Antimicrobial Activity of Lactobacillus Species Against Carbapenem-Resistant Enterobacteriaceae

Characterization of probiotics isolated from dietary supplements and evaluation of metabiotic-antibiotic combinations as promising therapeutic options against antibiotic-resistant pathogens using time-kill assay

BACKGROUND

The global probiotics dietary supplements market size is continuously growing. To overcome probiotics' health concerns, metabiotics are recognized as a safer alternative. Aiming to deal with the escalating antimicrobial resistance, the current work demonstrates synergistic metabiotic-antibiotic combinations against antibiotic-resistant pathogens.

METHODS

The probiotic properties of lactic acid bacteria (LAB) strains isolated from 3 commercial dietary supplements were characterized in vitro. The combinations of the cell-free supernatants (CFS) of selected probiotic strains and conventional antibiotics against Staphylococcus aureus and Escherichia coli clinical isolates were evaluated using the time-kill assay. To our knowledge, the current literature lacks sufficient time-kill assay studies revealing the kinetics of such metabiotic-antibiotic combinations against S. aureus and E. coli.

RESULTS

Four LAB strains isolated from dietary supplements as well as two reference strains were included in this study. The isolated LAB strains were identified by MALDI-TOF mass spectrometry as follows: P2: Lactobacillus acidophilus, P3: Lactiplantibacillus plantarum, P4: Lacticaseibacillus rhamnosus, and P5: Pediococcus acidilactici. The identification matched with that annotated by the manufacturers, except for P3. The tested strains could resist the acidic environment at pH 3. Excluding P2, the examined strains showed less than 1 log reduction in survivors upon the addition of reconstituted skimmed milk to pepsin at pH 2 and displayed an acceptable tolerance to 0.3% ox-bile. All the strains tolerated pancreatin. The hydrophobicity and autoaggregation capacities ranged between 7-92% and 36-66%, respectively. P2 was excluded owing to its inferior probiotic potential. Although the remaining strains showed excellent growth at 0.2% phenol, their growth was reduced at higher concentrations. L. plantarum and P. acidilactici strains possessed bile salt hydrolysis activity. The time-kill assay revealed promising synergistic activities of the combinations of CFS of L. rhamnosus P4 with either ceftazidime or gentamicin against E. coli and with only ceftazidime against S. aureus, as well as CFS of P. acidilactici P5 and ceftazidime against S. aureus.

CONCLUSIONS

Strict identification and evaluation of the probiotic strains incorporated in dietary supplements is crucial to ensure their safety and efficacy. The CFS of probiotics could be utilized to formulate novel biotherapeutics targeting problematic pathogens. However, future in vivo studies are required to evaluate the appropriate treatment regimen.

Probiotic cell-free supernatant as effective antimicrobials against Klebsiella pneumoniae and reduce antibiotic resistance development

This study evaluated the antimicrobial activity, resistance development, and synergistic potential of cell-free supernatant (CFSs) derived from Levilactobacillus brevis (Lb-CFS) and Lactiplantibacillus plantarum (Lp-CFS) against Klebsiella pneumoniae. Both CFSs exhibited potent growth inhibition, with minimum inhibitory concentrations (MICs) of 128 μg/mL and 64 μg/mL for Lb-CFS and Lp-CFS, respectively, and demonstrated dose-dependent bactericidal activity, achieving complete bacterial eradication at minimum bactericidal concentrations (MBC) within 6 h. The CFSs suppressed the expression of virulence genes (galF, wzi, and manC) and biofilm formation in a dose-dependent manner. Synergistic interactions were observed when combining CFSs with antibiotics, resulting in 2- to fourfold reductions in antibiotic MICs and MBCs. Notably, adaptive evolution experiments revealed significantly slower resistance development in K. pneumoniae against CFSs (twofold MIC/MBC increase) compared to antibiotics (16- to 128-fold increase) after 21 days. Furthermore, CFS-adapted strains exhibited increased antibiotic susceptibility, while antibiotic-adapted strains displayed cross-resistance to multiple antibiotics. No cross-resistance occurred between Lb-CFS and Lp-CFS, suggesting distinct adaptive mechanisms. These findings highlight the potential of probiotic-derived CFSs as effective antimicrobials with a lower propensity for inducing rapid resistance compared to conventional antibiotics, suggesting their promise in combating multidrug-resistant infections.

Utilizing Silk Sericin as a Biomaterial for Drug Encapsulation in a Hydrogel Matrix with Polycaprolactone: Formulation and Evaluation of Antibacterial Activity

Hydrogels have emerged as a potential tool for enhancing bioavailability and regulating the controlled release of therapeutic agents. Owing to its excellent biocompatibility, silk sericin-based hydrogels have garnered interest in biomedical applications. This study focuses on synthesizing a soft hydrogel by blending silk sericin (SS) and polycaprolactone (PCL) at room temperature. The physicochemical characteristics of the hydrogels have been estimated by different analytical techniques such as UV-visible spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The rheological studies demonstrate the non-Newtonian behavior of the hydrogels. Further, the porosity analysis indicates a commendable absorption capacity of the hydrogels. The swelling degree of the hydrogels has been checked in both distilled water and buffer solutions of different pHs (2-10). Moreover, the drug release profile of the hydrogels, using diclofenac sodium (DS) as a model drug, has revealed a substantial release of approximately 67% within the first 130 min with a drug encapsulation efficiency of 60.32%. Moreover, both the empty and the drug-loaded hydrogels have shown antibacterial properties against Gram-positive and Gram-negative bacteria, with the drug-loaded hydrogels displaying enhanced effectiveness. Additionally, the prepared hydrogels are biodegradable, demonstrating their future prospects in biomedical applications.

Exploring the potential of Lactocaseibacillus rhamnosus PMC203 in inducing autophagy to reduce the burden of Mycobacterium tuberculosis

Mycobacterium tuberculosis, a lethal pathogen in human history, causes millions of deaths annually, which demands the development of new concepts of drugs. Considering this fact, earlier research has explored the anti-tuberculosis potential of a probiotic strain, Lactocaseibacillus rhamnosus PMC203, leading to a subsequent focus on the molecular mechanism involved in its effect, particularly on autophagy. In this current study, immunoblotting-based assay exhibited a remarkable expression of autophagy marker LC3-II in the PMC203 treated group compared to an untreated group. A remarkable degradation of p62 was also noticed within treated cells compared to control. Furthermore, the immunofluorescence-based assay showed significant fold change in fluorescence intensity for alexa-647-LC3 and alexa-488-LC3, whereas p62 was degraded noticeably. Moreover, lysosomal biogenesis generation was elevated significantly in terms of LAMP1 and acidic vesicular organelles. As a result, PMC203-induced autophagy played a vital role in reducing M. tuberculosis burden within the macrophages in treated groups compared to untreated group. A colony -forming unit assay also revealed a significant reduction in M. tuberculosis in the treated cells over time. Additionally, the candidate strain significantly upregulated the expression of autophagy induction and lysosomal biogenesis genes. Together, these results could enrich our current knowledge of probiotics-mediated autophagy in tuberculosis and suggest its implications for innovatively managing tuberculosis.

Probiotic potential of autochthonous Lactobacillus species from buffalo calves in controlling multidrug resistant Escherichia coli

The aim of this study was to investigate the probiotic potential of autochthonous Lactobacillus species isolated from buffalo calves against multidrug-resistant Escherichia coli. A total of 252 rectal swabs were collected from healthy neonatal buffalo calves under 30 days old from six districts of Andhra Pradesh, India in a completely randomized design from August 2019 to August 2021, of which 190 Lactobacillus strains were isolated based on cultural, morphological, biochemical and molecular tests. Out of 190 isolates, 57 showed high levels of auto-aggregation (> 80.00%) and hydrophobicity (> 60.00%) and 51 of the 57 isolates had a zone of inhibition greater than 15.00 mm in diameter against multidrug-resistant E. coli in an Agar well diffusion assay. Among the 51 isolates, 36 were found to be acid and bile tolerant and showed varying levels of sensitivity to antibiotics such as erythromycin, clindamycin, tetracycline, chloramphenicol, and ampicillin. Among the 36 isolates, Limosilactobacillus reuteri 178, L. reuteri 209, L. fermentum 182, L. fermentum 211, and Lactiplanti-bacillus plantarum 34 were non-hemolytic, and none of the isolates were able to hydrolyse gelatine. Therefore, these five autochthonous Lactobacillus species may be used in probiotic or synbiotic formulations against multidrug resistant E. coli in buffalo calves.

Bee-Associated Beneficial Microbes-Importance for Bees and for Humans

Bees are one of the best-known and, at the same time, perhaps the most enigmatic insects on our planet, known for their organization and social structure, being essential for the pollination of agricultural crops and several other plants, playing an essential role in food production and the balance of ecosystems, being associated with the production of high-value-added inputs, and a unique universe in relation to bees' microbiota. In this review, we summarize information regarding on different varieties of bees, with emphasis on their specificity related to microbial variations. Noteworthy are fructophilic bacteria, a lesser-known bacterial group, which use fructose fermentation as their main source of energy, with some strains being closely related to bees' health status. The beneficial properties of fructophilic bacteria may be extendable to humans and other animals as probiotics. In addition, their biotechnological potential may ease the development of new-generation antimicrobials with applications in biopreservation. The concept of "One Health" brings together fundamental and applied research with the aim of clarifying that the connections between the different components of ecosystems must be considered part of a mega-structure, with bees being an iconic example in that the healthy functionality of their microbiota is directly and indirectly related to agricultural production, bee health, quality of bee products, and the functional prosperity for humans and other animals. In fact, good health of bees is clearly related to the stable functionality of ecosystems and indirectly relates to humans' wellbeing, a concept of the "One Health".

The effect of nano/microparticles of bee pollen on the shelf life of high-fat cooked sausage during refrigerated storage

Sausage is susceptible to oxidative changes in lipids and microbial spoilage due to the presence of water, fat, protein, and vitamins. Bee pollen (BP) as a source of potential antioxidants and antibacterial compounds can effectively prevent lipid peroxidation and microbial spoilage in meat products. The aim of the present study was to investigate the antibacterial and antioxidant activities of BP and the effects of nano/microparticles of bee pollen extract (n/m BP) at a concentration of 125 and 250 mg/100 g meat on the oxidative stability and microbial growth of high-fat sausage during 30 days of storage at 4°C. The formation of BP particles in the nano/micro range was confirmed by scanning electron microscopy. High concentrations of total phenolic compounds (28.26 ± 0.10 mg GAE/g BP) with antioxidant activity (EC50 = 5.4 ± 0.07 mg/mL) were detected in BP. Based on the microdilution assay, the minimum inhibitory concentration of n/m BP for all test bacteria was 1000 (μg/mL) and the minimum bactericidal concentration of n/m BP was 2000 (μg/mL) for Staphylococcus aureus and Bacillus cereus and 4000 (μg/mL) for Escherichia coli and Pseudomonas aeruginosa. The n/m BP treatment (250 mg/100 g meat) showed a higher pH value (p < .05) and lower TBARS values (p < .05) than the ascorbic acid treatment (100 mg/100 g meat) and the control during the storage period. The microbial analysis showed that the addition of n/m BP led to a significant decrease (p < .05) in the total bacterial count, coliforms, S. aureus, and fungal population compared to the other samples. The results show that the addition of n/m BP (125 mg/100 g) can improve the texture, taste, and overall acceptability of the sausage compared to the control sample. In conclusion, this study suggests that BP can replace synthetic antioxidants in high-fat sausages at the nano/microparticle level.

Feasibility of lactiplantibacillus plantarum postbiotics production in challenging media by different techniques

The postbiotic derived from Lactiplantibacillus plantarum bacteria was produced in three culture media: milk, MRS, and whey, and its antibacterial and antifungal properties were evaluated. To investigate the production efficiency of postbiotics, three methods, heating, sonication and centrifugation, were utilized to prepare postbiotics in MRS broth culture medium. The antibacterial potency of the postbiotic was evaluated using the agar well-diffusion method, and MIC and MBC tests were conducted for different treatments. The results of the study showed that the postbiotic prepared in food environments such as milk and cheese whey can have antibacterial and antifungal properties similar to the postbiotic prepared in the MRS culture medium. However, it is possible to enrich food matrices such as milk and cheese whey and make further adjustments in terms of pH settings. Additionally, the thermal process was able to create a nanoscale postbiotic, which is a significant achievement for the application of postbiotics in the food and pharmaceutical industries. The future outlook of postbiotics clearly indicates that the emergence of this generation of probiotics can have an attractive and functional position in the food and pharmaceutical industries. Therefore, future research focusing on this subject will contribute to the development of this generation of postbiotics.

Antimicrobial and Probiotic Potential of Lactobacilli Associated with Traditional Fermented Beverages

Fermented foods have been recognized as a source of probiotic bacteria which can have a positive effect when administered to humans and animals. Discovering new probiotics in fermented food products poses a global economic and health importance. In this study, we investigated the antimicrobial and probiotic potential of lactobacilli isolated from fermented beverages produced traditionally by ethnic groups in Northeast India. Out of thirty Lactobacilli, fifteen exhibited strong antimicrobial activity against Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter aerogenes with significant anti-biofilm and anti-quorum sensing activity. These isolates also showed characteristics associated with probiotic properties, such as tolerance to low pH and bile salts, survival in the gastric tract, auto-aggregation, and hydrophobicity without exhibiting hemolysis formation or resistance to certain antibiotics. The isolates were identified using gram staining, biochemical tests, and 16S rDNA sequencing. They exhibited probiotic potential, broad-spectrum of antibacterial activity, promising anti-biofilm, anti-quorum sensing activity, non-hemolytic, and tolerance to acidic pH and bile salts. Overall, four specific Lactobacillus isolates, Lactiplantibacillus plantarum BRD3A and Lacticaseibacillus paracasei RB10OW from fermented rice-based beverage, and Lactiplantibacillus plantarum RB30Y and Lacticaseibacillus paracasei MP11A from traditional local curd demonstrated potent antimicrobial and probiotic properties. These findings suggest that these lactobacilli isolates from fermented beverages have the potential to be used as probiotics with therapeutic benefits, highlighting the importance of traditional fermented foods for promoting gut health and infectious disease management.

Fermentation of Rubus dolichocarpus juice using Lactobacillus gasseri and Lacticaseibacillus casei and protecting phenolic compounds by Stevia extract during cold storage

This study aimed to investigate the biological activities of Lactobacillus gasseri SM 05 (L. gasseri) and Lacticaseibacillus casei subsp. casei PTCC 1608 (L. casei) in the black raspberry (Rubus dolichocarpus) juice (BRJ) environment, and also the anti-adhesion activity against Salmonella typhimurium (S. typhimurium) in fermented black raspberry juice (FBRJ). Results showed significant anti-adhesion activity in Caco-2 epithelial cells. In the anti-adhesion process, lactic acid bacteria (LAB) improve intestinal health by preventing the adhesion of pathogens. Adding LAB to BRJ produces metabolites with bacteriocin properties. Major findings of this research include improved intestinal health, improved antidiabetic properties, inhibition of degradation of amino acids, and increase in the nutritional value of foods that have been subjected to heat processing by preventing Maillard inhibition, and inhibition of oxidation of foodstuff by increased antioxidant activity of BRJ. Both species of Lactobacillus effectively controlled the growth of S. typhimurium during BRJ fermentation. Moreover, in all tests, as well as Maillard's and α-amylase inhibition, L. gasseri was more effective than L. casei. The phenolic and flavonoid compounds increased significantly after fermentation by both LAB (p < 0.05). Adding Stevia extract to FBRJ and performing the HHP process showed convenient protection of phenolic compounds compared to heat processing.

Isolation, characterization of Weissella confusa and Lactococcus lactis from different milk sources and determination of probiotic features

This study aimed to investigate the probiotic properties of Lactic Acid Bacteria (LAB) isolates derived from various milk sources. These isolates identified based on their morphological characteristics and 16S rRNA gene sequencing. Four strains of Lactococcus lactis and two strains of Weissella confusa were identified with over 96% 16S rRNA gene similarity according to the NCBI-BLAST results. The survival of the isolates was determined in low pH, pepsin, bile salts, and pancreatin, and their adhesion ability was assessed by in vitro cell adhesion assay, hydrophobicity, auto- and co-aggregation, and safety criteria were determined by hemolytic, gelatinase activities, and DNAse production ability tests. The results showed that the LAB isolates had different levels of resistance to various stress factors. L. lactis subsp. cremoris MH31 showed the highest resistance to bile salt, while the highest pH resistance was observed in L. lactis MH31 at pH 3.0. All the isolates survived in pepsin exposure at pH 3.0 for 3 h. The auto-aggregation test results showed that all strains exhibited auto-aggregation ranging from 84.9 to 91.4%. Co-aggregation percentage ranged from 19 - 54% and 17 - 57% against Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 29213, respectively. The hydrophobicity capacity of the LAB isolated ranged from 35-61%. These isolates showed different adhesion abilities to Caco-2 cells (81.5% to 92.6%). None of the isolates exhibited DNase, gelatinase and hemolytic activity (γ-hemolysis). All results indicate that these LAB strains have the potential to be used as probiotics.

Probiotic performance of B. subtilis MS. 45 improves aquaculture of rainbow trout Oncorhynchus mykiss during acute hypoxia stress

The aim of this study was to produce mutant strains of Bacillus subtilis with high probiotic performance for use in the aquaculture of rainbow trout Oncorhynchus mykiss. The main strain of B. subtilis (MS) was irradiated with gamma rays (5.3 KGy). Subsequently, the B. subtilis mutant strain no. 45 (MS. 45) was selected for bacterial growth performance, resistance to acidic conditions, resistance to bile salts and antibacterial activity against Aeromonas hydrophila and Pseudomonas fluorescens. After 60 days, the rainbow trout (70.25 ± 3.89 g) fed with MS. 45 and MS were exposed to hypoxia stress (dissolved oxygen = 2 ppm). Subsequently, immune indices (lysozyme, bacterial activity and complement activity), hematological indices [hematocrit, hemoglobin, WBC, RBC, mean corpuscular volume (MCV)] and antioxidant factors (T-AOC, SOD and MDA)) were analyzed after and before hypoxia exposure. The expression of immunological genes (IFN-γ, TNF-α, IL-1β, IL-8) in the intestine and the expression of hypoxia-related genes (HIF-1α, HIF-2α, FIH1) in the liver were compared between the different groups under hypoxia and normoxia conditions. Growth, immunological and antioxidant indices improved in group MS. 45 compared to the other groups. Stress indices and associated immunologic and hypoxia expressions under hypoxia and normoxia conditions improved in MS. 45 compared to the other groups. This resulted in improved growth, immunity and stress responses in fish fed with the microbial supplement of MS. 45 (P < 0.05) under hypoxia and normoxia conditions, (P < 0.05), resulting in a significant improvement in trout aquaculture.

Putative Role of Anti-microbial Peptide Recovered from Lactiplantibacillus spp. in Biocontrol Activity

Antimicrobial peptides (AMPs) stand as a promising alternative to conventional pesticides, leveraging a multifaceted approach to combat plant pathogens. This study focuses on identifying and characterizing the AMP produced by Lactiplantibacillus argentoratensis strain IT, demonstrating potent antibacterial activity against various harmful microorganisms. Evaluation of AMPs' antibacterial activity was conducted through an agar well diffusion assay, a reliable method for assessing secondary metabolite antimicrobial efficacy. The study unveils the antimicrobial potential of the purified extract obtained from Lactiplantibacillus argentoratensis IT, isolated from goat milk. Notably, the AMP exhibited robust antibacterial activity against phytopathogens affecting solanaceous crops, including the Gram-negative Ralstonia solanacearum. Expression conditions and purification methods were optimized to identify the peptide's mass and sequence, utilizing LC-MS and SDS-PAGE. This paper underscores the application potential of Lactiplantibacillus spp. IT as a biocontrol agent for managing bacterial infectious diseases in plants. Results indicate optimal AMP production at 37 °C, with a culture broth pH of 5 during fermentation. The obtained peptide sequence corresponded to peaks at 842.5 and 2866.4 m/z ratio, with a molecular weight of approximately 5 kDa according to tricine SDS-PAGE analysis. In conclusion, this study lays the foundation for utilizing Lactiplantibacillus spp. IT derived AMPs in plant biocontrol strategies, showcasing their efficacy against bacterial phytopathogens. These findings contribute valuable insights for advancing sustainable agricultural practices.

Novel Wild-Type Pediococcus and Lactiplantibacillus Strains as Probiotic Candidates to Manage Obesity-Associated Insulin Resistance

As the food and pharmaceutical industry is continuously seeking new probiotic strains with unique health properties, the aim of the present study was to determine the impact of short-term dietary intervention with novel wild-type strains, isolated from various sources, on high-fat diet (HFD)-induced insulin resistance. Initially, the strains were evaluated in vitro for their ability to survive in simulated gastrointestinal (GI) conditions, for adhesion to Caco-2 cells, for bile salt hydrolase secretion, for cholesterol-lowering and cellular cholesterol-binding ability, and for growth inhibition of food-borne pathogens. In addition, safety criteria were assessed, including hemolytic activity and susceptibility to antibiotics. The in vivo test on insulin resistance showed that mice receiving the HFD supplemented with Pediococcus acidilactici SK (isolated from human feces) or P. acidilactici OLS3-1 strain (isolated from olive fruit) exhibited significantly improved insulin resistance compared to HFD-fed mice or to the normal diet (ND)-fed group.

Bactericidal and Antioxidant Potential of Moringa oleifera Capped Silver Nanoparticles under Varied Conditions

Microbial infections have consistently been identified as one of the major threats to global health. In this regard, the current study was designed to synthesize and evaluate the antibacterial activity of Mo‐AgNPs at various concentrations (2, 4, and 8 mg/mL), temperatures (4 °C, 25 °C, 37 °C, and 85 °C) and pH (4, 7, and 11) against Gram‐negative bacteria (Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Aeromonas veronii) and Gram‐positive bacteria (Staphylococcus aureus, Bacillus subtilis) by the well diffusion method as well as antioxidant potential using DPPH assay at 2 mg/mL and 4 mg/mL. Fabrication of Mo‐AgNPs was authenticated by UV–visible spectroscopy (UV–Vis), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), and X‐ray diffraction (XRD). Mo‐AgNPs produced a significant zone of growth inhibition (21.0±0.3 mm) against B. subtilis at 8 mg/mL. At 25 °C, a significant zone of growth inhibition (21.0±0.8 mm) was measured against E. coli. Similarly, at pH 4, Mo‐AgNPs showed significantly highest growth inhibition zones of 12.0±7.5 mm, 12.0±6.3 mm, and 12.0±9.8 mm against P. aeruginosa, K. pneumoniae, and A. veronii, respectively. The present study results indicated that Mo‐AgNPs are stable under varied conditions. Significant free radical scavenging activity (82±0.5 %) of Mo‐AgNPs at 4 mg/mL was observed, which revealed the antioxidant potential of the Mo‐AgNPs.

Pharmacotechnical aspects of a stable probiotic formulation toward multidrug-resistance antibacterial activity: design and quality control

As a well-known group of the probiotic family, the Lactobacillus has increasingly contributed to hindering the growth of pathogens, particularly resistant species, in the last decades. Since antibiotic resistance has become a severe problem in global healthcare systems and considerably increased the mortality and morbidity rate in infectious diseases, we aimed to obtain a new stable formulation of Lactobacillus to overcome resistant infections. For this purpose, we designed various gel formulations containing Lactobacillus rhamnosus (L. rhamnosus) as an active pharmaceutical ingredient (API) in a water base and oil base gel, evaluated the probiotic stability in formulation to obtain an optimum formulation, and finally, investigated the antibacterial activities of that against two common hospital-associated multidrug-resistant pathogens, methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE). Furthermore, the pharmaceutical aspects of the optimum formulation, including stability, homogeneity, spreadability, pH value, conductivity, and rheological behavior, were assessed.The results indicated that the optimum formulation based on glycerol exhibited desirable pharmaceutical properties, including long-term stability, a perfect level of homogeneity, an acceptable range of spreadability with pseudo-plastic thixotropic behavior, and a promising antibacterial potential against MRSA and VRE. Our findings indicate that this novel probiotic formulation could be an excellent candidate to cope with antibiotic-resistant species, representing a hopeful treatment potential for topical applications, particularly in incurable infections. However, further in vivo studies seem warranted to evaluate their bactericidal activity against multi-drug resistant microorganisms.

Ligilactobacillus salivarius 7247 Strain: Probiotic Properties and Anti-Salmonella Effect with Prebiotics

The Ligilactobacillus salivarius 7247 (LS7247) strain, originally isolated from a healthy woman's intestines and reproductive system, has been studied for its probiotic potential, particularly against Salmonella Enteritidis (SE) and Salmonella Typhimurium (ST) as well as its potential use in synbiotics. LS7247 showed high tolerance to gastric and intestinal stress and effectively adhered to human and animal enterocyte monolayers, essential for realizing its probiotic properties. LS7247 showed high anti-Salmonella activity. Additionally, the cell-free culture supernatant (CFS) of LS7247 exhibited anti-Salmonella activity, with a partial reduction upon neutralization with NaOH (p < 0.05), suggesting the presence of anti-Salmonella factors such as lactic acid (LA) and bacteriocins. LS7247 produced a high concentration of LA, reaching 124.0 ± 2.5 mM after 48 h of cultivation. Unique gene clusters in the genome of LS7247 contribute to the production of Enterolysin A and metalloendopeptidase. Notably, LS7247 carries a plasmid with a gene cluster identical to human intestinal strain L. salivarius UCC118, responsible for class IIb bacteriocin synthesis, and a gene cluster identical to porcine strain L. salivarius P1ACE3, responsible for nisin S synthesis. Co-cultivation of LS7247 with SE and ST pathogens reduced their viability by 1.0-1.5 log, attributed to cell wall damage and ATP leakage caused by the CFS. For the first time, the CFS of LS7247 has been shown to inhibit adhesion of SE and ST to human and animal enterocytes (p < 0.01). The combination of Actigen prebiotic and the CFS of LS7247 demonstrated a significant combined effect in inhibiting the adhesion of SE and ST to human and animal enterocytes (p < 0.001). These findings highlight the potential of using the LS7247 as a preventive strategy and employing probiotics and synbiotics to combat the prevalence of salmonellosis in animals and humans caused by multidrug resistant (MDR) strains of SE and ST pathogens.

Evaluation of the Cariogenic and Anti-Cariogenic Potential of Human Colostrum and Colostrum-Derived Probiotics: Impact on S. mutans Growth, Biofilm Formation, and L. rhamnosus Growth

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.

Microbial Dynamics during labneh Ambaris Production in Earthenware Jars

The responses of various microbial populations to modifications in the physicochemical properties of a food matrix, as well as interactions between these populations already present, are the main factors that shape microbial dynamics in that matrix. This work focused on the study of microbial dynamics during labneh Ambaris production, a traditional Lebanese concentrated fermented goat milk made in jars during 3 months. This was assessed in two earthenware jars at a production facility. DNA metabarcoding of the ITS2 region as well as the V3-V4 region of the 16S rRNA gene was used to characterize the fungal and bacterial communities, respectively. Viable bacterial isolates were also identified by Sanger sequencing of the V1-V4 region of the 16S rRNA gene. Our results showed that the dominant microorganisms identified within labneh Ambaris (Lactobacillus kefiranofaciens, Lentilactobacillus kefiri, Lactococcus lactis, Geotrichum candidum, Pichia kudriavzevii and Starmerella sp.) settle early in the product and remain until the end of maturation with varying abundances throughout fermentation. Microbial counts increased during early fermentation stage, and remained stable during mid-fermentation, then declined during maturation. While microbial compositions were globally comparable between the two jars during mid-fermentation and maturation stages, differences between the two jars were mainly detected during early fermentation stage (D0 until D10). No significant sensorial differences were observed between the final products made in the two jars. Neither coliforms nor Enterobacteriaceae were detected in their viable state, starting D7 in both jars, suggesting the antimicrobial properties of the product.

Temperature, Salinity and Garlic Additive Shape the Microbial Community during Traditional Beetroot Fermentation Process

Plant-based traditional fermented products are attracting a lot of interest in global markets. An example of them is beetroot leaven, which is valued for its high bioactive compound content. The variety of production recipes and the spontaneous nature of red beet fermentation favor its high diversity. This study aimed to analyze the impact of external factors-temperature, brine salinity, and garlic dose-on the beetroot fermentation and bacterial metapopulation responsible for this process. The research results confirmed the significant influence of the selected and analyzed factors in shaping the leaven physicochemical profile including organic acid profile and betalain content. Analysis of bacterial populations proved the crucial importance of the first 48 h of the fermentation process in establishing a stable metapopulation structure and confirmed that this is a targeted process driven by the effect of the analyzed factors. Lactobacillaceae, Enterobacteriaceae, and Leuconostocaceae were observed to be the core microbiome families of the fermented red beet. Regardless of the impact of the tested factors, the leaven maintained the status of a promising source of probiotic bacteria. The results of this research may be helpful in the development of the regional food sector and in improving the quality and safety of traditionally fermented products such as beetroot leaven.

The Management of Recurrent Urinary Tract Infection: Non-Antibiotic Bundle Treatment

Recurrent urinary tract infections (rUTIs) are a common condition with high morbidity and negatively impact the quality of life. They account for approximately 25% of all antibiotic prescriptions and are a public health concern in an era of increasing multidrug-resistant organisms (MDROs). Several non-antibiotic treatment strategies have been tried to curb antimicrobial use, and many are effective to some degree, but no experience testing multimodal interventions. We created a "care bundle" consisting of behavioral interventions, vaginal and oral probiotics, D-mannose, and cranberry to be followed for six months. We enrolled women with rUTIs over three years. Changes in urinary tract infections, antibiotic use, chronic symptoms, and quality of life were compared in the six months before and after participation in the study. Forty-seven women were enrolled in the study, six of whom were excluded from the final analysis. We observed a 76% reduction in urinary tract infections (p < 0.001) and a reduction in total antibiotic exposure of more than 90% (p < 0.001); all chronic symptoms showed a trend toward reduction. Adherence to the bundle was high (87.2%). Overall, 80.5% of women experienced an improvement in their quality of life. In our experience, a bundle protocol is effective in reducing recurrences and antimicrobial use in a cohort of women with rUTIs and results in a subjective improvement in chronic symptoms and quality of life. Further research with larger sample size is needed to confirm these findings.

Effects of Cuminum cyminum L. essential oil and its nanoemulsion on oxidative stability and microbial growth in mayonnaise during storage

The present study aimed to investigate the effects of Cuminum cyminum L. essential oil (CEO) and its nanoemulsion (CEON) on oxidative stability and microbial growth of mayonnaise during storage. The GC analysis indicated that Cuminaldehyde (27.99%), o-Cymene (17.31%), γ-Terpinen (16.67%), and β-Pinene (9.35%) were the major components of CEO, respectively. The assessments of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) showed that Escherichia coli ATCC 25922 (MBCCEO = 12 and MBCCEON = 6 mg/mL) was the most resistant bacteria, and in contrast, Staphylococcus aureus ATCC 29213 (MBCCEO = 6 and MBCCEON = 3 mg/mL) was the most sensitive bacteria. In the radical-scavenging assay, CEON (IC50 = 5 ± 0.07 μg/mL) exhibited a higher antioxidant activity than CEO (IC50 = 10 ± 0.13 μg/mL). The results showed that applying the MBC of CEO and CEON in mayonnaise led to a significant decrease (p < .05) in acidity, peroxide value, number of acid-resistant bacteria and fungi, and total microbial count compared with the control sample. In conclusion, this study demonstrated that using CEON resulted in oxidative stability, microbial growth control, and desirable sensorial attributes in mayonnaise compared with CEO and control samples.

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.

Biochemical, functional and genomic characterization of a new probiotic Ligilactobacillus salivarius F14 from the gut of tribes of Odisha

Characterization of new potential probiotics is desirable in the field of research on probiotics for their extensive use in health and disease. Tribes could be an unusual source of probiotics due to their unique food habits and least dependence on medications and consumption of antibiotics. The aim of the present study is to isolate lactic acid bacteria from tribal fecal samples of Odisha, India, and characterize their genetic and probiotic attributes. In this context one of the catalase-negative and Gram-positive isolates, identified using 16S rRNA sequencing as Ligilactobacillus salivarius, was characterized in vitro for its acid and bile tolerance, cell adhesion and antimicrobial properties. The whole genome sequence was obtained and analyzed for strain level identification, presence of genomic determinants for probiotic-specific features, and safety. Genes responsible for its antimicrobial and immunomodulatory functions were detected. The secreted metabolites were analyzed using high resolution mass spectroscopy; the results indicated that the antimicrobial potential could be due to the presence of pyroglutamic acid, propionic acid, lactic acid, 2-hydroxyisocaproic acid, homoserine, and glutathione, and the immuno-modulating activity, contributed by the presence of short chain fatty acids such as acetate, propionate, and butyrate. So, to conclude we have successfully characterized a Ligilactobacillus salivarius species with potential antimicrobial and immunomodulatory ability. The health-promoting effects of this probiotic strain and/or its derivatives will be investigated in future.

Evaluation of Potential Probiotic Properties of Limosilactobacillus fermentum Derived from Piglet Feces and Influence on the Healthy and E. coli-Challenged Porcine Intestine

In this work, we evaluated the probiotic properties of Limosilactobacillus fermentum strains (FL1, FL2, FL3, FL4) isolated from feces of healthy piglets. The in vitro auto-aggregation, hydrophobicity, biofilm-forming capacity, survival in the gastrointestinal tract, antimicrobial activity and anti-oxidation capacity were evaluated. Four strains were resistant to simulated gastrointestinal conditions, including low pH, pepsin, trypsin and bile salts. They also maintained strong self-aggregation and cell surface hydrophobicity. Limosilactobacillus fermentum FL4, which had the strongest adhesion ability and antimicrobial effect on Enterotoxigenic Escherichia coli K88 (ETEC K88), was then tested in porcine intestinal organoid models. The in vitro experiments in basal-out and apical-out organoids demonstrated that L. fermentum FL4 adhered to the apical surfaces more efficiently than basolateral surfaces, had the ability to activate the Wnt/β-catenin pathway to protect the mucosal barrier integrity, stimulated the proliferation and differentiation of the intestinal epithelium, and repaired ETEC K88-induced damage. Moreover, L. fermentum FL4 inhibited inflammatory responses induced by ETEC K88 through the reduced expression of pro-inflammatory cytokines (TNF-α, IL-1β and IFN-γ) and higher levels of anti-inflammatory cytokines (TGF-β and IL-10). These results show that L. fermentum FL4 isolated from feces of healthy Tunchang piglets has the potential to be used as an anti-inflammatory probiotic and for mitigation of intestinal damage in piglets.

Limosilactobacillus fermentum KAU0021 Abrogates Mono- and Polymicrobial Biofilms Formed by Candida albicans and Staphylococcus aureus

Candida albicans and Staphylococcus aureus, representing two different kingdoms, are the most frequently isolated pathogens from invasive infections. Their pathogenic attributes, combined with drug resistance, make them a major threat and a challenge to successful treatments, mainly when involved in polymicrobial biofilm-associated infections. In the present study, we investigated the antimicrobial potential of Lactobacillus metabolite extracts (LMEs) purified from cell-free supernatant of four Lactobacillus strains (KAU007, KAU0010, KAU0021, and Pro-65). Furthermore, LME obtained from the strain KAU0021 (LMEKAU0021), being the most effective, was analyzed for its anti-biofilm property against mono- and polymicrobial biofilms formed by C. albicans and S. aureus. The impact of LMEKAU0021 on membrane integrity in single and mixed culture conditions was also evaluated using propidium iodide. The MIC values recorded for LMEKAU0021 was 406 µg/mL, 203 µg/mL, and 406 µg/mL against planktonic cells of C. albicans SC5314, S. aureus and polymicrobial culture, respectively. The LMEKAU0021 at sub-MIC values potentially abrogates both biofilm formation as well as 24 h mature mono- and polymicrobial biofilms. These results were further validated using different microscopy and viability assays. For insight mechanism, LMEKAU0021 displayed a strong impact on cell membrane integrity of both pathogens in single and mixed conditions. A hemolytic assay using horse blood cells at different concentrations of LMEKAU0021 confirmed the safety of this extract. The results from this study correlate the antimicrobial and anti-biofilm properties of lactobacilli against bacterial and fungal pathogens in different conditions. Further in vitro and in vivo studies determining these effects will support the aim of discovering an alternative strategy for combating serious polymicrobial infections caused by C. albicans and S. aureus.

Flufenamic Acid, a Promising Agent for the Sensitization of Colistin-Resistant Gram-Negative Bacteria to Colistin

The continuous development of multidrug-resistant (MDR) Gram-negative bacteria poses a serious risk to public health on a worldwide scale. Colistin is used as the last-line antibiotic for the treatment of MDR pathogens, and colistin-resistant (COL-R) bacterial emergence thus has the potential to have a severe adverse impact on patient outcomes. In this study, synergistic activity was observed when colistin and flufenamic acid (FFA) were combined and used for the in vitro treatment of clinical COL-R Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, and Acinetobacter baumannii strains, as shown by checkerboard and time-kill assays. Crystal violet staining and scanning electron microscopy revealed the synergistic action of colistin-FFA against biofilms. When used to treat murine RAW264.7 macrophages, this combination did not induce any adverse toxicity. Strikingly, the survival rates of bacterially infected Galleria mellonella larvae were improved by such combination treatment, which was also sufficient to reduce the measured bacterial loads in a murine thigh infection model. Mechanistic propidium iodide (PI) staining analysis further demonstrated the ability of these agents to alter bacterial permeability in a manner that enhanced the efficacy of colistin treatment. Together, these data thus demonstrate that colistin and FFA can be synergistically combined to combat the spread of COL-R Gram-negative bacteria, providing a promising therapeutic tool with the potential to protect against COL-R bacterial infections and improve patient outcomes. IMPORTANCE Colistin is a last-line antibiotic used for the treatment of MDR Gram-negative bacterial infections. However, increasing resistance to it has been observed during clinical treatment. In this work, we assessed the efficacy of the combination of colistin and FFA for the treatment of COL-R bacterial isolates, demonstrating that the combined treatment has effective antibacterial and antibiofilm activities. Due to its low cytotoxicity and good therapeutic effects in vitro, the colistin-FFA combination may be a potential candidate for research into a resistance-modifying agent to combat infections caused by COL-R Gram-negative bacteria.

An Overview of the Public Health Challenges in Diagnosing and Controlling Human Foodborne Pathogens

Pathogens found in food are believed to be the leading cause of foodborne illnesses; and they are considered a serious problem with global ramifications. During the last few decades, a lot of attention has been paid to determining the microorganisms that cause foodborne illnesses and developing new methods to identify them. Foodborne pathogen identification technologies have evolved rapidly over the last few decades, with the newer technologies focusing on immunoassays, genome-wide approaches, biosensors, and mass spectrometry as the primary methods of identification. Bacteriophages (phages), probiotics and prebiotics were known to have the ability to combat bacterial diseases since the turn of the 20th century. A primary focus of phage use was the development of medical therapies; however, its use quickly expanded to other applications in biotechnology and industry. A similar argument can be made with regards to the food safety industry, as diseases directly endanger the health of customers. Recently, a lot of attention has been paid to bacteriophages, probiotics and prebiotics most likely due to the exhaustion of traditional antibiotics. Reviewing a variety of current quick identification techniques is the purpose of this study. Using these techniques, we are able to quickly identify foodborne pathogenic bacteria, which forms the basis for future research advances. A review of recent studies on the use of phages, probiotics and prebiotics as a means of combating significant foodborne diseases is also presented. Furthermore, we discussed the advantages of using phages as well as the challenges they face, especially given their prevalent application in food safety.

Integrated Analysis of Gut Microbiome and Liver Metabolome to Evaluate the Effects of Fecal Microbiota Transplantation on Lipopolysaccharide/D-galactosamine-Induced Acute Liver Injury in Mice

Acute liver failure (ALF) refers to the occurrence of massive hepatocyte necrosis in a short time, with multiple complications, including inflammatory response, hepatic encephalopathy, and multiple organ failure. Additionally, effective therapies for ALF are lacking. There exists a relationship between the human intestinal microbiota and liver, so intestinal microbiota modulation may be a strategy for therapy of hepatic diseases. In previous studies, fecal microbiota transplantation (FMT) from fit donors has been used to modulate intestinal microbiota widely. Here, we established a mouse model of lipopolysaccharide (LPS)/D-galactosamine (D-gal) induced ALF to explore the preventive and therapeutic effects of FMT, and its mechanism of action. We found that FMT decreased hepatic aminotransferase activity and serum total bilirubin levels, and decreased hepatic pro-inflammatory cytokines in LPS/D-gal challenged mice (p < 0.05). Moreover, FMT gavage ameliorated LPS/D-gal induced liver apoptosis and markedly reduced cleaved caspase-3 levels, and improved histopathological features of the liver. FMT gavage also restored LPS/D-gal-evoked gut microbiota dysbiosis by modifying the colonic microbial composition, improving the abundance of unclassified_o_Bacteroidales (p < 0.001), norank_f_Muribaculaceae (p < 0.001), and Prevotellaceae_UCG-001 (p < 0.001), while reducing that of Lactobacillus (p < 0.05) and unclassified_f_Lachnospiraceae (p < 0.05). Metabolomics analysis revealed that FMT significantly altered LPS/D-gal induced disordered liver metabolites. Pearson's correlation revealed strong correlations between microbiota composition and liver metabolites. Our findings suggest that FMT ameliorate ALF by modulating gut microbiota and liver metabolism, and can used as a potential preventive and therapeutic strategy for ALF.

Potensi Probiotik Bakteri Asam Laktat Asal Madu dari Tiga Jenis Lebah yang Berbeda

Certain strains of Lactic acid bacteria (LAB) especially from the genus of Lactobacillus and Bifidobacteria have been recognized to have health beneficial effect as probiotics. Honey has been known to have health beneficial effects and contains lactic acid bacteria. However, information pertaining the characteristics of LAB from honey is still limited. The present research aimed to isolate LAB from different types of honey and to evaluate their potency as probiotic. The LAB were enumerated and isolated from honey produced by three different honeybees: Apis cerana, Heterotrigona itama, and Trigona laeviceps. The results showed the count of LAB in three different honey ranged from 5.0x101 to 2.3x107 CFU/mL and affected by different time of sampling. The highest of average LAB count was found in honey of Heterotrigona itama. There were 48 Gram positive catalase-negative bacterial isolates obtained from the three different honey types. Twelve isolates were selected based on their survival in bile salt. The twelve selected isolates were capable of growing in MRSB pH 2.5, and MRSB containing 0.3% bile salt. They also exhibited strong antibacterial activity against pathogenic bacteria. Identification based on 16S rRNA revealed that of the twelve isolates, nine were identified as Lactiplantibacillus plantarum and three others as Pediococcus acidilactici. The twelve isolates showed high survival at low pH dan bile salt and exhibited antimicrobial activity against pathogen, hence they are considered as probiotic candidates.

Inhibition of Pathogenic Microbes by the Lactic Acid Bacteria Limosilactobacillus Fermentum Strain LAB-1 and Levilactobacillus Brevis Strain LAB-5 Isolated from the Dairy Beverage Borhani

Lactic acid bacteria (LAB) with prominent antimicrobial effects against pathogens have been reported in several milk-based and plant-based foods. Borhani is a popular beverage prepared from the ingredients of both dairy and plant origins and is believed to be highly beneficial for health. Herein, we report the pathogen-inhibitory activity of two borhani-associated lactic acid bacteria (LAB), Limosilactobacillus fermentum strain LAB-1 and Levilactobacillus brevis strain LAB-5. Their antimicrobial activity was primarily assessed using the cell free supernatant (CFS) by agar diffusion technique in which both strains showed strong antimicrobial effects against several pathogenic and spoilage microorganisms including Acinetobacter baumannii, Bacillus cereus, Bacillus subtilis, Escherichia coli, Klebsiella pneumonia, Pseudomonas aeruginosa, Salmonella abony, Salmonella typhi, Shigella flexneri, and Staphylococcus aureus. The L. fermentum strain with its ability to inhibit all the target pathogens appeared to be more effective with larger inhibition-zone formation as compared to the L. brevis strain which also successfully inhibited all pathogens but had relatively little effects on A. baumannii. The extent of their inhibitory effect was further assessed by co-culture inhibition assay in which growth of the test microbes was monitored for 24 hours in presence of the CFS. The CFS of both lactic acid bacteria could effectively inhibit growth of the pathogenic microbes for a significant period of time. While the L. fermentum strain could almost completely stop growth of all test organisms, the L. brevis strain was particularly effective against Shigella flexneri and the Salmonella species. Our study, therefore, suggests the presence of beneficial lactic acid bacteria in borhani which can be of important use as antimicrobial agents in functional foods and therapeutics to help acquire protection against drug resistant pathogens.

Antimicrobial activity of dominant Ligilactobacillus animalis strains in healthy canine feces and their probiotic potential

The number of companion animals living with humans has continually increased over the last few decades, and so has the interest of owners and stakeholders in the animal food and probiotics industry. Currently, the probiotic bacteria added to the feed of companion animals predominantly originate from the lactic acid bacteria (LAB) used for humans; however, there are differences between the microbiota of humans and that of their companion animals. This study aimed to determine the dominant LAB in dog feces and investigate their functional properties. Ligilactobacillus animalis (formerly called Lactobacillus animalis) was identified as the dominant lactic acid bacterium in dog feces. It displayed various inhibitory effects against pathogenic and enteropathogenic bacteria. This finding suggests that Ligilactobacillus animalis can potentially be used in novel probiotics or as a food additive for dogs.

The effect of Lactobacillus with prebiotics on KPC-2-producing Klebsiella pneumoniae

Objectives

This study investigated the inhibitory effect of Lactobacillus spp. with prebiotics against Klebsiella pneumoniae carbapenemase-2 (KPC-2)-producing Klebsiella pneumoniae using both in vitro experiments and animal models.

Methods

Thirty-three Lactobacillus spp. strains were confirmed by 16S rDNA sequencing, and four different PFGE genotyped KPC-2-producing K. pneumoniae strains were selected for investigation. In vitro studies, including broth microdilution assays, changes in pH values in lactobacilli cultures with different prebiotics, time-kill tests of Lactobacillus spp. against KPC-2-producing K. pneumoniae and further in vivo Lactobacillus alone or in combination with prebiotics against KPC-2-producing K. pneumoniae in an animal model, were performed.

Results

The lower pH value of the cell-free supernatant was associated with a lower minimal inhibitory percentage of the Lactobacillus strain against KPC-2-producing K. pneumoniae. Furthermore, lactulose/isomalto-oligosaccharide/inulin and fructo-oligosaccharide can enhance the inhibitory effect of all 10⁷ CFU/ml Lactobacillus strains against KPC001. Three Lactobacillus strains (LYC1154, LYC1322, and LYC1511) that could be persistently detected in the stool were tested for their ability to reduce the amount of KPC001 in the feces individually or in combination. A significantly better effect in reducing the amount of KPC001 was observed for the combination of three different Lactobacillus species than for each of them alone. Furthermore, their inhibitory effect was enhanced after adding lactulose or isomalto-oligosaccharide (both p < 0.05).

Conclusion

This study demonstrates the inhibitory effect of probiotic Lactobacillus, including LYC1154, LYC1322, and LYC1511, with prebiotics such as lactulose or isomalto-oligosaccharide against the colonization of KPC-2-producing K. pneumoniae.

Lactiplantibacillus plantarum KAU007 Extract Modulates Critical Virulence Attributes and Biofilm Formation in Sinusitis Causing Streptococcus pyogenes

Streptococcus pyogenes is one of the most common bacteria causing sinusitis in children and adult patients. Probiotics are known to cause antagonistic effects on S. pyogenes growth and biofilm formation. In the present study, we demonstrated the anti-biofilm and anti-virulence properties of Lactiplantibacillus plantarum KAU007 against S. pyogenes ATCC 8668. The antibacterial potential of L. plantarum KAU007 metabolite extract (LME) purified from the cell-free supernatant of L. plantarum KAU007 was evaluated in terms of minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC). LME was further analyzed for its anti-biofilm potential using crystal violet assay and microscopic examination. Furthermore, the effect of LME was tested on the important virulence attributes of S. pyogenes, such as secreted protease production, hemolysis, extracellular polymeric substance production, and cell surface hydrophobicity. Additionally, the impact of LME on the expression of genes associated with biofilm formation and virulence attributes was analyzed using qPCR. The results revealed that LME significantly inhibited the growth and survival of S. pyogenes at a low concentration (MIC, 9.76 µg/mL; MBC, 39.06 µg/mL). Furthermore, LME inhibited biofilm formation and mitigated the production of extracellular polymeric substance at a concentration of 4.88 μg/mL in S. pyogenes. The results obtained from qPCR and biochemical assays advocated that LME suppresses the expression of various critical virulence-associated genes, which correspondingly affect various pathogenicity markers and were responsible for the impairment of virulence and biofilm formation in S. pyogenes. The non-hemolytic nature of LME and its anti-biofilm and anti-virulence properties against S. pyogenes invoke further investigation to study the role of LME as an antibacterial agent to combat streptococcal infections.

Characterization, High-Density Fermentation, and the Production of a Directed Vat Set Starter of Lactobacilli Used in the Food Industry: A Review

Lactobacilli have been widely concerned for decades. Bacteria of the genus Lactobacillus have been commonly employed in fermented food to improve the appearance, smell, and taste of food or prolong its shelf-life. They comprise 261 species (by March 2020) that are highly diverse at the phenotypic, ecological, and genotypic levels. Some Lactobacilli strains have been documented to be essential probiotics, which are defined as a group of living microorganisms that are beneficial to the health of the host when ingested in sufficiency. However, the characterization, high-density fermentation, and the production of a directed vat set (DVS) starter of Lactobacilli strains used in the food industry have not been systematically reported. This paper mainly focuses on reviewing Lactobacilli as functional starter cultures in the food industry, including different molecular techniques for identification at the species and strain levels, methods for evaluating Lactobacilli properties, enhancing their performance and improving the cell density of Lactobacilli, and the production techniques of DVS starter of Lactobacilli strains. Moreover, this review further discussed the existing problems and future development prospects of Lactobacilli in the food industry. The viability and stability of Lactobacilli in the food industry and gastrointestinal environment are critical challenges at the industrial scale. The new production equipment and technology of DVS starter of Lactobacilli strains will have the potential for large-scale application, for example, developing low-temperature spray drying, freezing granulation drying, and spray freeze-drying.

Quantitative and qualitative characterization of commercially available oral suspension of probiotic products containing Bacillus Clausii spores

Probiotics contain beneficial live bacteria that confer several health benefits to the host. For the past 50 years, spore-forming Bacillus species have been used in the form of probiotics. Among these, Bacillus clausii strains are used for the management of acute and antibiotic-associated diarrhoea. In the present work, we have evaluated the asserted label information on randomly chosen commercial Bacillus clausii spore suspension of probiotic products. The quality and number of viable bacteria were evaluated based on the colony count, antibiotic resistance, and hemolytic activity assays. The colony fingerprinting and 16S rRNA gene-sequencing techniques were used to confirm the presence of a univariate strain (Bacillus clausii). Our results corroborated the label count of 2 × 10⁹ CFU/5 mL in BACIPRO®, ENTEROGERMINA®, and TUFPRO® products. However, vegetative spore count was not found to match with the given label count in BENEGUT®, PROALANA-B®, β-LOCK®, and PROCILLUS® Bacillus clausii brands. In the hemolytic activity assay, except for β-LOCK®, the other 6 products showed gamma-hemolysis activity. Bacillus clausii isolated from all 7 probiotic products demonstrated resistance to several broad-spectrum antibiotics. The 16S rRNA gene-sequencing data detected genera of Bacillus and Bacillus clausii strain in the BACIPRO®, ENTEROGERMINA®, PROALANA-B®, BENEGUT®, and TUFPRO® products; however, Ralstonia mannitolilytica and Paenibacillus dendritiformis species were identified in β-LOCK® and PROCILLUS®, respectively. As correct label information was observed only in BACIPRO®, ENTEROGERMINA®, and TUFPRO® products, it is proposed that a more stringent quality check would minimize the possibility of mismatch concerning the label information.

Antimicrobial potential of probiotic cell-free and Carum copticum L. seed extracts co-nanoencapsulated in cellulose acetate fibers

The aim of this work was to co-nanoencapsulate Lactobacillus acidophilus (LCFE) and Bifidobacterium bifidum (BCFE) cell-free extract and zenyan (Carum copticum L.) seed water (ZWE) and ethanolic (ZEE) extract in electrospun cellulose acetate (CA) nanofibers and evaluate antimicrobial potential. The zeta potential, SEM image, antibacterial (MIC and MBC), and antifungal (MIC and MFC) activities were evaluated. TPC (total phenol content) of water and ethanol extract of zenyan seed were 14.05 and 136.44 mg GAE/g, respectively. A zeta potential of -40.25, -45.80, -43.71, 48.55, 35.50, 47.93, 31.50, 44.69, and -29.61 mV was found for nanofibers of pure CA (cellulose acetate), CA/LCFE, CA/BCFE, CA/ZWE, CA/ZEE, CA/LCFE/ZWE, CA/LCFE/ZEE, CA/BCFE/ZWE, and CA/LCFE/ZEE, respectively. CA electrospun nanofiber loaded with different extracts showed nanosized diameter and uniform structure. Nanoencapsulated extracts showed considerably higher antibacterial and antifungal activity compared to free extracts. Antibacterial activity of lactobacilli cell-free extract was higher than bifidobacteria, which indicated the presence of the higher amount of antibacterial compounds in lactobacilli extract. Gram-positive bacteria (S. aureus and L. monocytogenes) had the lowest MIC and MBC of free and nanoencapsulated extracts while Gram-negatives (E. coli, S. dysenteriae, and S. enteritidis) had higher MIC and MBC. CA-coated zenyan extracts (water and ethanolic) inhibited the growth of the assayed fungi at the MIC ranging 0.25 to 0.95%. These concentrations were 1.5-2 times lower than those obtained for pure extracts. For nanoencapsulated cell-free extracts of both probiotics, the MIC values were about five times lower than the free extracts. The highest antimicrobial activity obtained for CA nanofibers contained zenyan ethanolic extract and cell-free extract of lactobacilli or bifidobacteria.

Organic Acids Secreted by Lactobacillus spp. Isolated from Urine and Their Antimicrobial Activity against Uropathogenic Proteus mirabilis

The natural microbiota of the urinary tract includes Lactobacillus spp., which secrete molecules with antimicrobial properties and have antagonistic activity against many pathogens. This paper focuses on the antibacterial effect of Lactobacillus strains isolated from urine against clinical strains of Proteus mirabilis isolated from kidney stones and from urine with coexisting urolithiasis. The study involved analyzing the main antimicrobial molecules secreted by Lactobacillus. In order to indicate which agent had the strongest antimicrobial effect, the supernatants were made alkaline and treated with catalase and high temperature. Both treated and untreated supernatants were analyzed for their activity. Exposing uropathogens to all untreated cell-free supernatants of Lactobacillus significantly reduced their growth, and it was established that these properties were related to organic acid secretion by these strains. Using LC–MS/MS and spectrophotometric techniques, lactic, citric, and succinic acids were determined qualitatively and quantitatively. The influence of these acids on the P. mirabilis growth and biofilm formation and their influence on membrane permeability were also investigated. The results indicate that organic acids secreted by Lactobacillus strains have a high antibacterial potential and could be used as novel agents in the treatment of urinary tract infections caused by P. mirabilis.

Lactobacillus plantarum-derived postbiotics prevent Salmonella-induced neurological dysfunctions by modulating gut-brain axis in mice

Postbiotics are the inactive bacteria and/or metabolites of beneficial microbes which have been recently found to be as effective as their live probiotic. This study aimed to evaluate the benefits of Lactobacillus plantarum (LP)-derived postbiotics on ameliorating Salmonella-induced neurological dysfunctions. Mice were pretreated with LP postbiotics (heat-killed bacteria or the metabolites) or active bacteria, and then challenged with Salmonella enterica Typhimurium (ST). Results showed that LP postbiotics, particularly the metabolites, effectively prevented ST infection in mice, as evidenced by the inhibited weight loss, bacterial translocation, and tissue damages. The LP postbiotics markedly suppressed brain injuries and neuroinflammation (the decreased interleukin (IL)-1β and IL-6, and the increased IL-4 and IL-10). Behavior tests indicated that LP postbiotics, especially the metabolites, protected mice from ST-induced anxiety and depressive-like behaviors and cognitive impairment. A significant modulation of neuroactive molecules (5-hydroxytryptamine, gamma-aminobutyric acid, brain-derived neurotrophic factor, dopamine, acetylcholine, and neuropeptide Y) was also found by LP postbiotic pretreatment. Microbiome analysis revealed that LP postbiotics optimized the cecal microbial composition by increasing Helicobacter, Lactobacillus and Dubosiella, and decreasing Mucispirillum, norank_f_Oscillospiraceae, and Eubacterium_siraeum_group. Moreover, LP postbiotics inhibited the reduction of short-chain fatty acids caused by ST infection. Pearson's correlation assays further confirmed the strong relationship of LP postbiotics-mediated benefits and gut microbiota. This study highlights the effectiveness of postbiotics and provide a promising strategy for preventing infection-induced brain disorders by targeting gut–brain axis.

Production of plant-based fermented beverages possessing functional ingredients antioxidant, γ-aminobutyric acid and antimicrobials using a probiotic Lactiplantibacillus plantarum strain L42g as an efficient starter culture

Plant-based probiotic beverages have gained increasing interest due to demand from health-conscious consumers. In this study, we aimed to isolate and screen lactic acid bacteria possessing functional properties for use as a starter culture of fermented almond and coix beverages. Lactiplantibacillus plantarum L42g isolated from fermented beef was selected. Both intact cells and cell free supernatant of this strain exhibited high antioxidant activity based on 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging at 38.2% and 44.9%, respectively. L. plantarum L42g grown in MRS broth supplemented with 1% (w v^-1) monosodium glutamate (MSG) produced a large amount of γ-aminobutyric acid (GABA) at 496.7 μg mL^-1. Moreover, strain L42g displayed remarkable antibacterial activity against several potential foodborne bacterial pathogens, including Bacillus cereus, Listeria monocytogenes, Listeria inocua, Staphylococcus aureus, Streptococcus agalactiae, Escherichia coli, Salmonella enterica subsp. enterica serovar Typhimurium, Shigella sp., Vibrio cholerae and Vibrio parahaemolyticus. Strain L42g also possessed additional probiotic properties including abilities to tolerate gastrointestinal conditions, adhere to gut mucosa, co-aggregate with pathogens, be susceptible to antibiotics, and produce protease. Probiotic strain L42g was subsequently employed in fermenting almond and coix juices containing MSG (1%) supplementation. Levels of antioxidant, GABA and antibacterial formation along with cell growth were clearly higher in fermented almond juice than in fermented coix juice. Nonetheless, both fermented almond and coix juices meet the standards required for the consumption of fermented beverages. Therefore, L. plantarum strain L42g represents a promising starter culture for producing functional plant-based probiotic beverages.

A Japanese Herbal Formula, Daikenchuto, Alleviates Experimental Colitis by Reshaping Microbial Profiles and Enhancing Group 3 Innate Lymphoid Cells

Daikenchuto (DKT) is one of the most widely used Japanese herbal formulae for various gastrointestinal disorders. It consists of Zanthoxylum Fructus (Japanese pepper), Zingiberis Siccatum Rhizoma (processed ginger), Ginseng radix, and maltose powder. However, the use of DKT in clinical settings is still controversial due to the limited molecular evidence and largely unknown therapeutic effects. Here, we investigated the anti-inflammatory actions of DKT in the dextran sodium sulfate (DSS)-induced colitis model in mice. We observed that DKT remarkably attenuated the severity of experimental colitis while maintaining the members of the symbiotic microbiota such as family Lactobacillaceae and increasing levels of propionate, an immunomodulatory microbial metabolite, in the colon. DKT also protected colonic epithelial integrity by upregulating the fucosyltransferase gene Fut2 and the antimicrobial peptide gene Reg3g. More remarkably, DKT restored the reduced colonic group 3 innate lymphoid cells (ILC3s), mainly RORγt^high-ILC3s, in DSS-induced colitis. We further demonstrated that ILC3-deficient mice showed increased mortality during experimental colitis, suggesting that ILC3s play a protective function on colonic inflammation. These findings demonstrate that DKT possesses anti-inflammatory activity, partly via ILC3 function, to maintain the colonic microenvironment. Our study also provides insights into the molecular basis of herbal medicine effects, promotes more profound mechanistic studies towards herbal formulae and contributes to future drug development.

Pro-, pre- and synbiotics for the prevention of incidental ventilator-associated pneumonia among critically ill patients: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVES

This study investigated the preventive effects of pro-, pre- and synbiotics on ventilator-associated pneumonia (VAP) among critically ill patients.

METHODS

The PubMed, Web of Science, Ovid MEDLINE, Embase, Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov databases were searched for relevant articles written before 19 February 2022. Only randomized controlled trials (RCTs) comparing the clinical efficacy of pro-, pre- and synbiotics with placebos or standard treatments for the prevention of incidental VAP were included.

RESULTS

A total of 15 RCTs were included. Patients receiving pro-, pre- and synbiotics had a lower risk than the control group of contracting VAP (risk ratio [RR], 0.70; 95% CI, 0.57-0.85; I² = 67%). The duration of mechanical ventilation was significantly shorter in the study group than in the control group (mean difference [MD], -1.61 days; 95% CI, -2.72 to -0.50; I² = 86%), and the study group had a shorter duration of stay in the intensive care unit than the control group did (MD, -1.72 days; 95% CI, -3.22 to -0.23; I² = 87%).

CONCLUSIONS

Pro-, pre- and synbiotics can prevent VAP and the use of probiotics for patients who are critically ill should be supported.

Analysis and Characterization of Lactobacillus paragasseri and Lacticaseibacillus paracasei: Two Probiotic Bacteria that Can Degrade Intestinal Oxalate in Hyperoxaluric Rats

In the present study, we characterized the probiotic properties of two commercially available bacterial strains, Lactobacillus paragasseri UBLG-36 and Lacticaseibacillus paracasei UBLPC-87, and evaluated their ability to degrade oxalate in vitro and in a hyperoxaluria-induced nephrolithiasis rat model. UBLG-36 harboring two oxalate catabolizing genes, oxalyl coenzyme A decarboxylase (oxc) and formyl coenzyme A transferase (frc), was previously shown to degrade oxalate in vitro effectively. Here, we show that UBLPC-87, lacking both oxc and frc, could still degrade oxalate in vitro. Both these strains harbored several potential putative probiotic genes that may have conferred them the ability to survive in low pH and 0.3% bile, resist antibiotic stress, show antagonistic activity against pathogenic bacteria, and adhere to epithelial cell surfaces. We further evaluated if UBLG-36 and UBLPC-87 could degrade oxalate in vivo and prevent hyperoxaluria-induced nephrolithiasis in rats. We observed that rats treated with 4.5% sodium oxalate (NaOx) developed hyperoxaluria and renal stones. However, when pre-treated with UBLG-36 or UBLPC-87 before administering 4.5% NaOx, the rats were protected against several pathophysiological manifestations of hyperoxaluria. Compared to the hyperoxaluric rats, the probiotic pre-treated rats showed reduced urinary excretion of oxalate and urea (p < 0.05), decreased serum blood urea nitrogen and creatinine (p < 0.05), alleviated stone formation and renal histological damage, and an overall decrease in renal tissue oxalate and calcium content (p < 0.05). Taken together, both UBLG-36 and UBLPC-87 are effective oxalate catabolizing probiotics capable of preventing hyperoxaluria and alleviating renal damage associated with nephrolithiasis.

Optimization of cultural conditions for enhancement of anti-quorum sensing potential in the probiotic strain Lactobacillus rhamnosus GG against Pseudomonas aeruginosa

Disruption of quorum sensing (QS) system, which is a central regulator for pathogenesis of Pseudomonas aeruginosa, is referring to as quorum quenching (QQ). This study was undertaken to evaluate and enhance the anti-quorum sensing (AQS) potential of probiotic strain Lactobacillus rhamnosus GG. The cell-free supernatant (CFS) of this probiotic strain showed anti-quorum sensing activity against Pseudomonas aeruginosa, which was determined using well-diffusion agar-plate assay. Anti-quorum sensing potential of L. rhamnosus GG was enhanced by optimization of various cultural conditions using classical and statistical optimization approaches. Six variables were optimized using one-variable-at-a-time (OVAT) method. Four significant variables, viz., temperature, pH, incubation time, metal ion, and its concentration, were chosen for further optimization by response surface methodology (RSM) using central composite design (CCD). Analysis of variance (ANOVA) demonstrated that the regression model is highly significant, as indicated by F test with a low probability value (p  < 0.0002) and high value of coefficient of determination (0.8738) and also had significant influence on the generation of anti-quorum sensing effector molecules. Maximum production of anti-quorum sensing activity, in terms of zones of inhibition, was achieved under the following optimized conditions such as 37 °C temperature, pH 6.5, incubation time 24 h, and 2.5 mM concentration of zinc sulfate (ZnSO₄). The quadratic model predicted 1.3-fold increase anti-quorum sensing activity production over un-optimized cultural conditions. The present research is the first report representing the enhancement of anti-quorum sensing potential of L. rhamnosus GG.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-022-03187-2.

In vitro anti-tuberculosis effect of probiotic Lacticaseibacillus rhamnosus PMC203 isolated from vaginal microbiota

Mycobacterium tuberculosis (M. tb), the etiological agent of tuberculosis (TB), poses a severe challenge for public health and remains the number one cause of death as a single infectious agent. There are 10 million active cases of TB per year with 1.5 million deaths, and 2-3 billion people are estimated to harbor latent M. tb infection. Moreover, the emergence of multi-drug-resistant (MDR), extremely-drug-resistant (XDR), and the recent totally drug-resistant (TDR) M. tb is becoming a global issue that has fueled the need to find new drugs different from existing regimens. In these circumstances, probiotics can be a potential choice, so we focused on developing them as an anti-tuberculosis drug candidate. Here, we report the anti-tubercular activities of Lacticaseibacillus rhamnosus PMC203 isolated from the vaginal microbiota of healthy women. PMC203 exhibited a promising intracellular killing effect against both drug-sensitive and resistant M. tb infected murine macrophage cell line RAW 264.7 without showing any cytotoxicity. Additionally, it also inhibited the growth of M. tb under broth culture medium. PMC203 did not cause weight change or specific clinical symptoms in a 2-week repeated oral administration toxicity test in a guinea pig model. Here, we also found that PMC203 induces autophagy in a dose dependent manner by increasing the signal of well-known autophagy gene markers, suggesting a possible intracellular killing mechanism.

Acids produced by lactobacilli inhibit the growth of commensal Lachnospiraceae and S24-7 bacteria

The Lactobacillaceae are an intensively studied family of bacteria widely used in fermented food and probiotics, and many are native to the gut and vaginal microbiota of humans and other animals. Various studies have shown that specific Lactobacillaceae species produce metabolites that can inhibit the colonization of fungal and bacterial pathogens, but less is known about how Lactobacillaceae affect individual bacterial species in the endogenous animal microbiota. Here, we show that numerous Lactobacillaceae species inhibit the growth of the Lachnospiraceae family and the S24-7 group, two dominant clades of bacteria within the gut. We demonstrate that inhibitory activity is a property common to homofermentative Lactobacillaceae species, but not to species that use heterofermentative metabolism. We observe that homofermentative Lactobacillaceae species robustly acidify their environment, and that acidification alone is sufficient to inhibit growth of Lachnospiraceae and S24-7 growth, but not related species from the Clostridiales or Bacteroidales orders. This study represents one of the first in-depth explorations of the dynamic between Lactobacillaceae species and commensal intestinal bacteria, and contributes valuable insight toward deconvoluting their interactions within the gut microbial ecosystem.

Evaluation of different bacterial honey isolates as probiotics and their efficient roles in cholesterol reduction

Continue to hypothesize that honey is a storehouse of beneficial bacteria, and the majority of these isolates are levansucrase producers. Accordingly, ten bacterial strains were isolated from different honey sources. Four honey isolates that had the highest levansucrase production and levan yield were identified by the partial sequencing of the 16S rRNA gene as Achromobacter sp. (10A), Bacillus paralicheniformis (2M), Bacillus subtilis (9A), and Bacillus paranthracis (13M). The cytotoxicity of the selected isolates showed negative blood hemolysis. Also, they are sensitive to the tested antibiotics (Amoxicillin + Flucloxacillin, Ampicillin, Gentamicin, Benzathine benzylpenicillin, Epicephin, Vancomycin, Amikacin, and Zinol). The isolates had strong alkaline stability (pHs 9, 11) and were resistant to severe acidic conditions (29-100 percent). The tested isolates recorded complete tolerance to both H₂O₂ and the bile salt (0.3% Oxgall powder) after 24 h incubation. The cell-free supernatant of the examined strains had antifungal activities against C. Albicans with varying degrees. Also, isolates 2M and 13M showed strong activities against S. aureus. The isolates showed strong adhesion and auto-aggregation capacity. Isolate 10A showed the highest antioxidant activity (91.45%) followed by 2M (47.37%). The isolates recorded different catalase and protease activity. All isolates produced cholesterol oxidase and lipase with different levels. Besides, the four isolates reduced LDL (low-density lipoprotein) to different significant values. The cholesterol-reducing ability varied not only for strains but also for the time of incubation. The previous results recommended these isolates be used safely in solving the LDL problem.

Isolation of Efficient Xylooligosaccharides-Fermenting Probiotic Lactic Acid Bacteria from Ethnic Pickled Bamboo Shoot Products

Xylooligosaccharides (XOSs) are produced from xylan, which is a component of the hemicellulose that can be found in bamboo shoots. Naw Mai Dong, an ethnic pickled bamboo shoot product of northern Thailand, is generally characterized as acidic and has a sour taste. It can be considered a potential source of probiotic lactic acid bacteria (LAB). This study aimed to isolate efficient XOSs-fermenting probiotic LAB from ethnic pickled bamboo shoot products. A total of 51 XOSs-fermenting LAB were recovered from 24 samples of Naw Mai Dong, while 17 strains exhibited luxuriant growth in xylose and XOSs. Among these, seven strains belonging to Levicaseibacillus brevis and Pediococcus acidilactici exhibited similar growth in glucose, xylose, and XOSs, while the rest showed a weaker degree of growth in xylose and XOSs than glucose. Sixteen strains exhibited resistance under gastrointestinal tract conditions and displayed antimicrobial activity against foodborne pathogens. Notably, Lv. brevis FS2.1 possessed the greatest probiotic properties, with the highest %hydrophobicity index and %auto-aggregation. Effective degradation and utilization of XOSs by probiotic strains are dependent upon xylanase and β-xylosidase production, as well as xylose metabolism. It can be concluded that pickled bamboo shoot products can be a beneficial source of XOSs-fermenting probiotic LAB.

Probiotic Formulations: A Patent Landscaping Using the Text Mining Approach

The outstanding research outcomes and registrations of myriads of probiotic strains have flooded the health market with various innovative probiotic-based products and their patents. The study of patented formulations of probiotics can give an overall insight into its existing application. A landscaping review of patents for probiotic-based preparations is presented in the current work. The patent search was performed over commercially available patent databased and analysis tool-PatSeer Pro®. Search strings containing words "Formulation" and "Composition" resulted in more than 3700 patents. Landscaping review of 400 + patents from the last 20 years (2000-2020) was performed using the Text-Mining approach. Text-Mining helped to identify 19 technological clusters which represent these patents. These clusters include the patents of probiotic preparations on animal feed, human food, cosmetics, antimicrobial, antidiabetic, arthritis, etc. A review of this massive number of patents unveiled many exciting preparations. Probiotic-based innovative products for depression, diabetes, Parkinson's, tumor, acne, and animal husbandry are reviewed comprehensively. The present work also unravels a few new-flanged products like probiotic layered condoms, products for acute alcoholism, and traditional Chinese medicine with probiotics. The patent landscape of probiotic-based preparations has presented a whole scenario of probiotic-based preparations. It has also revealed many unexplored areas where innovation can be excelled.

Anticolonization of Carbapenem-Resistant Klebsiella pneumoniae by Lactobacillus plantarum LP1812 Through Accumulated Acetic Acid in Mice Intestinal

Carbapenem-resistant Klebsiella pneumoniae (CRKP) is highly prevalent and poses a significant threat to public health. In critically ill patients, gut colonization is considered to be the reservoir of recurrent CRKP infection. Therefore, eliminating CRKP carriage in the intestine is critical for preventing subsequent CRKP infection. In the present study, Lactobacillus plantarum LP1812, a probiotic that can inhibit CRKP in vitro, was used as a candidate probiotic to investigate its efficacy for CRKP anticolonization. Compared with the control, mice fed with 1×10 ⁸ CFU L. plantarum LP1812 exhibited significant CRKP clearance from 1×10 ⁴ CFU/mg to less than 10 CFU/mg in mice feces. Furthermore, 16S RNA gene sequencing revealed that L. plantarum LP1812 modulated mice microbiota by increasing the relative abundance of the genus Halomanas, Blautia, and Holdemania. Further KEGG pathway enrichment analysis revealed that fatty acid-utilizing bacteria, such as acetate-producing Bacteroidetes and Blautia flourished in mice fed with L. plantarum LP1812. Moreover, we found that the concentration of acetic acid was higher in L. plantarum LP1812, which inhibited the growth of K. pneumoniae strains in vitro. Meanwhile, mice intragastrically administered with acetic acid exhibited significantly increased CRKP elimination in vivo. In conclusion, L. plantarum LP1812 is a potential candidate for intestinal CRKP anticolonization by regulating the intestinal microbiota and inhibiting CRKP via increased acetic acid in the intestinal lumen.