Probiotic Potential Research Articles

Exploring the diversity of vaginal microbiota between healthy women and cervical cancer patients in India.

Introduction. Cervicovaginal diversity has been reported as a predictive biomarker for cervical cancer risk. We recently reported the bio-therapeutic potential of vaginal probiotics from healthy Indian women against vaginal pathogens, isolated from the invasive cervical cancer (ICC) patients.Gap Statement. The cervicovaginal microflora from cervical cancer patients has not yet been reported from Indian population.Aim. The present study aimed at comparing the cervicovaginal microbiome between healthy controls (HC) and ICC patients from the Indian population.Methodology. In total, 30 vaginal swabs (15 from HC and 15 from ICC) were subjected to 16S rRNA gene sequencing. Alpha diversity was evaluated by Shannon and Chao1 index; and beta diversity by principle coordinate analysis (PCoA) of weighted and unweighted UniFrac distances. The relative abundance of the microbial taxa was done according to linear discriminant analysis effect size (LEfSe).Results. Predominance of Staphylococcus spp. in ICC and Lactobacillus gasseri in HC groups was observed. Alpha-diversity was found to be higher in ICC as compared to HC but was statistically non-significant. LEfSe analysis revealed Bacteroides fragilis and Escherichia coli as the marker genera in ICC with a marked decrease in Lactobacillus sp. Contrarily, in HC, L. gasseri, L. iners and L. fermentum were found to be abundant.Conclusion. Differences in the vaginal microbiome between healthy and ICC women could help in the early prediction of cervical cancer risk and thus in designing prevention strategies.

Unlocking the Potential of Probiotics: A Comprehensive Review on Research, Production, and Regulation of Probiotics.

This review provides a comprehensive overview of the current state of probiotic research, covering a wide range of topics, including strain identification, functional characterization, preclinical and clinical evaluations, mechanisms of action, therapeutic applications, manufacturing considerations, and future directions. The screening process for potential probiotics involves phenotypic and genomic analysis to identify strains with health-promoting properties while excluding those with any factor that could be harmful to the host. In vitro assays for evaluating probiotic traits such as acid tolerance, bile metabolism, adhesion properties, and antimicrobial effects are described. The review highlights promising findings from in vivo studies on probiotic mitigation of inflammatory bowel diseases, chemotherapy-induced mucositis, dysbiosis, obesity, diabetes, and bone health, primarily through immunomodulation and modulation of the local microbiota in human and animal models. Clinical studies demonstrating beneficial modulation of metabolic diseases and human central nervous system function are also presented. Manufacturing processes significantly impact the growth, viability, and properties of probiotics, and the composition of the product matrix and supplementation with prebiotics or other strains can modify their effects. The lack of regulatory oversight raises concerns about the quality, safety, and labeling accuracy of commercial probiotics, particularly for vulnerable populations. Advancements in multi-omics approaches, especially probiogenomics, will provide a deeper understanding of the mechanisms behind probiotic functionality, allowing for personalized and targeted probiotic therapies. However, it is crucial to simultaneously focus on improving manufacturing practices, implementing quality control standards, and establishing regulatory oversight to ensure the safety and efficacy of probiotic products in the face of increasing therapeutic applications.

Hi-C metagenomics facilitate comparative genome analysis of bacteria and yeast from spontaneous beer and cider

Sequence-based analysis of fermented foods and beverages' microbiomes offers insights into their impact on taste and consumer health. High-throughput metagenomics provide detailed taxonomic and functional community profiling, but bacterial and yeast genome reconstruction and mobile genetic elements tracking are to be improved.We established a pipeline for exploring fermented foods microbiomes using metagenomics coupled with chromosome conformation capture (Hi-C metagenomics). The approach was applied to analyze a collection of spontaneously fermented beers and ciders (n = 12). The Hi-C reads were used to reconstruct the metagenome-assembled genomes (MAGs) of bacteria and yeasts facilitating subsequent comparative genomic analysis, assembly scaffolding and exploration of “plasmid-bacteria” links. For a subset of beverages, yeasts were isolated and characterized phenotypically.The reconstructed Hi-C MAGs primarily belonged to the Lactobacillaceae family in beers, along with Acetobacteraceae and Enterobacteriaceae in ciders, exhibiting improved quality compared to conventional metagenomic MAGs. Comparative genomic analysis of Lactobacillaceae Hi-C MAGs revealed clustering by niche and suggested genetic determinants of survival and probiotic potential. For Pediococcus damnosus, Hi-C-based networks of contigs enabled linking bacteria with plasmids. Analyzing phylogeny and accessory genes in the context of known reference genomes offered insights into the niche specialization of beer lactobacilli. The subspecies-level diversity of cider Tatumella spp. was disentangled using a Hi-C-based graph. We obtained highly complete yeast Hi-C MAGs primarily represented by Brettanomyces and Saccharomyces, with Hi-C-facilitated chromosome-level genome assembly for the former.Utilizing Hi-C metagenomics to unravel the genomic content of individual species can provide a deeper understanding of the ecological interactions within the food microbiome, aid in bioprospecting beneficial microorganisms, improving quality control and improving innovative fermented products.

Evaluation of Potential Probiotic Properties and In Vivo Safety of Lactic Acid Bacteria and Yeast Strains Isolated from Traditional Home-Made Kefir.

Probiotics are known for their health-promoting resources and are considered as beneficial microorganisms. The current study focuses on the isolation, and on a complete in vitro and in vivo characterization, of yeast and lactic acid bacteria acquired from traditional homemade kefir in order to assess their potentiality as probiotic candidates. In particular, the isolates Pichia kudriavzevii Y1, Lactococcus lactis subsp. hordniae LAB1 and Lactococcus lactis subsp. lactis LAB2 were subjected to in vitro characterization to evaluate their suitability as probiotics. Resistance to acid and bile salts, auto-aggregation, co-aggregation, hydrophobicity, and biofilm production capability were examined, as well as their antioxidant activity. A safety assessment was also conducted to confirm the non-pathogenic nature of the isolates, with hemolysis assay and antibiotic resistance assessment. Moreover, mortality in the invertebrate model Galleria mellonella was evaluated. Current findings showed that P. kudriavzevii exhibited estimable probiotic properties, placing them as promising candidates for functional foods. Both lactic acid bacteria isolated in this work could be classified as potential probiotics with advantageous traits, including antimicrobial activity against enteric pathogens and good adhesion ability on intestinal cells. This study revealed that homemade kefir could be a beneficial origin of different probiotic microorganisms that may enhance health and wellness.

Weissella sp. SNUL2 as potential probiotics with broad-spectrum antimicrobial activities

Probiotics have been applied to a wide range of bacteria, causing gastrointestinal and vaginal infections. However, probiotics generally possess limited antimicrobial spectra and are primarily utilized as dietary supplements. Recognizing the need for more versatile probiotics, this study focuses on isolating and characterizing strains suitable for antibiotic replacement. Among these strains, Weissella sp. SNUL2, derived from a traditional fermented food in Korea (i.e., Sikhae), emerged as a promising candidate. The correlation between optical density at 600 nm and colony-forming units was verified and applied in subsequent experiments. To assess the therapeutic potential of probiotics, antibacterial tests were conducted using a microplate reader to evaluate the inhibition of 60 bacterial strains (including common foodborne pathogens) induced by Weissella sp. SNUL2 cell-free supernatant (CFS). The results confirmed its broad-spectrum antibacterial properties compared to previously known probiotics. Furthermore, enzymatic treatment with proteinases (trypsin and pepsin) and a time-kill assay were conducted to elucidate the nature of the antibacterial substance in Weissella sp. SNUL2 CFS. Through sequential chromatography involving gel filtration and ion-exchange chromatography, specific fractions with enhanced antibacterial properties were identified. LC-MS/MS analysis of the secretome fraction revealed the presence of various proteins from the C39 family, peptidoglycan endopeptidases, and N-acetylmuramoyl-l-alanine amidase domain-containing protein precursors. Hence, the combined action of these proteins may contribute to Weissella sp. SNUL2's broad antimicrobial activity.

Effect of Probiotics in Stress-Associated Constipation Model in Zebrafish (Danio rerio) Larvae.

The pathophysiology of functional bowel disorders is complex, involving disruptions in gut motility, visceral hypersensitivity, gut-brain-microbiota interactions, and psychosocial factors. Light pollution, as an environmental stressor, has been associated with disruptions in circadian rhythms and the aggravation of stress-related conditions. In this study, we investigated the effects of environmental stress, particularly continuous light exposure, on intestinal motility and inflammation using zebrafish larvae as a model system. We also evaluated the efficacy of probiotics, specifically Bifidobacterium longum (B. longum), at alleviating stress-induced constipation. Our results showed that continuous light exposure in zebrafish larvae increased the cortisol levels and reduced the intestinal motility, establishing a stress-induced-constipation model. We observed increased inflammatory markers and decreased intestinal neural activity in response to stress. Furthermore, the expressions of aquaporins and vasoactive intestinal peptide, crucial for regulating water transport and intestinal motility, were altered in the light-induced constipation model. Administration of probiotics, specifically B. longum, ameliorated the stress-induced constipation by reducing the cortisol levels, modulating the intestinal inflammation, and restoring the intestinal motility and neural activity. These findings highlight the potential of probiotics to modulate the gut-brain axis and alleviate stress-induced constipation. Therefore, this study provides a valuable understanding of the complex interplay among environmental stressors, gut function, and potential therapeutic strategies.

Psychobiotics and the Microbiota-Gut-Brain Axis: Where Do We Go from Here?

The bidirectional relationship between the gut microbiota and the nervous system is known as the microbiota-gut-brain axis (MGBA). The MGBA controls the complex interactions between the brain, the enteric nervous system, the gut-associated immune system, and the enteric neuroendocrine systems, regulating key physiological functions such as the immune response, sleep, emotions and mood, food intake, and intestinal functions. Psychobiotics are considered tools with the potential to modulate the MGBA through preventive, adjunctive, or curative approaches, but their specific mechanisms of action on many aspects of health are yet to be characterized. This narrative review and perspectives article highlights the key paradigms needing attention as the scope of potential probiotics applications in human health increases, with a growing body of evidence supporting their systemic beneficial effects. However, there are many limitations to overcome before establishing the extent to which we can incorporate probiotics in the management of neuropsychiatric disorders. Although this article uses the term probiotics in a general manner, it remains important to study probiotics at the strain level in most cases.

Probiotic Properties of Lactococcus lactis Strains Isolated from Natural Whey Starter Cultures.

Lactococcus lactis is a lactic acid bacterium (LAB), generally recognized as safe, and has been widely used in the food industry, especially in fermented dairy products. Numerous studies have evaluated the technological and probiotic properties of lactococci; however, few studies have reported the probiotic characteristics of L. lactis strains isolated from dairy products. In this work, probiotic potential, including survival in simulated gastric juice, tolerance to bile salts, hydrophobicity, and auto- and co-aggregation, was evaluated in L. lactis strains from natural whey starter cultures. The results highlighted the potential probiotic properties of some strains under study, which showed high values of hydrophobicity and auto-aggregation and low values of co-aggregation with the tested pathogenic strains. In addition, studies of safety parameters, such as antibiotic susceptibility and haemolytic activity, confirmed the safety status of all strains under study. Finally, the four most promising strains were investigated for their ability to inhibit the enteroinvasive Escherichia coli (EIEC) and Salmonella Typhimurium adhesion to epithelial cells, using a model of co-cultured epithelial cells. The results demonstrated that L. lactis strains A3-A5-I4-I7 showed the ability to compete with pathogens as well as the ability to exert a protective effect on cells previously infected with E. coli or S. Typhimurium. The identification of new probiotic LAB strains from dairy products aims to produce novel functional foods.

Postbiotic characterization of a potential probiotic yeast isolate, and its microencapsulation in alginate beads coated layer-by-layer with chitosan

Considering biosafety concerns and survivability limitations of probiotics (PRO) under different stresses, application of postbiotics and encapsulated PRO has received considerable attentions. Accordingly, the objective of the present study was to investigate the postbiotic capabilities of a potential PRO yeast isolate and the effect of encapsulation with alginate (Alg) and chitosan (Ch) on its survival under SGI conditions. Sequencing results of the PCR products led to the identification of Saccharomyces cerevisiae as the selected potential PRO yeast isolated from wheat germ sourdough. High survival of the isolate under simulated gastrointestinal (SGI) conditions (95.74%), its proper adhesion abilities, as well as its potent inhibitory activity against Listeria monocytogenes (75.84%) and Aspergillus niger (77.35%) were approved. Interestingly, the yeast cell-free supernatant (CFS) showed the highest antioxidant (84.35%) and phytate-degrading (56.19%) activities compared to the viable and heat-dead cells of the isolate. According to the results of the HPLC-based assay, anti-ochratoxin A (OTA) capability of the dead cells was also significantly (P < 0.05) higher than that of the viable cell. Meanwhile, the yeast CFS had no anti-OTA and antimicrobial activities against the foodborne bacteria and fungi tested. Further, microencapsulation of the yeast isolate in Alg beads coated layer-by-layer with Ch (with 77.02% encapsulation efficacy and diameter of 1059 μm based on the field emission scanning electron microscopy analysis) significantly enhanced its survivability under SGI conditions in comparison with the free cells. In addition, electrostatic cross-linking between negatively charged carboxylic groups of Alg and positively charged amino groups of Ch was verified in accordance with Fourier transform infrared and zeta potential data. Human and/or industrial food trials in future are needed for practical applications of these emerging ingredients.

Probiotics and Synbiotics as Potential Biotics in Gut Health-Promoting Nutrition

Disorders of gut health can impact a variety of health problems, including the digestive system, immunity, and even mental health. The aim of this study was to investigate the potential of probiotics and synbiotics as potential biotics in nutrition to improve gut health. This study used qualitative research methods. The data collection technique for this is literature study. The data that has been collected is then analyzed in three stages, namely data reduction, data presentation and drawing conclusions. The research results show that probiotics and synbiotics are potential biotics in nutrition that can improve intestinal health. Probiotics and synbiotics can help modulate the composition of the body's beneficial microbiota. In addition, it can help reduce levels of pathogenic bacteria and help reduce persistent inflation of the intestines, which can improve the balance of the body's beneficial microbiota

Search for Influence Factors in Lactobacilli with Probiotic Properties Isolated from Traditional Kazakh Foods.

The aim of this study was to investigate the factors influencing the probiotic potential of lactobacilli isolated from traditional Kazakh foods, focusing on the identification and characterisation of multifunctional proteins. The basis of the methodological approach in this scientific study is an empirical, experimental study of the factors of influence produced by lactobacilli, which were obtained from traditional Kazakh foods and have pronounced probiotic properties. In this scientific work, results were obtained indicating that the expressed factors of probiotic action can perform adhesive and signalling functions by analogy with homologous proteins of pathogenic and commensal/probiotic bacteria. This largely determines the usefulness of these factors for studying the mechanisms of their probiotic action. In addition, it was found that potential probiotic strains of lactobacilli, which were isolated from food products traditional for Kazakhstan, contain adhesion proteins to the components of the mammalian organism, namely human plasminogen and porcine mucin. It is going about ENO, GAPDH, and p66/DnaK, which, along with P40 and P75 muramidases, are classified as probiotic factors. They are also called multifunctional proteins and are designated as factors of probiotic action. The practical significance of the results obtained during the implementation of this study lies in the possibility of their application in the planning and implementation of activities in the field of ensuring food security in Kazakhstan.

Dual effects of a bacteriocin-producing Lactiplantibacillus pentosus CF-6HA, isolated from fermented aloreña table olives, as potential probiotic and antimicrobial agent

The probiotic potential of Lactiplantibacillus pentosus CF-6HA isolated from traditionally fermented Aloreña table olives was analyzed in vitro and in silico. Results obtained suggested that this strain can be catalogued as “talented” bacterium exhibiting bacteriocin production with antimicrobial activity against human/animal and plant pathogens, such as Pseudomonas syringae and Verticillium dahliae. The robustness, safety and probiotic potential of L. pentosus CF-6HA was confirmed by in silico analysis. In addition, a plethora of coding genes for defense and adaptability to different life styles besides functional properties were identified. In this sense, defense mechanisms of L. pentosus CF-6HA consist of 17 ISI elements, 98 transposases and 13 temperate phage regions as well as a CRISPR (clustered regularly interspaced short palindromic repeats)/cas system. Moreover, the functionality of this strain was confirmed by the presence of genes coding for secondary metabolites, exopolysaccharides and other bioactive molecules. Finally, we demonstrated the ability of L. pentosus CF-6HA to biotransform selenite to nanoparticles (SeNPs) highlighting its potential role in selenium bioremediation to be exploited in foods, agriculture and the environment; but also for the bio-enrichment of fermented foods with selenium.

In Vitro Profiling of Potential Fish Probiotics, Enterococcus hirae Strains, Isolated from Jade Perch, and Safety Properties Assessed Using Whole Genome Sequencing.

The demands of intensified aquaculture production and escalating disease prevalence underscore the need for efficacious probiotic strategies to enhance fish health. This study focused on isolating and characterising potential probiotics from the gut microbiota of the emerging aquaculture species jade perch (Scortum barcoo). Eighty-seven lactic acid bacteria and 149 other bacteria were isolated from the digestive tract of five adult jade perch. The screening revealed that 24 Enterococcus hirae isolates inhibited the freshwater pathogens Aeromonas sobria and Streptococcus iniae. Co-incubating E. hirae with the host gut suspensions demonstrated a two- to five-fold increase in the size of growth inhibition zones compared to the results when using gut suspensions from tilapia (a non-host), indicating host-specificity. Genome analysis of the lead isolate, E. hirae R44, predicted the presence of antimicrobial compounds like enterolysin A, class II lanthipeptide, and terpenes, which underlay its antibacterial attributes. Isolate R44 exhibited desirable probiotic characteristics, including survival at pH values within the range of 3 to 12, bile tolerance, antioxidant activity, ampicillin sensitivity, and absence of transferable antimicrobial resistance genes and virulence factors commonly associated with hospital Enterococcus strains (IS16, hylEfm, and esp). This study offers a foundation for sourcing host-adapted probiotics from underexplored aquaculture species. Characterisation of novel probiotics like E. hirae R44 can expedite the development of disease mitigation strategies to support aquaculture intensification.

Investigating the Metabolism of Estrogens in Ligilactobacillus salivarius Strains Isolated from Human Milk and Vaginal Microbiota.

The interplay between enterohepatic circulation and the gut microbiota is the main driver determining systemic levels of estrogens and their metabolites. Nevertheless, the role of potentially probiotic microorganisms in estrogen metabolism has not been investigated so far. In this work, we have explored the ability of six Ligilactobacillus salivarius strains isolated from human milk and vaginal samples to degrade and/or conjugate parental estrogens in vitro and under aerobic conditions. The quantification of estrogens and their derivatives was carried out in cell-free supernatants by LC-QQQ-MS. All the tested L. salivarius strains achieved an average degradation rate of estrone and estriol of 98% and 55%, respectively, whereas 17β-estradiol was preferentially conjugated (up to 40%). The presence of seven out of ten genes encoding enzymes relevant for estrogen metabolism was further confirmed by PCR, highlighting their genetic potential for degrading, conjugating and/or deconjugating estrogens. The tested L. salivarius strains may be considered potential probiotics affecting the fate of endogenous estrogens. Clinical trials targeting populations with estrogen-dependent conditions will be required to elucidate the true potential of these strains for the restoration and maintenance of a healthy host estrobolome.

Probiotic Potential of Autochthonous Lactobacillus against Avian Pathogenic Escherichia coli

Background: The aim of current study was to investigate the probiotic potential of autochthonous Lactobacillus species against pathogenic Escherichia coli in poultry. Method: A total of 73 samples were collected from cloacal swabs and tissues of desi and commercial chicken. The Lactobacillus were isolated based on cultural, biochemical and molecular teats. The probiotic potency was tested in vitro and antimicrobial activity and ABST was carried by Agar well diffusion and disc diffusion methods, respectively. Nucleotide sequencing was done by Sanger sequencing. Haemolysis and gelatin hydrolysis assays were used as safety testes. Result: From 73 cloacal swabs and tissues of desi and commercial chicken, 56 Lactobacillus were isolated of which 22 showed high autoaggregation and hydrophobicity potential. Based on survivability at acidic pH (2.5) and bile concentrations (0.5%), 16 isolates were selected and were subjected to well diffusion assay against pathogenic E. coli. All the isolates showed zone of inhibition against E. coli ranging from 10 -18 mm. ABST revealed that all the isolates are sensitive to chloramphenicol, ampicillin and erythromycin and 75% of the isolates were resistant to streptomycin, gentamicin and vancomycin. Only one isolate out of 16 tested was non hemolytic and none of the isolates tested positive for gelatine hydrolysis. Sequencing result of selected isolate revealed 96.82% of its similarity to Lactobacillus fermentum.

Anti-oral cancer properties of potential probiotic lactobacilli isolated from traditional milk, cheese, and yogurt

This study investigates the probiotic and anti-cancer effects of 21 isolated Lactobacillus strains from cheese, milk, and yogurt in Kermanshah, Iran, on oral cancer cell lines KB and OSCC. Four selected isolates (Y33, M45, C5, and C28) displayed good viability and resistance to specific antibiotics. Notably, strains C28 and Y33 exhibited the best results, showing susceptibility or semi-susceptibility to five antibiotics. Y33, with high cell surface hydrophobicity (62%), demonstrated significant anti-pathogenic activity, inhibiting the growth of tested pathogens and displaying strong adhesion to human intestinal Caco-2 cells (52%). Further assessments, including acridine orange/ethidium bromide staining and mRNA expression analysis, revealed four isolates (C5, C28, M45, and Y33) with promising probiotic properties. Particularly, Y33’s protein-based extract metabolites showed dose- and time-dependent inhibition of KB and OSCC cancer cell lines, inducing apoptosis without significant cytotoxic effects on normal cells. Y33 (Lactiplantibacillus plantarum) exhibited the strongest probiotic potential, surpassing conventional anti-cancer drugs, suggesting its therapeutic potential for preventing oral cancer cell proliferation and improving survival rates in oral cancer patients.

Evaluation of Probiotic Bacteria Isolated from Indigenous Honeybee Species of Pakistan

The honey bee gut is inhabited by many useful bacteria such as Lactic Acid Bacteria (LAB). These LAB possess active probiotic properties that are beneficial to other animals and even humans. The LAB is declared as generally recognized as safe (GRAS). The LAB is non-pathogenic and produces different metabolites having antimicrobial potential. In the current study LAB species isolated from four honey bee species (Apis melifera, Apis dorsata, Apis cerana, and Apis florae) prevalent in Pakistan were identified and investigated for their probiotic potential. The strains were identified using morphological, biochemical, and molecular techniques as genus Lactobacillus and Lactococcus. Current results confirmed that the honey bee gut has a rich source of lactic acid bacteria. Isolated strains were further evaluated for their ability to resist physiological stresses encountered in the human gastrointestinal tract. Safety testing of the isolates such as hemolytic assay revealed that these isolates have γ-hemolytic activity and were adjudged to be safe. Hence the present study concluded that honey bee gut is thesource of potential probiotic bacteria and can be used in pharmaceuticals, fermented foods, and nutraceuticals and may be used as a natural food preservative

Novel Probiotic Candidates in Artisanal Feta-Type Kefalonian Cheese: Unveiling a Still-Undisclosed Biodiversity.

Autochthonous dairy lactic acid bacteria (LAB) isolates encompass a natural source of starter, adjunct, or probiotic candidates. In this context, traditionally manufactured, using exclusively animal rennet, Feta-type cheeses were collected from five farms located in different regions of Kefalonia island (Greece). The primary objective of this study was to isolate and characterize novel LAB, thereby exploring the unmapped microbial communities of Kefalonian Feta-type cheese and identifying new potential probiotics. The initial screening, included a preliminary gastrointestinal (GI) tolerance assessment (acidic conditions and bile salts), followed by their safety evaluation (hemolytic activity and antibiotic susceptibility). Based on the preliminary screening, selected strains underwent molecular identification and were further investigated for their probiotic attributes (lysozyme and phenol resistance, antimicrobial traits, antidiabetic aspects, cholesterol reduction and adhesion, adhesion to Caco-2 cells, and milk acidification potential). The results showed that 49, out of the 93 retrieved isolates, exhibited resistance to GI conditions, whereas 18 met the safety criteria. The molecular identification revealed strains belonging to the species Lactiplantibacillus plantarum, Limosilactobacillus fermentum, Lacticaseibacillus rhamnosus, and Lacticaseibacillus paracasei. The selected rod-shaped 14 isolates displayed a potential probiotic character. The best-performing isolates concerning cholesterol assimilation and adhesion, α-glucosidase inhibition, and epithelial adherence were Lpb. plantarum F89, F162, and F254 and Lcb. paracasei F214 and F216, whereas Lcb. paracasei F70 showed potential as a defined strain starter. The present study explores for the first time the biodiversity of traditionally fermented microbial communities in Kefalonian Feta-type cheese, revealing novel potential probiotic strains that can contribute to the development of innovative functional food products.

Isolation, molecular characterization and antibiogram of Lactic acid bacteria from dairy cattle sources of Mizoram, India

A total of 250 samples of dairy cattle sources comprised of 100 cattle faeces, 75 raw milk, and 75 fermented milk samples which were randomly collected from different areas of Aizawl district of Mizoram that have been analyzed bacteriologically for enumeration and isolation of Lactic acid bacteria (LAB). The 90 phenotypically positive LAB isolates were further analyzed molecularly by 16S-rRNA gene analysis and 42 isolates were found positive. A total of 20 PCR positive LAB isolates were randomly selected and sequenced, out of which 11 isolates were positive for LAB after sequence analysis, belonging to six species of LAB, namely Lactibantibacillus plantarum (4), Lactobacillus fermentum (2), Lactobacillus brevis (2), Bacillus coagulance (1), Enterococcus faecium (1) and Weissella cibaria (1). The phylogenetic tree was constructed to check the relatedness of the strains with other referral LAB strains from NCBI gene bank. These 11 isolates were further analyzed for antibiogram. All 11 LAB strains tested for antibiotic sensitivity were 100% resistant to kanamycin, whereas intermediate resistance was shown by Lactobacillus brevis FM046 to clindamycin and three strains namely Lactobacillus fermentum FM011, Bacillus coagulans FM033 and Lactobacillus brevis FM046 to penicillin. All the 11 LAB strains were 100% sensitive to most of the tested antibiotics namely amikacin, ampicillin, azithromycin, cefoxitin, cefpodoxime, ceftriaxone, erythromycin, gentamicin and rifampicin. The LAB strains detected from the dairy cattle sources of Mizoram with sensitive antibiogram might be further studied for their probiotic potential.

Characterization of the broad-spectrum antibacterial activity of bacteriocin-like inhibitory substance-producing probiotics isolated from fermented foods

Antimicrobial peptides, such as bacteriocin, produced by probiotics have become a promising novel class of therapeutic agents for treating infectious diseases. Selected lactic acid bacteria (LAB) isolated from fermented foods with probiotic potential were evaluated for various tests, including exopolysaccharide production, antibiotic susceptibility, acid and bile tolerance, antibacterial activity, and cell adhesion and cytotoxicity to gastric cell lines. Six selected LAB strains maintained their high viability under gastrointestinal conditions, produced high exopolysaccharides, showed no or less cytotoxicity, and adhered successfully to gastric cells. Furthermore, three strains, Weissella confusa CYLB30, Lactiplantibacillus plantarum CYLB47, and Limosilactobacillus fermentum CYLB55, demonstrated a strong antibacterial effect against drug-resistant Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella enterica serovar Choleraesuis, Enterococcus faecium, and Staphylococcus aureus. Whole genome sequencing was performed on these three strains using the Nanopore platform; then, the results showed that all three strains did not harbor genes related to toxins, superantigens, and acquired antimicrobial resistance, in their genome. The bacteriocin gene cluster was found in CYLB47 genome, but not in CYLB30 and CYLB55 genomes. In SDS-PAGE, the extract of CYLB30 and CYLB47 bacteriocin-like inhibitory substance (BLIS) yielded a single band with a size of less than 10 kDa. These BLIS inhibited the growth and biofilm formation of drug-resistant P. aeruginosa and methicillin-resistant S. aureus (MRSA), causing membrane disruption and inhibiting adhesion ability to human skin HaCaT cells. Moreover, CYLB30 and CYLB47 BLIS rescued the larvae after being infected with P. aeruginosa and MRSA infections. In conclusion, CYLB30 and CYLB47 BLIS may be potential alternative treatment for multidrug-resistant bacteria infections.