In Vitro Characterization of Lactobacillus Strains Isolated from Fruit Processing By-Products as Potential Probiotics

Evaluation of Antifungal and Biopreservative Potential of Orange Peel-derived Lactobacillus fermentum O1.1 in Cherry Tomatoes

Cherry tomatoes, consumed worldwide, have a short shelf life and are highly susceptible to significant pre- and postharvest losses, largely due to fungal pathogens like Alternaria alternata and Fusarium oxysporum. With the growing demand for nutritious food products free from synthetic preservatives, biopreservation has emerged as a safe and reliable method for controlling fungal growth in food. Biopreservation using lactic acid bacteria (LAB), known for producing antimicrobial metabolites, presents a promising approach at both the farm and industrial scales. This study investigates the antifungal potential of Lactobacillus fermentum O1.1, an isolate obtained from orange peel, against A. alternata and F. oxysporum. The growth performance of this isolate was assessed in various plant-based media, including watermelon rind (WMR), banana peel, and orange peel, in addition to MRS medium. Among these, WMR was found to be the most supportive medium for its growth. The cell-free supernatant (CFS) of Lb. fermentum O1.1 grown in WMR medium exhibited maximum inhibition of F. oxysporum (79.1%) and A. alternata (68%). Furthermore, cherry tomatoes infected with A. alternata and treated with the WMR-based CFS showed a reduced disease incidence (DI) of 16.78 ± 0.05%, compared to 40.17 ± 4.53% DI with the MRS-based CFS. Similarly, tomatoes infected with F. oxysporum and treated with the WMR-based CFS demonstrated a DI of 10.34 ± 4.86%, in contrast to 45.67 ± 4.53% DI with the MRS-based CFS. At room temperature (25 ± 2 °C), the WMR-based CFS extended the shelf life of cherry tomatoes from 2 to 5 days and decreased fungal susceptibility, with a reduction in DI by 16.78 ± 0.05% and 10.34 ± 4.86%, respectively. These findings suggest that Lb. fermentum O1.1 has significant potential as a biopreservative agent against fungal spoilage in cherry tomatoes.

As next-generation probiotics: acetic acid bacteria isolated from Kombucha beverages produced with Anatolian hawthorn leaves

This research examined acetic acid bacteria (AAB) isolated from Kombucha beverages produced with Anatolian hawthorn (Crataegus orientalis) as next-generation probiotics. Eighty-six AAB were isolated from the samples and investigated in terms of biosafety, viability in vitro gastrointestinal conditions, technological and bioactive properties, and also in vitro adhesion abilities. Seventy-six isolates demonstrating γ-hemolysis exhibited resistance to erythromycin and ampicillin. Besides, these isolates survived at low pH and in the presence of bile salts. However, the majority of AAB isolates showed tolerance to phenol, pepsin, and pancreatin. Also, twenty-one isolates showed protease enzyme activity, while eight isolates had amylase enzyme activity. Despite most of the isolates showed viability at 1.5% salt, only 19 isolates survived at 10% salt. Most AAB isolates exhibited inhibition zones ranging from 8 to 26 mm against test bacteria, their antioxidant activities were above 80%. Additionally, some isolates exhibited auto-aggregation ability ranging from 0.66 to 23.62% and co-aggregation ability ranging from 1.18 to 71.32%, while hydrophobicity ranged from 1.32 to 69.87% toward xylene. Finally, the indigenous 76 AAB isolates that had remarkable probiotic properties were characterized based on 16S rRNA gene sequencing, and the isolates belonged to Komagateibacter sp. (64.47%), Komagateibacter saccharivorans (15.79%), K. rhaeticus (11.84%), and Gluconobacter sp. (7.90%). As a result, the isolates identified as Gluconobacter sp. A21, Komagataeibacter sp. A139, Gluconobacter sp. A141, and Komagataeibacter sp. A146, which showed high viability under gastrointestinal conditions, safe and acceptable in terms of technological, bioactive, and adhesion properties and could be evaluated as next-generation probiotics.

Characterization of Lactiplantibacillus plantarum strains isolated from Algerian fruits for probiotic and biotechnological applications

Twenty-one lactic acid bacteria (LAB) strains were isolated from Algerian fruits such as white mulberry (Morus alba L.), prickly pear (Opuntia ficus-indica), date (Phoenix dactylifera L.), grape (Vitis vinifera) and fig (Ficus carica). The initial screening showed that ten out of twenty-one strains were tolerant to acid pH and bile salts and were further identified as Lactiplantibacillus (L.) plantarum strains by MALDI-TOF mass spectrometry and 16S rDNA sequencing. The identified strains were then characterized for their surface properties such as self-aggregation, hydrophobicity and biofilm formation. The resulting data were then statistically processed using Principal Component Analysis (PCA), after which only 5 strains were selected for further analysis. These five strains, designated L. plantarum F8, F13, FB23, D21 and M1, were found to be safe and able to adhere to human epithelial colorectal adenocarcinoma Caco-2 cells. In particular, all these strains were active against Escherichia coli ATCC 8739 and Staphylococcus aureus ATCC 6538 through the production of lactic acid (up to 12 g.l-1) or bacteriocins, namely plantaricins, or their combination. In addition, these strains showed high antioxidant activity against the synthetic free radicals 2,2-diphenyl-2-picrylhydrazyl (DPPH) and 2,2-azino-bis: 3-ethyl-benzothiazoline-6-sulphonic acid (ABTS +) radical. These results demonstrate the importance of these L. plantarum strains for the development of new functional foods and probiotics and as biopreservatives. This study deepens and enriches the knowledge of lactobacilli from plant raw materials by focusing on the functional properties of new strains of L. plantarum isolated from Algerian fruits. In fact, with the growing interest in natural preservatives and probiotics, the results of this study could contribute to the development of new biotechnological products aimed at improving gut health, reducing food-borne illnesses and extending the shelf life of food by preventing spoilage.

Antimicrobial Activity of Probiotic Bacteria Isolated from Plants: A Review

Lactic acid bacteria (LAB) constitute a heterogeneous group of bacteria isolated from fermented foods, animals, plants, and mammalian guts, with many health-promoting properties. Probiotics with antagonistic properties against human pathogens and foodborne bacteria have garnered significant attention from the scientific fraternity. A dedicated review focusing on plant-derived probiotic bacteria and their antagonistic properties has not been comprehensively reviewed. Thus, this review aimed at providing an overview of LAB isolates derived from several unconventional sources such as fruits, seeds, fruit pulp, leaves, roots, vegetables, grasses, and flowers and with their antibacterial, antifungal, and antiviral properties. This paper reviewed the antimicrobial properties of different genera, Lactobacillus, Leuconostoc, Weissella, Enterococcus, Pediococcus, Bacillus, and Fructobacillus, their postbiotics, and paraprobiotics. Several important mechanisms, including the secretion of bacteriocins, bacteriocin-like substances, reuterin, organic acids (lactic and acetic), peptides, exopolysaccharides, and hydrogen peroxide, have been attributed to their antimicrobial actions against pathogens. However, their precise mode of action is poorly understood; hence, further research should be conducted to reveal detailed mechanisms. Finally, the review discusses the summary and future implications. Given the significance, LAB and derived antimicrobial compounds can potentially be exploited in food preservation and safety or for medicinal applications after evaluating their safety.

Revealing the Potential Impacts of Nutraceuticals Formulated with Freeze-Dried Jabuticaba Peel and Limosilactobacillus fermentum Strains Candidates for Probiotic Use on Human Intestinal Microbiota

This study evaluated the impacts of novel nutraceuticals formulated with freeze-dried jabuticaba peel (FJP) and three potentially probiotic Limosilactobacillus fermentum strains on the abundance of bacterial groups forming the human intestinal microbiota, metabolite production, and antioxidant capacity during in vitro colonic fermentation. The nutraceuticals had high viable counts of L. fermentum after freeze-drying (≥ 9.57 ± 0.09 log CFU/g). The nutraceuticals increased the abundance of Lactobacillus ssp./Enterococcus spp. (2.46-3.94%), Bifidobacterium spp. (2.28-3.02%), and Ruminococcus albus/R. flavefaciens (0.63-4.03%), while decreasing the abundance of Bacteroides spp./Prevotella spp. (3.91-2.02%), Clostridium histolyticum (1.69-0.40%), and Eubacterium rectale/C. coccoides (3.32-1.08%), which were linked to positive prebiotic indices (> 1.75). The nutraceuticals reduced the pH and increased the sugar consumption, short-chain fatty acid production, phenolic acid content, and antioxidant capacity, besides altering the metabolic profile during colonic fermentation. The combination of FJP and probiotic L. fermentum is a promising strategy to produce nutraceuticals targeting intestinal microbiota.

Physiological and Technological Properties of Probiotic Lacticaseibacillus rhamnosus GG Encapsulated with Alginate-Chitosan Mixture and Its Incorporation in Whole Milk

This study developed and evaluated chitosan-sodium alginate capsules containing the probiotic Lacticaseibacillus rhamnosus GG using extrusion and emulsification techniques. The encapsulated L. rhamnosus GG cells were also evaluated for technological and probiotic-related physiological functionalities, as well as when incorporated in UHT and powdered milk. Extrusion (86.01 ± 1.26%) and emulsification (74.43 ± 1.41%) encapsulation techniques showed high encapsulation efficiency and high survival rates of L. rhamnosus GG during 28 days of refrigeration and room temperature storage, especially emulsification capsules (> 81%). The encapsulated L. rhamnosus GG cells showed high survival rates during exposure to simulated gastrointestinal conditions (72.65 ± 1.09-114.15 ± 0.44%). L. rhamnosus GG encapsulated by extrusion and emulsification performed satisfactorily in probiotic-related physiological (pH and bile salts tolerance) and technological properties (positive proteolytic activity, diacetyl and exopolysaccharides production, high NaCl tolerance (> 91%), besides having high heat tolerance (> 76%)). L. rhamnosus GG in extrusion and emulsification capsules had high survival rates (> 89%) and did not significantly affect physicochemical parameters in Ultra-High Temperature (UHT) and powdered milk during storage. The results demonstrate that L. rhamnosus GG can be successfully encapsulated with alginate-chitosan as a protective material through extrusion and emulsification techniques. UHT and powdered milk could serve as appropriate delivery systems to increase the intake of this encapsulated probiotic by consumers.

Investigating Safety and Technological Traits of a Leading Probiotic Species: Lacticaseibacillus paracasei

Lacticaseibacillus spp. are genetically close lactic acid bacteria species widely used in fermented products for their technological properties as well as their proven beneficial effects on human and animal health. This study, the first to include such a large collection of heterogeneous isolates (121) obtained from international collections belonging to Lacticaseibacillus paracasei, aimed to characterize the safety traits and technological properties of this important probiotic species, also making comparisons with other genetically related species, such as Lacticaseibacillus casei and Lacticaseibacillus zeae. These strains were isolated from a variety of heterogeneous sources, including dairy products, sourdoughs, wine, must, and human body excreta. After a preliminary molecular characterization using repetitive element palindromic PCR (Rep-PCR), Random Amplification of Polymorphic DNA (RAPD), and Sau-PCR, particular attention was paid to safety traits, evaluating antibiotic resistance profiles, biogenic amine (BA) production, the presence of genes related to the production of ethyl carbamate and diaminobenzidine (DAB), and multicopper oxidase activity (MCO). The technological characteristics of the strains, such as the capability to grow at different NaCl and ethanol concentrations and different pH values, were also investigated, as well as the production of bacteriocins. From the obtained results, it was observed that strains isolated from the same type of matrix often shared similar genetic characteristics. However, phenotypic traits were strain-specific. This underscored the vast potential of the different strains to be used for various purposes, from probiotics to bioprotective and starter cultures for food and feed production, highlighting the importance of conducting comprehensive evaluations to identify the most suitable strain for each purpose with the final aim of promoting human health.

Safety Evaluation of a Novel Potentially Probiotic Limosilactobacillus fermentum in Rats

Limosilactobacillus (L) fermentum (strains 139, 263, 296) is a novel probiotic mixture isolated from fruit processing by-products. The use of this formulation has been associated with improvements in cardiometabolic, inflammatory, and oxidative stress parameters. The present study evaluated the safety of a potential multi-strain probiotic by genotoxicity (micronucleus assay) and subchronic toxicity study (13-week repeated dose). In the genotoxicity evaluation, L. fermentum 139, 263, 296 did not increase the frequency of micronuclei in erythrocytes of rats of both sexes at doses up to 1010 CFU/mL. In the subchronic toxicity study, the administration of L. fermentum did not promote adverse health effects, such as behavioral changes, appearance of tumors, changes in hematological and biochemical parameters. In addition, higher doses of L. fermentum 139, 263, 296 have been shown to reduce the levels of pro-inflammatory cytokines. Administration of potentially probiotic L. fermentum did not promote adverse health effects in rats and could be evaluated as a potential probiotic for humans.

A Mix of Potentially Probiotic Limosilactobacillus fermentum Strains Alters the Gut Microbiota in a Dose- and Sex-Dependent Manner in Wistar Rats

Multi-strain Limosilactobacillus (L.) fermentum is a potential probiotic with reported immunomodulatory properties. This study aimed to evaluate the composition, richness, and diversity of the gut microbiota in male and female rats after treatment with a multi-strain of L. fermentum at different doses. Thirty rats (fifteen male and fifteen female) were allocated into a control group (CTL), a group receiving L. fermentum at a dose of 108 CFU (Lf-108), and a group receiving L. fermentum at a dose of 1010 CFU (Lf-1010) for 13 weeks. Gut microbiota and serum cytokine levels were evaluated after L. fermentum treatment. Male CTL rats had a lower relative abundance of Bifidobacteriaceae and Prevotella and a lower alpha diversity than their female CTL counterparts (p < 0.05). In addition, male CTL rats had a higher Firmicutes/Bacteroidetes (F/B) ratio than female CTL rats (p < 0.05). In female rats, the administration of L. fermentum at 108 CFU decreased the relative abundance of Bifidobacteriaceae and Anaerobiospirillum and increased Lactobacillus (p < 0.05). In male rats, the administration of L. fermentum at 1010 CFU decreased the F/B ratio and increased Lachnospiraceae and the diversity of the gut microbiota (p < 0.05). The relative abundance of Lachnospiraceae and the alpha-diversity of gut microbiota were negatively correlated with serum levels of IL1β (r = -0.44) and TNFα (r = -0.39), respectively. This study identified important changes in gut microbiota between male and female rats and showed that a lower dose of L. fermentum may have more beneficial effects on gut microbiota in females, while a higher dose may result in more beneficial effects on gut microbiota in male rats.

Limosilactobacillus fermentum Strains as Novel Probiotic Candidates to Promote Host Health Benefits and Development of Biotherapeutics: A Comprehensive Review

Fruits and their processing by-products are sources of potentially probiotic strains. Limosilactobacillus (L.) fermentum strains isolated from fruit processing by-products have shown probiotic-related properties. This review presents and discusses the results of the available studies that evaluated the probiotic properties of L. fermentum in promoting host health benefits, their application by the food industry, and the development of biotherapeutics. The results showed that administration of L. fermentum for 4 to 8 weeks promoted host health benefits in rats, including the modulation of gut microbiota, improvement of metabolic parameters, and antihypertensive, antioxidant, and anti-inflammatory effects. The results also showed the relevance of L. fermentum strains for application in the food industry and for the formulation of novel biotherapeutics, especially nutraceuticals. This review provides evidence that L. fermentum strains isolated from fruit processing by-products have great potential for promoting host health and indicate the need for a translational approach to confirm their effects in humans using randomized, double-blind, placebo-controlled trials.

Effects of Simulated Gastrointestinal Conditions on Combined Potentially Probiotic Limosilactobacillus fermentum 296, Quercetin, and/or Resveratrol as Bioactive Components of Novel Nutraceuticals

This study evaluated the effects of simulated gastrointestinal conditions (SGIC) on combined potentially probiotic Limosilactobacillus fermentum 296 (~ 10 log CFU/mL), quercetin (QUE, 160 mg), and/or resveratrol (RES, 150 mg) as the bioactive components of novel nutraceuticals. Four different nutraceuticals were evaluated during exposure to SGIC and analyzed the plate counts and physiological status of L. fermentum 296, contents and bioaccessibility of QUE and RES, and antioxidant capacity. Nutraceuticals with QUE and RES had the highest plate counts (4.94 ± 0.32 log CFU/mL) and sizes of live cell subpopulations (28.40 ± 0.28%) of L. fermentum 296 after SGIC exposure. An index of injured cells (Gmean index, arbitrary unit defined as above 0.5) indicated that part of L. fermentum 296 cells could be entered the viable but nonculturable state when the nutraceuticals were exposed to gastric and intestinal conditions while maintaining vitality. The nutraceuticals maintained high contents (QUE ~ 29.17 ± 0.62 and RES ~ 23.05 mg/100 g) and bioaccessibility (QUE ~ 41.0 ± 0.09% and RES ~ 67.4 ± 0.17%) of QUE and RES, as well as high antioxidant capacity (ABTS assay ~ 88.18 ± 1.16% and DPPH assay 75.54 ± 0.65%) during SGIC exposure, which could be linked to the protective effects on L. fermentum 296 cells. The developed nutraceuticals could cross along the gastrointestinal tract with high concentrations of functioning potentially probiotic cells and bioavailable phenolic compounds to exert their beneficial impacts on consumer health, being an innovative strategy for the co-ingestion of these bioactive components.

Evaluating the Stability of a Novel Nutraceutical Formulation Combining Probiotic Limosilactobacillus fermentum 296, Quercetin, and Resveratrol Under Different Storage Conditions

This study evaluated the stability of a novel nutraceutical formulation composed of the probiotic Limosilactobacillus fermentum 296, quercetin (QUE), and resveratrol (RES) (LFQR) under different storage conditions. The effects of different relative humidities (RH; 11, 22, and 33%) and storage temperatures (refrigeration temperature -4 °C and room temperature -25 °C) on the stability of LFQR were evaluated through the determination of thermal stability, viable cell counts, bacterial physiological status, antioxidant capacity, and contents of QUE and RES during long-term storage. RH did not affect endothermic reactions and mass reduction in LFQR. After a 15-day-humidification period, L. fermentum 296 had higher viable cell counts in LFQR under refrigeration temperature storage when compared to room temperature storage regardless of the RH. The physiological status of L. fermentum 296 in LFQR was overall similar during 90 days of storage (11% RH) under refrigeration and room temperature. L. fermentum 296 had the highest viable cell counts (> 6 log CFU/g) in LFQR up to day 90 of refrigeration storage (11% RH). LFQR kept high contents of QUE and RES and maintained antioxidant capacity during 90 days of storage under refrigeration and room temperature. The results showed that the higher stability and functionality of LFQR during long-term storage should be guaranteed under 11% RH and refrigeration temperature.

Biopreservation of Fresh Sardines (Sardina pilchardus) Using Lactiplantibacillus plantarum OV50 Isolated from Traditional Algerian Green Olives Preparations

Lactiplantibacillus plantarum OV50 is a novel strain that was isolated from Algerian olives. Prior to its use as a natural biopreservative, OV50 underwent characterization for various functions. OV50 shows no proteolytic, lipolytic, or hemolytic activity. In addition, it is non-cytotoxic to eukaryotic cells and does not exhibit acquired antibiotic resistance. OV50 was tested with Pseudomonas aeruginosa ATCC 27835, Staphylococcus aureus ATCC 6538, Escherichia coli ATCC 8739, and Vibrio cholerae ATCC 14035 in a sardine based-medium at 37 °C and 7 °C. At 37 °C, OV50 completely inhibited the growth of these foodborne pathogens for a maximum of 6 h. At 7 °C, it suppressed their growth for a maximum of 8 days, except for S. aureus ATCC 6538, whose growth was reduced from 4 to 2 log CFU/mL. Microbiological counts, total volatile basic nitrogen (TVB-N), and peroxide values (PV) concentrations were determined in fresh sardines inoculated with OV50 and kept at 7 °C for 12 days. The inoculated sardines showed a significant reduction in TVB-N levels at D8 (34.9 mg/100 g) compared to the control (59.73 mg/100 g) and in PV concentrations at D4 (6.67 meq/kg) compared to the control (11.44 meq/kg), as well as a significant reduction in the numbers of Enterobacterales, Coliforms, Pseudomonas spp., Vibrio spp., and S. aureus At D8 and D12 compared to the control. Taken together, these results indicate that OV50 can improve the microbiological safety, freshness, and quality of sardines.

Unrevealing the in vitro impacts of Cereus jacamaru DC. cladodes flour on potentially probiotic strains, selected bacterial populations, and metabolic activity of human intestinal microbiota

This study investigated the potential impacts of the flour from Cereus jamacaru cactus cladodes (CJF), a cactus native to the Brazilian Caatinga biome, on the growth and metabolism of different potentially probiotic strains, as well as on the abundance of selected intestinal bacterial populations and microbial metabolic activity during in vitro colonic fermentation with a pooled human fecal inoculum. Cultivation of the probiotics in a medium with C. jamacaru cladodes flour (20 g/L) resulted in viable cell counts of up to 9.8 log CFU/mL, positive prebiotic activity scores (0.73-0.91), decreased pH and sugar contents, and increased lactic, acetic, and propionic acid production over time, indicating enhanced probiotic growth and metabolic activity. CJF overall increased the relative abundance of Lactobacillus spp./Enterococcus spp. (2.12-3.29%) and Bifidobacterium spp. (4.08-4.32%) and decreased the relative abundance of Bacteroides spp./Prevotella spp. (8.35-6.81%), Clostridium histolyticum (6.91-3.59%), and Eubacterium rectale/Clostridium coccoides (7.70-3.95%) during 48 h of an in vitro colonic fermentation using a pooled human fecal inoculum. CJF stimulated the microbial metabolic activity, with decreased pH, sugar consumption, lactic and short-chain fatty acid production, alterations in overall metabolic profiling and phenolic compound contents, and maintenance of high antioxidant capacity during colonic fermentation. These results show that CJF stimulated the growth and metabolic activity of distinct potential probiotics, increased the relative abundance of beneficial intestinal bacterial groups, and stimulated microbial metabolism during in vitro colonic fermentation. Further studies using advanced molecular technologies and in vivo experimental models could forward the investigation of the potential prebiotic properties of CJF.

Assessment of probiotic properties of lactic acid bacteria isolated from an artisanal Colombian cheese

Lactic Acid Bacteria play an important role in the milk fermentation processes of traditional cheeses and have become an important target for the development of novel cheese cultures because of their ability to confer health benefits. This study aimed to evaluate the probiotic potential of 12 Lactic Acid Bacteria (LAB) strains previously isolated and molecularly identified from an artisanal Colombian Double-Cream Cheese. Probiotic properties, including safety (hemolysis and sensibility to antibiotics), pH and bile salt tolerance, auto-aggregation, cell surface hydrophobicity, antibacterial activity, and exopolysaccharide production, were examined. None of the strains were hemolytic, and Pediococcus (16, 18) and Lactobacillus (28, 29) were found to be sensitive to all antibiotics. Moreover, all the strains tolerated pH (3.0, 6.5 and 8.0) and bile salt conditions (0.3, 0.6 and 1.0 % w/v). Pediococcus pentosaceus (16), Leuconostoc citreum (17), Pediococcus acidilactici (18), Enterococcus faecium (21,22), Enterococcus faecalis (24) and Limosilactobacillus fermentum (29) exhibited medium autoaggregation and affinity to chloroform. Six of the strains exhibited a ropy exopolysaccharide phenotype. Antibacterial activity against foodborne pathogens, Salmonella Typhimurium ATCC 14028, Listeria monocytogenes ATCC 19111, Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 25923, was found to be strain dependent, with the strains 16, 18, 21, 26, 28 and 29 presenting a higher inhibition (>4 mm) against all of them. According to Principal Component Analysis, P. pentosaceus (16), Leu. mesenteroides (26), L. casei (28), L. fermentum (29), and E. faecium (21) showed strong probiotic properties. Our findings suggest that five strains out of the 12 sampled strains are potential probiotics that could be used in the processing of traditional dairy products on an industrial scale to improve their quality.

In Vitro Effect of the Cell-Free Supernatant of the Lactobacillus casei Strain IMAU60214 against the Different Pathogenic Properties of Diarrheagenic Escherichia coli

Enteroaggregative Escherichia coli (EAEC) and enterohemorrhagic E. coli (EHEC) are E. coli pathotypes associated with unmanageable diarrhea in children and adults. An alternative to the treatment of infections caused by these microorganisms is the use of the bacteria of the Lactobacillus genus; however, the beneficial effects on the intestinal mucosa are specific to the strain and species. The interest of this study consisted of analyzing the coaggregation properties of Lactobacillus casei IMAU60214, as well as the effect of cell-free supernatant (CSF) on growth and anti-cytotoxic activity in a cell model of the human intestinal epithelium for an agar diffusion assay (HT-29) and the inhibition of biofilm formation on plates of DEC strains of the EAEC and EHEC pathotypes. The results showed that L. casei IMAU60214 exhibits time-dependent coaggregation (35-40%) against EAEC and EHEC that is similar to the control E. coli ATCC 25922. The CSF showed antimicrobial activity (20-80%) against EAEC and EHEC depending on the concentration. In addition, the formation and dispersion of biofilms of the same strains decrease, and the proteolytic pre-treatment with catalase and/or proteinase K (1 mg/mL) of CSF reduces the antimicrobial effect. When evaluating the effect in HT-29 cells pre-treated with CFS on the toxic activity induced by the EAEC and EHEC strains, a reduction of between 30 and 40% was observed. The results show that L. casei IMAU60214 and its CSF have properties that interfere with some properties associated with the virulence of the EAEC and EHEC strains that cause intestinal infection, which supports their use for the control and prevention of infections caused by these bacteria.

Ligilactobacillus murinus Strains Isolated from Mice Intestinal Tract: Molecular Characterization and Antagonistic Activity against Food-Borne Pathogens

Considering the objectives of “One Health” and the Sustainable development Goals “Good health and well-being” for the development of effective strategies to apply against bacterial resistance, food safety dangers, and zoonosis risks, this project explored the isolation and identification of Lactobacillus strains from the intestinal tract of recently weaned mice; as well as the assessment of antibacterial activity against clinical and zoonotic pathogens. For molecular identification, 16S rRNA gene-specific primers were used and, via BLAST-NCBI, 16 Ligilactobacillus murinus, one Ligilactobacillus animalis, and one Streptococcus salivarius strains were identified and registered in GenBank after the confirmation of their identity percentage and the phylogenetic analysis of the 16 Ligilactobacillus murinus strains and their association with Ligilactobacillus animalis. The 18 isolated strains showed antibacterial activity during agar diffusion tests against Listeria monocytogenes ATCC 15313, enteropathogenic Escherichia coli O103, and Campylobacter jejuni ATCC 49943. Electrophoretic and zymographic techniques confirmed the presence of bacteriolytic bands with a relative molecular mass of 107 kDa and another of 24 kDa in Ligilactobacillus murinus strains. UPLC-MS analysis allowed the identification of a 107 kDa lytic protein as an N-acetylmuramoyl-L-amidase involved in cytolysis and considered a bacteriolytic enzyme with antimicrobial activity. The 24 kDa band displayed similarity with a portion of protein with aminopeptidase function. It is expected that these findings will impact the search for new strains and their metabolites with antibacterial activity as an alternative strategy to inhibit pathogens associated with major health risks that help your solution.

Exploring the antimicrobial effects of a phenolic-rich extract from jabuticaba depulping waste against enterotoxigenic Escherichia coli

This study evaluated the effects of a phenolic-rich extract from jabuticaba [Myrciaria jaboticaba (Vell.) Berg] depulping waste (PEJ) on the survival, antibiotic susceptibility, virulence, and cellular functions of various enterotoxigenic Escherichia coli (ETEC) strains. The minimum inhibitory concentration of PEJ against the five tested ETEC strains was 125 mg mL-1. PEJ at 125 and 250 mg mL-1 caused reductions in viable cell counts of ≥ 3 and ≥ 5 log CFU mL-1 in ETEC over 24 h, respectively. PEJ at subinhibitory concentrations (31.25 and 62.5 mg mL-1) reduced the viable cell counts of ETEC when exposed to in vitro gastrointestinal conditions, besides decreasing the biofilm formation, cell surface hydrophobicity, mucin adhesion, and swimming and swarming motility. PEJ (31.25 and 62.5 mg mL-1) increased the susceptibility of the tested ETEC strains to various clinically relevant antibiotics. The exposure to PEJ (62.5 and 125 mg mL-1) impaired the membrane permeability and enzymatic and efflux pump activities in ETEC cells. PEJ effectively reduces survival, increases antibiotic susceptibility, and attenuates virulence in ETEC. These effects could be linked to a PEJ multi-target action disturbing various cellular functions in ETEC cells. PEJ could be a candidate for developing innovative solutions to prevent and treat ETEC infections.

Effects of Probiotic Fermented Fruit Juice-Based Biotransformation by Lactic Acid Bacteria and Saccharomyces boulardii CNCM I-745 on Anti-Salmonella and Antioxidative Properties

Fermentation is an effective process for providing various beneficial effects in functional beverages. Lactic acid bacteria and yeast fermentation-based biotransformation contribute to enhancement of nutritional value and digestibility, including lactose intolerance reduction and control of infections. In this study, the probiotic fermented fruit juice (PFJ) was produced by Lactobacillus plantarum TISTR 1465, Lactobacillus salivarius TISTR 1112, and Saccharomyces boulardii CNCM I-745 while mixed fruit juice (MFJ) was used as the basic medium for microorganism growth. The potential function, the anti-salmonella activity of PFJ, was found to be effective at 250 mg/ml of MIC and 500 mg/ml of MBC. Biofilm inhibition was performed using the PFJ samples and showed at least 70% reduction in cell attachment at the MIC concentration of Salmonella Typhi DMST 22842. The antioxidant activities of PFJ were determined and the results revealed that FSB.25 exhibited 78.40 ± 0.51 mM TE/ml by FRAP assay, while FPSB.25 exhibited 3.44 ± 0.10 mM TE/ml by DPPH assay. The volatile compounds of PFJ were characterized by GC-MS, which identified alcohol, aldehyde, acid, ester, ketone, phenol, and terpene. The most abundant organic acid and alcohol detected in PFJ were acetic acid and 2-phenylethanol, and the most represented terpene was β-damascenone. The sensory attributes showed scores higher than 7 on a 9-point hedonic scale for the FPB.25, illustrating that it was well accepted by panelists. Taken together, our results showed that PFJ could meet current consumer demand regarding natural and functional, fruit-based fermented beverages.

Nutrition and Health through the Use of Probiotic Strains in Fermentation to Produce Non-Dairy Functional Beverage Products Supporting Gut Microbiota

Pure viable strains of microorganisms identified and characterised as probiotic cultures are used in the fermentation process to prepare functional beverages. The fermented probiotic products can be consumed as a source of nutrition and also for the maintenance of healthy gut microbiota. The functional beverages contain the substrates used for the preparation of product with a specific culture or a mixture of known strains used to perform the fermentation, hence these drinks can be considered as a healthy formulation of synbiotic products. If a beverage is prepared using agriculturally sourced materials, the fermented substrates with their oligosaccharides and fiber content act as prebiotics. Both the components (probiotic strain/s and prebiotic substrate) exist in a synergistic relationship in the product and contribute to several benefits for nutrition and gut health. The preparation of such probiotic beverages has been studied using non-dairy-based materials, including fruits, vegetables, nuts, grains, and cassava, a staple diet source in many regions. The consumption of beverages prepared with the use of probiotics, which contain active microbial cells and their metabolites, contributes to the functional properties of beverages. In addition, the non-dairy probiotic products can be used by consumers of all groups and food cultures, including vegans and vegetarians, and particularly consumers with allergies to dairy-based products. The aim of this article is to present a review of published research highlighting specific probiotic strains, which have the potential to enhance sustainability of healthy GIT microbiota, used in the fermentation process for the preparation of non-dairy beverages.

The absence of PNPase activity in Enterococcus faecalis results in alterations of the bacterial cell-wall but induces high proteolytic and adhesion activities

Enterococci are lactic acid bacteria (LAB) used as starters and probiotics, delineating their positive attributes. Nevertheless, enterococci can be culprit for thousands of infectious diseases, including urinary tract infections, bacteremia and endocarditis. Here, we aim to determine the impact of polynucleotide phosphorylase (PNPase) in the biology of Enterococcus faecalis 14; a human isolate from meconium. Thus, a mutant strain deficient in PNPase synthesis, named ΔpnpA mutant, was genetically obtained. After that, a transcriptomic study revealed a set of 244 genes differentially expressed in the ΔpnpA mutant compared with the wild-type strain, when exploiting RNAs extracted from these strains after 3 and 6 h of growth. Differentially expressed genes include those involved in cell wall synthesis, adhesion, biofilm formation, bacterial competence and conjugation, stress response, transport, DNA repair and many other functions related to the primary and secondary metabolism of the bacteria. Moreover, the ΔpnpA mutant showed an altered cell envelope ultrastructure compared with the WT strain, and is also distinguished by a strong adhesion capacity on eukaryotic cell as well as a high proteolytic activity. This study, which combines genetics, physiology and transcriptomics enabled us to show further biological functions that could be directly or indirectly controlled by the PNPase in E. faecalis 14.

Screening and Molecular Identification of Lactic Acid Bacteria Producing β-Glucan in Boza and Cider

The goal of this study was screening and molecular identification of Lactic Acid Bacteria (LAB) producing β-glucan from different species isolated from boza and cider compared to a standard strain for Lactobacillus rhamnosus NRRL 1937 (LGG). From 48 unknown isolates, four LAB strains were selected. Based on the NCBI database, their nomenclature was A3, B6, and C9 for Limosilactobacillus fermentum SH1, SH2, and SH3 along with D6 for Leuconostoc mesenteroides SH4. Also, their similarity values were 100%, 99.8%, 100%, and 100%, respectively. The potential of Exopolysaccharide (EPS) (as β-glucan) production for selected LAB strains by gtf gene, conventional PCR and gene expression using both LGG as a control and LAB 16S rRNA gene as a house-keeping gene was investigated. In addition, EPS (mg/100 mL), cell mass (mg/100 mL), pH, total carbohydrate%, total protein% and β-glucan% by the HPLC for all selected LAB isolates were studied. All results of genetic and chemical tests proved the superiority of B6 treatment for L. fermentum SH2. The results showed the superiority of B6 treatment in gtf gene expression (14.7230 ± 0.070-fold) followed by C9 and A3 treatments, which were 10.1730 ± 0.231-fold and 8.6139 ± 0.320-fold, respectively. while D6 treatment recorded the lowest value of gene expression (0.8566 ± 0.040-fold) compared to the control LGG (one-fold). The results also demonstrated that B6 treatment was superior to the other treatments in terms of EPS formation, with a value of 481 ± 1.00 mg/100 mL, followed by the C9 treatment at 440 ± 2.00 mg/100 mL, compared to the LGG (control) reaching 199.7 ± 3.51 mg/100 mL. Also, the highest % of quantitative and qualitative β-glucan in EPS was observed in B6 followed by C9, D6 and A3 which were 5.56 ± 0.01%, 4.46 ± 0.01%, 0.25 ± 0.008% and 0.12 ± 0.008%, respectively compared to control (0.31 ± 0.01%). Finally, the presented results indicate the importance of screening the local LAB isolates to obtain a superior strain for β-glucan production which will be introduced in a subsequent study under optimum conditions.

Evaluation of the Potential Probiotic Yeast Characteristics with Anti-MRSA Abilities

Methicillin-resistant Staphylococcus aureus (MRSA) is a disreputable pathogenic bacterium that has been proven to colonize the intestinal tract. The goal of this study is to find anti-MRSA probiotic yeast from food and evaluate its probiotic characteristics and safety. Finally, 15 strains were isolated from fruit peel with anti-MRSA ability. Using DNA sequence analysis, they were identified as the genus Hanseniaspora (7 strains) and Starmerella (8 strains). Starmerella bacillaris CC-PT4 (CGMCC No. 23573) that was isolated from the grape peel has good auto-aggregation ability and hydrophobicity, and can tolerate 0.3% bile, pH 2, simulated gastric fluid (SGF), and simulated intestinal fluid (SIF). Strikingly, Starmerella bacillaris CC-PT4, like commercial probiotic Saccharomyces boulardii CNCM I-745 (Florastor ^®), can adapt to the temperature of the human body (37 ℃). After safety assessment, this strain is sensitive to amphotericin B and cannot produced β-hemolytic activities. Overall, this study provides a new candidate for probiotic yeast with anti-MRSA ability.

Limosilactobacillus fermentum, Current Evidence on the Antioxidant Properties and Opportunities to be Exploited as a Probiotic Microorganism

The unbalance in the production and removal of oxygen-reactive species in the human organism leads to oxidative stress, a physiological condition commonly linked to the occurrence of cancer, neurodegenerative, inflammatory, and metabolic disorders. The implications of oxidative stress in the gut have been associated with gut microbiota impairments and gut dysbiosis. Some lactobacilli strains have shown an efficient antioxidant system capable of protecting against oxidative stress and related-chronic diseases. Recently, in vitro and experimental studies and some clinical trials have demonstrated the efficacy of the administration of various Limosilactobacillus fermentum strains to modulate beneficially the host antioxidant system resulting in the amelioration of a variety of systemic diseases phenotypes. This review presents and discusses the currently available studies on identifying L. fermentum strains with anti-oxidant properties, their sources, range of the administered doses, and duration of the intervention in experiments with animals and clinical trials. This review strives to serve as a relevant and well-cataloged reference of L. fermentum strains with capabilities of inducing anti-oxidant effects and health-promoting benefits to the host, envisaging their broad applicability to disease control.

Lactic acid bacteria and their bacteriocins: new potential weapons in the fight against methicillin-resistant Staphylococcus aureus

Alternative solutions are eminently needed to combat the escalating number of infections caused by methicillin-resistant Staphylococcus aureus (MRSA). Bacteriocins produced by lactic acid bacteria are promising candidates for next-generation antibiotics. Studies have found that these stable and nontoxic ribosomally synthesized antimicrobial peptides exhibit significant potency against other bacteria, including antibiotic-resistant strains. Here the authors review previous studies on bacteriocins that have been effectively employed to manage MRSA infections. The authors' review focuses on the beneficial traits of bacteriocins for further application as templates for the design of novel drugs. Treatments that combine bacteriocins with other antimicrobials to combat pervasive MRSA infections are also highlighted. In short, future studies should focus on the pharmacodynamics and pharmacokinetics of bacteriocins-antimicrobials to understand their interactions, as this aspect would likely determine their efficacy in MRSA inhibition.

Sensory and flavor-aroma profiles of passion fruit juice fermented by potentially probiotic Lactiplantibacillus plantarum CCMA 0743 strain

Several non-dairy probiotic beverages are already available to consumers and have been considered suitable carriers for probiotic bacteria. This study aimed to investigate the effect of Lactiplantibacillus plantarum CCMA 0743 in single and co-culture on the volatile compounds and sensory profiles of fermented passion fruit juice. The viability of strains inoculated in juice and MRS matrices was evaluated in a simulated gastrointestinal condition. The bacterial viability after 28 days of refrigerated storage of the juices was also evaluated. L. plantarum CCMA 0743 showed high viability (6.18 Log CFU/mL) after passage throughout simulated digestion in the passion fruit juice matrix. Both juices maintained high probiotic counts (>8.0 Log CFU/mL) during storage. Also, the yellow color was stable after 28 days of storage. Volatile compounds of passion fruit juices were modified after the fermentation process, such as ketones and alcohol formation degradation. The sensory profile of passion fruit juice was modified by single and co-culture fermentations. The fermented samples were mainly correlated with the terminologies "salty, acidic and bitter tastes" and "sweetener aftertaste". Overall, passion fruit juice proved to be an adequate food matrix to deliver the evaluated strains. However, individual strains or strain-strain interactions with the food matrix affect the fermented product, demonstrating that strain and matrices evaluations are essential for developing novel products with acceptable characteristics.

Potentially Probiotic Limosilactobacillus fermentum Fruit-Derived Strains Alleviate Cardiometabolic Disorders and Gut Microbiota Impairment in Male Rats Fed a High-Fat Diet

High-fat diet (HFD) consumption is a risk factor for dyslipidemias, insulin resistance, and arterial hypertension linked with gut dysbiosis. Probiotic administration has been suggested as a safe therapeutic strategy for gut microbiota modulation and treatment and/or prevention of cardiometabolic disorders. Here, we assessed the effects of a potentially probiotic formulation containing strains of the Limosilactobacillus (L.) fermentum 139, 263, and 296 on the cardiometabolic disorders and gut microbiota derangements provoked by the HFD consumption. Male Wistar rats were allocated into control diet (CTL, n = 6), HFD (n = 6), and HFD receiving L. fermentum formulation (HFD-LF, n = 6) groups for 4 weeks. L. fermentum formulation (10⁹ colony-forming unit (CFU)/ml of each strain) was daily administered by oral gavage. After 4-week follow-up, biochemical measurements, blood pressure (BP), heart rate (HR), sympathetic tone, and gut microbiota composition were evaluated. HFD consumption for 4 weeks increased lipid profile, insulin resistance, sympathetic tone, and blood pressure and impaired gut microbiota composition in male rats. Administration of L. fermentum formulation improved the gut microbiota composition, lipid profile, insulin resistance, autonomic dysfunction, and BP in rats fed with a HFD. Administration of a potentially fruit-derived probiotic formulation of L. fermentum strains improved gut microbiota composition and alleviated hyperlipidemia, insulin resistance, and sympathetic hyperactivity and increased BP in rats fed a HFD. Our findings may encourage the development of randomized controlled trials to assess the effects of L. fermentum treatment in subjects with cardiometabolic disorders.

Selection of Lactic Acid Bacteria with In Vitro Probiotic-Related Characteristics from the Cactus Pilosocereus gounellei (A. Weber ex. K. Schum.) Bly. ex Rowl

Pilosocereus gounellei (A. Weber ex. K. Schum.) Bly. ex Rowl., popularly known as xique-xique, is a cactus from the Caatinga biome, which is rich in bioactive compounds but has not been previously studied as a source of lactic acid bacteria (LAB) with probiotic aptitudes. This study aimed to identify, characterize, and select LAB isolates with in vitro probiotic-related characteristics from xique-xique cladodes and fruit. Isolates with the most promising probiotic-related characteristics were evaluated regarding their in vitro technological properties and capability of surviving in chestnut milk, whey protein drink, and mate tea with mint during 21 days of refrigeration storage. Seventeen recovered isolates had typical characteristics of LAB. Six out of these seventeen LAB isolates passed the safety tests and were included in experiments to evaluate the in vitro probiotic-related characteristics. Based on the results of a principal component analysis, the isolates 69, 82, 98, and 108 had the best performances in experiments to evaluate the probiotic-related characteristics. In addition to showing good technological properties, the four selected LAB isolates had high viable counts (>7.3 log cfu/mL) and high sizes of physiologically active cell subpopulations in chestnut milk, whey protein drink, and mate tea during refrigeration storage. These four isolates were identified by 16S-rRNA sequencing as being Lacticaseibacillus paracasei or Lacticaseibacillus casei. The results indicate xique-xique as a source of potentially probiotic LAB isolates.

Limosilactobacillus fermentum Strains with Claimed Probiotic Properties Exert Anti-oxidant and Anti-inflammatory Properties and Prevent Cardiometabolic Disorder in Female Rats Fed a High-Fat Diet

This study assessed the effects of a mixed formulation containing Limosilactobacillus (L.) fermentum 139, L. fermentum 263, and L. fermentum 296 on cardiometabolic parameters, inflammatory markers, short-chain fatty acid (SCFA) fecal contents, and oxidative stress in colon, liver, heart, and kidney tissues of female rats fed a high-fat diet (HFD). Female Wistar rats were allocated into control diet (CTL, n = 6), HFD (n = 6), and HFD receiving L. fermentum formulation (HFD-LF, n = 6). L. fermentum formulation (1 × 10⁹ CFU/mL of each strain) was administered two twice a day for 4 weeks. Administration of L. fermentum increased acetate and succinate fecal contents and reduced hyperlipidemia and hyperglycemia in rats fed a HFD (p < 0.05). Administration of L. fermentum decreased low-grade inflammation and improved antioxidant capacity along the gut, liver, heart, and kidney tissues in female rats fed a HFD (p < 0.05). Administration of L. fermentum prevented dyslipidemia, inflammation, and oxidative stress in colon, liver, heart, and kidney in female rats fed a HFD.

Application of Potentially Probiotic Fruit-Derived Lactic Acid Bacteria Loaded into Sodium Alginate Coatings to Control Anthracnose Development in Guava and Mango During Storage

This study evaluated the efficacy of potentially probiotic fruit-derived lactic acid bacteria (LAB) strains loaded into sodium alginate (SA) coatings to control the anthracnose development in guava cv. Paluma and mango cv. Palmer caused by distinct pathogenic Colletotrichum species (C. asianum, C. fructicola, C. tropicale, C. siamense, C. karstii, and C. gloeosporioides) during 15 days of room temperature storage (25 ± 0.5 °C). The effects of the formulated coatings on physicochemical parameters indicative of overall postharvest quality of guava and mango were evaluated. The eight examined LAB strains caused strong inhibition on the mycelial growth of all target Colletotrichum species in vitro. LAB strains with the highest inhibitory effects (Levilactobacillus brevis 59, Lactiplantibacillus pentosus 129, and Limosilactobacillus fermentum 263) on the target Colletotrichum species were incorporated into SA coatings. These strains had viable counts of > 6 log CFU/mL in SA coatings during 15 days of room temperature storage. Application of coatings with SA + L. brevis 59, SA + L. pentosus 129, and SA + L. fermentum 263 delayed the development and decreased the severity of anthracnose lesions in guava and mango artificially contaminated with either of the tested Colletotrichum species. These coatings impacted positively on some physicochemical parameters indicative of postharvest quality and more prolonged storability of guava and mango. The formulated SA coatings loaded with tested fruit-derived potentially probiotic LAB strains could be innovative and effective strategies to control postharvest anthracnose and extend the storability of guava and mango.

Effects of a Mixed Limosilactobacillus fermentum Formulation with Claimed Probiotic Properties on Cardiometabolic Variables, Biomarkers of Inflammation and Oxidative Stress in Male Rats Fed a High-Fat Diet

High-fat diet (HFD) consumption has been linked to dyslipidemia, low-grade inflammation and oxidative stress. This study investigated the effects of a mixed formulation with Limosilactobacillusfermentum 139, L. fermentum 263 and L. fermentum 296 on cardiometabolic parameters, fecal short-chain fatty acid (SCFA) contents and biomarkers of inflammation and oxidative stress in colon and heart tissues of male rats fed an HFD. Male Wistar rats were grouped into control diet (CTL, n = 6), HFD (n = 6) and HFD with L. fermentum formulation (HFD-Lf, n = 6) groups. The L.fermentum formulation (1 × 10⁹ CFU/mL of each strain) was administered twice a day for 4 weeks. After a 4-week follow-up, biochemical parameters, fecal SCFA, cytokines and oxidative stress variables were evaluated. HFD consumption caused hyperlipidemia, hyperglycemia, low-grade inflammation, reduced fecal acetate and propionate contents and increased biomarkers of oxidative stress in colon and heart tissues when compared to the CTL group. Rats receiving the L. fermentum formulation had reduced hyperlipidemia and hyperglycemia, but similar SCFA contents in comparison with the HFD group (p < 0.05). Rats receiving the L. fermentum formulation had increased antioxidant capacity throughout the colon and heart tissues when compared with the control group. Administration of a mixed L. fermentum formulation prevented hyperlipidemia, inflammation and oxidative stress in colon and heart tissues induced by HFD consumption.

Bioprospecting of Palmyra Palm (Borassus flabellifer) Nectar: Unveiling the Probiotic and Therapeutic Potential of the Traditional Rural Drink

The present study investigates the therapeutic and probiotic attributes of traditional Toddy Palm Nectar (TPN). Glucose was found to be the highest with 4.37 mg/ml and arabinose was the least with 2.85 mg/ml. The average ethanol concentration of fresh TPN was found to be 0.3 mg/ml. The nutritional profile of TPN revealed 18 volatile fatty acids, the major one being hexadecenoic acid (M/Z 74). Amino acid profiling showed 26 amino acids, with OH-lysine-2 the highest (12.86%). About 120 morphologically distinct lactic acid bacteria (LAB) were isolated from 26 TPN samples, based on differential growth and in vitro probiotic characteristics. After 16S rRNA sequencing, four indigenous LAB strains were identified as Lactobacillus plantarum group OUBN1, Enterococcus faecium OUBN3, Pediococcus acidilactici OUBN4, and Pediococcus pentosaceous OUBN5 and their sequences were deposited to NCBI. Microbiological safety evaluation studies showed the absence of hemolytic, gelatinolytic and proteolytic activity. The bacterial isolate OUBN3 showed a maximum survival rate of 6.91 ± 0.04 log cfu/ml at acidic pH 2.5 and isolate OUBN5 showed 6.94 ± 0.02 log cfu/ml at pH 3.0. Similarly, the isolate OUBN5 showed 7.92 ± 0.03 log cfu/ml to 0.3% ox-bile after 4 h and 8.94 ± 0.03 log cfu/ml to simulated gastric juice after 3 h of treatments. OUBN1 expressed the highest autoaggregation (81.76 ± 1.25%), cell surface hydrophobicity (79.71 ± 3.42%), and displayed the maximum coaggregation with E. coli MTCC452 (76.96%), K. pneumoniae MTCC109 (75.62%), and S. aureus MTCC902 (70.69%). All strains showed significant antibiotic and antimicrobial activity. Isolate OUBN1 displayed hydroxyl radical scavenging activity (68.71 ± 1.0%) with an IC50 value of 75.62 μg/ml and the highest anti-cancer activity (percentage inhibition of 88.55) against HT-29 cells. Based on the characteristics observed, L. plantarum group OUBN1 and P. pentosaceous OUBN5 were found to be potential isolates to employ as probiotic microbiota in food and forage preparations. These findings reinforce the fact that LAB isolated from TPN could be exploited as an alternative means toward potential therapeutic applications.

Isolation, Identification, and Screening of Lactic Acid Bacteria with Probiotic Potential in Silage of Different Species of Forage Plants, Cocoa Beans, and Artisanal Salami

The objective of this study was to isolate and characterize lactic acid bacteria with probiotic potential in silages of different species of forage plants, cocoa beans, and artisanal salami. The obtained isolates were submitted to the following evaluations: (i) screening for tolerance to pH 2 and bile salts, (ii) genotypic identification of isolates, (iii) survival in simulated gastric and pancreatic conditions, (iv) antimicrobial activity, (v) antibiotic susceptibility and safety, and (vi) properties associated with adhesion capacity. A total of 82 isolates were obtained and were screened for pH 2.0 tolerance and capacity to growth in the presence of bile salts (1.0 and 2.0%). Only 19 strains simultaneously presented tolerance to pH 2.0 and bile salts. These 19 strains were evaluated for genetic profile by Box-PCR. Subsequently, the selected strains were subjected to partial sequencing of the 16S rRNA gene. The species Lactobacillus plantarum was prevalent. The identified strains were evaluated for survival under simulated gastric and pancreatic conditions. Some strains have shown tolerance in both conditions. Different strains showed variations in antimicrobial activity, susceptibility to antibiotics, and properties associated with adhesion (hydrophobicity, autoaggregation, coaggregation, and adhesion to CaCo2 cells). All strains were negative for hemolysis, DNase, gelatinase, and biogenic amine synthesis activity. The L. plantarum SBR64.7 strain can be considered the most promising for it presented the lowest viability reduction when exposed to gastric and pancreatic juices.

Selection of lactic acid bacteria with promising probiotic aptitudes from fruit and ability to survive in different food matrices

Lactic acid bacteria (LAB) are among the most prevalent microorganisms forming the autochthonous microbiota of fruit. This study aimed to select LAB isolates with probiotic aptitudes from apple, banana, grape, and orange through evaluation of in vitro safety, technological, and functional-related properties. The ability of most promising selected isolates to survive in commercial apple and orange juice, meat stew, vegetable puree, and UHT milk during 28 days of refrigeration storage was evaluated. Ninety-three isolates identified preliminarily as LAB were recovered from fruit and 66 of these isolates passed safety tests. Most of these isolates were pre-identified as belonging to Lactobacillus or Enterococcus genus based on MALDI-ToF MS profiling. These 66 isolates were categorized into three homogeneous groups based on a preliminary cluster analysis run with data from experiments to measure technological characteristics. Nine LAB isolates were selected as the most promising for probiotic use based on a principal component analysis run with data from experiments to measure probiotic-related properties. Four of these isolates were sensitive to different antibiotics and identified (16S-rRNA gene sequencing) as Lactobacillus brevis (recently reclassified as L. brevis) or Lactobacillus spp. These 4 selected isolates had high viable counts and high percentages of physiologically active cells in apple and orange juice, beef stew, vegetable puree, and UHT milk during refrigeration storage. The results showed that apple, banana, orange, and grape are potential sources of LAB with aptitudes to be exploited for a possible probiotic use and distinguished abilities to survive in different food matrices.

Oral administration of Lactobacillus fermentum post-weaning improves the lipid profile and autonomic dysfunction in rat offspring exposed to maternal dyslipidemia

BACKGROUND

Maternal dyslipidemia alters the gut microbiota composition and contributes to the development of arterial hypertension (AH) in offspring. Here, we evaluated the effects of a new Lactobacillus fermentum probiotic formulation given post-weaning on cardiometabolic parameters and gut microbiota in male and female rat offspring from dams exposed to maternal dyslipidemia during pregnancy and lactation.

METHODS

Wistar rats (n = 14) were fed with a control diet (CTL = 7) or a dyslipidemic diet (DLP = 7) during pregnancy and lactation. After weaning, male and female offspring received a standard diet up to 90 days of life. Rats were allocated into three groups: CTL group + saline solution (n = 14); DLP group + saline solution (n = 14) and DLP group receiving a probiotic cocktail (n = 14). A vehicle or probiotic formulation containing L. fermentum 139, L. fermentum 263 and L. fermentum 296 (ratio 1 : 1 : 1, 1 × 109 CFU mL-1) was administered daily by oral gavage for 8 weeks.

RESULTS

The intervention with the probiotic formulation of L. fermentum in male and female offspring reduced total cholesterol (TC) and increased HDL-c, but did not affect the insulin resistance induced by maternal dyslipidemia. Additionally, the male and female rats that received the probiotic formulation of L. fermentum demonstrated improvement in fecal Lactobacillus sp. counts, blood pressure and sympathetic tone, without affecting baroreflex modulation.

CONCLUSION

The probiotic formulation containing L. fermentum improved the lipid profile and autonomic dysfunction in male and female offspring exposed to maternal dyslipidemia.

Probiotic properties of yeasts isolated from Brazilian fermented table olives

AIMS

To investigate the probiotic potential of yeasts isolated from naturally fermented Brazilian table olives.

METHODS AND RESULTS

Eighteen yeast strains were tested in terms of: safety; survival of gastrointestinal and digestion conditions; antimicrobial activity; cellular hydrophobicity; autoaggregation ability and adhesion to epithelial cells; coaggregation and inhibition of pathogenic bacteria adhesion. Six yeasts showed favourable results for all probiotic attributes: Saccharomyces cerevisiae CCMA 1746, Pichia guilliermondii CCMA 1753, Candida orthopsilosis CCMA 1748, Candida tropicalis CCMA 1751, Meyerozyma caribbica CCMA 1758 and Debaryomyces hansenii CCMA 1761. These yeasts demonstrated resistance to 37°C, pH 2·0 and bile salts, and survived in vitro digestion (≥10⁶  CFU per ml). Furthermore, the yeasts exhibited a hydrophobic cell surface (42·5-92·2%), autoaggregation capacity (41·0-91·0%) and adhesion to Caco-2 (62·0-82·8%) and HT-29 (57·6-87·3%) epithelial cell lines. Also, the strains showed antimicrobial activity against Salmonella Enteritidis as well as the ability to coaggregate and reduce the adhesion of this pathogen to intestinal cells.

CONCLUSIONS

Autochthonous yeasts from naturally fermented Brazilian table olives have probiotic properties, with potential for development of new probiotic food products.

SIGNIFICANCE AND IMPACT OF STUDY

These data are important and contribute to the knowledge of new potential probiotic yeasts capable of surviving gastrointestinal tract conditions and inhibiting pathogenic bacteria.

Mining indigenous honeybee gut microbiota for Lactobacillus with probiotic potential

The present study was done to explore the diversity of lactic acid bacteria (LAB) associated with the gastrointestinal tract (GIT) of honeybee species endemic to northeastern Pakistan. Healthy worker bees belonging to Apis mellifera, A. dorsata, A. cerana and A. florea were collected from hives and the surroundings of a major apiary in the region. The 16S rRNA amplicon sequencing revealed a microbial community in A. florea that was distinct from the others in having an abundance of Lactobacillus and Bifidobacteria. However, this was not reflected in the culturable bacteria obtained from these species. The isolates were characterized for safety parameters, and 20 LAB strains deemed safe were evaluated for resistance to human GIT stresses like acid and bile, adhesion and adhesiveness, and anti-pathogenicity. The five most robust strains, Enterococcus saigonensis NPL780a, Lactobacillus rapi NPL782a, Lactobacillus kunkeei NPL783a, and NPL784, and Lactobacillus paracasei NPL783b, were identified through normalized Pearson (n) principal components analysis (PCA). These strains were checked for inhibition of human pathogens, antibiotic resistance, osmotic tolerance, metabolic and enzymatic functions, and carbohydrate utilization, along with antioxidative and cholesterol-removing potential. The findings suggest at least three strains (NPL 783a, 784 and 782a) as candidates for further in vitro and in vivo investigations of their potential health benefits and application as novel probiotic adjuncts.

Development and in vitro evaluation of novel nutraceutical formulations composed of Limosilactobacillus fermentum, quercetin and/or resveratrol

This study developed and carried out an in vitro evaluation of nutraceutical formulations composed of potentially probiotic Limosilactobacillus fermentum (L. fermentum 139, L. fermentum 263 or L. fermentum 296), quercetin and/or resveratrol. L. fermentum strains had counts of >9 log CFU/g and contents of QUE and RES of >200 µg/mg in formulations after freeze-drying. Formulations with QUE and RES protected L. fermentum during exposure to in vitro acidic stomach conditions. L. fermentum strains had counts of >6 log CFU/g on day 60 and/or 90 of refrigeration storage. Contents of QUE (>29%) and RES (>50%) in formulations were potentially bioaccessible. Higher counts of L. fermentum and higher contents of QUE and RES were found in formulations stored under refrigerated rather than under room temperature. All nutraceutical formulations had antioxidant properties. Combinations of probiotic L. fermentum and QUE and/or RES should be an innovative strategy to develop added-value nutraceutical formulations.