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The mechanism of metabolites produced by lactic acid bacteria in mediating microbial interactions has been difficult to ascertain. This study comparatively evaluated the antimicrobial effect of the novel bacterium Pediococcus acidilactici CCFM18 and explored the global chemical view of its interactions with indicator bacteria. P. acidilactici CCFM18 had sufficiently strong antimicrobial activity to effectively inhibit the growth of the indicator bacteria and enhance their intracellular reactive oxygen species (ROS) level. The emerging technique of matrix-assisted laser desorption ionization–time-of-flight (MALDI-TOF) imaging mass spectrometry indicated that P. acidilactici CCFM18 increased the production of pediocin PA-1 and the penocin A profile during its interaction with the indicator bacteria, thus differing from P. acidilactici CCFM28 (a commonly used laboratory strain). Strikingly, the production of coagulin A was triggered only by signaling molecules made by the competing strain L. thermophilus, suggesting an idiosyncratic response from P. acidilactici CCFM18. Bioinformatic mining of the P. acidilactici CCFM18 draft genome sequence revealed gene loci that code for the complex secondary metabolites analyzed via MSI. Taken together, these results illustrate that chemical interactions between P. acidilactici CCFM18 and indicator bacteria exhibit high complexity and specificity and can drive P. acidilactici CCFM18 to produce different secondary metabolites. [ABSTRACT FROM AUTHOR]

Fungal contamination of food and animal feed, especially by mycotoxigenic fungi, is not only a global food quality concern for food manufacturers, but it also poses serious health concerns because of the production of a variety of mycotoxins, some of which present considerable food safety challenges. In today's mega‐scale food and feed productions, which involve a number of processing steps and the use of a variety of ingredients, fungal contamination is regarded as unavoidable, even good manufacturing practices are followed. Chemical preservatives, to some extent, are successful in retarding microbial growth and achieving considerably longer shelf‐life. However, the increasing demand for clean label products requires manufacturers to find natural alternatives to replace chemically derived ingredients to guarantee the clean label. Lactic acid bacteria (LAB), with the status generally recognized as safe (GRAS), are apprehended as an apt choice to be used as natural preservatives in food and animal feed to control fungal growth and subsequent mycotoxin production. LAB species produce a vast spectrum of antifungal metabolites to inhibit fungal growth; and also have the capacity to adsorb, degrade, or detoxify fungal mycotoxins including ochratoxins, aflatoxins, and Fusarium toxins. The potential of many LAB species to circumvent spoilage associated with fungi has been exploited in a variety of human food and animal feed stuff. This review provides the most recent updates on the ability of LAB to serve as antifungal and anti‐mycotoxigenic agents. In addition, some recent trends of the use of LAB as biopreservative agents against fungal growth and mycotoxin production are highlighted. [ABSTRACT FROM AUTHOR]

We investigated the protection offered by the probiotic Lactobacillus plantarum CCFM639 against waterborne Al exposure in tilapia. Fish were allocated to control, CCFM639-only, Al-only or Al plus CCFM639 groups. The fish were exposed to 2.73 mg/L Al ions for 4 weeks. The probiotic was incorporated into the fish diet at 10 8 CFU/g and provided twice daily. Our results showed that L . plantarum CCFM639 significantly enhanced feed utilization, growth performance and antioxidant ability in the absence of waterborne Al exposure. When fish were exposed to Al, dietary supplementation with the strain effectively decreased the death rate and accumulation of Al in tissues, and enhanced growth performance. Moreover, Al-induced changes in hematobiochemical parameters and hepatic oxidative stress and histopathology were also alleviated. Therefore, L . plantarum CCFM639 may be a novel dietary supplement for fish to enhance growth performance and prevent aquaculture and food safety problems induced by Al pollution. [ABSTRACT FROM AUTHOR]

Aluminium (Al) is a neurotoxin that has a diverse range of negative effects on cerebral function. In our previous study, a candidate probiotic, Lactobacillus plantarum CCFM639, was selected for its ability to alleviate Al toxicity in vitro and in vivo . Our aim was to investigate the neuroprotective potential of L. plantarum CCFM639 in Al-induced neuronal injury. L. plantarum CCFM639 or defetoxamine was given to mice by gavage once daily for 14 weeks. During the first 8 weeks, aluminium chloride was administered orally to all mice via drinking water. The results showed that L. plantarum CCFM639 significantly improved memory deficits of Al-exposed mice. This candidate probiotic also reduced the accumulation of Al in the brains, restored integrity of tight junction proteins, alleviated cerebral oxidative stress and decreased the levels of pro-inflammatory cytokines in the mice brain. Thus, L. plantarum CCFM639 demonstrates significant neuroprotective potential in Al-induced neuronal injury. [ABSTRACT FROM AUTHOR]

Some studies reported that probiotic could relieve allergy-induced damage to the host, but how to get a useful probiotic is still a challenge. In this study, the protective effects of three lactic acid bacteria (La, Lp and Lc) were evaluated in a mouse model, and its relationship with the in vitro properties was analyzed. The in vitro results indicated that La with the capacity to inhibit IL-4 production could have a better anti-allergy effect in vivo than two others. However, the animal trials showed that all LAB strains could alleviate allergen-induced airway inflammation. Among them, LAB strain Lp had a better effect in inhibiting allergic response through a modulation of Th1/Th2 balance and an increase of regulatory T cells. This difference could be explained by that different LAB strains have a strain-specific effect on gut microbiota closely associated with host immune responses. Finally, this study did not only obtain an effective anti-allergy probiotic strain via animal study, but also indicate that probiotic-induced effect on intestinal microbiota should be considered as an important screening index, apart from its inherent characteristics. [ABSTRACT FROM AUTHOR]

Aluminium (Al) is the most abundant metal in the earth's crust. Al exposure can cause a variety of adverse physiological effects in humans and animals. Our aim was to demonstrate that specific probiotic bacteria can play a special physiologically functional role in protection against Al toxicity in mice. Thirty strains of lactic acid bacteria (LAB) were tested for their aluminium-binding ability, aluminium tolerance, their antioxidative capacity, and their ability to survive the exposure to artificial gastrointestinal (GI) juices. Lactobacillus plantarum CCFM639 was selected for animal experiments because of its excellent performance in vitro. Forty mice were divided into four groups: control, Al only, Al plus CCFM639, and Al plus deferiprone (DFP). CCFM639 was administered at 10 CFU once daily for 10 days, followed by a single oral dose of aluminium chloride hexahydrate at 5.14 mg aluminium (LD) for each mouse. The results showed that CCFM639 treatment led to a significant reduction in the mortality rates with corresponding decrease in intestinal aluminium absorption and in accumulation of aluminium in the tissues and amelioration of hepatic histopathological damage. This probiotic treatment also resulted in alleviation of hepatic, renal, and cerebral oxidative stress. The treatment of L. plantarum CCFM639 has potential as a therapeutic dietary strategy against acute aluminium toxicity. [ABSTRACT FROM AUTHOR]

Background: Mucosal vaccine based on lactic acid bacteria is an attractive concept for the prevention and treatment of allergic diseases, but their mechanisms of action in vivo are poorly understood. Therefore, we sought to investigate how recombinant major dust mite allergen Der p2-expressing Lactococcus lactis as a mucosal vaccine induced the immune tolerance against house dust mite allergy in a mouse model. Methods: Three strains of recombinant L. lactis producing Der p2 in different cell components (extracellular, intracellular and cell wall) were firstly constructed. Their prophylactic potential was evaluated in a Der p2-sensitised mouse model, and immunomodulation properties at the cellular level were determined by measuring cytokine production in vitro. Results: Der p2 expressed in the different recombinant L. lactis strains was recognized by a polyclonal anti-Der p2 antibody. Oral treatment with the recombinant L. lactis prior sensitization significantly prevented the development of airway inflammation in the Der p2-sensitized mice, as determined by the attenuation of inflammatory cells infiltration in the lung tissues and decrease of Th2 cytokines IL-4 and IL-5 levels in bronchoalveolar lavage. In addition, the serum allergen-specific IgE levels were significantly reduced, and the levels of IL-4 in the spleen and mesenteric lymph nodes cell cultures were also markedly decreased upon allergen stimulation in the mice fed with the recombinant L. lactis strains. These protective effects correlated with a significant up-regulation of regulatory T cells in the mesenteric lymph nodes. Conclusion: Oral pretreatment with live recombinant L. lactis prevented the development of allergen-induced airway inflammation primarily by the induction of specific mucosal immune tolerance. [ABSTRACT FROM AUTHOR]

Peanut allergy (PNA) has becoming a non-negligible health concern worldwide. Thus far, allergen-specific immunotherapy aimed at inducing mucosal tolerance has widely been regarded as a major management strategy for PNA. The safety profiles and the intrinsic probiotic properties of lactic acid bacteria (LAB) render them attractive delivery vehicles for mucosal vaccines. In the present study, we exploited genetically modified Lactococcus lactis to produce peanut allergen Ara h 2 via different protein-targeting systems and their immunomodulatory potency for allergic immune responses in mice were investigated. By comparison with the strain expressing the cytoplasmic form of Ara h 2 (LL1), the strains expressing the secreted and anchored forms of Ara h 2 (LL2 and LL3) were more potent in redirecting a Th2-polarized to a non-allergic Th1 immune responses. Induction of SIgA and regulatory T cells were also observed at the local levels by orally administration of recombinant L. lactis. Our results indicate that allergen-producing L. lactis strains modulated allergic immune responses and may be developed as promising mucosal vaccines for managing allergic diseases. [ABSTRACT FROM AUTHOR]

Background: There are still a large variety of microorganisms among aquatic animals, especially probiotic lactic acid bacteria in cold water fishes at high latitudes have not been fully developed. Hence, the present study aims to evaluate the probiotic potential of cold-adapted Lactobacillus strains isolated from the intestinal tract of cold water fishes (Xinjiang) and select candidates to be used as new food preservative agents and/or probiotic additives in feeding of aquaculture. Results: A total of 43 Lactobacillus spp. were isolated from 16 kinds of intestinal tract of cold-water fishes. They were characterized by phenotypic methods, identified using Rep-PCR and 16S rRNA gene sequencing as four species: Lactobacillus sakei (22 isolates), Lactobacillus plantarum (16 isolates), Lactobacillus casei (4 isolates) and Lactobacillus paracasei (1 isolate). The in vitro tests included survival in low pH and bile, antimicrobial activity (against Escherichia coli, Salmonella enterica subsp. enterica serovar Typhimurium, Salmonella enterica subsp. enterica, Listeria monocytogenes, and Listeria innocua), resistance to 15 antibiotics and hemolytic tests. Among all 43 lactobacilli isolates, the 22 isolates showed a wide range of antimicrobial activity against 6 different pathogenic strains. There were twenty isolates growing at optimal temperature ranging 16~20 °C, which were initially considered to be cold-adapted strains. Two (2) Lb. sakei strains and 2 Lb. plantarum strains demonstrated the highest survivability after 4 h of exposure at pH 2.0. Most of the tested strains cannot be cultured after exposed into 0.5% bile solution for 4 h, while 2 Lb. plantarum strains (E-HLM-3, CQ-CGC-2) and 1 Lb. sakei strain M-DGM-2 survived even at 2% bile concentration. In addition, the safety assessment showed that 22 strains without any detectable hemolytic activity and resistant to glycopeptides (vancomycin, teicoplanin), levofloxacin, aztreonam, amikacin and oxacillin, while all the studied lactobacilli showed sensitivity to or semi-tolerant to other antibiotics. Conclusions: Based on all the experiments, 3 strains, including E-HLM-3, CQ-CGC-2, and M-DGM-2 might be a candidate of choice for using in the food preservative agents and/or probiotic additives in feeding of aquaculture. [ABSTRACT FROM AUTHOR]

Adding specific lactic acid bacteria to yogurt has been known to enhance both its benefits and flavor. However, differences among the strains of the same species present significant challenges. In this study, we constructed a phylogenetic tree of 232 Limosilactobacillus fermentum strains and selected seven strains with distinct evolutionary relationships for yogurt fermentation. L. fermentum FFJ12, which possesses more glycoside hydrolases (GH), had the highest growth rate and acid production. Conversely, L. fermentum FBJSY21_1, containing less GH, showed poor acid production. Yogurt texture might be related to amino acid synthesis. L. fermentum induced a high abundance of dibenzoyl- L -tartaric acid anhydride, leading to a wine-like flavor in yogurt. Additionally, L. fermentum upregulated citric acid and 4-acetamidobenzoic acid levels; and downregulated phenylalanine abundance. This study provided novel insights into the selection of potential probiotics for yogurt fermentation, thereby promoting the development of precision yogurt. • Effects of seven phylogenetically diverse Limosilactobacillus fermentum on yogurt fermentation and storage. • L. fermentum with more GHs resulted in faster acidification of yogurt and higher levels of bacteria. • L. fermentum induced a high abundance of dibenzoyl- L -tartaric acid anhydride, leading to a wine-like flavor in yogurt. • L. fermentum upregulated citric acid and 4-acetamidobenzoic acid levels while downregulating phenylalanine abundance. [ABSTRACT FROM AUTHOR]

In the present study 114 lactic acid bacteria strains, isolated from raw mare milks from pastoral areas for ethnic minorities in northwest China, were screened for probiotic traits, and their characteristics were compared with those of Lactobacillus rhamnosus GG, a commercial strain. Among the 114 strains identified, the most common species was Pediococcus pentosaceus (n = 52), followed by Leuconostoc lactis (n = 35), Lactobacillus helveticus (n = 7), Lactobacillus plantarum (n = 6), Lactobacillus kefiri (n = 5), Lactobacillus curvatus (n = 4), Lactobacillus paracasei (n = 3), and Lactococcus garvieae (n = 3). Based on acid and bile salt tolerance, 15 strains were further selected. All selected strains were subjected to a series of in vitro tests to assess their technological properties, including cell surface hydrophobicity (13.6–56.2%), autoaggregation ability (9.26–38.30%), coaggregation ability, and heat and lysozyme survival rates (84.74–94.01% and 80.52–99.37%, respectively). In vitro antagonism showed that Lb. plantarum (M5–19, M8–60, M8–59) exhibited the most strong inhibitory activity against 7 tested pathogens. Moreover, antibiotic resistance and hemolytic activity were investigated for safety assessment. No strain exhibited hemolytic activity, and most of the strains were sensitive to a series of 14 antibiotics of clinical importance. Ultimately, the principal component analysis of all data obtained above showed that 2 Lb. plantarum strains (M8–59, M8–60) and Lb. paracasei M1–36 exhibited the best potential for their inclusion as adjunct functional cultures in local fermented dairy products. [ABSTRACT FROM AUTHOR]

Cadmium (Cd) is a toxic heavy metal that causes adverse health effects in humans and animals. In the present study, 33 strains of lactic acid bacteria (LAB) were screened for their potential probiotic capacity against Cd toxicity. The Cd binding ability was investigated first, and 10 strains with comparatively higher Cd binding properties were selected for further study through the evaluation of Cd tolerance, antioxidative capacity and acid and bile salt tolerance. The results revealed that as a reference strain, Lactobacillus rhamnosus GG had good Cd tolerance, antioxidative capacity and acid and bile tolerance, but the Cd binding ability of this strain was poor. Another strain, Lactobacillus plantarum CCFM8610, showed significantly better binding ability and Cd tolerance than the other tested strains. This strain also exhibited relatively good antioxidative properties and resistance to the simulated gastrointestinal conditions. This study suggests that L . plantarum CCFM8610 could be used as a potential probiotic in food applications against Cd toxicity. [ABSTRACT FROM AUTHOR]

House dust mite allergy accounts for a majority of severe allergic asthma cases, and there is a need for new prevention and treatment strategies. Specific probiotics have shown beneficial effects in the treatment of allergic diseases, owning to their inherent immunomodulatory properties. To obtain new and effective anti-allergy probiotics, cytokine profiles of 25 lactic acid bacteria strains were measured by in vitro co-culture with mice spleen cells. Of the various strains, strong IL-10-inducing Streptococcus thermophilus CCFM218 (ST218) significantly suppressed IL-4 secretion in vitro and was postulated to have a better anti-allergy effect in vivo . To determine the anti-allergy property of ST218, its protective effect on allergic response was evaluated in a mouse allergy model together with Lactobacillus rhamnosus GG. In contrast to LGG, ST218 had a better suppressive effect on allergic response in vivo , characterized by increased specific IgG2a and IL-10 levels in serum, regulatory T cells in the mesenteric lymph nodes and a reduction in serum Th2 cytokine IL-4. It indicated that ST218 was an excellent anti-allergy strain that can be favorable to use in the treatment or prevention of allergic diseases. [ABSTRACT FROM AUTHOR]

Abstract: To improve the microbiological security of food products, 285 lactic acid bacteria were isolated from koumiss and pickles, and their antimicrobial properties were characterised. Among the strains, Pediococcus acidilactici P9, a strain isolated from a local pickled vegetable, produced an antagonistic substance that inhibited Listeria monocytogenes and Shigella. The substance was heat (121 °C for 20 min) and pH (2.0–10.0) stable, but sensitive to proteolytic enzymes. The production of bacteriocins started at the exponential phase and reached its maximum at the stationary phase, indicating that it was growth related. P. acidilactici P9 also showed an ability to protect HT-29 from invasion by L. monocytogenes and the inhibition rate reached 35.89%. P. acidilactici P9 showed a potential for application in food products as a biopreservative. [Copyright &y& Elsevier]

Abstract: In this study, 11 lactic acid bacteria (LAB) strains were screened for potential new probiotics using in vitro methods, including acid and bile salt tolerance, adhesion, antioxidative and α-glucosidase inhibitory activity. The results indicated that Lactobacillus casei 2W and Lactobacillus rhamnosus Z7 showed better potential probiotic properties and α-glucosidase inhibitory activity in vitro. The characteristics of L. casei 2W were better than those of L. rhamnosus GG, and L. rhamnosus Z7 was the most similar strain to L. rhamnosus GG, which had an antidiabetic capability. This finding suggested that L. casei 2W and L. rhamnosus Z7 could be used as potential antidiabetic probiotics. Further research is required to examine the α-glucosidase inhibitory activity of these strains. [Copyright &y& Elsevier]

Abstract: In the present study, 339 lactic acid bacteria (LAB) strains, isolated from fermented dough, pickles, salted meat, baby feces and fermented dairy products, were screened for the antagonistic activity against enteroinvasive Escherichia coli (EIEC). Through the analysis of the inhibition zone of the lactobacilli spent culture supernatant on the growth of EIEC, 22 LAB strains were selected for further analysis. Using the in vitro assays of adhesion to HT-29 cell lines and tolerance to gastrointestinal conditions (acid and bile), two isolates, Lactobacillus plantarum CCFM 233 and L. plantarum CCFM 231 were shown not only to inhibit the growth of EIEC significantly, but also to have high adhesion to HT-29 cell lines and good tolerance to low acid and high bile. Furthermore, the two strains could strongly antagonize the adhesion and invasion of EIEC to the HT-29 cell lines. This study suggests that L. plantarum CCFM 233 and L. plantarum CCFM 231 could be used as potential probiotics in food applications against EIEC. [Copyright &y& Elsevier]

Patulin (PAT) is a widespread mycotoxin that harms the health of both humans and animals. In this study, among the 17 tested Lactobacillus plantarum strains, L. plantarum 13M5, isolated from traditional Chinese fermented foods, showed the highest PAT degradation rate of up to 43.8% (PAT 5 mg/L). Evaluation of the living and dead 13M5 cells revealed that only the living cells had the ability to remove PAT and degrade it into E -ascladiol. A cell-based assay revealed that L. plantarum 13M5 administration alleviated PAT-induced injuries in Caco-2 cells, including cytotoxicity, oxidative stress, and tight junction disruption. Our results suggest that L. plantarum 13M5 has the potential to reduce PAT toxicity and can thus be used as a probiotic supplement to reduce or eliminate the toxicity of PAT ingested from diet. • Lactobacillus plantarum 13M5 degrades patulin through intracellular products. • Through HR-MS detection, E -ascladiol is presumed to be degradation product. • Lactobacillus plantarum 13M5 can removal patulin in apple juice (raw/commercial). • 4.Base on Caco-2 cell model, the toxicity of patulin can be interfered by Lactobacillus plantarum 13M5. [ABSTRACT FROM AUTHOR]