Probiotic characteristics of Lactobacillus fermentum strains isolated from tulum cheese

Probiotic Characteristics and Anti-Inflammatory Effects of Limosilactobacillus fermentum 664 Isolated from Chinese Fermented Pickles

Limosilactobacillus fermentum (L. fermentum) is widely used in industrial food fermentations, and its probiotic and health-promoting roles attracted much attention in the past decades. In this work, the probiotic potential of L. fermentum 664 isolated from Chinese fermented pickles was assessed. In addition, the anti-inflammatory properties and mechanisms were investigated using lipopolysaccharide (LPS)-stimulated RAW264.7 cells. Results indicated that L. fermentum 664 demonstrated excellent acid and bile salt tolerance, adhesion capability, antimicrobial activity, and safety profile. L. fermentum 664 downregulated the release of inflammatory mediators, including tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-1β (IL-1β), and cyclooxygenase-2 (COX-2) stimulated with LPS. Moreover, L fermentum 664 inhibited the nuclear translocation of the nuclear factor κB (NF-κB) and the activation of mitogen-activated protein kinases (MAPKs) induced by LPS. This action was associated with a reduction in reactive oxygen species (ROS) levels and an enhanced expression of heme oxygenase-1 (HO-1) protein. Additionally, whole genome sequencing indicated that L. fermentum 664 contained genes that encode proteins with antioxidant and anti-inflammatory functions, including Cytochrome bd ubiquinol oxidase subunit I (CydA), Cytochrome bd ubiquinol oxidase subunit II (CydB), and NAD(P)H dehydrogenase quinone 1 (NQO1). In conclusion, our study suggested that L. fermentum 664 has the potential to become a probiotic and might be a promising strategy for the prevention of inflammation.

Co-administration of probiotic and vitamin D significantly improves cognitive function in schizophrenic patients: A double-blinded randomized controlled trial

AIM

Manipulation of the intestinal microbiome and supplying vitamin D can attenuate psychiatric symptoms in schizophrenic patients. The current study tried to evaluate the effects of probiotic/vitamin D supplementation on the cognitive function and disease severity of schizophrenic patients.

METHODS

In the present study, 70 patients (aged 18-65) with schizophrenia were recruited. Participants were randomly allocated to the placebo (n = 35) and intervention (probiotic supplements+400 IU vitamin D, n = 35) groups. Severity of disease and cognitive function (primary outcomes) were evaluated by Positive and Negative Syndrome Scale (PANSS) and Montreal Cognitive Assessment (MoCA) tests, respectively. Moreover, lipid profile, body mass index (BMI), gastrointestinal (GI) problems, serum C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR) were evaluated as secondary outcomes.

RESULTS

A total of 69 patients completed the study. The MoCA score was increased by 1.96 units in the probiotic-containing supplement group compared to the placebo (p = 0.004). Also, the percentage of subjects with MoCA score ≥ 26 rose significantly in the intervention group (p = 0.031). Moreover, TC (p = 0.011), FBS (p = 0.009), and CRP (p < 0.001) significantly decreased in the supplement group compared to the placebo. Although the probiotic supplement reduced PANSS score by 2.82 units, the difference between the study groups was not statistically significant (p = 0.247).

CONCLUSION

Co-administration of probiotics and vitamin D has beneficial effects on the improvement of cognitive function in schizophrenic patients.

The anticancer effect of potential probiotic L. fermentum and L. plantarum in combination with 5-fluorouracil on colorectal cancer cells

5-Fluorouracil (5-FU) is an effective chemotherapy drug in the treatment of colorectal cancer (CRC). However, auxiliary or alternative therapies must be sought due to its resistance and potential side effects. Certain probiotic metabolites exhibit anticancer properties. In this study evaluated the anticancer and potential therapeutic activities of cell extracts potential probiotic strains, Limosilactobacillus fermentum and Lactiplantibacillus plantarum isolated from the mule milk and the standard probiotic strain Lacticaseibacillus rhamnosus GG (LGG) against the human colon cancer cell line (HT-29) and the normal cell line (HEK-293) alone or in combination with 5-FU. In this study, L. plantarum and L. fermentum, which were isolated from mule milk, were identified using biochemical and molecular methods. Their probiotic properties were investigated in vitro and compared with the standard probiotic strain of the species L. rhamnosus GG. The MTT assay, acridine orange/ethidium bromide (AO/EB) fluorescent staining, and flow cytometry were employed to measure the viability of cell lines, cell apoptosis, and production rates of Th17 cytokines, respectively. The results demonstrated that the combination of lactobacilli cell extracts and 5-FU decreased cell viability and induced apoptosis in HT-29 cells. Furthermore, this combination protected HEK-293 cells from the cytotoxic effects of 5-FU, enhancing their viability and reducing apoptosis. Moreover, the combination treatment led to an increase in the levels of IL-17A, IFN-γ, and TNF-α, which can enhance anti-tumor immunity. In conclusion, the cell extracts of the lactobacilli strains probably can act as a potential complementary anticancer therapy.

Milk and Its Derivatives as Sources of Components and Microorganisms with Health-Promoting Properties: Probiotics and Bioactive Peptides

Milk is a source of many valuable nutrients, including minerals, vitamins and proteins, with an important role in adult health. Milk and dairy products naturally containing or with added probiotics have healthy functional food properties. Indeed, probiotic microorganisms, which beneficially affect the host by improving the intestinal microbial balance, are recognized to affect the immune response and other important biological functions. In addition to macronutrients and micronutrients, biologically active peptides (BPAs) have been identified within the amino acid sequences of native milk proteins; hydrolytic reactions, such as those catalyzed by digestive enzymes, result in their release. BPAs directly influence numerous biological pathways evoking behavioral, gastrointestinal, hormonal, immunological, neurological, and nutritional responses. The addition of BPAs to food products or application in drug development could improve consumer health and provide therapeutic strategies for the treatment or prevention of diseases. Herein, we review the scientific literature on probiotics, BPAs in milk and dairy products, with special attention to milk from minor species (buffalo, sheep, camel, yak, donkey, etc.); safety assessment will be also taken into consideration. Finally, recent advances in foodomics to unveil the probiotic role in human health and discover novel active peptide sequences will also be provided.

Synthesis of an autochthonous microbial community by analyzing the core microorganisms responsible for the critical flavor of bran vinegar

Traditional bran vinegar brewing unfolds through natural fermentation, a process driven by spontaneous microbial activity. The unique metabolic activities of various microorganisms lead to distinct flavors and qualities in each batch of vinegar, making it challenging to consistently achieve the desired characteristic flavor compounds. Therefore, identifying the critical microbial species responsible for flavor production and designing starter cultures with improved fermentation efficiency and characteristic flavors are effective methods to address this discrepancy. In this study, 11 core functional microbial species affecting the fermentation flavor of Sichuan shai vinegar (Cupei were placed outside solarization and night-dew for more than one year, and vinegar was the liquid leached from Cupei) (SSV), were revealed by combining PacBio full-length diversity sequencing based on previous metagenomics. The effects of environmental factors and microbial interactions on the growth of 11 microorganisms during fermentation were verified using fermentation experiments. Ultimately, the microbial community was strategically synthesized using a 'top-down' approach, successfully replicating the distinctive flavor profile of Sichuan shai vinegar (SSV). The results showed that the interaction between microorganisms and environmental factors affected microorganism growth. Compared with traditional fermentation, the synthetic microbial community's vinegar-fermented grains (Cupei) can reproduce the key flavor of SSV and is conducive to the production of amino acids. In this study, the key flavor of SSV was reproduced through rational design of the synthetic microbial community. This achievement holds profound significance for the broader application of microbiome assembly strategies in the realm of fermented foods.

Diversity of the Microbiota of Traditional Izmir Tulum and Izmir Brined Tulum Cheeses and Selection of Potential Probiotics

High-throughput DNA sequencing (HTS) was used to study the microbial diversity of commercial traditional Izmir Tulum (IT) and Izmir Brined Tulum (IBT) cheeses from Izmir, Türkiye. Simultaneously, cultivation-dependent methods were used to isolate, identify and characterize bacterial strains displaying probiotic potential. At the phylum level, Firmicutes dominated the microbiota of both cheese types comprising >98% of the population. Thirty genera were observed, with Streptococcus being the most abundant genus and with Streptococcus thermophilus and S. infantarius subsp. infantarius being the most abundant species. Genera, including Bifidobacterium and Chryseobacterium, not previously associated with IT and IBT, were detected. IT cheeses displayed higher operational taxonomic units (OTUs; Richness) and diversity index (Simpson) than IBT cheeses; however, the difference between the diversity of the microbiota of IT and IBT cheese samples was not significant. Three Lacticaseibacillus paracasei strains isolated from IBT cheeses exhibited probiotic characteristics, which included capacity to survive under in vitro simulated gastrointestinal conditions, resistance to bile salts and potential to adhere to HT-29 human intestinal cells. These findings demonstrate that Tulum cheeses harbor bacterial genera not previously reported in this cheese and that some strains display probiotic characteristics.

Safety aspects, probiotic potentials of yeast and lactobacillus isolated from fermented foods in North-Eastern India, and its anti-inflammatory activity

Lactobacillus and yeast obtained from fermented foods in North-East India were tested for safety and probiotic properties. All the lactobacilli and yeast tested negative for the catalase, indole, urease, phenylalanine, hemolysis, gelatin hydrolysis, and biogenic amine production tests, indicating that they are safe to use as probiotics in food supplements. Lactiplantibacillus plantarum KGL3A (accession no. MG722814) was capable of resisting the replicated gastric fluid (pH 2) till 2 h of exposure, whereas both KGL3A and Lacticaseibacillus rhamnosus K4E (accession no. KX950834.1) strains were able to resist pH 3 till 2 h of exposure with a reduction in overall viable cell count from 7.48 log CFU/mL to 1.09 log CFU/mL and 7.77 log CFU/mL to 0.83 log CFU/mL, respectively. In vitro gastric juice simulation conditions were tolerated by the yeast Saccharomyces cerevisiae WBS2A. The cell surface hydrophobicity (CSH) towards hydrocarbons (n-hexadecane) was seen highest in L. plantarum KGL3A (77.16± 0.84%) and Limosilactobacillus fermentum KGL4 accession no. MF951099 (72.60 ± 2.33%). The percentage auto-aggregation ranged from 8.70 to 25.53 after 2 h, which significantly increased to 10.50 to 26.94 during the fifth hour for cultures. Also, a higher percentage of co-aggregation was found for the culture L. rhamnosus K4E with S. typhi (34.18 ± 0.03%), E. coli (32.97 ± 0.02 %) and S. aureus (26.33 ± 0.06 %) and for the yeast S. cerevisiae WBS2A, a higher percentage of co-aggregation was found with Listeria monocytogenes (25.77 ± 0.22%). The antioxidant activity and proteolytic activity were found to be higher for Lactobacillus helveticus K14 and L. rhamnosus K4E. The proportion of decreased cholesterol was noticeably higher in KGL4 (29.65 ± 4.30%). β glucosidase activity was significantly higher in the L. fermentum KGL4 strain (0.359 ± 0.002), and α galactosidase activity was significantly higher in the L. rhamnosus K4E strain (0.415 ± 0.016). MTT assays suggested that KGL4 and WBS2A at a lower dose did not exhibit cytotoxicity.

Artificial intelligence-assisted analysis reveals amino acid effects and interactions on Limosilactobacillus fermentum growth

To understand the growth of lactic acid bacteria (LAB), Limosilactobacillus fermentum, in response to medium compositions, a deep neural network (DNN) was designed using amino acids (AAs) as explanatory variables and LAB growth as the objective variable. Sixty-four different patterns of free AAs were set using an orthogonal array. The best DNN model had high accuracy with low mean square errors and predicted that Asp would affect LAB growth. Bayesian optimization (BO) using this model recommended an optimal growth media comprising maximum amounts of Asn, Asp, Lys, Thr, and Tyr and minimum amounts of Gln, Pro, and Ser. Furthermore, this proposed media was empirically validated to promote LAB growth. The absence of Gln, Ser, and Pro indicates that the different growth trends among the DNN-BO-optimized media were likely caused by the interactions among the AAs and the other components.

Lactobacillus spp. isolated from prebiotic-derived raw goat milk: probiotic characteristics, cholesterol assimilation and folate production

OBJECTIVES

This work provides to evaluate cholesterol assimilation and folic acid production by determining the probiotic properties of Lactobacillus spp. from raw goat milk with prebiotic properties.

RESULTS

We isolated Lactobacilli from goat milk and identified API 50, CHL, and 16sRNA. Probiotic properties were determined according to bile salt and acidic tolerance, hydrophobicity, hemolytic activity, antibiotic sensitivity, antagonistic effect, and exopolysaccharide production. In addition, the cholesterol assimilation and folate production of cultures were determined.

CONCLUSIONS

L. plantarum GM-12 and L. plantarum GM-15 showed the highest folate production and the highest cholesterol assimilation.These two strains are strong candidates for use as potential probiotics and starter cultures.

Probiotic bacteria from 10 different traditional Iranian cheeses: Isolation, characterization, and investigation of probiotic potential

In this study, 10 different traditional Iranian cheeses, which are still consumed by people in rural areas of Iran, were examined to isolate new strains of probiotic bacteria. Isolated bacteria were identified by 16s rRNA gene amplification and subjected to series of in vitro tests to find out their probiotic potential. A total of 2345 colonies were collected and 465 of them were confirmed as lactic acid bacteria (LAB), of which Lactiplantibacillus plantarum, Lactobacillus bulgaricus, and Lacticaseibacillus casei were the top three isolated bacteria. Among the different species of LAB isolated in this study, Lactip. plantarum was the most isolated species, and seven isolates had the significant criteria for being a probiotic strain than other isolates indicating the most adaptable properties of this species. Lactiplantibacillus plantarum was the most resistant bacteria in the bile resistance test and was also the most durable bacteria in gastrointestinal conditions, for example, acidic environment (pH = 2.5) and trypsin. In contrast, Lacticaseibacillus casei was the most susceptible bacterial strain. Lactobacillus rhamnosus showed the most antibacterial effect against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. This study showed that probiotic strains isolated from local cheeses could be considered as suitable biopreservatives and used as specific starter cultures for the production of functional cheeses.

Lacticaseibacillus rhamnosus FM9 and Limosilactobacillus fermentum Y57 Are as Effective as Statins at Improving Blood Lipid Profile in High Cholesterol, High-Fat Diet Model in Male Wistar Rats

Elevated serum cholesterol is a major risk factor for coronary heart diseases. Some Lactobacillus strains with cholesterol-lowering potential have been isolated from artisanal food products. The purpose of this study was to isolate probiotic Lactobacillus strains from traditional yoghurt (dahi) and yogurt milk (lassi) and investigate the impact of these strains on the blood lipid profile and anti-obesity effect in a high cholesterol high fat diet model in Wistar rats. Eight candidate probiotic strains were chosen based on in vitro probiotic features and cholesterol reduction ability. By 16S rDNA sequencing, these strains were identified as Limosilactibacillus fermentum FM6, L. fermentum FM16, L. fermentum FM12, Lacticaseibacillus rhamnosus FM9, L. fermentum Y55, L. fermentum Y57, L. rhamnosus Y59, and L. fermentum Y63. The safety of these strains was investigated by feeding 2 × 10⁸ CFU/mL in saline water for 28 days in a Wistar rat model. No bacterial translocation or any other adverse effects were observed in animals after administration of strains in water, which indicates the safety of strains. The cholesterol-lowering profile of these probiotics was evaluated in male Wistar rats using a high-fat, high-cholesterol diet (HFCD) model. For 30 days, animals were fed probiotic strains in water with 2 × 10⁸ CFU/mL/rat/day, in addition to a high fat, high cholesterol diet. The cholesterol-lowering effects of various probiotic strains were compared to those of statin. All strains showed improvement in total cholesterol, LDL, HDL, triglycerides, and weight gain. Serum cholesterol levels were reduced by 9% and 8% for L. rhamnosus FM9 and L. fermentum Y57, respectively, compared to 5% for the statin-treated group. HDL levels significantly improved by 46 and 44% for L. rhamnosus FM9 and L. fermentum Y57, respectively, compared to 46% for the statin-treated group. Compared to the statin-treated group, FM9 and Y57 significantly reduced LDL levels by almost twofold. These findings show that these strains can improve blood lipid profiles as effectively as statins in male Wistar rats. Furthermore, probiotic-fed groups helped weight control in animals on HFCD, indicating the possible anti-obesity potential of these strains. These strains can be used to develop food products and supplements to treat ischemic heart diseases and weight management. Clinical trials, however, are required to validate these findings.

Dairy Lactic Acid Bacteria and Their Potential Function in Dietetics: The Food-Gut-Health Axis

Fermented dairy products are the good source of different species of live lactic acid bacteria (LAB), which are beneficial microbes well characterized for their health-promoting potential. Traditionally, dietary intake of fermented dairy foods has been related to different health-promoting benefits including antimicrobial activity and modulation of the immune system, among others. In recent years, emerging evidence suggests a contribution of dairy LAB in the prophylaxis and therapy of non-communicable diseases. Live bacterial cells or their metabolites can directly impact physiological responses and/or act as signalling molecules mediating more complex communications. This review provides up-to-date knowledge on the interactions between LAB isolated from dairy products (dairy LAB) and human health by discussing the concept of the food–gut-health axis. In particular, some bioactivities and probiotic potentials of dairy LAB have been provided on their involvement in the gut–brain axis and non-communicable diseases mainly focusing on their potential in the treatment of obesity, cardiovascular diseases, diabetes mellitus, inflammatory bowel diseases, and cancer.

Probiotic Characterization of Cholesterol-Lowering Lactobacillus fermentum MJM60397

Lactobacillus fermentum MJM60397 was subjected to in vitro safety tests and in vivo probiotic characterization. The MJM60397 strain was susceptible to antibiotics and was found to be non-mucinolytic and non-hemolytic, and does not produce bioamines. In addition, MJM60397 tolerated simulated oro-gastrointestinal conditions and adhered to Caco-2 cells. MJM60397 also exhibited bile salt hydrolase activity and could deconjugate bile acids. The hypocholesterolemic effects of strain MJM60397 were studied in high-fat diet-induced hypercholesterolemic male ICR mice. The mice were fed a high-cholesterol diet (HCD) and were divided into the following three experimental groups: HCD-control (HCD-Con), mice fed with HCD + L. fermentum MJM60397 (HCD-MJM60397), and mice fed with HCD + L. acidophilus ATCC 43121 (HCD-L.ac) as the positive control. Simultaneously, a normal control diet (NCD) group was maintained. After 7 weeks, the total cholesterol and low-density lipoprotein (LDL) cholesterol levels were significantly reduced in the livers of the HCD-MJM60397 mice when compared to those in the HCD-Con and HCD-L.ac mice. Fecal total bile acid content was significantly (P < 0.05) higher in the HCD-MJM60397 group than in the NCD, HCD-Con, and HCD-L.ac groups. Analysis of gene expression revealed higher expression of LDLR gene in the livers of the HCD-MJM60397 and HCD-L.ac mice than in the livers of the HCD-Con mice. These findings show that the hypocholesterolemic effects of the MJM60397 strain were attributable to its bile salt deconjugating activity, which resulted in decreased bile acid absorption and increased excretion of bile acids in the feces. These results indicate that L. fermentum MJM60397 could be developed into a potential probiotic for reducing the serum cholesterol levels.

Homology- and cross-resistance of Lactobacillus plantarum to acid and osmotic stress and the influence of induction conditions on its proliferation by RNA-Seq

In this study, homology- and cross-resistance of Lactobacillus plantarum L1 and Lactobacillus plantarum L2 to acid and osmotic stress were investigated. Meanwhile, its proliferation mechanism was demonstrated by transcriptomic analysis using RNA sequencing. We found that the homologous-resistance and cross-resistance of L. plantarum L1 and L. plantarum L2 increased after acid and osmotic induction treatment by lactic acid and sodium lactate solution in advance, and the survival rate of live bacteria was improved. In addition, the count of viable bacteria of L. plantarum L2 significantly increased cultivated at a pH 5.0 with a 15% sodium lactate sublethal treatment, compared with the control group. Further study revealed that genes related to membrane transport, amino acid metabolism, nucleotide metabolism, and cell growth were significantly upregulated. These findings will contribute to promote high-density cell culture of starter cultures production in the fermented food industry.

Planococcus maritimus ML1206 Isolated from Wild Oysters Enhances the Survival of Caenorhabditis elegans against Vibrio anguillarum

With the widespread occurrence of aquaculture diseases and the broad application of antibiotics, drug-resistant pathogens have increasingly affected aquatic animals’ health. Marine probiotics, which live under high pressure in a saltwater environment, show high potential as a substitute for antibiotics in the field of aquatic disease control. In this study, twenty strains of non-hemolytic bacteria were isolated from the intestine of wild oysters and perch, and a model of Caenorhabditis elegans infected by Vibrio anguillarum was established. Based on the model, ML1206, which showed a 99% similarity of 16S rRNA sequence to Planococcus maritimus, was selected as a potential marine probiotic, with strong antibacterial capabilities and great acid and bile salt tolerance, to protect Caenorhabditis elegans from being damaged by Vibrio anguillarum. Combined with plate counting and transmission electron microscopy, it was found that strain ML1206 could significantly inhibit Vibrio anguillarum colonization in the intestinal tract of Caenorhabditis elegans. Acute oral toxicity tests in mice showed that ML1206 was safe and non-toxic. The real-time qPCR results showed a higher expression level of genes related to the antibacterial peptide (ilys-3) and detoxification (ugt-22, cyp-35A3, and cyp-14A3) in the group of Caenorhabditis elegans protected by ML1206 compared to the control group. It is speculated that ML1206, as a potential probiotic, may inhibit the infection caused by Vibrio anguillarum through stimulating Caenorhabditis elegans to secrete antibacterial effectors and detoxification proteins. This paper provides a new direction for screening marine probiotics and an experimental basis to support the potential application of ML1206 as a marine probiotic in aquaculture.

Strain-Specific Effects of Bifidobacterium longum on Hypercholesterolemic Rats and Potential Mechanisms

Hypercholesterolemia is an independent risk factor of cardiovascular disease, which is among the major causes of death worldwide. The aim of this study was to explore whether Bifidobacterium longum strains exerted intra-species differences in cholesterol-lowering effects in hypercholesterolemic rats and to investigate the potential mechanisms. SD rats underwent gavage with each B. longum strain (CCFM 1077, I3, J3 and B3) daily for 28 days. B. longum CCFM 1077 exerted the most potent cholesterol-lowering effect, followed by B. longum I3 and B3, whereas B. longum B3 had no effect in alleviating hypercholesterolemia. Divergent alleviation of different B. longum strains on hypercholesterolemia can be attributed to the differences in bile salt deconjugation ability and cholesterol assimilation ability in vitro. By 16S rRNA metagenomics analysis, the relative abundance of beneficial genus increased in the B. longum CCFM 1077 treatment group. The expression of key genes involved in cholesterol metabolism were also altered after the B. longum CCFM 1077 treatment. In conclusion, B. longum exhibits strain-specific effects in the alleviation of hypercholesterolemia, mainly due to differences in bacterial characteristics, bile salt deconjugation ability, cholesterol assimilation ability, expressions of key genes involved in cholesterol metabolism and alterations of gut microbiota.

Probiotic Properties of Lactiplantibacillus plantarum LB5 Isolated from Kimchi Based on Nitrate Reducing Capability

The purpose of this study was to investigate the probiotic properties of lactic acid bacteria isolated from Korean radish water kimchi (dongchimi). A total of 800 isolates of lactic acid bacteria were isolated from kimchi, and the strain having reduction and tolerance capability for nitrate and nitrite was selected and identified as Lactiplantibacillus plantarum LB5 (LPLB5) by 16S rRNA sequencing. LPLB5 showed higher tolerance to acidic pH values (pH 2.5), 0.3% bile salts, and heat treatment (40, 50, and 60 °C). Antibacterial activity showed strong inhibition against four food-borne pathogenic bacteria (E. coli O157:H7 ATCC 35150, Pseudomonas aeruginosa KCCM 12539, Listeria monocytogenes KCCM 40307, and Staphylococcus aureus ATCC 25923). The strain did not show any antibiotic resistance, β-hemolytic activity, or ability to produce β-glucuronidase. LPLB5 also exhibited a 30% auto-aggregation ability and 33–60% co-aggregation ability with four pathogenic bacteria (E. coli O157: H7 ATCC 35150, E. coli KCTC 2571, L. monocytogenes ATCC 51776, and S. aureus ATCC 25923). Moreover, the strain showed approximately 40% 2,2-diphenyl-1-picryl-hydrazyl (DPPH) radical- and 10% 2-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical-scavenging activity. In cell culture studies, human colon epithelial cells (Caco-2) were treated with LPLB5 (10⁶ and 10⁷ CFU/mL); the bacteria showed more than 70% adherence onto and a 32% invasion rate into the Caco-2 cells. LPLB5 significantly decreased the mRNA expression levels of pro-inflammatory cytokines (interleukin-1 beta (IL-1β), interleukin 6 (IL-6), and tumor necrosis factor-alpha (TNF-α)) and increased the mRNA expression levels of anti-inflammatory cytokines (interleukin-4 (IL-4), interleukin-10 (IL-10), and interferon-gamma (IFN-γ)) in lipopolysaccharide-stimulated Caco-2 cells. Our data suggest that LPLB5 is safe and possesses probiotic, antioxidant, and anti-inflammatory activities.

A newly isolated E. thailandicus strain d5B with exclusively antimicrobial activity against C. difficile might be a novel therapy for controlling CDI

Colitis induced by C. difficile is one of the most common and costly healthcare-related infections for humans. Probiotics are one of the most promising approaches for controlling CDI. Here, we presented the isolation, safety, and probiotic property evaluation of a novel E. thailandicus strain, d5B, with effective antimicrobial activity against C. difficile. Strain d5B showed strong bactericidal effects on at least 54C. difficile strains. Safety tests showed that strain d5B was sensitive to clinically important antibiotics, and had no haemolytic and cytotoxic activities. Whole genomic analysis showed strain d5B only contained one aminoglycoside resistance gene located in the chromosome. Moreover, d5B was devoid of functional virulence genes. Finally, strain d5B exhibited probiotic properties, such as tolerance to the gastrointestinal tract, and adhered well to HT-29 cells. In conclusion, the E. thailandicus strain d5B should be investigated further for useful properties as a novel candidate probiotic for controlling CDI.

Complete Genome Sequence of Lactobacillus fermentum Strain AGR1485, a Human Oral Isolate

Lactobacillus fermentum is found in food products and is generally considered safe. L. fermentum AGR1485 promotes barrier integrity in Caco-2 cells and has genetic similarities to other known probiotic L. fermentum strains. L. fermentum AGR1485 has potential as a probiotic and was sequenced to explore these probiotic properties. The genome is a 2.2-Mbp circular chromosome with no plasmids and a GC content of 51.

Lactobacillus fermentum is found in food products and is generally considered safe. L. fermentum AGR1485 promotes barrier integrity in Caco-2 cells and has genetic similarities to other known probiotic L. fermentum strains. L. fermentum AGR1485 has potential as a probiotic and was sequenced to explore these probiotic properties. The genome is a 2.2-Mbp circular chromosome with no plasmids and a GC content of 51.15%.

Effect of Lyophilized, Encapsulated Lactobacillus fermentum and Lactulose Feeding on Growth Performance, Heavy Metals, and Trace Element Residues in Rainbow Trout (Oncorhynchus mykiss) Tissues

Heavy metals naturally occur in the environment and are causing great concern all around the world. Accumulation of heavy metals in fish tissues can lead to serious adverse effects in humans when consumed in the amounts exceeding the safe consumption levels. In this study, Lactobacillus fermentum 1744 (ATCC 14931) and lactulose were used in the fish diet in order to investigate their effects on growth performance, intestinal villous morphology, and heavy metals residues. Fishes were randomly allocated into three replicates of five different treatments. The control group received the basal diet, while the experimental groups were fed on the basal diet supplemented with encapsulated and lyophillized probiotic, lactulose (prebiotic) and L. fermentum, and lactulose as synbiotic. All the groups were fed three times daily for a period of 56 days. At the end of growth period, 10 fish per replicate were randomly collected in order to take the samples of the fillet, gills, and liver. Results showed that the encapsulated L. fermentum plus lactulose improve growth performance and exclude absorption and accumulation of heavy metals in rainbow trout liver and gills. The villous height were increased in all the samples except the group 2 fed on the lactulose (p < 0.05).

Comparative study of host-associated and commercial probiotic effects on serum and mucosal immune parameters, intestinal microbiota, digestive enzymes activity and growth performance of roach (Rutilus rutilus caspicus) fingerlings

The study aimed to isolate host-associated probiotic (HAP) lactic acid bacteria from intestine of adult Caspian roach and compare the efficacy of HAP with a commercially available probiotic strain (Pediococcus acidilactici) on the growth and feed utilisation, digestive enzymes and systemic and mucosal immune system of roach fingerling. The HAP strain isolated from roach intestine was Enterococcus faecium strain CGMCC1.2136. The experiment was a simple completely randomized design and lasted for eight weeks. Two hundred and seventy fish with an average weight of 12 g randomly distributed into nine tanks. The trial consisted of three treatments with three respective replications. During the experimental period, fish received basal diet without any bacterial supplementation (as the control group), basal diet enriched with 10⁸ CFU g^-1 HAP or 10⁷ CFU g^-1 CP. At the end of the experiment, serum immune parameters of those fish fed HAP including alkaline phosphatase activity, total protein content, total immunoglobulin level, lysozyme activity and complement activity (ACH50) were significantly higher that other experimental groups (P < 0.05). Similarly, dietary supplementation of HAP resulted in better mucosal immune parameters in comparison to control group and commercial probiotic administration (P < 0.05). Intestinal heterotrophic bacteria and autochthonous LAB counts of those fish fed HAP were significantly higher than other experimental groups at the end of the experiment as well as 15 days seizing probiotic administrations (P < 0.05). Fish fed with HAP containing diet presented significantly higher amylase, lipase and protease activity in comparison to the CP fed fish and the control group (P < 0.05). Growth indices of those fish fed HAP were significantly higher than other treatments (P < 0.05). The highest carcass protein and ash content along with the lowest body moisture content belonged to those fish received HAP (P < 0.05). In conclusion, the use host-HAP resulted in better immune competence and growth performance and it seems aquaculture sector should probably focus on the development of probiotics isolated from the cultured species instead of using terrestrial probiotics with greatly different requirements and environmental conditions.

Lactobacillus fermentum: a bacterial species with potential for food preservation and biomedical applications

Lactic acid-producing bacteria are the most commonly used probiotics that play an important role in protecting the host against harmful microorganisms, strengthening the host immune system, improving feed digestibility, and reducing metabolic disorders. Lactobacillus fermentum (Lb. fermentum) is a Gram-positive bacterium belonging to Lactobacillus genus, and many reportedly to enhance the immunologic response as well as prevent community-acquired gastrointestinal and upper respiratory infections. Additionally, Lb. fermentum strains produce diverse and potent antimicrobial peptides, which can be applied as food preservative agents or as alternatives to antibiotics. Further functions attributed to probiotic Lb. fermentum strains are their abilities to decrease the level of blood stream cholesterol (as cholesterol-lowering agents) and to potentially help prevent alcoholic liver disease and colorectal cancer among humans. Finally, Lb. fermentum is a key microorganism in sourdough technology, contributing to flavor, texture, or health-promoting dough ingredients, and has recently been used to develop new foods stuffs such as fortified and functional foods with beneficial attributes for human health. Development of such new foodstuffs are currently taking important proportions of the food industry market. Furthermore, an increasing awareness of the consumers prompts the food-makers to implement alternative environmental friendly solutions in the production processes and/or suitable biological alternative to limit the use of antibiotics in feed and food. Here, we give an account on the application of Lb. fermentum strains in the biomedical and food preservation fields, with a focus on probiotic features such as bacteriocin production. We also summarize the use of Lb. fermentum as cell factories with the aim to improve the efficacy and health value of functional food.

Lactobacillus fermentum strains of dairy-product origin adhere to mucin and survive digestive juices

Introduction. There is an ever present need to isolate and characterize indigenous bacterial strains with potential probiotic health benefits for humans.Aim. Lactobacillus fermentum of dairy origin was focused because of its propensity to adhere to the intestinal glycoprotein, mucin.Methodology. The lactobacillus strains were screened for mucin adhesion, resistance to low pH and bile, autoaggregation, hydrophobicity, and survival in an in vitro digestion model. The cholesterol-lowering and oxalate-degrading effects of selected strains were also determined. Safety was assessed for haemolytic, mucinolytic and gelatinase activity, biogenic amine production, antibiotic resistance and phenol resistance. Expression of the 32-mmub adhesion-related gene was also measured following strain exposure to simulated gastrointestinal tract (GIT) digestion.Results. The selected mucin-adhesive strains were tolerant to acid (pH 3.0) and bile (0.25 %) and demonstrated >85 % survival following simulated human digestion in the presence of milk. The digestive treatment did not affect the adhesive potential of PL20, and PL27, regardless of the food matrix. The simulated digestion had less effect on their adhesion than on the type strain and it also did not correlate with the mmub gene expression level as determined by qPCR. The selected strains exhibited cholesterol removal (36-44 %) and degraded oxalate (66-55 %). Neither of these strains exhibited undesirable characteristics.Conclusion. These preliminary findings suggest a functionality in the two strains of L. fermentum with high colonization potential on GIT mucosal membranes and possible health-promoting effects. This prima facie evidence suggests the need for further studies to test these probiotic candidates as live biotherapeutic agents in vivo.

Functional Properties of Food Origin Lactobacillus in the Gastrointestinal Ecosystem-In Vitro Study

In the current study, the probiotic activity of ten Lactobacillus (Lb.) strains, previously isolated from the traditional Polish fermented vegetable, was characterized. Strains were assessed for adhesion to human intestinal epithelial Caco-2 cells and regulation of selected cytokine production (IL-1β, IL-6, IL-10, IL-23, and TNF-α) by THP-1 macrophages. The effect of tested strains on Caco-2 cell apoptosis was also investigated using a caspase-3 assay. Adhesion capacity was strain-dependent (1.29-8.24% of initial population). Highest adhesion was observed for Lb. brevis O24. All Lactobacillus strains investigated in this study stimulated two- to threefold increase in TNF-α, IL-1β, and IL-6 production, compared to the control. Additionally, selected strains of Lactobacillus caused a significant decrease of pro-inflammatory cytokine production by lipopolysaccharide (LPS)-stimulated THP-1 cells. Almost all Lactobacillus investigated in this study are potent stimulators of IL-10 production. All tested Lactobacillus cells slightly increased the caspase-3 activity in Caco-2 cells. Lb. casei O18 was the most inducing strain. The tested strains had no effect on staurosporine (STS)-induced caspase-3 activity. According to these results, the most promising strains are Lb. plantarum O20, two strains Lb. brevis O22 and O24, and Lb. rhamnosus K3. These newly identified lactobacilli hold promise for use as probiotics in functional food applications.

Multifunctional properties of Lactobacillus plantarum strains WiKim83 and WiKim87 as a starter culture for fermented food

This study aimed to evaluate the safety (hemolysis and enzyme activity), probiotic properties (gastrointestinal tract tolerance, adhesion, hydrophobicity, and auto-aggregation), and functional characteristics (antimicrobial, antioxidant, and β-galactosidase activities) of lactic acid bacteria (LAB), isolated from kimchi, in order to select a multifunctional LAB strain for starter culture in fermented food. The five isolated strains included Lactobacillus plantarum WiKim83, L. plantarum WiKim84, Pediococcus pentosaceus WiKim85, P. pentosaceus WiKim86, and L. plantarum WiKim87, as identified by 16S rRNA gene sequence analysis; they were confirmed to be nonhemolytic and not able to produce β-glucuronidase, a carcinogenic enzyme. Probiotic properties of the five LAB strains were evaluated relative to those of commercial Lactobacillus rhamnosus GG, and results revealed probiotic potential of three strains (L. plantarum WiKim83, L. plantarum WiKim84, and L. plantarum WiKim87) to be superior. L. plantarum WiKim84 showed high antimicrobial activity against pathogens, and L. plantarum WiKim83 exhibited the highest antioxidant and β-galactosidase activities. Based on the probiotic and functional properties, the main characteristics of each strain were highlighted and two of them, L. plantarum WiKim83 and L. plantarum WiKim87, were selected as the most potent by principal component analysis. These strains showed antimicrobial, β-galactosidase, and antioxidant activities, which recommend their suitability as starter culture in various fermented foods.

Mechanistic Insights Into Probiotic Properties of Lactic Acid Bacteria Associated With Ethnic Fermented Dairy Products

Gut microbes and their metabolites maintain the health and homeostasis of the host by communicating with the host via various biochemical and physical factors. Changing lifestyle, chronic intake of foods rich in refined carbohydrates and fats have caused intestinal dysbiosis and other lifestyle-based diseases. Thus, supplementation with probiotics has gained popularity as biotherapies for improving gut health and treating disorders. Research shows that probiotic organisms enhance gastrointestinal health, immunomodulation, generation of essential micronutrients, and prevention of cancer. Ethnically fermented milk and dairy products are hotspots for novel probiotic organisms and bioactive compounds. These ethnic fermented foods have been traditionally prepared by indigenous populations, and have preserved unique microflora for ages. To apply these unique microflora for amelioration of human health, it is important that probiotic properties of the bacterial species are well studied. Majority of the published research and reviews focus on the probiotic organisms and their properties, fermented food products, isolation techniques, and animal studies with their health pathologies. As a consequence, there is a dearth of information about the underlying molecular mechanism behind probiotics associated with ethnically prepared dairy foods. This review is targeted at stimulating research on understanding these mechanisms of bacterial species and beneficial attributes of ethnically fermented dairy products.

The Foodborne Strain Lactobacillus fermentum MBC2 Triggers pept-1-Dependent Pro-Longevity Effects in Caenorhabditis elegans

Lactic acid bacteria (LAB) are involved in several food fermentations and many of them provide strain-specific health benefits. Herein, the probiotic potential of the foodborne strain Lactobacillus fermentum MBC2 was investigated through in vitro and in vivo approaches. Caenorhabditis elegans was used as an in vivo model to analyze pro-longevity and anti-aging effects. L. fermentum MBC2 showed a high gut colonization capability compared to E. coli OP50 (OP50) or L.rhamnosus GG (LGG). Moreover, analysis of pumping rate, lipofuscin accumulation, and body bending showed anti-aging effects in L. fermentum MBC2-fed worms. Studies on PEPT-1 mutants demonstrated that pept-1 gene was involved in the anti-aging processes mediated by this bacterial strain through DAF-16, whereas the oxidative stress protection was PEPT-1 independent. Moreover, analysis of acid tolerance, bile tolerance, and antibiotic susceptibility were evaluated. L. fermentum MBC2 exerted beneficial effects on nematode lifespan, influencing energy metabolism and oxidative stress resistance, resulted in being tolerant to acidic pH and able to adhere to Caco-2 cells. Overall, these findings provide new insight for application of this strain in the food industry as a newly isolated functional starter. Furthermore, these results will also shed light on C. elegans molecular players involved in host-microbe interactions.

Lactobacillus fermentum strains from human breast milk with probiotic properties and cholesterol-lowering effects

The study aimed to identify two lactic acid bacteria from human breast milk and evaluate for their probiotic potential. Lactobacillus fermentum strains showed various degree of antibiotic susceptibility profile to clinical commercial antibiotics. The MA-7 and MA-8 strains have never lost their vitality at pH 2 and 3. Lactobacillus fermentum MA-8 exhibited more resistance to 0.3 and 1% bile concentrations than MA-7 strain. Both of the L. fermentum strains can tolerate the simulated gastric and intestinal juices. The strains showed high auto-aggregation percentages varied from 95 to 98%. Both isolates also exhibited gamma hemolytic activity. The cholesterol lowering activity of MA-7 and MA-8 strains was varied from 34.84 to 91.15%. The supernatants showed higher anti-cholesterol activity compared to pellets. The results demonstrated that both L. fermentum strains maybe good probiotic candidates and may have potential as health biotherapeutic with cholesterol-lowering effects.

Characterization, yield optimization, scale up and biopreservative potential of fermencin SA715, a novel bacteriocin from Lactobacillus fermentum GA715 of goat milk origin

BACKGROUND

Emergence of antibiotic resistance and growing consumer trend towards foods containing biopreservatives stimulated the search for alternative antimicrobials. This research is aimed at characterizing, investigating the mechanism of action, scale up optimization and evaluating the biopreservative potential of a bacteriocin from Lactobacillus fermentum.

RESULTS

Fermencin SA715 is a novel, broad-spectrum, non-pore-forming and cell wall-associated bacteriocin isolated from L. fermentum GA715 of goat milk origin. A combination of hydrophobic interaction chromatography, solid-phase extraction and reversed-phase HPLC was necessary for purification of the bacteriocin to homogeneity. It has a molecular weight of 1792.537 Da as revealed by MALDI-TOF mass spectrometry. Fermencin SA715 is potent at micromolar concentration, possesses high thermal and pH stability and inactivated by proteolytic enzymes thereby revealing its proteinaceous nature. Biomass accumulation and production of fermencin SA715 was optimum in a newly synthesized growth medium. Fermencin SA715 did not occur in the absence of manganese(II) sulphate. Tween 80, ascorbic acid, sodium citrate and magnesium sulphate enhanced the production of fermencin SA715. Sucrose is the preferred carbon source for growth and bacteriocin production. Sodium chloride concentration higher than 1% suppressed growth and production of fermencin SA715. Optimum bacteriocin production occurred at 37 °C and pH 6-7. Scale up of fermencin SA715 production involved batch fermentation in a bioreactor at a constant pH of 6.5 which resulted in enhanced production. Fermencin SA715 doubled the shelf life and improved the microbiological safety of fresh banana. Bacteriocin application followed by refrigeration tripled the shell life of banana.

CONCLUSIONS

This study reveals the huge potential of fermencin SA715 as a future biopreservative for bananas and reveals other interesting characteristics which can be exploited in the preservation of other foods. Furthermore insights on the factors influencing the production of fermencin SA715 have been revealed and optimized condition for its production has been established facilitating future commercial production.

Probiotic Lactobacillus fermentum strain JDFM216 stimulates the longevity and immune response of Caenorhabditis elegans through a nuclear hormone receptor

Here, we examined the functionality of Lactobacillus fermentum strain JDFM216, a newly isolated probiotic bacterium, using a Caenorhabditis elegans model. We determined bacterial colonization in the intestinal tract of C. elegans by plate counting and transmission electron microscopy and examined the survival of C. elegans using a solid killing assay. In addition, we employed DNA microarray analysis, quantitative real time-polymerase chain reaction, and immunoblotting assays to explore health-promoting pathways induced by probiotic bacteria in C. elegans. Initially, we found that the probiotic bacterium L. fermentum strain JDFM216 was not harmful to the C. elegans host. Conditioning with JDFM216 led to its colonization in the nematode intestine and enhanced resistance in nematodes exposed to food-borne pathogens, including Staphylococcus aureus and Escherichia coli O157:H7. Interestingly, this probiotic strain significantly prolonged the life span of C. elegans. Whole-transcriptome analysis and transgenic worm assays revealed that the health-promoting effects of JDFM216 were mediated by a nuclear hormone receptor (NHR) family and PMK-1 signaling. Taken together, we described a new C. elegans-based system to screen novel probiotic activity and demonstrated that preconditioning with the probiotic L. fermentum strain JDFM216 may positively stimulate the longevity of the C. elegans host via specific pathway.

Study on the chemical and microbial composition and probiotic characteristics of dominant lactic acid bacteria in fermented poultry slaughterhouse waste

This study aimed to evaluate the quality of fermented poultry slaughterhouse waste and isolate and identify the probiotic bacteria present in it. Poultry slaughterhouse waste samples supplemented with 5% starter culture and 0.2% propionic acid received one of four experimental treatments, which consisted of further supplementation with: (1) 10% molasses (M10); (2) 15% molasses (M15); (3) 10% molasses with 200ppm butylated hydroxytoluene (MB10); and (4) 15% molasses with 200ppm butylated hydroxytoluene (MB15). All experimental treatments (silages) were fermented for 6days with sampling before fermentation (day 1) and at the end of days 3 and 6. The pH of the silages decreased during the fermentation as it was lower on days 3 and 6 than day 1 (P<0.05). On day 6 of the experiment, the number of lactic acid bacteria in MB15 was significantly (P<0.05) higher than in MB10. The percentage of non-protein nitrogen increased (P<0.05) on days 3 and 6 of fermentation. The amount of malondialdehyde indicated that the peroxidation ratio decreased (P<0.05) with increasing the fermentation time. Among the 23 lactic acid bacteria detected in MB15, nine isolates (39.1%) belonged to the species Lactobacillus plantarum, ten (43.5%) belonged to the species Lactobacillus rhamnosus, and four (43.5%) belonged to the species Lactobacillus fermentum. The isolates LPL9, LRH25, and LFE26 were identified as the strain of L. plantarum, L. ramnosus, and L. fermentum, respectively, that demonstrated the best characteristics for use as a probiotic. The results of this experiment indicated that the fermentation is an advisable method for reusing the nutrients of poultry slaughterhouse waste and producing a probiotic supplement.