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Breast cancer is associated with high mortality and morbidity rates. As about 20–30% of patients exhibiting ER-positive phenotype are resistant to hormonal treatment with the standard drug tamoxifen, finding new therapies is a necessity. Postbiotics, metabolites, and macromolecules isolated from probiotic bacteria cultures have been proven to have sufficient bioactivity to exert prohealth and anticancer effects, making them viable adjunctive agents for the treatment of various neoplasms, including breast cancer. In the current study, postbiotics derived from L. plantarum and L. rhamnosus cultures were assessed on an in vitro breast cancer model as potential adjunctive agents to therapy utilizing tamoxifen and a candidate aziridine–hydrazide hydrazone derivative drug. Cell viability and cell death processes, including apoptosis, were analyzed for neoplastic MCF-7 cells treated with postbiotics and synthetic compounds. Cell cycle progression and proliferation were analyzed by PI-based flow cytometry and Ki-67 immunostaining. Postbiotics decreased viability and triggered apoptosis in MCF-7, modestly affecting the cell cycle and showing a lack of negative impact on normal cell viability. Moreover, they enhanced the cytotoxic effect of tamoxifen and the new candidate drug toward MCF-7, accelerating apoptosis and the inhibition of proliferation. This illustrates postbiotics' potential as natural adjunctive agents supporting anticancer therapy based on synthetic drugs. [ABSTRACT FROM AUTHOR]

The emergence of antimicrobial resistance remains one of the greatest public health concerns. Biofilm formation has been postulated as a mechanism of microbial pathogens to resist antimicrobial agents. Lactic Acid Bacteria (LAB) and their metabolites have been proposed to combat bacterial biofilms due to their antimicrobial activity. In this vein, the aim of the present study was to investigate the biofilm removal potential of cell-free supernatants (CFSs) of five wild-type Lacticaseibacillus rhamnosus strains, isolated from Greek natural products, in comparison to the commercially available L. rhamnosus GG strain, against biofilms formed by common foodborne pathogens (Salmonella Enteritidis, Salmonella Typhimurium, Escherichia coli, Listeria monocytogenes, and Staphylococcus aureus). The biofilm removal activity of LAB was assessed on a two-day-old mature biofilm using a microtiter plate-based procedure. Both non-neutralized and neutralized CFSs removed biofilms in a concentration-dependent manner. The biofilm removal activity of the non-neutralized CFSs was significantly higher compared to the neutralized CFSs, as expected, with ranges of 60–89% and 30–80%, respectively. The biofilm removal efficiency of L. rhamnosus OLXAL-3 was significantly higher among the wild-type L. rhamnosus strains tested (20–100% v/v). In conclusion, our results suggest the great potential of the application of wild-type L. rhamnosus strain' CFSs as effective natural agents against pathogenic bacterial biofilms. [ABSTRACT FROM AUTHOR]

It has been reported that pineapple (Ananas comosus) contains healthy nutrients and phytochemicals associated with antioxidant and anti-inflammatory capacities. However, a substantial amount of pineapple residue is produced due to a lack of valorization applications at the industrial scale, resulting in the loss of valuable nutrients. Solid-state fermentation (SSF) is proposed as an innovative strategy to enhance the release of bound phenolics from pineapple residues. In this work, the effects of SSF of pineapple peels with Lactobacillus plantarum, Lactobacillus rhamnosus, and Aspergillus oryzae on the release of phenolic compounds and their antioxidant and anti-inflammatory activities were evaluated, respectively. Pineapple peel extracts after SSF showed an increase in the release of phenolic compounds (248.11% with L. plantarum, 182% with A. oryzae, and 180.10% with L. rhamnosus), which led to an increase in the cellular antioxidant (81.94% with L. rhamnosus) and anti-inflammatory potential (nitric oxide inhibition of 62% with L. rhamnosus) compared to non-fermented extracts. Therefore, SSF of pineapple peels with L. plantarum, L. rhamnosus, and A. oryzae thrives as a new approach for the production of secondary metabolites with remarkable biological benefits, which can be the precursors for novel biofortified and nutraceutical-enriched foods that meet the needs of the most demanding and health-conscious consumers. [ABSTRACT FROM AUTHOR]

Breast cancer is associated with high mortality and morbidity rates. As about 20–30% of patients exhibiting ER-positive phenotype are resistant to hormonal treatment with the standard drug tamoxifen, finding new therapies is a necessity. Postbiotics, metabolites, and macromolecules isolated from probiotic bacteria cultures have been proven to have sufficient bioactivity to exert prohealth and anticancer effects, making them viable adjunctive agents for the treatment of various neoplasms, including breast cancer. In the current study, postbiotics derived from L. plantarum and L. rhamnosus cultures were assessed on an in vitro breast cancer model as potential adjunctive agents to therapy utilizing tamoxifen and a candidate aziridine–hydrazide hydrazone derivative drug. Cell viability and cell death processes, including apoptosis, were analyzed for neoplastic MCF-7 cells treated with postbiotics and synthetic compounds. Cell cycle progression and proliferation were analyzed by PI-based flow cytometry and Ki-67 immunostaining. Postbiotics decreased viability and triggered apoptosis in MCF-7, modestly affecting the cell cycle and showing a lack of negative impact on normal cell viability. Moreover, they enhanced the cytotoxic effect of tamoxifen and the new candidate drug toward MCF-7, accelerating apoptosis and the inhibition of proliferation. This illustrates postbiotics’ potential as natural adjunctive agents supporting anticancer therapy based on synthetic drugs.

ABSTRACTFermented foods and beverages are a significant source of dietary bacteria that enter the gastrointestinal (GI) tract. However, little is known about how these microbes survive and adapt to the small intestinal environment. Colony-forming units (CFU) enumeration and viability qPCR of Lacticaseibacillus rhamnosus CNCM I-3690 in the ileal effluent of 10 ileostomy subjects during 12-h post consumption of a dairy product fermented with this strain demonstrated the high level of survival of this strain during human small intestine passage. Metatranscriptome analyses revealed the in situ transcriptome of L. rhamnosus in the small intestine, which was contrasted with transcriptome data obtained from in vitro cultivation. These comparative analyses revealed substantial metabolic adaptations of L. rhamnosus during small intestine transit, including adjustments of carbohydrate metabolism, surface-protein expression, and translation machinery. The prominent presence of L. rhamnosus in the effluent samples did not elicit an appreciable effect on the composition of the endogenous small intestine microbiome, but significantly altered the ecosystem’s overall activity profile, particularly of pathways associated with carbohydrate metabolism. Strikingly, two of the previously recognized gut-brain metabolic modules expressed in situ by L. rhamnosus (inositol degradation and glutamate synthesis II) are among the most dominantly enriched activities in the ecosystem’s activity profile. This study establishes the survival capacity of L. rhamnosus in the human small intestine and highlights its functional adjustment in situ, which we postulate to play a role in the probiotic effects associated with this strain.

Human colostrum (HC) is essential for oral health as it is rich in probiotics that could affect the growth of the cariogenic S. mutans and its biofilm formation; hindering dental caries in advance. In this study, HC was collected from 36 healthy mothers 1–3 days postpartum. The effect of HC on oral health was carried out by assessing the impact of HC and its derived probiotics' cell-free supernatants (CFS) on the growth of S. mutans (using modified well diffusion) and its biofilm formation (using microtiter plate assay). Moreover, the effect of whole HC on L. rhamnosus, a probiotic oral bacterium, was examined. Probiotics were isolated and identified phenotypically by API 50 CH carbohydrate fermentation and genotypically by 16S rRNA amplification. The in vitro study revealed that HC has cariogenic activity and is associated with biofilm formation. Biofilm strength was inversely proportional to HC dilution (p-value < 0.0001). Nevertheless, HC and colostrum-derived probiotics improve oral health by inhibiting the growth of caries-inducing S. mutans with lower inhibition to L. rhamnosus probiotics. The CFS of isolated probiotics reduced the biofilm formation via the cariogenic S. mutans. These results are not only promising for caries eradication, but they also highlight the importance of breastfeeding infants from their first hours to shape healthy oral microbiota, protecting them from various diseases including dental caries. [ABSTRACT FROM AUTHOR]

Milk contaminated with aflatoxin can lead to liver cancer. Aflatoxin B1 (AFB1), a serious animal feed contaminant, is transformed into Aflatoxin M1 (AFM1) and secreted in milk. In this study, a biological method using probiotic bacteria, Lactobacillus rhamnosus (L. rhamnosus) in combination with Saccharomyces cerevisiae (S. cerevisiae), was used to assess their antiaflatoxigenic effect in animal milk. A Box–Behnken design was used to establish the optimal ratio of L. rhamnosus and S. cerevisiae, incubation time, and temperature for efficient AFM1 detoxification from milk. To achieve this, the primary, interaction, and quadratic effects of the chosen factors were investigated. To investigate the quadratic response surfaces, a second-order polynomial model was built using a three-factor, three-level Box–Behnken design. The quantity of AFM1 was detected by the ELISA technique. The results of these experiments obtained an optimum condition in AFM1 detoxification of the three tested factors in order to maximize their effect on AFM1 detoxification in milk. The model was tested in three highly contaminated milk samples to assure the efficacy of the model. AFM1 detoxification was up to 98.4% in contaminated milk samples. These promising results provide a safe, low-cost, and low-time-consuming solution to get rid of the problem of milk contamination with AFM1. [ABSTRACT FROM AUTHOR]

Xylooligosaccharides (XOS) are emerging prebiotic that may improve the viability of probiotics and gastrointestinal health. XOS derived from corncob was evaluated for its prebiotic activity with three different probiotic strains. The present study focused on XOS to encapsulate Lactobacillus rhamnosus (LGG) and explore it's in vitro survival & stability upon storage through structural interactive optimization of encapsulation materials. L. rhamnosus (LGG) showed the highest viability 9.86 ± 0.04 log CFU/mL upon XOS. Among three different carrier types namely, Sodium alginate (SA), Chitosan & Sodium tripolyphosphate (STPP), Whey protein liquid - maltodextrin complex, the SA showed the highest encapsulation efficiency 87.6 ± 0.1%, yield and cost effectiveness. XOS and SA were used for encapsulation of LGG with different formulations. The stability of free and encapsulated LGG was assessed using gastrointestinal conditions. All the treatments provided better encapsulation efficiency > 80 %. M2 formulation showed the highest encapsulation efficiency 92 ± 1%, maximum viability in simulated gastric juice 8.7 ± 0.1 log CFU/mL and bile solution 8.6 ± 0.2 log CFU/mL, resulting significantly (p < 0.05) improved survival when compared with free bacteria. The microcapsules were then incorporated into yoghurt and the results showed that there was an increased survival of probiotics because of the protection of cells by microencapsulation and the promoting effect of XOS on the probiotics growth. The XOS extracted from corncob was successfully incorporated as a prebiotic encapsulation material for effective delivery of L. rhamnosus LGG. The different combinations of wall materials with XOS provided an opportunity to produce beads with better structure and protection. [ABSTRACT FROM AUTHOR]

This research aimed to evaluate goat milk rich in Omega-3 PUFA from animals fed extruded flaxseed as a raw material to produce fermented milk using beneficial lactobacilli. Experimental fermented milks were produced using Lacticaseibacillus paracasei Shirota and two potential probiotic lactobacilli, namely Lacticaseibacillus rhamnosus A2 and Lacticaseibacillus paracasei FS109. The fermented milks were produced using milk from goats fed a basal diet without any supplementation (CON) and milk from goats supplemented with 200 g/d of extruded linseed (LIN). All lactobacilli tested grew well both in CON and LIN milk, reaching high numbers during fermentation. The colony count ranged between 8 and 10 Log CFU/mL, despite slow acidification activity, which occurred especially in milk fermented by L. FS109. By contrast, an undesired post-acidification occurred, more pronounced in CON than in LIN milk, which still highlighted the strong acid-tolerance of L. Shirota and L. rhamnosus A2 in particular. This research showed that goat milk enriched in PUFA had no negative effect on the viability of the tested Lactobacilli. Both values of L. Shirota and L. rhamnosus "live cells" throughout the cold storage of the products were higher than those recommended to guarantee the quality of fermented milk products, making them beneficial to consumers' health. [ABSTRACT FROM AUTHOR]

Lactic acid bacteria (LAB) play a very important role as natural bio-preservatives in foods. Accordingly, the inhibitory effect of Lactobacillus rhamnosus (L. rhamnosus) on 4 fungi species of Yarrowia, Penicillium expansum (P. expansum), Saccharomyces cerevisiae (S. cerevisiae), Aspergillus niger (A. niger), Kluyveromyces lactis (K. lactis) was investigated. Then P. expansum was selected as the most important contaminant mould in yoghurt to study the use of L. rhamnosus to reduce selective spoilage of P. expansum in yoghurt. Also, the effect of this bioprotective culture on the count of starter bacteria and some characteristics of yoghurt was determined. L. rhamnosus (106 cfu /mL) was inoculated into the milk along with yoghurt starter bacteria, so that four samples were produced T0 (L. rhamnosus = 0, P. expansum = 0), T1 (L. rhamnosus = 106 cfu/mL, P. expansum = 0), T2 (L. rhamnosus = 0, P. expansum = 105cfu/mL); T3 (L. rhamnosus = 106 cfu/mL, P. expansum = 105cfu/mL). All samples were analysed for pH, acidity, viscosity, syneresis, microbial (survival of Streptococcus thermophilus and Lactobacillus bulgaricus and P. expansum) and overall acceptability. L. rhamnosus had an inhibitory effect on the survival of P. expansum (p

A growing number of people choose plant-based milk products to replace dairy for health reasons or veganism. Since fermentation is a promising method to improve the nutritional value of plant-based milk, this study aimed to establish the process of oat milk fermentation and to evaluate the effect of fermented oat milk (FOM) on modulating antigen-specific immune response in ovalbumin (OVA)-sensitized mice. The FOM was prepared by fermentation of oat milk with Streptococcus thermophilus, Lactobacillus bulgaricus and proteolytic L. rhamnosus. Addition of 1% glucose improved the process of fermentation. FOM was stable while stored at 4°C within seven days. Oral administration with FOM (0.4 and 2 g/kg body weight) did not alter the serum level of OVA-specific IgG and spleen index. However, FOM had comparable potency with commercial dairy yogurt to lower stimulation index, IL-2, IFN-γ and IL-4 production and to promote TGF-β and IL-10 secretion by OVA-stimulated splenocytes.

Fish is considered the main source of protein in Egypt, especially due to the shortage of red meat. In this study, one hundred random samples of Nile fish represented by Clarias lazera (C. lazera) and Oreochromis niloticus (O. niloticus) (25 of each fish species) and marine fish represented by Sardina pilchardus (S. pilchardus) and Mullus barbatus (M. barbatus) (25 of each fish species) were collected at different periods of time from various fish markets in Shibin Elkom city, Egypt. The samples had been analyzed using an atomic absorption spectrophotometer for the detection of mercury (Hg), lead (Pb), cadmium (Cd), and arsenic (As). In addition to Lactobacillus rhamnosus (L. rhamnosus ) used in decontamination of artificially inoculated fish fillet with different heavy metals. The mean values of Hg were 1.44 ± 0.03 of 1.13 ± 0.01, 0.81± 0.02 and 0.59± 0.01 mg/kg in C. lazera, O. niloticus, S. pilchardus and M. barbatus, respectively. Also, for Pb values were 0.78 ± 0.01, 0.61 ± 0.01, 0.39 ± 0.02 and 0.08 to 0.53 mg /kg C. lazera, O. niloticus, S. pilchardus and M.barbatus, respectively. The mean values of Cd were 0.43± 0.01, 0.26± 0.01, 0.04 to 0.49 and 0.05± 0.01mg/ kg in examined C. lazera, O. niloticus, S. pilchardus and M.barbatus, respectively. Meanwhile, as residues were 0.29± 0.01 and 0.16 ± 0.01 mg/kg in C. lazera and O. niloticus only. The L. Rhamnosus can reduce Hg, Pb, Cd and as experimentally inoculated to fish fillets with percentages 67.7%, 76.3%, 75% and 59%, respectively. [ABSTRACT FROM AUTHOR]

The emergence of antimicrobial resistance remains one of the greatest public health concerns. Biofilm formation has been postulated as a mechanism of microbial pathogens to resist antimicrobial agents. Lactic Acid Bacteria (LAB) and their metabolites have been proposed to combat bacterial biofilms due to their antimicrobial activity. In this vein, the aim of the present study was to investigate the biofilm removal potential of cell-free supernatants (CFSs) of five wild-type Lacticaseibacillus rhamnosus strains, isolated from Greek natural products, in comparison to the commercially available L. rhamnosus GG strain, against biofilms formed by common foodborne pathogens (Salmonella Enteritidis, Salmonella Typhimurium, Escherichia coli, Listeria monocytogenes, and Staphylococcus aureus). The biofilm removal activity of LAB was assessed on a two-day-old mature biofilm using a microtiter plate-based procedure. Both non-neutralized and neutralized CFSs removed biofilms in a concentration-dependent manner. The biofilm removal activity of the non-neutralized CFSs was significantly higher compared to the neutralized CFSs, as expected, with ranges of 60–89% and 30–80%, respectively. The biofilm removal efficiency of L. rhamnosus OLXAL-3 was significantly higher among the wild-type L. rhamnosus strains tested (20–100% v/v). In conclusion, our results suggest the great potential of the application of wild-type L. rhamnosus strain’ CFSs as effective natural agents against pathogenic bacterial biofilms.

It has been reported that pineapple (Ananas comosus) contains healthy nutrients and phytochemicals associated with antioxidant and anti-inflammatory capacities. However, a substantial amount of pineapple residue is produced due to a lack of valorization applications at the industrial scale, resulting in the loss of valuable nutrients. Solid-state fermentation (SSF) is proposed as an innovative strategy to enhance the release of bound phenolics from pineapple residues. In this work, the effects of SSF of pineapple peels with Lactobacillus plantarum, Lactobacillus rhamnosus, and Aspergillus oryzae on the release of phenolic compounds and their antioxidant and anti-inflammatory activities were evaluated, respectively. Pineapple peel extracts after SSF showed an increase in the release of phenolic compounds (248.11% with L. plantarum, 182% with A. oryzae, and 180.10% with L. rhamnosus), which led to an increase in the cellular antioxidant (81.94% with L. rhamnosus) and anti-inflammatory potential (nitric oxide inhibition of 62% with L. rhamnosus) compared to non-fermented extracts. Therefore, SSF of pineapple peels with L. plantarum, L. rhamnosus, and A. oryzae thrives as a new approach for the production of secondary metabolites with remarkable biological benefits, which can be the precursors for novel biofortified and nutraceutical-enriched foods that meet the needs of the most demanding and health-conscious consumers.

Lactic acid bacteria (LAB) play a very important role as natural bio-preservatives in foods. Accordingly, the inhibitory effect of Lactobacillus rhamnosus (L. rhamnosus) on 4 fungi species of Yarrowia, Penicillium expansum (P. expansum), Saccharomyces cerevisiae (S. cerevisiae), Aspergillus niger (A. niger), Kluyveromyces lactis (K. lactis) was investigated. Then P. expansum was selected as the most important contaminant mould in yoghurt to study the use of L. rhamnosus to reduce selective spoilage of P. expansum in yoghurt. Also, the effect of this bioprotective culture on the count of starter bacteria and some characteristics of yoghurt was determined. L. rhamnosus (106 cfu /mL) was inoculated into the milk along with yoghurt starter bacteria, so that four samples were produced T0 (L. rhamnosus = 0, P. expansum = 0), T1 (L. rhamnosus = 106 cfu/mL, P. expansum = 0), T2 (L. rhamnosus = 0, P. expansum = 105 cfu/mL); T3 (L. rhamnosus = 106 cfu/mL, P. expansum = 105 cfu/mL). All samples were analysed for pH, acidity, viscosity, syneresis, microbial (survival of Streptococcus thermophilus and Lactobacillus bulgaricus and P. expansum) and overall acceptability. L. rhamnosus had an inhibitory effect on the survival of P. expansum (p<0.05) but was not able to completely control it. L. rhamnosus in T3 sample had an inhibitory effect from the first day to the end of storage. Furthermore, during the storage, the survival of yoghurt starter bacteria in probiotic yoghurt samples was higher than the control (p<0.05). T3 had lower pH, viscosity and overall acceptability score compared to the control and its syneresis was higher (p<0.05). In general, the addition of 106 cfu/mL of L. rhamnosus did not have a complete inhibitory effect on P. expansum (105 CFU/mL) until the end of storage time. [ABSTRACT FROM AUTHOR]

A growing number of people choose plant-based milk products to replace dairy for health reasons or veganism. Since fermentation is a promising method to improve the nutritional value of plant-based milk, this study aimed to establish the process of oat milk fermentation and to evaluate the effect of fermented oat milk (FOM) on modulating antigen-specific immune response in ovalbumin (OVA)-sensitized mice. The FOM was prepared by fermentation of oat milk with Streptococcus thermophilus, Lactobacillus bulgaricus and proteolytic L. rhamnosus. Addition of 1% glucose improved the process of fermentation. FOM was stable while stored at 4°C within seven days. Oral administration with FOM (0.4 and 2 g/kg body weight) did not alter the serum level of OVA-specific IgG and spleen index. However, FOM had comparable potency with commercial dairy yogurt to lower stimulation index, IL-2, IFN-γ and IL-4 production and to promote TGF-β and IL-10 secretion by OVA-stimulated splenocytes. [ABSTRACT FROM AUTHOR]

Human colostrum (HC) is essential for oral health as it is rich in probiotics that could affect the growth of the cariogenic S. mutans and its biofilm formation; hindering dental caries in advance. In this study, HC was collected from 36 healthy mothers 1–3 days postpartum. The effect of HC on oral health was carried out by assessing the impact of HC and its derived probiotics’ cell-free supernatants (CFS) on the growth of S. mutans (using modified well diffusion) and its biofilm formation (using microtiter plate assay). Moreover, the effect of whole HC on L. rhamnosus, a probiotic oral bacterium, was examined. Probiotics were isolated and identified phenotypically by API 50 CH carbohydrate fermentation and genotypically by 16S rRNA amplification. The in vitro study revealed that HC has cariogenic activity and is associated with biofilm formation. Biofilm strength was inversely proportional to HC dilution (p-value < 0.0001). Nevertheless, HC and colostrum-derived probiotics improve oral health by inhibiting the growth of caries-inducing S. mutans with lower inhibition to L. rhamnosus probiotics. The CFS of isolated probiotics reduced the biofilm formation via the cariogenic S. mutans. These results are not only promising for caries eradication, but they also highlight the importance of breastfeeding infants from their first hours to shape healthy oral microbiota, protecting them from various diseases including dental caries.

Foodborne pathogens and their biofilms pose a risk to human health through food chain. However, the bacteriocin resources combating this threat are still limited. Here, Lacticaseibacillus rhamnosus, one of the most used probiotics in food industry, was prepared on a large scale using alternating tangential flow (ATF) perfusion-based technology. Compared to the conventional fed-batch approach, ATF perfusion remarkably increased the viable cells of L. rhamnosus CLK 101 to 11.93 ± 0.14 log CFU/mL. Based on obtained viable cells, we purified and characterized a novel bacteriocin CLK_01 with a broad spectrum of activity against both Gram-positive and Gram-negative foodborne pathogens. LC-MS/MS analysis revealed that CLK_01 has a molecular mass of 701.49 Da and a hydrophobic amino acid composition of I–K–K–V-T-I. As a novel bacteriocin, CLK_01 showed high thermal stability and acid-base tolerance over 25–121 °C and pH 2–10. It significantly reduced cell viability of bacterial pathogens (p

Influenza is an important zoonotic disease that persistently threatens global public health. While it is widely acknowledged that probiotics can modulate the host response to protect the host against infectious disease, the prophylactic efficacy on respiratory viral infection and the detailed mechanism remains elusive. Lactobacillus , the most commonly used probiotic widely applied in food production, has garnered significant attention. In our study utilizing both C57BL/6 and BALB/c mouse models, we explored the protective effect against two strains of influenza virus, A/Mink/China/01/2014(H9N2) and A/California/04/2009(H1N1), through the administration of Lactiplantibacillus plantarum strain 16 ( L. plantarum 16) and Lacticaseibacillus rhamnosus strain P118 ( L. rhamnosus P118), aiming to identify robust probiotic strains with antiviral properties. Our findings indicate that administering L. plantarum 16 or L. rhamnosus P118 alone does not provide sufficient protection against influenza. However, the co-administration of L. plantarum 16 and L. rhamnosus P118 dramatically reduces viral titers in the respiratory tract and lung, thereby markedly alleviating the clinical symptoms, improving prognosis, and reducing mortality. The mechanisms underlying this effect involve the modulation of host gut microbiota and metabolism through the co-administration of L. plantarum 16 and L. rhamnosus P118, resulting in enrichment of Firmicutes and enhancement of phenylalanine-related metabolism, ultimately leading to an augmentation of the antiviral immune response. Notably, we identified that the circulating metabolic molecule 2-Hydroxycinnamic acid plays a significant role in combating influenza. Our data suggest the potential utility of L. plantarum 16 and L. rhamnosus P118 two-bacterium or 2-Hydroxycinnamic acid in preventing influenza.IMPORTANCEVaccination represents the most optimal strategy to control influenza. Nevertheless, influenza viruses constantly evolve due to antigenic drift and shift, leading to the need for regular updates on influenza vaccines. Additionally, vaccination failure poses significant challenges to influenza prevention. Therefore, it is essential and beneficial to identify novel or universal antiviral measures to protect against influenza. While cumulative data suggest that probiotics offer protection against infectious diseases, the specific mechanisms, such as the effective metabolites or components, remain largely unknown. Our research discovered the capacity of combinational two-bacterium Lactiplantibacillus plantarum 16 and Lacticaseibacillus rhamnosus P118 to fight against influenza infection in a mouse model. The protection may occur through modulating the host's gut microbiota and metabolism, further influencing the host's antiviral immune response. Notably, we have identified a novel metabolic molecule, 2-Hydroxycinnamic acid, capable of enhancing antiviral response and restricting viral replication in vivo ., Competing Interests: The authors declare no conflict of interest.

Milk contaminated with aflatoxin can lead to liver cancer. Aflatoxin B1 (AFB1), a serious animal feed contaminant, is transformed into Aflatoxin M1 (AFM1) and secreted in milk. In this study, a biological method using probiotic bacteria, Lactobacillus rhamnosus (L. rhamnosus) in combination with Saccharomyces cerevisiae (S. cerevisiae), was used to assess their antiaflatoxigenic effect in animal milk. A Box–Behnken design was used to establish the optimal ratio of L. rhamnosus and S. cerevisiae, incubation time, and temperature for efficient AFM1 detoxification from milk. To achieve this, the primary, interaction, and quadratic effects of the chosen factors were investigated. To investigate the quadratic response surfaces, a second-order polynomial model was built using a three-factor, three-level Box–Behnken design. The quantity of AFM1 was detected by the ELISA technique. The results of these experiments obtained an optimum condition in AFM1 detoxification of the three tested factors in order to maximize their effect on AFM1 detoxification in milk. The model was tested in three highly contaminated milk samples to assure the efficacy of the model. AFM1 detoxification was up to 98.4% in contaminated milk samples. These promising results provide a safe, low-cost, and low-time-consuming solution to get rid of the problem of milk contamination with AFM1.

This research aimed to evaluate goat milk rich in Omega-3 PUFA from animals fed extruded flaxseed as a raw material to produce fermented milk using beneficial lactobacilli. Experimental fermented milks were produced using Lacticaseibacillus paracasei Shirota and two potential probiotic lactobacilli, namely Lacticaseibacillus rhamnosus A2 and Lacticaseibacillus paracasei FS109. The fermented milks were produced using milk from goats fed a basal diet without any supplementation (CON) and milk from goats supplemented with 200 g/d of extruded linseed (LIN). All lactobacilli tested grew well both in CON and LIN milk, reaching high numbers during fermentation. The colony count ranged between 8 and 10 Log CFU/mL, despite slow acidification activity, which occurred especially in milk fermented by L. FS109. By contrast, an undesired post-acidification occurred, more pronounced in CON than in LIN milk, which still highlighted the strong acid-tolerance of L. Shirota and L. rhamnosus A2 in particular. This research showed that goat milk enriched in PUFA had no negative effect on the viability of the tested Lactobacilli. Both values of L. Shirota and L. rhamnosus “live cells” throughout the cold storage of the products were higher than those recommended to guarantee the quality of fermented milk products, making them beneficial to consumers’ health.

During fermentation and food processing, Lacticaseibacillus rhamnosus ATCC 53103 can encounter many adverse conditions, and acid stress is one of them. The purpose of the present study was to investigate the influence of acid stress on the global translational and transcriptional regulation of Lacticaseibacillus rhamnosus ATCC 53103. Two pH values (pH 6.0 vs. pH 5.0) were applied, the effects of which were studied via ribosome profiling and RNA sequencing assay. Under acid stress, many genes showed differential changes at the translational and transcriptional levels. A total of 10 genes showed different expression trends at the two levels. The expression of 337 genes—which mainly participated in the ABC transporters, amino acid metabolism, and ribosome functional group assembly pathways—was shown to be regulated only at the translational level. The translational efficiency of a few genes participating in the pyrimidine and amino acid metabolism pathways were upregulated. Ribosome occupancy data suggested that ribosomes accumulated remarkably in the elongation region of open reading frame regions under acid stress. This study provides new insights into Lacticaseibacillus rhamnosus ATCC 53103 gene expression under acid stress, and demonstrates that the bacterium can respond to acid stress with synergistic translational and transcriptional regulation mechanisms, improving the vitality of cells. [ABSTRACT FROM AUTHOR]

To determine whether osmotic pressure affects the translation efficiency of Lactobacillus rhamnosus , the ribosome profiling assay was performed to analyze the changes in translation efficiency in L. rhamnosus ATCC 53103. Under osmotic stress, differentially expressed genes (DEGs) involved in fatty acid biosynthesis and metabolism, ribosome, and purine metabolism pathways were co-regulated with consistent expression direction at translation and transcription levels. DEGs involved in the biosynthesis of phenylalanine, tyrosine, and tryptophan, and the phosphotransferase system pathways also were co-regulated at translation and transcription levels, while they showed opposite expression direction at two levels. Moreover, DEGs involved in the two-component system, amino acid metabolism, and pyruvate metabolism pathways were only regulated at the transcription level. And DEGs involved in fructose and mannose metabolism were only regulated at the translation level. The translation efficiency of DEGs involved in the biosynthesis of amino acids was downregulated while in quorum sensing and PTS pathways was upregulated. In addition, the ribosome footprints accumulated in open reading frame regions resulted in impaired translation initiation and elongation under osmotic stress. In summary, L. rhamnosus ATCC 53103 could respond to osmotic stress by translation regulation and control the balance between survival and growth of cells by transcription and translation. [ABSTRACT FROM AUTHOR]

To determine whether osmotic pressure affects the translation efficiency of Lactobacillus rhamnosus, the ribosome profiling assay was performed to analyze the changes in translation efficiency in L. rhamnosus ATCC 53103. Under osmotic stress, differentially expressed genes (DEGs) involved in fatty acid biosynthesis and metabolism, ribosome, and purine metabolism pathways were co-regulated with consistent expression direction at translation and transcription levels. DEGs involved in the biosynthesis of phenylalanine, tyrosine, and tryptophan, and the phosphotransferase system pathways also were co-regulated at translation and transcription levels, while they showed opposite expression direction at two levels. Moreover, DEGs involved in the two-component system, amino acid metabolism, and pyruvate metabolism pathways were only regulated at the transcription level. And DEGs involved in fructose and mannose metabolism were only regulated at the translation level. The translation efficiency of DEGs involved in the biosynthesis of amino acids was downregulated while in quorum sensing and PTS pathways was upregulated. In addition, the ribosome footprints accumulated in open reading frame regions resulted in impaired translation initiation and elongation under osmotic stress. In summary, L. rhamnosus ATCC 53103 could respond to osmotic stress by translation regulation and control the balance between survival and growth of cells by transcription and translation.

The present work aimed at characterizing in vitro the lactic acid bacteria Fructobacillus fructosus SS66, Lactococcus garvieae SS79, Fructobacillus fructosus SS72, Lactobacillus kunkeei SS70, Lactobacillus rhamnosus SS73, isolated from the digestive tract of bees Apis mellifera. Their probiotic capacity was evaluated by enzymatic tests, growth stability at different temperatures (37 and 45°C) at a range of pH (3.5; 4.5; 5.5; 5.5; 6.5), tolerance to artificial gastric juice (AGJ), bile salts (0.3, 05 and 1 %), and adhesion tests such as aggregation, self-aggregation and hydrophobicity and microbial antagonism. The results showed that all strains grew at 37°C at acidic pH 6.5 and 5.5 and did not grow at pH 4.5; they produced hydrogen peroxide and did not reveal hemolytic activity. The strains tolerated AGJ pH 3 for 3 h at 37 °C and bile salts up to 1%. No strain showed self-aggregation and only two (L. rhamnosus SS73 and L. kunkeei SS70) produced coaggregation against Escherichia coli. Hydrophobicity was variable among the strains, F. fructosus SS72 exhibiting a high value, L. rhamnosus SS73 and L. kunkeei SS70 a medium value and L. garvieae SS79 and F. fructosus SS66 a low one. All strains showed a broad spectrum of antimicrobial activity and inhibitory effect against Paenibacillus larvae and other human and animal pathogens. The best-performing strains were L. kunkeei SS70 and L. rhamnosus SS73, which were susceptible to the antimicrobial agents used, with the exception of Sulfonamide and Vancomycin. From these results, they can be incorporated into a probiotic inoculum to evaluate their effect in vivo. [ABSTRACT FROM AUTHOR]

During fermentation and food processing, Lacticaseibacillus rhamnosus ATCC 53103 can encounter many adverse conditions, and acid stress is one of them. The purpose of the present study was to investigate the influence of acid stress on the global translational and transcriptional regulation of Lacticaseibacillus rhamnosus ATCC 53103. Two pH values (pH 6.0 vs. pH 5.0) were applied, the effects of which were studied via ribosome profiling and RNA sequencing assay. Under acid stress, many genes showed differential changes at the translational and transcriptional levels. A total of 10 genes showed different expression trends at the two levels. The expression of 337 genes—which mainly participated in the ABC transporters, amino acid metabolism, and ribosome functional group assembly pathways—was shown to be regulated only at the translational level. The translational efficiency of a few genes participating in the pyrimidine and amino acid metabolism pathways were upregulated. Ribosome occupancy data suggested that ribosomes accumulated remarkably in the elongation region of open reading frame regions under acid stress. This study provides new insights into Lacticaseibacillus rhamnosus ATCC 53103 gene expression under acid stress, and demonstrates that the bacterium can respond to acid stress with synergistic translational and transcriptional regulation mechanisms, improving the vitality of cells.

Background: Infantile colic is a disturbing problem for parents. The Rome IV criteria are the last modality for the diagnosis of colic. Available medications have variable effects on the treatment of colic. However, no definite treatment has been identified yet. Aims: To our knowledge, few clinical trials have compared the efficacy of synbiotics in infantile colic, so the present study was conducted. Material and methods: This study was performed on 120 infants (51.66% boys; mean age: 42.09 ± 21.14 days; mean birth weight: 3,155 ± 420 g) with the diagnosis of infantile colic resistant to conservative therapy. The infants were randomly divided into groups A and B. A synbiotic containing B. infantis, L. reuteri, L. rhamnosus, and fructooligosaccharides (FOS) (PediLact® [Zist-Takhmir Co., Tehran, Iran] drop) was administered to group A, while group B received a synbiotic containing B. lactis and FOS (BBCare® [Zist-Takhmir Co., Tehran, Iran] drop). The primary outcome was the response rate to each synbiotic, and the secondary outcome was the complications of each synbiotic. Results: The response rate to both synbiotics was significant after 1 week of intervention (1.97 ± 0.91 [44.95%] versus 1.64 ± 0.77 [54.23%], p = 0.000). Both groups showed a significant response rate to each synbiotic after 1 month of intervention too (1.19 ± 0.84 [63.48%] versus 0.70 ± 0.48 [79.65%], p = 0.000). The response rate was significantly higher in group B compared to group A after 1 week (54.23% versus 44.95%) and after 1 month (79.65% versus 63.48%) of intervention. Neither synbiotic was associated with adverse effects. Conclusion: The present study showed that both synbiotics were effective in the treatment of infantile colic. However, the synbiotic containing B. lactis was significantly more effective than the synbiotic containing B. infantis, L. reuteri, and L. rhamnosus in infantile colic.

In the current study, Lactobacillus rhamnosus (KCC-51) and Lactobacillus paracasei (KCC-52) were isolated and investigated for their biological potential including antibacterial activity, probiotic potential, nutritional changes, fermentation ability, and microbial population in experimental silages at high moisture (HM) and low moisture (LM) conditions. These strains showed significant antibacterial activity and probiotic activities. There are no significant changes in the dry matter content (DM) and nutritional profiles of control, KCC-51, and KCC-52 treated silages. High lactic acid (LA) and low butyric acid (BA) levels were noted in the HM (LA: 4.82 ± 0.34 and 5.5 ± 0.03, BA: 0.01 ± 0.01 and 0.008 ± 0.001, %DM) and LM (LA: 2.27 ± 0.32 and 2.61 ± 0.2, BA: 0.017 ± 0.001 vs. 0.006 ± 0.05, %DM) silages treated with KCC-51 and KCC-52 respectively, compared to non-inoculated silages. KCC-51 and KCC-52 treatment increased acceptable range of acetic acid (AA) in HM (0.33 ± 0.02 and 0.24 ± 0.007, %DM) and LM (0.22 ± 0.007 and 0.35 ± 0.02, %DM) silages compared to non-inoculated silages (0.22 ± 0.03 and 0.17 ± 0.05, %DM). Rich LAB and low yeast counts were noted in the silages treated with KCC-51 and KCC-52, it indicated that the addition of these inoculants strongly dominated the enterobacterial growth and preserved the silage quality with essential metabolites. It suggests that L. rhamnosus and the L. paracasei could be used as potent inoculants for the silage production with enriched nutrients. [ABSTRACT FROM AUTHOR]

Many studies suggest that probiotic, prebiotic and symbiotic foods may be beneficial in the prevention and management of nutrition and health, the objective of this work was to develop a symbiotic drink based on coconut water. Fermentation was performed using lyophilized Lactobacillus rhamnosus SP1 and inulin as a source of soluble fiber. Different formulations were developed, determining the concentrations of fiber and probiotics. The growth of the probiotic in MRS broth was evaluated, using the plate counting technique in different periods of time. The fermentation time of the drink was 8 h and the shelf life in refrigeration was 14 days evaluated by pH and hedonic scale. The pH of the final drink was 3.48 and the probiotic content was 82 × 10 8 CFU/ml. It is concluded that coconut water can be processed by adding probiotic and prebiotic characteristics with sensory acceptance and adequate preservation characteristics.

To overcome texture and flavor challenges in fermented plant-based product development, the potential of microorganisms is generating great interest in the food industry. This study examines the effect of Lactobacillus rhamnosus on physicochemical properties of fermented soy, oat, and coconut. L. rhamnosus was combined with different lactic acid bacteria strains and Bifidobacterium. Acidification, titratable acidity, and viability of L. rhamnosus and Bifidobacterium were evaluated. Oscillation and flow tests were performed to characterize rheological properties of fermented samples. Targeted and untargeted volatile organic compounds in fermented samples were assessed, and sensory evaluation with a trained panel was conducted. L. rhamnosus reduced fermentation time in soy, oat, and coconut. L. rhamnosus and Bifidobacterium grew in all fermented raw materials above 107 CFU/g. No significant effect on rheological behavior was observed when L. rhamnosus was present in fermented samples. Acetoin levels increased and acetaldehyde content decreased in the presence of L. rhamnosus in all three bases. Diacetyl levels increased in fermented oat and coconut samples when L. rhamnosus was combined with a starter culture containing Streptococcus thermophilus and with another starter culture containing S. thermophilus, L. bulgaricus and Bifidobacterium. In all fermented oat samples, L. rhamnosus significantly enhanced fermented flavor notes, such as sourness, lemon, and fruity taste, which in turn led to reduced perception of base-related attributes. In fermented coconut samples, gel firmness perception was significantly improved with L. rhamnosus. The findings suggest that L. rhamnosus can improve fermentation time and sensory perception of fermented plant-based products.

Lactobacillus strains dominate the vaginal habitat and they are associated with a lower risk of genital infections. In addition, they contribute to the conservation of the vaginal microbiota by producing postbiotic agents. Previous studies have shown that their predominance involves antimicrobial activity against urogenital pathologies. In this context, probiotics may improve treatment outcomes. The aim of this study was to evaluate the probiotic properties of lactobacilli strains of vaginal origin using a multidisciplinary approach. For this purpose, safety criteria, ability to resist at low pH and bile salts, antimicrobial activity, ability to produce biofilm, capacity to produce hydrogen peroxide and more importantly, auto-aggregation, co-aggregation (with Candida spp.) and adhesion to human cells were evaluated. The strains belonged to the species of L. crispatus, L. gasseri, L. rhamnosus and L. delbruckii. Among these, a strain of L. rhamnosus named AD3 showed the best probiotic properties. As probiotics are already in use in many clinical practice and there are no major safety concerns, L. rhamnosus AD3 showed promise in becoming a prevention and complementary treatment option for urogenital diseases. Indeed, these results suggest that strain L. rhamnosus AD3 is non-pathogenic and likely to be safe for human consumption. This study revealed the great amensalistic properties of a new L. rhamnosus strain which can aim to be used as probiotic in pharmaceutical applications.

In the current study, Lactobacillus rhamnosus (KCC-51) and Lactobacillus paracasei (KCC-52) were isolated and investigated for their biological potential including antibacterial activity, probiotic potential, nutritional changes, fermentation ability, and microbial population in experimental silages at high moisture (HM) and low moisture (LM) conditions. These strains showed significant antibacterial activity and probiotic activities. There are no significant changes in the dry matter content (DM) and nutritional profiles of control, KCC-51, and KCC-52 treated silages. High lactic acid (LA) and low butyric acid (BA) levels were noted in the HM (LA: 4.82 ± 0.34 and 5.5 ± 0.03, BA: 0.01 ± 0.01 and 0.008 ± 0.001, %DM) and LM (LA: 2.27 ± 0.32 and 2.61 ± 0.2, BA: 0.017 ± 0.001 vs. 0.006 ± 0.05, %DM) silages treated with KCC-51 and KCC-52 respectively, compared to non-inoculated silages. KCC-51 and KCC-52 treatment increased acceptable range of acetic acid (AA) in HM (0.33 ± 0.02 and 0.24 ± 0.007, %DM) and LM (0.22 ± 0.007 and 0.35 ± 0.02, %DM) silages compared to non-inoculated silages (0.22 ± 0.03 and 0.17 ± 0.05, %DM). Rich LAB and low yeast counts were noted in the silages treated with KCC-51 and KCC-52, it indicated that the addition of these inoculants strongly dominated the enterobacterial growth and preserved the silage quality with essential metabolites. It suggests that L. rhamnosus and the L. paracasei could be used as potent inoculants for the silage production with enriched nutrients.

Texture and flavor are currently the main challenges in the development of plant-based dairy alternatives. To overcome them, the potential of microorganisms for fermentation of plant-based raw materials is generating great interest in the food industry. This study examines the effect of Lactobacillus rhamnosus, LGG® (LGG® is a trademark of Chr. Hansen A/S) on the physicochemical properties of fermented soy, oat, and coconut. LGG® was combined with different lactic acid bacteria (LAB) strains and Bifidobacterium, BB-12® (BB-12® is a trademark of Chr. Hansen A/S). Acidification, titratable acidity, and growth of LGG® and BB-12® were evaluated. Oscillation and flow tests were performed to analyze the rheological properties of fermented samples. Acids, carbohydrates, and volatile organic compounds in fermented samples were identified, and a sensory evaluation with a trained panel was conducted. LGG® reduced fermentation time in all three bases. LGG® and BB-12® grew in all fermented raw materials above 107 CFU/g. LGG® had no significant effect on rheological behavior of the samples. Acetoin levels increased and acetaldehyde content decreased in the presence of LGG® in all three bases. Diacetyl levels increased in fermented oat and coconut samples when LGG® was combined with YOFLEX® YF-L01 and NU-TRISH® BY-01 (YOFLEX® and NU-TRISH® are trademarks of Chr. Hansen A/S). In all fermented oat samples, LGG® significantly enhanced fermented flavor notes, such as sourness, lemon, and fruity taste, which in turn led to reduced perception of the attributes related to the base. In fermented coconut samples, gel firmness perception was significantly improved in the presence of LGG®. These findings suggest supplementation of LAB cultures with LGG® to improve fermentation time and sensory perception of fermented plant-based products.

The genus Lactobacillus includes, among others, Lactobacillus casei, Lactobacillus paracasei and Lactobacillus rhamnosus, species that are collectively referred to as the Lactobacillus casei group. Many studies have shown that strains belonging to this group may decrease lactose intolerance, the effects of inflammatory bowel disease, diarrhea, constipation, food allergies and even colon cancer. Moreover, evidences exists of positive effects of these bacteria on mucosal immunity and blood cholesterol level. Because of their beneficial influence on human health, many of them are used as food additives and probiotic pharmaceuticals. It should be stressed that health-promoting properties are not attributed at the species level, but to specific strains. Therefore, procedures are necessary to allow specific identification at each phylogenetic level—genus, species and strain. In this paper we present a practical overview of molecular methods for the identification and differentiation of L. casei bacteria. The research included 30 bacterial strains belonging to three species: L.casei, L. paracasei and L. rhamnosus. Among the tested procedures were genus- and species-specific PCR, multiplex-PCR, Real-Time HRM analysis, RFLP-PCR, rep-PCR, RAPD-PCR, AFLP-PCR, and proteomic methods such as MALDI-TOF MS typing and SDS-PAGE fingerprinting. The obtained results showed that multiplex-PCR and MALDI-TOF MS turned out to be the most useful methods to identify the tested bacteria at the species level. At the strain level, the AFLP-PCR method showed the highest discriminatory power. We hope that the presented results will allow for the easy selection of an appropriate procedure, depending on the experiment conducted and the equipment capabilities of any given laboratory.

Bacterial diversity of 15 extra virgin olive oils, obtained from different Italian varieties, including Frantoio, Coratina, Bosana, and Semidana, was analyzed in this study. All bacterial isolates were genotyped using RAPD and REP-PCR method and grouped by means of cluster analyses. Sequencing of 16S rDNA of 51 isolates, representative of 36 clusters, led to the identification of Bacillus spp., Brevibacillus spp., Micrococcus spp., Staphylococcus spp., Pantoea spp., Kocuria spp., Lysinbacillus spp., and Lactobacillus spp., most of which reported for first time in olive oils. Phenotypic characterization of the 51 isolates, some of which ascribed to potentially probiotic species, indicate that two of them have beta-glucosidase activity while 37% present lipolytic activity. Preliminary evaluation of probiotic potential indicates that 31% of the isolates show biofilm formation ability, 29% acidic pH resistance, and 25% bile salt resistance. Finally, 29% of the isolates were sensitive to antibiotics while the remaining 71%, that include bacterial species well-recognized for their ability to disseminate resistance genes in the environment, showed a variable pattern of antibiotic resistance. The results obtained underline that microbial diversity of extra virgin olive oils represents an unexpected sink of microbial diversity and poses safety issues on the possible biotechnological exploitation of this microbial biodiversity.

Consumer's demand for naturally preserved food products is growing and the use of bioprotective cultures is an alternative to chemical preservatives or a complementary tool to hurdle technologies to avoid or delay fungal spoilage of dairy products. To develop antifungal cultures for the dairy product biopreservation, experiments were conducted both in vitro and in situ. Firstly, the antifungal activity of 32 strains of lactic acid bacteria (LAB) and propionibacteria was screened alone, and then on combinations based on 5 selected lactobacilli strains. This screening was performed in yogurt and cheese models against four major spoilage fungi previously isolated from contaminated dairy products (Penicillium commune, Mucor racemosus, Galactomyces geotrichum, and Yarrowia lipolytica). Selected combinations were then tested as adjunct cultures in sour cream and semi-hard cheeses produced at a pilot scale to evaluate their antifungal activity during challenge tests against selected fungal targets (P. commune, M. racemosus, and Rhodotorula mucilaginosa) and shelf life tests; and their impact on product organoleptic properties. The screening step allowed selecting two binary combinations, A1 and A3 composed of Lactobacillus plantarum L244 and either Lactobacillus harbinensis L172 or Lactobacillus rhamnosus CIRM-BIA1113, respectively. In situ assays showed that the A1 combination delayed the growth of P. commune, M. racemosus and R. mucilaginosa for 2–24 days on sour cream depending of the antifungal culture inoculum, without effect on organoleptic properties at low inoculum (106 colony-forming units (CFU)/mL). Moreover, the A1 and A3 combinations also delayed the growth of P. commune in semi-hard cheese for 1–6 days and 1 day, respectively. Antifungal cultures neither impacted the growth of starter cultures in both sour cream and cheese nor the products' pH, although post acidification was observed in sour cream supplemented with these combinations at the highest concentrations (2.107 CFU/mL). The combination of both in vitro and in situ screening assays allowed developing 2 antifungal combinations exhibiting significant antifungal activity and providing future prospects for use as bioprotective cultures in dairy products.

Consumer's demand for naturally preserved food products is growing and the use of bioprotective cultures is an alternative to chemical preservatives or a complementary tool to hurdle technologies to avoid or delay fungal spoilage of dairy products. To develop antifungal cultures for the dairy product biopreservation, experiments were conducted both in vitro and in situ. Firstly, the antifungal activity of 32 strains of lactic acid bacteria (LAB) and propionibacteria was screened alone, and then on combinations based on 5 selected lactobacilli strains. This screening was performed in yogurt and cheese models against four major spoilage fungi previously isolated from contaminated dairy products (Penicillium commune, Mucor racemosus, Galactomyces geotrichum , and Yarrowia lipolytica). Selected combinations were then tested as adjunct cultures in sour cream and semi-hard cheeses produced at a pilot scale to evaluate their antifungal activity during challenge tests against selected fungal targets (P. commune, M. racemosus , and Rhodotorula mucilaginosa) and shelf life tests; and their impact on product organoleptic properties. The screening step allowed selecting two binary combinations, A1 and A3 composed of Lactobacillus plantarum L244 and either Lactobacillus harbinensis L172 or Lactobacillus rhamnosus CIRM-BIA1113, respectively. In situ assays showed that the A1 combination delayed the growth of P. commune, M. racemosus and R. mucilaginosa for 2–24 days on sour cream depending of the antifungal culture inoculum, without effect on organoleptic properties at low inoculum (106 colony-forming units (CFU)/mL). Moreover, the A1 and A3 combinations also delayed the growth of P. commune in semi-hard cheese for 1–6 days and 1 day, respectively. Antifungal cultures neither impacted the growth of starter cultures in both sour cream and cheese nor the products' pH, although post acidification was observed in sour cream supplemented with these combinations at the highest concentrations (2.107 CFU/mL). The combination of both in vitro and in situ screening assays allowed developing 2 antifungal combinations exhibiting significant antifungal activity and providing future prospects for use as bioprotective cultures in dairy products. [ABSTRACT FROM AUTHOR]

The present study was performed to design sucuk production with microencapsulated and free cells of Lactobacillus rhamnosus and to investigate the effect of this production method on probiotic viability and quality characteristics on the final product. L. rhamnosus was microencapsulated with an optimal coating material combination by using response surface methodology and subsequently used in sucuk production as a probiotic culture. Microencapsulation protected L. rhamnosus against gastric and other stress conditions in sucuk composition. Sucuk production with microencapsulated L. rhamnosus was found to be similar to traditional sucuk in terms of textural, physicochemical, and sensorial properties. Novel sucuk production was developed with the use of free or microencapsulated probiotics. The addition of probiotics to the sucuk promoted the health benefits associated with lactic acid bacteria and contributed to an increase in the consumption of such products. In summary, the results of this study can provide data to the meat industry for the possible utilization of microencapsulated or free probiotics in sucuk processing as demanded by conscientious consumers. [ABSTRACT FROM AUTHOR]

Foodborne pathogens and their biofilms pose a risk to human health through food chain. However, the bacteriocin resources combating this threat are still limited. Here, Lacticaseibacillus rhamnosus, one of the most used probiotics in food industry, was prepared on a large scale using alternating tangential flow (ATF) perfusion-based technology. Compared to the conventional fed-batch approach, ATF perfusion remarkably increased the viable cells of L. rhamnosus CLK 101 to 11.93 ± 0.14 log CFU/mL. Based on obtained viable cells, we purified and characterized a novel bacteriocin CLK&#95;01 with a broad spectrum of activity against both Gram-positive and Gram-negative foodborne pathogens. LC-MS/MS analysis revealed that CLK&#95;01 has a molecular mass of 701.49 Da and a hydrophobic amino acid composition of I-K-K-V-T-I. As a novel bacteriocin, CLK&#95;01 showed high thermal stability and acid-base tolerance over 25-121 °C and pH 2-10. It significantly reduced cell viability of bacterial pathogens ( p  < 0.001), and strongly inhibited their biofilm formation. Scanning electron microscopy demonstrated deformation of pathogenic cells caused by CLK&#95;01, leading to cytoplasmic content leakage and bacterial death. Summarily, we employed ATF perfusion to obtain viable L. rhamnosus , and presented that bacteriocin CLK&#95;01 could serve as a promising biopreservative for controlling foodborne pathogenic bacteria and their biofilms., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Authors.)

Se evaluó el efecto de diferentes tipos de cultivos probióticos en yogurt sobre poblaciones conocidas de Staphylococcus aureus, Escherichia coli O157:H7, Listeria monocytogenes y Salmonella enteritidis. Los tres tipos diferentes de yogurt comercial utilizados fueron: sin probióticos adicionados, con probióticos CHR HANSEN® (Lactobacillus casei CRL_431 y L. acidophilus CRL_730) y otro con los mismos probióticos mencionados anteriormente, adicionado con cultivo de Lactobacillus rhamnosus (LR-35). Se inoculó aproximadamente 109 UFC/mL de cada bacteria potencialmente patógena en los diferentes tipos de yogurt, se mantuvo en refrigeración a 4ºC durante la vida útil de cada uno de estos alimentos (aproximadamente 30 días) y se realizó un recuento bacteriano cada cuatro días incluyendo el mismo día de la inoculación. Los resultados obtenidos demuestran que, existe diferencia en cuanto a inhibición entre los yogures sin probióticos y el yogurt comercial con probióticos, observándose un efecto inhibitorio evidente, por parte del segundo sobre las poblaciones de S. aureus, E. coli O157:H7 y L. monocytogenes. Con respecto a los yogures comerciales con probióticos más L. rhamnosus, no se observó alguna diferencia con respecto al efecto inhibitorio que poseen los yogures con probióticos L. casei y L. acidophilus . En los yogures en que se evaluó S. enteritidis se obtuvo la muerte de ésta al cabo de cuatro días. El presente estudio confirma el efecto antagónico que poseen los cultivos probióticos sobre bacterias potencialmente patógenas para el ser humano y animales que pueden estar contenidas en los alimentos.No obstante, el uso del probiótico Lactobacillus rhamnosus no ejerce un efecto inhibitorio adicional.Evaluation of the effect of Lactobacillus rhamnosus probiotic culture added to yogurt over Staphylococcus aureus, Escherichia coli O157:H7, listeria monocytogenes and Salmonella enteritidis populations. The effect of different types of probiotics present in yogurt over known populations of Staphylococcus aureus, Escherichia coli O157:H7, Listeria monocytogenes and Salmonella enteritidis was evaluated. The three types of yogurt used were: without added probiotics, with added probiotics (Lactobacillus casei CRL_431 and L. acidophilus CRL_730 CHR HANSEN®) and another one with the same probiotics mentioned above and Lactobacillus rhamnosus (LR-35) culture. About 109 CFU/ mL of each potentially pathogenic bacteria was added to each type of yogurt tested, and kept in refrigeration at 4ºC during its shelf life, about 30 days. Bacterial count was done the initial day and every four days. Results obtained show that there is a difference in the inhibition between yogurts without added probiotics and the commercial yogurt with added probiotics; there is a clear inhibitory effect of the last one over S. aureus, E coli O157:H7 and Listeria monocytogenes. The yogurt with added probiotics and L. rhamnosus did not show any additional inhibitory effect over the bacteria tested when compared with the yogurt with added probiotics. S. enteritidis could not be evaluated because it was not detectable in any yogurt samples evaluated four days after its inoculation. This study confirms the antagonic effect of probiotic cultures over potentially pathogenic bacteria for human beings and animals that may be present in food. Nevertheless, the use of L. rhamnosus did not produce any additional inhibitory effect.

Fermented foods and beverages are a significant source of dietary bacteria that enter the gastrointestinal (GI) tract. However, little is known about how these microbes survive and adapt to the small intestinal environment. Colony-forming units (CFU) enumeration and viability qPCR of Lacticaseibacillus rhamnosus CNCM I-3690 in the ileal effluent of 10 ileostomy subjects during 12-h post consumption of a dairy product fermented with this strain demonstrated the high level of survival of this strain during human small intestine passage. Metatranscriptome analyses revealed the in situ transcriptome of L. rhamnosus in the small intestine, which was contrasted with transcriptome data obtained from in vitro cultivation. These comparative analyses revealed substantial metabolic adaptations of L. rhamnosus during small intestine transit, including adjustments of carbohydrate metabolism, surface-protein expression, and translation machinery. The prominent presence of L. rhamnosus in the effluent samples did not elicit an appreciable effect on the composition of the endogenous small intestine microbiome, but significantly altered the ecosystem's overall activity profile, particularly of pathways associated with carbohydrate metabolism. Strikingly, two of the previously recognized gut-brain metabolic modules expressed in situ by L. rhamnosus (inositol degradation and glutamate synthesis II) are among the most dominantly enriched activities in the ecosystem's activity profile. This study establishes the survival capacity of L. rhamnosus in the human small intestine and highlights its functional adjustment in situ , which we postulate to play a role in the probiotic effects associated with this strain.

Experts view the development of functional foods as an opportunity for innovation for the meat industry in line with consumers’ concerns on food nutrition, well being and food safety. The main microbiota of fermented sausages consists of lactobacilli, which suggests that properly characterized strains could be selected as starter cultures. The selection of strains from human origin was considered in order to promote their survival in the host. Lactobacillus rhamnosus CTC1679 dominated during the ripening process and temporarily colonized the gastrointestinal tract of healthy volunteers, confirming that this strain could be delivered as a potential probiotic in fermented sausages. [ABSTRACT FROM AUTHOR]

La caroube (Ceratonia siliqua.L) est fréquemment utilisée par les industries agroalimentaires et pharmaceutiques, pour sa richesse en oligosaccharides et en fibres alimentaires. Ces substances font de la caroube un candidat potentiel au statut prébiotique. L'objectif de ce travail s'intéresse dans un premier temps à la caractérisation de L. fermentum et L . rhamnosus pour leur attribuer le statut de probiotique et dans un deuxième temps, à évaluer l'effet de caroube (Ceratonia siliqua.L) sur la croissance de ces deux bactéries. Des essais préliminaires ont révélé que les concentrations optimales d'utilisation de l'extrait de caroube sont de 1 et de 8% (P/V) pour L. rhamnosus et L. fermentum, respectivement. L'effet de ces deux concentrations optimales d'extrait de caroube a été évalué sur la croissance de ces deux souches candidats au statut probiotique. Les résultats montrent que la croissance de L. fermentum appréciée après 24 h d'incubation en présence de 8% d'extrait de caroube est quasi identique au témoin (absorbance à 625 nm : 1,08 vs 1,13) ce qui laisse penser que cette souche possède une bonne adaptation au milieu à base de caroube. Par ailleurs, la croissance de L. rhamnosus est réduite en présence de 1% (p/v) de cet extrait par rapport au témoin (0,88 vs 1,59). Mais cette réduction reste non significative. Par ce fait, cette étude indique que l'extrait de gousse de caroube a une capacité de ralentir la prolifération de L. fermentum et L. rhamnosus. [ABSTRACT FROM AUTHOR]