RESUMO

This study evaluated the effects of a fibre and phenolic-rich flour (IGF) prepared from Isabel grape by-products on the growth and metabolism of different probiotics and distinct bacterial populations part of the human intestinal microbiota during an in vitro colonic fermentation. IGF was submitted to simulated gastrointestinal digestion before use in the experiments. IGF favoured the growth of the probiotics Lactobacillus acidophilus La-05, L. casei L-26 and Bifidobacterium lactis Bb-12, with viable counts of >7 log CFU per ml, as well as caused decreases in pH values and increases in organic acid production in the growth medium during 48 h of cultivation. IGF increased the population of beneficial micro-organisms forming the human intestinal microbiota, particularly Lactobacillus spp., decreased the pH values, and increased the lactic acid and short-chain fatty acid (acetic, butyric and propionic acids) production during 24 h of in vitro colonic fermentation. These results indicate the potential prebiotic effects of IGF, which should represent a novel sustainable added-value ingredient with functional properties and gut-health benefits.

Assuntos

Microbiota , Probióticos , Vitis , Fermentação , Farinha , Humanos , Lactobacillus acidophilus/metabolismo , Fenóis/análise , Fenóis/farmacologia , Probióticos/metabolismo , Probióticos/farmacologia

RESUMO

This study aimed to evaluate the inhibitory effects of phenolic-rich extracts from acerola (Malpighia emarginata D.C., PEA), cashew apple (Anacardium occidentale L., PEC) and mango (Mangifera indica L., PEM) by-products on distinct enterotoxigenic Escherichia coli (ETEC) strains. The capability of PEA and PEC of impairing various physiological functions of ETEC strains was investigated with multiparametric flow cytometry. Procyanidin B2 , myricetin and p-coumaric acid were the major phenolic compounds in PEA, PEC and PEM, respectively. PEA and PEC had lower minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) (MIC: 31·25 mg ml-1 ; MBC: 62·5 mg ml-1 ) on ETEC strains than PEM (MIC and MIC: >1000 mg ml-1 ). PEA and PEC (15·6, 31·2, 62·5 mg ml-1 ) caused viable count reductions (P < 0·05) on ETEC strains after 24 h of exposure, notably the ≥3 log reductions caused by 62·5 mg ml-1 . The 24 h exposure of ETEC strains to PEA and PEC (31·2, 62·5 mg ml-1 ) led to high sizes of cell subpopulations with concomitant impairments in cell membrane polarization and permeability, as well as in enzymatic, respiratory and efflux activities. PEA and PEC are effective in inhibiting ETEC through a multi-target action mode with disturbance in different physiological functions.

Assuntos

Anacardium , Escherichia coli Enterotoxigênica , Infecções por Escherichia coli , Mangifera , Fenóis/farmacologia , Extratos Vegetais/farmacologia

RESUMO

Cheeses are able to serve as suitable matrices for supplying probiotics to consumers, enabling appropriate conditions for bacteria to survive gastric transit and reach the gut, where they are assumed to promote beneficial processes. The present study aimed to evaluate the microbiological, immunological, and histological changes in the gut of Salmonella Enteritidis-challenged rats fed goat cheese supplemented with the probiotic strain Lactobacillus rhamnosus EM1107. Thirty male albino Wistar rats were randomly distributed into 5 experimental groups with 6 animals each: negative (NC) and positive (PtC) control groups, control goat cheese (CCh), goat cheese added with L. rhamnosus EM1107 (LrCh), and L. rhamnosus EM1107 only (EM1107). All animals, except NC group were challenged with Salmonella Enteritidis (109 cfu in 1 mL of saline through oral gavage). Microbial composition was assessed with high-throughput 16S rRNA sequencing by means of Illumina MiSeq (Illumina, San Diego, CA). Nuclear factor kappa B (NF-κB) from the animal cecum tissue was determined by real-time PCR and interleukins (TNF-α, IL-1ß, IL-10, and IFN-γ) by means of ELISA. Myeloperoxidase and malondialdehyde levels were determined biochemically. The administration of the L. rhamnosus EM1107 probiotic strain, either as a pure culture or added to a cheese matrix, was able to reduce Salmonella colonization in the intestinal lumen and lessen tissue damage compared with rats from PtC group. In addition, the use of cheese for the probiotic strain delivery (LrCh) was associated with a marked shift in the gut microbiota composition toward the increase of beneficial organisms such as Blautia and Lactobacillus and a reduction in NF-κB expression. These findings support our hypothesis that cheeses might be explored as functional matrices for the efficacious delivery of probiotic strains to consumers.

Assuntos

Queijo/microbiologia , Cabras , Intestinos/imunologia , Intestinos/microbiologia , Lacticaseibacillus rhamnosus/metabolismo , Probióticos , Salmonella enteritidis/imunologia , Animais , Ceco/metabolismo , Ceco/microbiologia , Microbioma Gastrointestinal , Masculino , RNA Ribossômico 16S , Ratos , Ratos Wistar

RESUMO

AIMS: This study evaluated whether by-products from industrial processing of acerola (Malpighia glabra L.; AB) and guava (Psidium guajava L.; GB) fruit may stimulate the growth and metabolism of probiotic Lactobacillus and Bifidobacterium and induce changes in human colonic microbiota. METHODS AND RESULTS: The ability of non-digested and digested AB or GB to stimulate the growth ad metabolism of Lactobacillus acidophilus LA-05, Lactobacillus casei L-26 and Bifidobacterium animalis subsp. lactis BB-12 was evaluated. Changes in populations of distinct bacterial groups of human colonic microbiota induced by digested AB and GB were evaluated using an in vitro colonic fermentation system. Non-digested and digested AB and GB favoured probiotic growth. No difference among counts of probiotics in media with glucose, fructooligosaccharides and non-digested and digested AB and GB was found during a 48-h cultivation. Cultivation of probiotics in media with non-digested and digested AB and GB resulted in decreased pH, increased organic acid production and sugar consumption over time. Digested AB and GB caused overall beneficial changes in abundance of Bifidobacterium spp., Lactobacillus-Enterococcus, Eubacterium rectall-Clostridium coccoides and Bacteroides-Provotella populations, besides to decrease the pH and increase the short-chain fatty acid production during a 24-h in vitro colonic fermentation. CONCLUSION: AB and GB could be novel prebiotic ingredients because they can stimulate the growth and metabolism of probiotics and induce overall beneficial changes in human colonic microbiota. SIGNIFICANCE AND IMPACT OF THE STUDY: AB and GB stimulated the growth and metabolism of probiotics, in addition to induce beneficial alterations in human colonic microbiota composition and increase short-chain fatty acid production. These results characterize AB and GB as potential prebiotic ingredients and fruit processing by-products as sources of added-value compounds.

Assuntos

Bifidobacterium animalis/crescimento & desenvolvimento , Colo/microbiologia , Lactobacillus/crescimento & desenvolvimento , Malpighiaceae/metabolismo , Prebióticos/análise , Probióticos/análise , Psidium/metabolismo , Resíduos/análise , Bifidobacterium animalis/metabolismo , Clostridiales , Ácidos Graxos Voláteis/metabolismo , Fermentação , Frutas/química , Frutas/metabolismo , Microbioma Gastrointestinal , Humanos , Lactobacillus/metabolismo , Lactobacillus acidophilus/crescimento & desenvolvimento , Malpighiaceae/química , Oligossacarídeos/análise , Oligossacarídeos/metabolismo , Probióticos/metabolismo , Psidium/química

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

AIMS: This study evaluated the efficacy of essential oil from Origanum vulgare L. (oregano; OVEO) and Rosmarinus officinalis L. (rosemary; ROEO) to inactivate sessile cells of Salmonella enterica serovar Enteritidis 86 (SE86) in young and mature biofilms formed on stainless steel. METHODS AND RESULTS: Ultrastructural alterations and damage in different physiological functions caused by OVEO and ROEO in noncultivable sessile cells of SE86 were investigated using scanning electron microscopy and flow cytometry. OVEO (2·5 µl ml-1 ) and ROEO (40 µl ml-1 ) were effective to eradicate young and mature biofilms formed by SE86 sessile cells on stainless steel surfaces; however, the efficacy varied with exposure time. OVEO and ROEO caused alterations in morphology of SE86 sessile cells, inducing the occurrence of bubbles or spots on cell surface. OVEO and ROEO compromised membrane polarization, permeability and efflux activity in noncultivable SE86 sessile cells. These findings show that OVEO and ROEO act by a multitarget mechanism on SE86 membrane functions. CONCLUSIONS: ROEO and OVEO showed efficacy to eradicate SE86 sessile cells in preformed biofilms on stainless steel, displaying a time-dependent effect and multitarget action mode on bacterial cell membrane. SIGNIFICANCE AND IMPACT OF THE STUDY: The study provides for the first time the effects of OVEO and ROEO on morphology and physiological functions of noncultivable sessile cells of S. Enteritidis biofilms preformed on stainless steel surfaces.

Assuntos

Biofilmes/efeitos dos fármacos , Óleos Voláteis/farmacologia , Origanum/química , Óleos de Plantas/farmacologia , Rosmarinus/química , Salmonella enteritidis/efeitos dos fármacos , Salmonella enteritidis/crescimento & desenvolvimento , Salmonella enteritidis/fisiologia , Aço Inoxidável/análise

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

Fruits are among the main natural sources of phenolic compounds (PC). These compounds exert important antioxidant properties primarily associated with the presence of hydroxyl groups in their molecular structure. Additionally, the antibacterial effects of fruit phenolic-rich extracts or individual PC commonly found in fruits have been an emerging research focus in recent years. This review discusses by first time the available literature regarding the inhibitory effects of fruit PC on pathogenic bacteria, including not only their direct effects on bacterial growth and survival, but also their effects on virulence factors and antibiotic resistance, as well as the possible mechanism underlying these inhibitory properties. The results of the retrieved studies show overall that the antibacterial effects of fruit PC vary with the target bacteria, type of PC and length of exposure to these compounds. The type of solvent and procedures used for extraction and fruit cultivar also seem to influence the antibacterial effects of phenolic-rich fruit extracts. Fruit PC have shown wide-spectrum antibacterial properties besides being effective antibiotic resistance modifying agents in pathogenic bacteria and these effects have shown to be associated with interruption of efflux pump expression/function. Furthermore, fruit PC can cause down regulation of a variety of genes associated with virulence features in pathogenic bacteria. Results of available studies indicate the depolarization and alteration of membrane fluidity as mechanisms underlying the inhibition of pathogenic bacteria by fruit PC. These data reveal fruit PC have potential antimicrobial properties, which should be rationally exploited in solutions to control pathogenic bacteria.

Assuntos

Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Frutas/química , Fenóis/farmacologia , Compostos Fitoquímicos/farmacologia , Antibacterianos/isolamento & purificação , Viabilidade Microbiana/efeitos dos fármacos , Fenóis/isolamento & purificação , Compostos Fitoquímicos/isolamento & purificação , Virulência/efeitos dos fármacos

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

Copper tungstate (CuWO4) crystals were synthesized by the sonochemistry (SC) method, and then, heat treated in a conventional furnace at different temperatures for 1h. The structural evolution, growth mechanism and photoluminescence (PL) properties of these crystals were thoroughly investigated. X-ray diffraction patterns, micro-Raman spectra and Fourier transformed infrared spectra indicated that crystals heat treated and 100°C and 200°C have water molecules in their lattice (copper tungstate dihydrate (CuWO4·2H2O) with monoclinic structure), when the crystals are calcinated at 300°C have the presence of two phase (CuWO4·2H2O and CuWO4), while the others heat treated at 400°C and 500°C have a single CuWO4 triclinic structure. Field emission scanning electron microscopy revealed a change in the morphological features of these crystals with the increase of the heat treatment temperature. Transmission electron microscopy (TEM), high resolution-TEM images and selected area electron diffraction were employed to examine the shape, size and structure of these crystals. Ultraviolet-Visible spectra evidenced a decrease of band gap values with the increase of the temperature, which were correlated with the reduction of intermediary energy levels within the band gap. The intense photoluminescence (PL) emission was detected for the sample heat treat at 300°C for 1h, which have a mixture of CuWO4·2H2O and CuWO4 phases. Therefore, there is a synergic effect between the intermediary energy levels arising from these two phases during the electronic transitions responsible for PL emissions.