant decrease in MPO levels. However, considering the systemic parameters, immunoglobulin (Ig)E and IgG anti-ovalbumin, which are essentials for triggering the allergic process, there was no effect, suggesting that the yeast promotes a local but not a systemic effect in the model evaluated. In addition, we found that only high doses of viable 905 were able to attenuate the signs of inflammation. In conclusion, oral administration of 905 led to a local effect that depends on the viability of the yeast.

Assuntos

Hipersensibilidade Alimentar/prevenção & controle , Inflamação/prevenção & controle , Probióticos/administração & dosagem , Saccharomyces cerevisiae/fisiologia , Administração Oral , Animais , Modelos Animais de Doenças , Feminino , Hipersensibilidade Alimentar/imunologia , Imunoglobulina E/sangue , Imunoglobulina E/imunologia , Fatores Imunológicos/administração & dosagem , Fatores Imunológicos/imunologia , Interleucina-17/sangue , Interleucina-17/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Viabilidade Microbiana , Peroxidase/metabolismo

RESUMO

This study evaluated the effects of Bifidobacterium longum 51A on the intestinal mucosa and inflammatory response in experimental colitis. Colitis was induced by administration of 3.5% dextran sodium sulphate (DSS) solution for 7 days. Two periods of administration were performed: treatment (T) group, mice received Bifidobacterium only during disease induction (7 days); total treatment (TT) group, mice received Bifidobacterium for 10 days before and during disease induction. The probiotic effects on intestinal permeability, inflammatory infiltrate, histological analysis, cytokines, chemokines and sIgA were evaluated. Bifidobacterium administration in the T group showed reduction in intestinal permeability and lower IL-1ß, myeloperoxidase, and eosinophil peroxidase levels compared to those in the colitis group (P<0.05). Bifidobacterium administration in the TT group attenuated severe lesions in the colon and reduced eosinophil peroxidase level (P<0.05). B. longum 51A treatment modality was more effective than total treatment and reduced the inflammatory response and its consequences on intestinal epithelium.

Assuntos

Bifidobacterium longum , Doenças Inflamatórias Intestinais/tratamento farmacológico , Probióticos/uso terapêutico , Animais , Colite/induzido quimicamente , Colo/efeitos dos fármacos , Colo/microbiologia , Colo/patologia , Citocinas/metabolismo , Modelos Animais de Doenças , Peroxidase de Eosinófilo/metabolismo , Feminino , Imunoglobulina A Secretora/metabolismo , Inflamação/tratamento farmacológico , Doenças Inflamatórias Intestinais/imunologia , Doenças Inflamatórias Intestinais/microbiologia , Interleucina-1beta/metabolismo , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/patologia , Intestinos/efeitos dos fármacos , Intestinos/patologia , Camundongos , Camundongos Endogâmicos BALB C , Peroxidase/metabolismo

RESUMO

Fermented whey dairy beverages are dairy products obtained by fermentation from a mixture of milk and whey. These beverages have important health benefits, which could be improved with the addition of probiotic cultures. This study assessed the protective effect of the cosupplementation of a probiotic culture (Lactobacillus casei 01) with a fermented whey dairy beverage against infection by Salmonella enterica ssp. enterica serovar Typhimurium in a murine model. Two fermented whey dairy beverages were prepared: conventional (FWB; starter culture) and probiotic (PFWB; starter and probiotic cultures). In the first set of experiments, Balb/C female mice were treated with FWB or PFWB, challenged with Salmonella Typhimurium, and analyzed for clinical signs, weight loss, and mortality for 20 d postinfection. In the second set of experiments, mice were treated with FWB or PFWB, challenged with Salmonella Typhimurium, and killed on d 10 postinfection. The liver, colon, and ileum were used for myeloperoxidase, eosinophil peroxidase, and histological analysis and translocation to the liver. The contents from the small intestine were used for secretory IgA determination. The FWB treatment showed a better effect on animal survival (70%), translocation of the pathogen to the liver (2 out of 10), histopathology (fewer lesions), and inflammation than PFWB, which presented 50% animal survival, translocation in 5 out of 10 animals, and higher lesions. The control group presented 40% animal survival, translocation in 6 out of 10 animals, and severe lesions. Therefore, FWB was deemed to have a greater protective effect against Salmonella Typhimurium infection in the murine model compared with PFWB.

Assuntos

Produtos Fermentados do Leite , Salmonelose Animal/prevenção & controle , Salmonella typhimurium , Soro do Leite , Animais , Bebidas , Feminino , Promoção da Saúde , Imunoglobulina A Secretora/análise , Inflamação/prevenção & controle , Intestino Delgado/imunologia , Intestino Delgado/patologia , Lacticaseibacillus casei/fisiologia , Fígado/microbiologia , Fígado/patologia , Camundongos , Camundongos Endogâmicos BALB C , Probióticos , Salmonelose Animal/imunologia , Salmonelose Animal/patologia , Proteínas do Soro do Leite

RESUMO

The aim of the study was to assess the efficacy of Saccharomyces boulardii in experimental treatment of giardiasis and its impact on intestinal integrity and some functions of gerbils infected with Giardia lamblia. 28 gerbils (Meriones unguiculatus), aged 4-6 weeks, were divided into four groups: untreated and uninfected control (CT); infected with G. lamblia (IGL); treated with S. boulardii (SB); and infected with G. lamblia and treated with S. boulardii (ITSB). The SB and ITSB groups received S. boulardii 15 days prior to being infected with G. lamblia. The treatment continued until completion of the experiment (22nd day). The IGL and ITSB groups were gavage-inoculated with G. lamblia ensuring one-week infection. 4 h before euthanasia, all animals were gavaged with a solution containing diethylenetriamine-pentaacetic acid (DTPA) marked with technetium-99mTc DTPA to determine intestinal permeability. The small intestine was removed for histopathological, morphometric analysis and count of trophozoites adhered to the mucosa. The selected probiotic caused an approximate reduction of 70% of parasite load, which was determined by attached trophozoites (P<0.01) and immune-marked trophozoites (P<0.05). Treatment with S. boulardii (SB and ITSB groups) also increased the height of the intestinal villi and crypt depth compared to the CT and IGL groups (P<0.05). The area of mucus production and the number of goblet cells of the SB and ITSB groups were higher compared to the CT and IGL groups (P<0.01). The animals treated with S. boulardii also exhibited a significant increase of intraepithelial lymphocytes counts (P<0.01). There was no difference in the intestinal permeability between the groups studied. The efficacy of S. boulardii in reducing damages caused by Giardia was demonstrated, with an approximate reduction of 70% of the parasite load, suggesting its use as a coadjuvant in giardiasis treatment.

Assuntos

Giardia lamblia/fisiologia , Giardíase/tratamento farmacológico , Probióticos/administração & dosagem , Saccharomyces boulardii/fisiologia , Animais , Modelos Animais de Doenças , Gerbillinae , Giardia lamblia/efeitos dos fármacos , Giardia lamblia/crescimento & desenvolvimento , Giardíase/parasitologia , Humanos , Intestino Delgado/parasitologia , Intestino Delgado/patologia , Masculino

RESUMO

A healthy skin provides a protective barrier against pathogenic micro-organisms. Recent studies have shown that probiotics, as those of Bifidobacterium genus, could act beneficially in dermatology, both when ingested and by topical use. In the present study, we evaluated by in vitro antagonism assays and using two skin cell lines the potential of four strains of Bifidobacterium spp. Among the four bifidobacteria, Bifidobacterium longum 51A was the only one able to inhibit the growth of the eight pathogenic indicators tested. Production of some cytokines and extracellular matrix proteins was determined when ccc or inactivated cells of the bifidobacteria were incubated with keratinocyte and/or fibroblast cell cultures. Significant results were observed only for IL-6, IL-8 and IL-18 production, and inactivated Bifidobacterium pseudolongum 1191A was the only one which significantly stimulated collagen production, whereas lumican was stimulated by treatments with live Bifidobacterium bifidum 1622A , B. longum 51A and B. pseudolongum 1191A . Highest adhesion and internalization capabilities were observed with B. bifidum 1622A and Bifidobacterium breve 1101A . Concluding, B. longum 51A was highlighted for its antagonistic capacity and B. bifidum 1622A and B. pseudolongum 1191A for stimulating the production of cytokines and proteins of the extracellular matrix. SIGNIFICANCE AND IMPACT OF THE STUDY: The skin is the first line of defence against invasive micro-organisms, and its local microbiota provides additional protective functions based on antagonism against pathogenic micro-organisms and immunomodulation. Based on in vitro assays using Bifidobacterium spp. we demonstrated the antagonistic potential, as well as capacity in stimulating the production of cytokines and proteins of the extracellular matrix that these bacteria may exert on skin cells. This positive influence suggests the use of a consortium of these bifidobacteria in a topical product for dermatological treatments.

Assuntos

Antibiose/fisiologia , Bifidobacterium/metabolismo , Citocinas/metabolismo , Proteínas da Matriz Extracelular/metabolismo , Probióticos/metabolismo , Pele/microbiologia , Bifidobacterium/classificação , Candida albicans/crescimento & desenvolvimento , Linhagem Celular , Humanos , Malassezia/crescimento & desenvolvimento , Propionibacterium acnes/crescimento & desenvolvimento , Staphylococcus aureus/crescimento & desenvolvimento , Staphylococcus epidermidis/crescimento & desenvolvimento

RESUMO

The use of probiotics to prevent or treat mucosal inflammation has been studied; however, the combined effect of probiotics and prebiotics is unclear. The aim of this study was to test whether oral administration of a synbiotic (Simbioflora®) preparation containing Lactobacillus paracasei, Lactobacillus rhamnosus, Lactobacillus acidophilus and Bifidobacterium lactis plus fructooligosaccharide could help control mucosal inflammation in experimental mucositis induced by 5-fluorouracil (5-FU). Male BALB/c mice were randomly divided into six groups: control (CTL), control + prebiotic (CTL+P), control + synbiotic (CTL+S), mucositis (MUC), mucositis + prebiotic (MUC+P), and mucositis + synbiotic (MUC+S). Mice from the CTL+S, MUC+S, CTL+P, and MUC+P groups received synbiotic or prebiotic daily by oral gavage for 13 days. Mice in the CTL and MUC groups received the same volume of saline. On day 11, mice in the MUC, MUC+P, and MUC+S groups received an intraperitoneal injection of 300 mg/kg 5-FU to induce mucositis. After 72 h, all mice were euthanised. Intestinal permeability, intestinal histology, and biochemical parameters were analysed. Group MUC showed a greater weight loss and increased intestinal permeability (0.020 counts per min [cpm]/g) compared to the CTL group (0.01 cpm/g) P<0.05. Both treatments attenuated weight loss compared to the MUC group. Nonetheless, the synbiotic caused a greater reduction in intestinal permeability (0.012 cpm/g) compared to the MUC (0.020 cpm/g) and MUC+P (0.016 cpm/g) groups P<0.05. Mice in groups MUC+P and MUC+S displayed significant recovery of lesions and maintenance of the mucus layer. There were no differences in the short-chain fatty acid concentrations in the faeces between the MUC and CTL groups (P>0.05). Increased acetate and propionate concentrations were evidenced in the faeces of the MUC+P and MUC+S groups. Only the synbiotic treatment increased the butyrate concentration (P<0.05). The results indicate that administration of synbiotic can decrease mucosal damage caused by mucositis.

Assuntos

Mucosite/prevenção & controle , Simbióticos/administração & dosagem , Administração Oral , Animais , Bifidobacterium animalis/crescimento & desenvolvimento , Bifidobacterium animalis/metabolismo , Peso Corporal , Ácidos Graxos Voláteis/análise , Fezes/química , Fluoruracila/administração & dosagem , Fluoruracila/toxicidade , Trato Gastrointestinal/patologia , Lactobacillus/crescimento & desenvolvimento , Lactobacillus/metabolismo , Camundongos Endogâmicos BALB C , Mucosite/induzido quimicamente , Oligossacarídeos/administração & dosagem , Oligossacarídeos/metabolismo , Resultado do Tratamento

RESUMO

Allergic asthma is a chronic disease mainly characterised by eosinophil inflammation and airway remodelling. Many studies have shown that the gut microbiota of allergic individuals differs from that of non-allergic individuals. Although high levels of bifidobacteria have been associated with healthy persons, Bifidobacterium adolescentis ATCC 15703, a gut bacteria, has been associated with allergic individuals in some clinical studies. The relationship between B. adolescentis ATCC 15703 and asthma or allergies has not been well elucidated, and its effect may be dependent on the host's genetic profile or disease state. To elucidate this question, we evaluated the role of preventive B. adolescentis ATCC 15703 treatment on experimental allergic airway inflammation in two genetically different mouse strains, Balb/c and C57BL/6 (B6). Balb/c mice display a greater predisposition to develop allergic responses than B6 mice. Oral preventive treatment with B. adolescentis ATCC 15703 modulated experimental allergic airway inflammation, specifically in Balb/c mice, which showed decreased levels of eosinophils in the airway. B6 mice did not exhibit any significant alterations in eosinophils but showed an increased influx of total leukocytes and neutrophils into the airway. The mechanism underlying the beneficial effects of these bacteria in experimental allergic mice may involve products of bacteria metabolism, as dead bacteria did not mimic the ability of live B. adolescentis ATCC 15703 to attenuate the influx of eosinophils into the airway. To conclude, preventive oral B. adolescentis ATCC 15703 treatment can attenuate the major characteristic of allergic asthma, eosinophil airway influx, in Balb/c but not B6 mice. These results suggest that oral treatment with this specific live bacterial strain may have therapeutic potential for the treatment of allergic airway disease, although its effect is mouse-strain-dependent.

Assuntos

Asma/prevenção & controle , Bifidobacterium adolescentis/crescimento & desenvolvimento , Probióticos/administração & dosagem , Sistema Respiratório/patologia , Administração Oral , Animais , Modelos Animais de Doenças , Eosinófilos/imunologia , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Resultado do Tratamento

RESUMO

STING (stimulator of interferon genes) is a cytosolic sensor for cyclic dinucleotides and also an adaptor molecule for intracellular DNA receptors. Although STING has important functions in the host defense against pathogens and in autoimmune diseases, its physiological relevance in intestinal homeostasis is largely unknown. In this study, we show that STING-/- mice presented defective protective mechanisms of intestinal mucosa, including decreased number of goblet cells, diminished mucus production, and lower levels of secretory IgA, when compared with wild-type (WT) mice. Fecal content and microbiota DNA could activate STING, indicating a role of this molecule in gut. Microbiota composition was altered in STING-/- mice toward a more inflammatory profile, evidencing a reduction in the Allobacolum and Bifidobacterium groups along with increase in Disulfovibrio bacteria. Absence of STING lead to decrease in induced intraepithelial lymphocytes (IEL) and to increase in group 1 innate lymphoid cell (ILC1) as well as ILC3 frequencies and decrease in ILC2 in the colon. Development and function of Foxp3+ and LAP+ regulatory T cells were also compromised in STING-/- mice. Moreover, these mice were highly susceptible to dextran sodium sulfate-induced colitis, T-cell-induced colitis, and enteric Salmonella typhimurium infection when compared with WT animals. Therefore, our results identify an important role of STING in maintaining gut homeostasis and also a protective effect in controlling gut inflammation.

Assuntos

Colite/imunologia , Microbioma Gastrointestinal/fisiologia , Mucosa Intestinal/imunologia , Intestinos/fisiologia , Linfócitos/imunologia , Proteínas de Membrana/metabolismo , Infecções por Salmonella/imunologia , Salmonella typhimurium/imunologia , Linfócitos T Reguladores/imunologia , Animais , Colite/induzido quimicamente , Colite/genética , Sulfato de Dextrana , Feminino , Fatores de Transcrição Forkhead/metabolismo , Homeostase , Imunidade Inata , Imunoglobulina A Secretora/sangue , Masculino , Proteínas de Membrana/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Infecções por Salmonella/genética , Células Th1/imunologia

RESUMO

The indigenous microbiota is the population of microorganisms normally present on the surface and mucosa of an individual, where it performs essential health functions, including the colonisation resistance (CR) against pathogens. To identify the bacteria responsible and the mechanisms involved in the CR, the germ-free (GF) animal model has been used, because in vitro studies cannot always be extrapolated to what occurs in vivo. In this study, ex vivo antagonism assays against seven enteropathogenic bacteria using stools from 15 healthy human donors confirmed that the CR showed individual variation. Using in vitro antagonism assays, 14 strains isolated from dominant faecal microbiota of donors with elevated CR were selected for mono-association in GF mice to test the in vivo antagonism against Salmonella enterica ser. Typhimurium. Mice mono-associated with Enterococcus hirae strain 8.2, Bacteroides thetaiotaomicron strain 16.2 and Lactobacillus ruminis strain 18.1 had significant reductions in faecal counts of the pathogen during the challenge. After five days of infection, the group associated with E. hirae 8.2 showed a reduction in the translocation of S. Typhimurium to the spleen, while the group associated with L. ruminis 18.1 presented an increased translocation to the liver. The histological data confirmed these results and revealed that the mice associated with E. hirae 8.2 showed fewer lesions on ileum and liver, compared to the damage caused by S. Typhimurium alone, while in mice associated with L. ruminis 18.1 there was significantly worse lesions. Concluding, from the dominant faecal microbiota from healthy human with high CR, through ex vivo, in vitro and in vivo assays, a bacterium was characterised for its high CR potential, being a candidate for probiotic use.

Assuntos

Antibiose/fisiologia , Bacteroides thetaiotaomicron/crescimento & desenvolvimento , Streptococcus faecium ATCC 9790/crescimento & desenvolvimento , Lactobacillus/crescimento & desenvolvimento , Microbiota/efeitos dos fármacos , Probióticos/farmacologia , Infecções por Salmonella/terapia , Salmonella typhimurium/crescimento & desenvolvimento , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Criança , Pré-Escolar , Modelos Animais de Doenças , Feminino , Vida Livre de Germes , Humanos , Masculino , Camundongos , Pessoa de Meia-Idade , Infecções por Salmonella/microbiologia , Adulto Jovem

RESUMO

Indigenous microbiota plays a crucial role in the development of several intestinal diseases, including mucositis. Gastrointestinal mucositis is a major and serious side effect of cancer therapy, and there is no effective therapy for this clinical condition. However, some probiotics have been shown to attenuate such conditions. To evaluate the effects of Saccharomyces cerevisiae UFMG A-905 (Sc-905), a potential probiotic yeast, we investigated whether pre- or post-treatment with viable or inactivated Sc-905 could prevent weight loss and intestinal lesions, and maintain integrity of the mucosal barrier in a mucositis model induced by irinotecan in mice. Only post-treatment with viable Sc-905 was able to protect mice against the damage caused by chemotherapy, reducing the weight loss, increase of intestinal permeability and jejunal lesions (villous shortening). Besides, this treatment reduced oxidative stress, prevented the decrease of goblet cells and stimulated the replication of cells in the intestinal crypts of mice with experimental mucositis. In conclusion, Sc-905 protects animals against irinotecan-induced mucositis when administered as a post-treatment with viable cells, and this effect seems to be related with the reduction of oxidative stress and preservation of intestinal mucosa.

Assuntos

Mucosite/dietoterapia , Probióticos/uso terapêutico , Saccharomyces cerevisiae , Animais , Camptotecina/análogos & derivados , Modelos Animais de Doenças , Absorção Intestinal , Mucosa Intestinal/patologia , Intestino Delgado/patologia , Irinotecano , Jejuno/patologia , Peroxidação de Lipídeos , Masculino , Camundongos , Mucosite/induzido quimicamente , Mucosite/patologia , Estresse Oxidativo , Redução de Peso

RESUMO

In the present study, the protective potential of Saccharomyces cerevisiae strain UFMG A-905 was evaluated in a murine model of acute ulcerative colitis (UC). Six groups of Balb/c mice were used: not treated with yeast and not challenged with dextran sulphate sodium (DSS) (control); treated with S. cerevisiae UFMG A-905 (905); treated with the non-probiotic S. cerevisiae W303 (W303); challenged with DSS (DSS); treated with S. cerevisiae UFMG A-905 and challenged with DSS (905 + DSS); and treated with S. cerevisiae W303 and challenged with DSS (W303 + DSS). Seven days after induction of UC, mice were euthanised to remove colon for enzymatic, immunological, and histopathological analysis. In vivo intestinal permeability was also evaluated. An improvement of clinical manifestations of experimental UC was observed only in mice of the 905 + DSS group when compared to animals from DSS and W303 + DSS groups. This observation was confirmed by histological and morphometrical data and determination of myeloperoxidase and eosinophil peroxidase activities, intestinal permeability and some pro-inflammatory cytokines. S. cerevisiae UFMG A-905 showed to be a potential alternative treatment for UC when used in an experimental animal model of the disease.

Assuntos

Colo/patologia , Doenças Inflamatórias Intestinais/terapia , Probióticos/administração & dosagem , Saccharomyces cerevisiae/crescimento & desenvolvimento , Animais , Modelos Animais de Doenças , Feminino , Masculino , Camundongos Endogâmicos BALB C , Resultado do Tratamento

RESUMO

Gout is an acute inflammatory disease characterised by the presence of uric acid crystals in the joint. This event promotes neutrophil infiltration and activation that leads to tissue damage. We investigated here whether the oral administration of the probiotic strain Bifidobacterium longum 5(1A) (BL) could ameliorate monosodium urate crystal (MSU)-induced inflammation in a murine model of gout. Mice received oral administration of BL or saline daily for 7 days and then were injected with MSU in the knee cavity. Treatment with BL significantly alleviated the inflammatory parameters, as seen by reduced hypernociception, reduced neutrophil accumulation in the joint and myeloperoxidase activity in periarticular tissue. There was inhibition of the production of CXCL1 and interleukin(IL)-1ß in joints. Levels of the anti-inflammatory cytokine IL-10 were significantly higher in the knee tissue of mice treated with than control mice injected with MSU. In conclusion, oral BL treatment reduced the inflammatory response in an experimental murine model of gout, suggesting it may be useful as an adjuvant treatment in patients with gout.

Assuntos

Bifidobacterium , Supressores da Gota/administração & dosagem , Gota/patologia , Gota/terapia , Inflamação/patologia , Inflamação/terapia , Probióticos/administração & dosagem , Administração Oral , Animais , Citocinas/análise , Modelos Animais de Doenças , Camundongos Endogâmicos C57BL , Líquido Sinovial/química , Ácido Úrico/análise

RESUMO

Inflammatory bowel diseases (IBD) are chronic inflammatory conditions, characterised by remissions and relapses episodes, whose main manifestations are ulcerative colitis and Crohn's disease. Ulcerative colitis (UC), one of the main forms of IBD, has as standard treatment the use of corticosteroids and anti-inflammatory drugs. The use of antibiotics has been also reported, but the possible adverse effects, such as disturbance of the indigenous microbiota or resistance induction, should be taken into consideration, and thus the use of probiotics emerges as a possible alternative option of treatment. In this study, the oral administration of Bifidobacterium longum subsp. infantis BB-02 was evaluated as a preventive strategy for acute experimental UC induced in female BALB/c mice by ingestion of 3.5% dextran sulphate sodium in drinking water during 7 days. During this time, the daily disease activity index was evaluated, and on the seventh day the animals were euthanised to collect intestines and liver for analysis. Treatment with the probiotic resulted in clinical improvement of the animals. The histological and morphometric analyses showed a reduction of lesions and oedema in the gut, but there was no increase in the production of mucin. The dosage of secretory immunoglobulin A was significantly higher in the colitis group and reduced in the group treated with the probiotic. There was also a reduction in the inflammation of the colon, as demonstrated by a decrease in neutrophils infiltration, and KC/CXCL-1 levels. The intestinal permeability, which is typically increased during the onset of IBD, was also reduced by treatment with probiotic. Based on these data, it can be concluded that the bacterium B. infantis BB-02 has a probiotic potential for the attenuation of UC, but further studies should be conducted to verify the mechanism of protective action of the bacterium.

Assuntos

Bifidobacterium/fisiologia , Doenças Inflamatórias Intestinais/tratamento farmacológico , Probióticos/administração & dosagem , Animais , Modelos Animais de Doenças , Feminino , Humanos , Imunoglobulina A/imunologia , Doenças Inflamatórias Intestinais/imunologia , Doenças Inflamatórias Intestinais/microbiologia , Camundongos , Camundongos Endogâmicos BALB C

RESUMO

This study aimed to demonstrate the expression of growth hormone receptor (GH-R) mRNA and protein in goat ovarian follicles in order to investigate the effects of GH on the survival and development of preantral follicles. The ovaries were processed for the isolation of follicles to study GH-R mRNA expression or to localization of GH-R by immunohistochemical analysis. Pieces of ovarian cortex were cultured for 7 days in minimum essential medium(+) (MEM(+)) in the presence or absence of GH at different concentrations (1, 10, 50, 100, and 200 ng/mL). High expression levels of GH-R mRNA were observed in granulosa/theca cells from large antral follicles. However, preantral follicles do not express mRNA for GH-R. Immunohistochemistry demonstrated that the GH-R protein was expressed in the oocytes/granulosa cells of antral follicles, but any protein expression was observed in preantral follicles. The highest (P < 0.05) rate of normal follicles and intermediate follicles was observed after 7 days in MEM(+) plus 10 ng/mL GH (70%). In conclusion, GH-R mRNA and protein are expressed in caprine antral follicles, but not in preantral follicles. Moreover, GH maintains the survival of goat preantral follicles and promotes the development of primordial follicles.

Assuntos

Cabras/fisiologia , Hormônio do Crescimento/farmacologia , Folículo Ovariano/crescimento & desenvolvimento , Receptores da Somatotropina/metabolismo , Animais , Técnicas de Cultura de Células , Feminino , Cabras/genética , Células da Granulosa/efeitos dos fármacos , Células da Granulosa/metabolismo , Folículo Ovariano/efeitos dos fármacos , RNA Mensageiro/metabolismo , Receptores da Somatotropina/fisiologia , Técnicas de Cultura de Tecidos

RESUMO

A imunodeficiência felina (IF) é uma doença viral, que devido à sua alta morbidade e imunodepressão associada a prováveis infecções oportunistas, a torna uma importante enfermidade infecciosa em gatos domésticos. No Brasil, as taxas de prevalência são variáveis, havendo carência de informações epidemiológicas em diferentes regiões do país. Logo, o objetivo deste estudo foi determinar a prevalência de anticorpos para o vírus da IF, utilizando o teste de imunocromatografia rápida (TICR), bem como avaliar os aspectos epidemiológicos da doença. Para isso, utilizou-se o kit do TICR da Bioeasy® de acordo com as recomendações do fabricante em 50 gatos da rotina de atendimentos da Unidade Hospital Veterinária da Universidade Estadual do Ceará – UHV/UECE, no período de março a maio do ano de 2013. Verificou-se que a prevalência de animais positivos para IF foi 30% (15/50), sendo que 26,6% (4/15) eram animais assintomáticos e 73,3% (11/15) sintomáticos. As principais manifestações clínicas observa

RESUMO

A leptospirose é uma doença infectocontagiosa que possui caráter zoonótico, causada por diferentes sorovares de Leptospira interrogans. Os cães são considerados a principal fonte da leptospirose humana em áreas urbanas, pois vivem em estreito contato com o homem e podem eliminar leptospiras vivas através da urina durante vários meses, mesmo sem apresentar nenhuma manifestação clínica característica. O objetivo do trabalho foi determinar a prevalência de anticorpos anti-Leptospiras em cães atendidos na Unidade Hospitalar Veterinária da Universidade Estadual do Ceará durante o período de agosto de 2011 a maio de 2013. Foram examinadas 37 amostras de soro sanguíneo de cães com suspeita clínica de leptospirose, com idades diversas e ambos os sexos. O diagnóstico da leptospirose foi realizado pela técnica de soroaglutinação microscópica, utilizando-se uma coleção de 22 sorovares. A soroprevalência encontrada foi de 32,4% (12/37) e os sorovares mais prevalentes foram Copenhageni com 18,9% (7/37) e Icterohaemorrhagiae com 13,5% (5/37), seguidos por Cynopteri e Andamana com