Bioconjugate based on cisplatin and bacterial exopolysaccharide with reduced side effects: A novel proposal for cancer treatment.

BACKGROUND: In the search for alternatives that attenuate the toxicity associated to oncologic treatment with cisplatin (CDDP) and considering the potential health-beneficial properties of exopolysaccharides (EPS) produced by lactic acid bacteria, it was aimed on this study to evaluate the cytotoxic, toxicologic and antitumoral efficacy of a bioconjugate based on CDDP and EPS, on the experimental tumor of sarcoma 180. METHODS: After the synthesis of the cis-[Pt(NH3)2(Cl)2] complex and of the conjugate containing Lactobacillus fermentum exopolysaccharide was tested both in vitro and in vivo for evaluating the acute toxicity. RESULTS: The antitumoral study was performed using mice transplanted with sarcoma 180. The bioconjugate showed low to medium cytotoxicity for the cell lines tested, as well moderated acute toxicity. After determining the LD50, the following experimental groups were established for the antitumor assay: Control (NaCl 0,9%), CDDP (1 mg/kg), EPS and bioconjugate composition (200 mg/kg). The bioconjugate promoted a 38% regression in tumor mass when compared to the control, and a regression of 41% when compared to CDDP. Liver histopathological analysis revealed discrete alterations in animals treated with (CDDP + EPS) when compared to control. The bioconjugate also minimized changes in the renal parenchyma resulting from the tumor. CONCLUSION: Our results indicate that when CDDP is associated with EPS, this composition was more biocompatible, showing itself as a potent chemotherapeutic agent and lower tissue toxicity.

Evaluation of the Survival of Lactobacillus fermentum K73 during the Production of High-Oleic Palm Oil Macroemulsion Powders Using Rotor-Stator Homogenizer and Spray-Drying Technique.

This study aimed to evaluate the survival of the probiotic Lactobacillus fermentum when it is encapsulated in powdered macroemulsions to develop a probiotic product with low water activity. For this purpose, the effect of the rotational speed of the rotor-stator and the spray-drying process was assessed on the microorganism survival and physical properties of probiotic high-oleic palm oil (HOPO) emulsions and powders. Two Box-Behnken experimental designs were carried out: in the first one, for the effect of the macro emulsification process, the numerical factors were the amount of HOPO, the velocity of the rotor-stator, and time, while the factors for the second one, the drying process, were the amount of HOPO, inoculum, and the inlet temperature. It was found that the droplet size (ADS) and polydispersity index (PdI) were influenced by HOPO concentration and time, ζ-potential by HOPO concentration and velocity, and creaming index (CI) by speed and time of homogenization. Additionally, HOPO concentration affected bacterial survival; the viability was between 78-99% after emulsion preparation and 83-107% after seven days. The spray-drying process showed a similar viable cell count before and after the drying process, a reduction between 0.04 and 0.8 Log10 CFUg-1; the moisture varied between 2.4% and 3.7%, values highly acceptable for probiotic products. We concluded that encapsulation of L. fermentum in powdered macroemulsions at the conditions studied is effective in obtaining a functional food from HOPO with optimal physical and probiotic properties according to national legislation (>106 CFU mL-1 or g-1).

Effects of Lactobacillus fermentum Administration on Intestinal Morphometry and Antibody Serum Levels in Salmonella-Infantis-Challenged Chickens.

There are no studies reporting the effects of Salmonella enterica subsp. enterica serovar Infantis (S. Infantis) on intestinal architecture and immunoglobulin serum levels in chickens. Here, we measured these parameters and hypothesized whether probiotic administration could modulate the observed outcomes. Two-hundred 1-day-old COBB 500 male chicks were allocated into four groups: (I) the control, (II) the group treated with L. fermentum, (III) the group exposed to S. Infantis, and (IV) the group inoculated with both bacteria. At 11 days post infection, blood was gathered from animals which were then euthanized, and samples from the small intestine were collected. Intestinal conditions, as well as IgA and IgM serum levels, were assessed. S. Infantis reduced villus-height-to-crypt-depth (VH:CD) ratios in duodenal, jejunal, and ileal sections compared to control conditions, although no differences were found regarding the number of goblet cells, muc-2 expression, and immunoglobulin concentration. L. fermentum improved intestinal measurements compared to the control; this effect was also evidenced in birds infected with S. Infantis. IgM serum levels augmented in response to the probiotic in infected animals. Certainly, the application of L. fermentum elicited positive outcomes in S. Infantis-challenged chickens and thus must be considered for developing novel treatments designed to reduce unwanted infections.

Potential role of Limosilactobacillus fermentum as a probiotic with anti-diabetic properties: A review.

Oxidative stress, inflammation, and gut microbiota impairments have been implicated in the development and maintenance of diabetes mellitus. Strategies capable of recovering the community of commensal gut microbiota and controlling diabetes mellitus have increased in recent years. Some lactobacilli strains have an antioxidant and anti-inflammatory system capable of protecting against oxidative stress, inflammation, and diabetes mellitus. Experimental studies and some clinical trials have demonstrated that Limosilactobacillus fermentum strains can beneficially modulate the host antioxidant and anti-inflammatory system, resulting in the amelioration of glucose homeostasis in diabetic conditions. This review presents and discusses the currently available studies on the identification of Limosilactobacillus fermentum strains with anti-diabetic properties, their sources, range of dosage, and the intervention time in experiments with animals and clinical trials. This review strives to serve as a relevant and well-cataloged reference of Limosilactobacillus fermentum strains capable of inducing anti-diabetic effects and promoting health benefits.

Bioprotective potential of lactic acid bacteria and their metabolites against enterotoxigenic Escherichia coli.

Escherichia coli is one of the main pathogens that impacts swine production. Given the need for methods for its control, the in vitro effect of lactic acid bacteria (LAB) and their metabolites against E. coli F4 was evaluated through cell culture and microbiological analysis. The strains Limosilactobacillus fermentum 5.2, Lactiplantibacillus plantarum 6.2, and L. plantarum 7.1 were selected. To evaluate the action of their metabolites, lyophilized cell-free supernatants (CFS) were used. The effect of CFS was evaluated in HT-29 intestinal lineage cells; in inhibiting the growth of the pathogen in agar; and in inhibiting the formation of biofilms. The bioprotective activity of LAB was evaluated via their potential for autoaggregation and coaggregation with E. coli. The CFS did not show cytotoxicity at lower concentrations, except for L. fermentum 5.2 CFS, which is responsible for cell proliferation at doses lower than 10 mg ml-1. The CFS were also not able to inhibit the growth of E. coli F4 in agar; however, the CFS of L. plantarum 7.1 resulted in a significant decrease in biofilm formation at a dose of 40 mg ml-1. Regarding LAB, their direct use showed great potential for autoaggregation and coaggregation in vitro, thus suggesting possible effectiveness in animal organisms, preventing E. coli fixation and proliferation. New in vitro tests are needed to evaluate lower doses of CFS to control biofilms and confirm the bioprotective potential of LAB, and in vivo tests to assess the effect of LAB and their metabolites interacting with animal physiology.

The Probiotic Lactobacillus fermentum Biocenol CCM 7514 Moderates Campylobacter jejuni-Induced Body Weight Impairment by Improving Gut Morphometry and Regulating Cecal Cytokine Abundance in Broiler Chickens.

This research was conducted to investigate if the administration of the probiotic Lactobacillus fermentum could influence body weight, intestinal morphometry and the cecal cytokine response in Campylobacter jejuni-infected chickens. Seventy-two 1-day old COBB 500 male chicks were allocated randomly into four experimental groups. (I) Control group (C), in which chicks were left untreated. (II) LB group, treated with L. fermentum. (III) Cj group, infected with C. jejuni and (IV) coexposure group in which both bacteria were administered. Body weight was registered and then all birds were slaughtered; samples from the small intestine and caecum were collected at 4- and 7-days post infection. The experiment lasted eleven days. Villi height and crypt depth ratios of the duodenum, jejunum and ileum were evaluated using appropriate software, while reverse transcription quantitative PCR (RT-qPCR) was utilized for assessing transcript levels of key cecal inflammatory cytokines (IL-1ß, IL-18, IL-17, IL-15, IL13 and IL-4). Campylobacter-infected birds showed lower body weight values than those supplemented with the probiotic; these birds, in turn, proved to be heavier than those reared under control conditions. L. fermentum administration improved morphometrical parameters of the duodenum, jejunum and ileum; in general, villi were larger and crypts deeper than those identified in control conditions. Moreover, the negative effects elicited by C. jejuni were not observed in chickens exposed to the probiotic. Significant differences were also determined with regards to transcript abundance of all evaluated cytokines in the caecum. C. jejuni induced a downregulation of the studied interleukins; however, such a response was heightened by administration of L. fermentum, with an increase rate of transcription that promoted a more effective response to a C. jejuni infection. The effects of experimental treatments proved to vary between sampling points. Conclusively, these results demonstrate that L. fermentum lessens the negative effects elicited by C. jejuni on body weight by alleviating the impact on intestinal morphometry and cecal cytokine response, which ultimately improve chicken growth performance.

Lactobacillus fermentum: Could EPS production ability be responsible for functional properties?

Exopolysaccharides (EPS) production is a characteristic that has been widely described for many lactic acid bacteria (LAB) of different genera and species, but little is known about the relationship between the functional properties of the producing bacteria and EPS synthesis. Although many studies were addressed towards the application of EPS-producing LAB in the manufacture of several dairy products (fermented milk, cheese) due to their interesting technological properties (increased hardness, water holding capacity, viscosity, etc.), there are not many reports about the functional properties of the EPS extract itself, especially for the genus Lactobacillus. The aim of the present revision is to focus on the species Lactobacillus fermentum with reported functional properties, with particular emphasis on those strains capable of producing EPS, and try to establish if there is any linkage between this property and their functional/probiotic roles, considering the most recent bibliography.

The Exopolysaccharide of Lactobacillus fermentum UCO-979C Is Partially Involved in Its Immunomodulatory Effect and Its Ability to Improve the Resistance against Helicobacter pylori Infection.

Lactobacillus fermentum UCO-979C (Lf979C) beneficially modulates the cytokine response of gastric epithelial cells and macrophages after Helicobacter pylori infection in vitro. Nevertheless, no in vivo studies were performed with this strain to confirm its beneficial immunomodulatory effects. This work evaluated whether Lf979C improves protection against H. pylori infection in mice by modulating the innate immune response. In addition, we evaluated whether its exopolysaccharide (EPS) was involved in its beneficial effects. Lf979C significantly reduced TNF-α, IL-8, and MCP-1 and augmented IFN-γ and IL-10 in the gastric mucosa of H. pylori-infected mice. The differential cytokine profile induced by Lf979C in H. pylori-infected mice correlated with an improved reduction in the pathogen gastric colonization and protection against inflammatory damage. The purified EPS of Lf979C reduced IL-8 and enhanced IL-10 levels in the gastric mucosa of infected mice, while no effect was observed for IFN-γ. This work demonstrates for the first time the in vivo ability of Lf979C to increase resistance against H. pylori infection by modulating the gastric innate immune response. In addition, we advanced knowledge of the mechanisms involved in the beneficial effects of Lf979C by demonstrating that its EPS is partially responsible for its immunomodulatory effect.

The probiotic Lactobacillus fermentum 296 attenuates cardiometabolic disorders in high fat diet-treated rats.

BACKGROUND AND AIM: High-fat (HF) diet consumption has been associated with gut dysbiosis and increased risk of dyslipidemia, type 2 diabetes mellitus and hypertension. Probiotic administration has been suggested as a safe therapeutic strategy for the treatment of cardiometabolic disorders. This study was designed to assess the effects of probiotic Lactobacillus (L.) fermentum 296, a fruit-derived bacteria strain, against cardiometabolic disorders induced by HF diet. METHODS AND RESULTS: Male Wistar rats were divided into control diet (CTL); HF diet; and HF diet treated with Lactobacillus fermentum 296 (HF + Lf 296). The L. fermentum 296 strain at 1 × 109 colony forming units (CFU)/ml were daily administered by oral gavage for 4 weeks. The results showed that rats fed with HF diet displayed insulin resistance, reduced Lactobacillus spp. counts in feces, serum lipids, and oxidative profile. Rats fed on HF diet also demonstrated augmented blood pressure associated with sympathetic hyperactivity and impaired baroreflex control. The administration of L. fermentum 296 for 4 weeks recovered fecal Lactobacillus sp. counts and alleviated hyperlipidemia, sympathetic hyperactivity, and reduced systolic blood pressure in HF rats without affecting baroreflex sensibility. CONCLUSION: Our results suggest the ability of L. fermentum 296 improve biochemical and cardiovascular parameters altered in cardiometabolic disorders.

Evaluation of the Immunomodulatory Activities of the Probiotic Strain Lactobacillus fermentum UCO-979C.

Lactobacillus fermentum UCO-979C, a strain isolated from a human stomach, was previously characterized by its potential probiotic properties. The UCO-979C strain displayed the ability to beneficially regulate the innate immune response triggered by Helicobacter pylori infection in human gastric epithelial cells. In this work, we conducted further in vitro studies in intestinal epithelial cells (IECs) and in vivo experiments in mice in order to characterize the potential immunomodulatory effects of L. fermentum UCO-979C on the intestinal mucosa. Results demonstrated that the UCO-979C strain is capable to differentially modulate the immune response of IECs triggered by Toll-like receptor 4 (TLR4) activation through the modulation of TLR negative regulators' expression. In addition, we demonstrated for the first time that L. fermentum UCO-979C is able to exert its immunomodulatory effect in the intestinal mucosa in vivo. The feeding of mice with L. fermentum UCO-979C significantly increased the production of intestinal IFN-γ, stimulated intestinal and peritoneal macrophages and increased the number of Peyer's patches CD4+ T cells. In addition, L. fermentum UCO-979C augmented intestinal IL-6, reduced the number of immature B220+CD24high B cells from Peyer's patches, enhanced the number of mature B B220+CD24low cells, and significantly increased intestinal IgA content. The results of this work revealed that L. fermentum UCO-979C has several characteristics making it an excellent candidate for the development of immunobiotic functional foods aimed to differentially regulate immune responses against gastric and intestinal pathogens.

Lactobacillus fermentum UCO-979C beneficially modulates the innate immune response triggered by Helicobacter pylori infection in vitro.

Helicobacter pylori infection is associated with important gastric pathologies. An aggressive proinflammatory immune response is generated in the gastric tissue infected with H. pylori, resulting in gastritis and a series of morphological changes that increase the susceptibility to cancer development. Probiotics could present an alternative solution to prevent or decrease H. pylori infection. Among them, the use of immunomodulatory lactic acid bacteria represents a promising option to reduce the severity of chronic inflammatory-mediated tissue damage and to improve protective immunity against H. pylori. We previously isolated Lactobacillus fermentum UCO-979C from human gastric tissue and demonstrated its capacity to reduce adhesion of H. pylori to human gastric epithelial cells (AGS cells). In this work, the ability of L. fermentum UCO-979C to modulate immune response in AGS cells and PMA phorbol 12-myristate 13-acetate (PMA)-differentiated THP-1 (human monocytic leukaemia) macrophages in response to H. pylori infection was evaluated. We demonstrated that the UCO-979C strain is able to differentially modulate the cytokine response of gastric epithelial cells and macrophages after H. pylori infection. Of note, L. fermentum UCO-979C was able to significantly reduce the production of inflammatory cytokines and chemokines in AGS and THP-1 cells as well as increase the levels of immunoregulatory cytokines, indicating a remarkable anti-inflammatory effect. These findings strongly support the probiotic potential of L. fermentum UCO-979C and provide evidence of its beneficial effects against the inflammatory damage induced by H. pylori infection. Although our findings should be proven in appropriate experiments in vivo, in both H. pylori infection animal models and human trials, the results of the present work provide a scientific rationale for the use of L. fermentum UCO-979C to prevent or reduce H. pylori-induced gastric inflammation in humans.

Lactobacillus fermentum UCO-979C strongly inhibited Helicobacter pylori SS1 in Meriones unguiculatus.

Searching for bacterial probiotics active upon Helicobacter pylori continue to be an important clinical challenge because of the increased prevalence of this highly priority pathogen in humans. In this work, we assess the in vivo anti-H. pylori SS1 (cagA+/vacAs2m2+) properties of a previously isolated human gastric probiotic strain Lactobacillus fermentum UCO-979C by using a Meriones unguiculatus (Mongolian gerbil) model. Animals were administered with a saline suspension of L. fermentum UCO-979C or H. pylori SS1 as negative and positive control for H. pylori colonisation controls, prior to assayed the challenge group that was administered with these two species per animal for detecting protective activity of the probiotic strain against colonisation. The results showed that L. fermentum UCO-979C strongly inhibited the colonisation of H. pylori decreasing up to 87% of the colonisation in the antrum by the pathogen, suggesting that this probiotic strain has a strong probiotic activity against H. pylori in the most valuable animal model for in vivo assays nowadays.

Ethanol addition enhances acid treatment to eliminate Lactobacillus fermentum from the fermentation process for fuel ethanol production.

Fermentation is one of the most critical steps of the fuel ethanol production and it is directly influenced by the fermentation system, selected yeast, and bacterial contamination, especially from the genus Lactobacillus. To control the contamination, the industry applies antibiotics and biocides; however, these substances can result in an increased cost and environmental problems. The use of the acid treatment of cells (water-diluted sulphuric acid, adjusted to pH 2·0-2·5) between the fermentation cycles is not always effective to combat the bacterial contamination. In this context, this study aimed to evaluate the effect of ethanol addition to the acid treatment to control the bacterial growth in a fed-batch system with cell recycling, using the industrial yeast strain Saccharomyces cerevisiae PE-2. When only the acid treatment was used, the population of Lactobacillus fermentum had a 3-log reduction at the end of the sixth fermentation cycle; however, when 5% of ethanol was added to the acid solution, the viability of the bacterium was completely lost even after the first round of cell treatment. The acid treatment +5% ethanol was able to kill L. fermentum cells without affecting the ethanol yield and with a low residual sugar concentration in the fermented must. SIGNIFICANCE AND IMPACT OF THE STUDY: In Brazilian ethanol-producing industry, water-diluted sulphuric acid is used to treat the cell mass at low pH (2·0) between the fermentative cycles. This procedure reduces the number of Lactobacillus fermentum from 107 to 104  CFU per ml. However, the addition of 5% ethanol to the acid treatment causes the complete loss of bacterial cell viability in fed-batch fermentation with six cell recycles. The ethanol yield and yeast cell viability are not affected. These data indicate the feasibility of adding ethanol to the acid solution replacing the antibiotic use, offering a low cost and a low amount of residue in the biomass.

Modelo de quesería artesanal bajo un signo distintivo en el Caribe colombiano: caso Atlántico

Introducción. Se presenta una propuesta de signo distintivo para la producción y comercialización de queso costeño de alto impacto en el departamento del Atlántico y en la región Caribe colombiana. Objetivo. Proponer a los productores de queso costeño, un modelo de producción y comercialización del producto, que siente las bases para convertir la quesería artesanal en un instrumento de desarrollo regional, a partir de la fabricación de un producto inocuo de base biotecnológica. Materiales y métodos. Estudio de tipo descriptivo abordado desde los aspectos socio-cultural y biotecnológico, para la identificación de valores colectivos relacionados con tradición quesera, preferencias de producción, asociatividad, cumplimiento de normas legales, signo distintivo y uso de cultivos lácticos autóctonos en sus procesos productivos para incorporar características del queso típico de la región. Resultados. Mediante el desarrollo de un signo distintivo es posible no solo el posicionamiento del queso costeño en el mercado como producto de alto valor, sino dejar atrás la indiferenciación actual propia de un producto básico, y lograr la reducción de riesgo de contaminación, teniendo en cuenta el valor agregado que representan los inóculos microbianos como innovación biotecnológica en la calidad del producto. Conclusión. El modelo presentado convenció al productor de que bajo el signo distintivo su producto tiene mayor valor agregado y, en consecuencia, podrá obtener un precio mayor al actual.

Introduction. A distinctive sign proposal is presented for high-impact production and marketing of coast cheese in the state of Atlántico and in the Colombian Caribbean region. Objective. To propose coast cheese producers a production and marketing model of the product; a model which lays the foundation to covert craft cheese factories into a regional development instrument from the manufacture of a biotechnological-based innocuous product. Materials and methods. Descriptive research addressed from social-cultural and biotechnological aspects for the identification of collective values associated to cheese-making tradition, production preferences, association capacity, compliance with legal regulations, distinctive sign, and use of native dairy cultures in their production processes in order to incorporate characteristics of the typical cheese of the region. Results. Through the development of a distinctive sign, it is possible not only to position the coast cheese in the market as a high-value product but also to left behind the present non-differentiation typical of a basic product and to achieve the decrease of contamination risks, bearing into account the value added brought by microbial inoculation as biotechnological innovation in the product quality. Conclusion. The model shown has convinced the producers that under the distinctive sign their product has better value added and then they would be able to gain a higher price.

Introdução. Se apresenta uma proposta de signo distintivo para a produção e comercialização de queijo litorâneo de alto impacto no departamento do Atlântico e na região do Caribe colombiano. Objetivo. Propor aos produtores de queijo litorâneo, um modelo de produção e comercialização do produto, que sente as bases para converter a indústria do queijo artesanal num instrumento de desenvolvimento regional, a partir da fabricação de um produto inócuo de base biotecnológica. Materiais e métodos. Estudo de tipo descritivo abordado desde os aspectos sociocultural e biotecnológico, para a identificação de valores coletivos relacionados com a tradição da indústria do queijo, preferências de produção, associatividade, cumprimento de normas legais, signo distintivo e uso de cultivos lácteos autóctones nos seus processos produtivos para incorporar características do queijo típico da região. Resultados. Mediante o desenvolvimento de um signo distintivo é possível não só o posicionamento do queijo litorâneo no mercado como produto de alto valor, senão deixar atrás a indiferença atual própria de um produto básico, e conseguir a redução do risco de contaminação, tendo em conta o valor agregado que representam os inócuos microbianos como inovação biotecnológica na qualidade do produto. Conclusão. O modelo apresentado convenceu ao produtor de que sob o signo distintivo seu produto tem maior valor agregado e, por consequência, poderá obter um preço maior ao atual.

Lactobacillus fermentum ATCC 23271 Displays In vitro Inhibitory Activities against Candida spp.

Lactobacilli are involved in the microbial homeostasis in the female genital tract. Due to the high prevalence of many bacterial diseases of the female genital tract and the resistance of microorganisms to various antimicrobial agents, alternative means to control these infections are necessary. Thus, this study aimed to evaluate the probiotic properties of well-characterized Lactobacillus species, including L. acidophilus (ATCC 4356), L. brevis (ATCC 367), L. delbrueckii ssp. delbrueckii (ATCC 9645), L. fermentum (ATCC 23271), L. paracasei (ATCC 335), L. plantarum (ATCC 8014), and L. rhamnosus (ATCC 9595), against Candida albicans (ATCC 18804), Neisseria gonorrhoeae (ATCC 9826), and Streptococcus agalactiae (ATCC 13813). The probiotic potential was investigated by using the following criteria: (i) adhesion to host epithelial cells and mucus, (ii) biofilm formation, (iii) co-aggregation with bacterial pathogens, (iv) inhibition of pathogen adhesion to mucus and HeLa cells, and (v) antimicrobial activity. Tested lactobacilli adhered to mucin, co-aggregated with all genital microorganisms, and displayed antimicrobial activity. With the exception of L. acidophilus and L. paracasei, they adhered to HeLa cells. However, only L. fermentum produced a moderate biofilm and a higher level of co-aggregation and mucin binding. The displacement assay demonstrated that all Lactobacillus strains inhibit C. albicans binding to mucin (p < 0.001), likely due to the production of substances with antimicrobial activity. Clinical isolates belonging to the most common Candida species associated to vaginal candidiasis were inhibited by L. fermentum. Collectively, our data suggest that L. fermentum ATCC 23271 is a potential probiotic candidate, particularly to complement candidiasis treatment, since presented with the best probiotic profile in comparison with the other tested lactobacilli strains.

Probiotic Lactobacillus fermentum UCO-979C biofilm formation on AGS and Caco-2 cells and Helicobacter pylori inhibition.

The ability of the human isolate Lactobacillus fermentum UCO-979C to form biofilm and synthesize exopolysaccharide on abiotic and biotic models is described. These properties were compared with the well-known Lactobacillus casei Shirota to better understand their anti-Helicobacter pylori probiotic activities. The two strains of lactobacilli synthesized exopolysaccharide as detected by the Dubois method and formed biofilm on abiotic and biotic surfaces visualized by crystal violet staining and scanning electron microscopy. Concomitantly, these strains inhibited H. pylori urease activity by up to 80.4% (strain UCO-979C) and 66.8% (strain Shirota) in gastric adenocarcinoma (AGS) cells, but the two species showed equal levels of inhibition (~84%) in colorectal adenocarcinoma (Caco-2) cells. The results suggest that L. fermentum UCO-979C has probiotic potential against H. pylori infections. However, further analyses are needed to explain the increased activity observed against the pathogen in AGS cells as compared to L. casei Shirota.

Inhibition of Staphylococcus aureus biofilm by Lactobacillus isolated from fine cocoa.

BACKGROUND: Biofilm production represents an important virulence and pathogenesis factor for Staphylococcus aureus. The formation of biofilms on medical devices is a major concern in hospital environments, as they can become a constant source of infection. Probiotic bacteria, such as Lactobacillus fermentum and L. plantarum, have been found to inhibit biofilm formation; however little is known about the underlying mechanism. In this study, we tested the activity of supernatants produced by L. fermentum TCUESC01 and L. plantarum TCUESC02, isolated during the fermentation of fine cocoa, against S. aureus CCMB262 biofilm production. We measured inhibition of biofilm formation in vitro and analyzed biofilm structure by confocal and electronic microscopy. Additionally, we quantified the expression of S. aureus genes icaA and icaR involved in the synthesis of the biofilm matrix by real-time PCR. RESULTS: Both Lactobacillus supernatants inhibited S. aureus growth. However, only L. fermentum TCUESC01 significantly reduced the thickness of the biofilm, from 14 µm to 2.83 µm (at 18 mg∙mL-1, 90 % of the minimum inhibitory concentration, MIC), 3.12 µm (at 14 mg∙mL-1, 70 % of the MIC), and 5.21 µm (at 10 mg∙mL-1, 50 % of the MIC). Additionally, L. fermentum TCUESC01 supernatant modulated the expression of icaA and icaR. CONCLUSIONS: L. fermentum TCUESC01 reduces the formation of S. aureus biofilm under subinhibitory conditions. Inhibition of biofilm production probably depends on modulation of the ica operon.

Lactobacillus fermentum CRL1446 Ameliorates Oxidative and Metabolic Parameters by Increasing Intestinal Feruloyl Esterase Activity and Modulating Microbiota in Caloric-Restricted Mice.

The purpose of this study was to determine whether the administration of the feruloyl esterase (FE)-producing strain Lactobacillus fermentum CRL1446 enhances metabolic and oxidative parameters in caloric-restricted (CR) mice. Balb/c male mice were divided into ad libitum fed Group (ALF Group), CR diet Group (CR Group) and CR diet plus L. fermentum Group (CR-Lf Group). CR diet was administered during 45 days and CRL1446 strain was given in the dose of 108 cells/mL/day/mouse. FE activity was determined in intestinal mucosa and content at Day 1, 20 and 45. Triglyceride, total cholesterol, glucose, thiobarbituric acid reactive substances (TBARS) levels and glutathione reductase activity were determined in plasma. Gut microbiota was evaluated by high-throughput sequencing of 16S rRNA gene amplicons. At Day 45, total intestinal FE activity in CR-Lf Group was higher (p = 0.020) than in CR and ALF groups and an improvement in both metabolic (reductions in triglyceride (p = 0.0025), total cholesterol (p = 0.005) and glucose (p < 0.0001) levels) and oxidative (decrease of TBARS levels and increase of plasmatic glutathione reductase activity (p = 0.006)) parameters was observed, compared to ALF Group. CR diet increased abundance of Bacteroidetes and CRL1446 administration increased abundance of Bifidobacterium and Lactobacillus genus. L. fermentun CRL1446 exerted a bifidogenic effect under CR conditions.

Feruloyl esterase activity is influenced by bile, probiotic intestinal adhesion and milk fat.

Cinnamoyl esterases (CE) are microbial and mammalian intestinal enzymes able to release antioxidant hydroxycinnamic acids from their non-digestible ester-linked forms naturally present in vegetable foods. Previous findings showed that oral administration of Lactobacillus fermentum CRL1446 increased intestinal CE activity and improved oxidative status in mice. The aim of this work was to evaluate the in vitro CE activity of L. fermentum CRL1446 and the effect of bile on this activity, as well as strain resistance to simulated gastrointestinal tract (GIT) conditions and its ability to adhere to intestinal epithelium and influence its basal CE activity. L. fermentum CRL1446 and L. fermentum ATCC14932 (positive control for CE activity) were able to hydrolyse different synthetic hydroxycinnamates, with higher specificity toward methyl ferulate (3,853.73 and 899.19 U/g, respectively). Feruloyl esterase (FE) activity was mainly intracellular in L. fermentum CRL1446 and cell-surface associated in L. fermentum ATCC14932. Both strains tolerated simulated GIT conditions and were able to adhere ex vivo to intestinal epithelium. Pre-incubation of L. fermentum strains with bile increased FE activity in both whole cells and supernatants (~2-fold), compared to controls, suggesting that cells were permeabilised by bile, allowing more substrate to enter the cell and/or leakage of FE enzymes. Three-fold higher FE activities were detected in intestinal tissue fragments with adhered L. fermentum CRL1446 cells compared to control fragments (without bacteria), indicating that this strain provides exogenous FE activity and could stimulate esterase activity in the intestinal mucosa. Finally, we found that milk fat had a negative effect on FE activity of intestinal tissue, in absence or presence of adhered L. fermentum. These results help explaining the increase in intestinal FE activity previously observed in mice fed with L. fermentum CRL1446, and support the potential use of this strain for the development of new functional foods directed to oxidative stress-related ailments.

Technological, rheological and sensory characterizations of a yogurt containing an exopolysaccharide extract from Lactobacillus fermentum Lf2, a new food additive.

Lactobacillus fermentum Lf2, an autochthonous strain isolated as a non starter culture in Cremoso cheese, produces high EPS levels (~1g/L) in optimized conditions (SDM broth, pH6.0, 30°C, 72h). Technological (texture profile and rheological analysis) and sensory properties of non-fat yogurts with 300 and 600mg EPS/L were studied at 3 and 25days after manufacture. Yogurts with different EPS concentrations showed higher hardness values than the control group at both periods of time, being the only significant difference that remained stable during time. The consistency index was also higher for the treated samples at both times evaluated, being significantly different for samples with 300mg/L of EPS extract, while the flow behavior index was lower for EPS-added yogurts. The thixotropic index was lower (P<0.05) for samples with the highest EPS extract concentration at the end of the storage time. Regarding the sensory analysis, those yogurts with 600mg/L of EPS extract presented the highest values of consistency at 3days of storage. No considerable differences for defects (milk powder, acid, bitter and cooked milk flavors) were perceived between treated and control samples at both times evaluated. Syneresis was also studied and samples with 600mg/L of EPS extract presented the lowest syneresis values at 25days of storage, which considerably decreased with the time of storage. In conclusion, the EPS from L. fermentum Lf2, used as an additive, provided yogurt with creamy consistency and increased hardness, without the presence of unwanted defects and improving the water holding capacity of the product. All the analysis done showed the potential of this extract to be used as a technofunctional natural ingredient, and it should be considered its positive impact on health, according to previous studies.