Selection of a candidate probiotic strain of Pediococcus pentosaceus from the faecal microbiota of horses by in vitro testing and health claims in a mouse model of Salmonella infection

Isolation of lactic acid bacteria from the reproductive tract of mares as potentially beneficial strains to prevent equine endometritis

Endometritis, the inflammation of the endometrium, is the leading cause of subfertility in mares, and therefore responsible for major economic losses in the horse industry worldwide. It is generally treated with uterine lavages combined with ecbolic agents and local or systemic antibiotics. However, since antibiotic overuse has been associated with antimicrobial resistance in mares with persistent endometritis, new prevention and treatment alternatives are needed. One such alternative could be the use of probiotic lactic acid bacteria (LAB) isolated from the host. Thanks to their species specificity, resident microbiota may restore ecological equilibrium within the host, and therefore, help prevent infections and improve physiological functions. In the present study, 257 bacterial strains were isolated from 77 healthy mares, and 88.76% (n = 228) of them were phenotypically classified as LAB. Within this group, 65.79% were able to inhibit at least one strain from each of the genera that most commonly cause equine endometritis (Streptococcus equi subsp. zooepidemicus, Escherichia coli, and Staphylococcus spp.). Five strains (RCE11, RCE20, RCE91, RCE99, and RCE167) were selected on the basis of their beneficial properties: ability to autoaggregate and adhere to equine epithelial cells, high inhibition of and co-aggregation with all the bacteria isolated from clinical cases of endometritis evaluated, and negative co-inhibition between one another. All five were finally identified as Enterococcus spp., namely E. faecium (two strains), E. hirae (two strains), and E. gallinarum (one strain). Further studies will assess their safety and biotechnological potential for the design of a multi-strain probiotic formula to prevent equine endometritis.

Phenotypic and genotypic characterizations of bacteria isolated from the respiratory microbiota of healthy turkeys with potential for probiotic composition

Desirable characteristics of Staphylococcus sp., Streptococcus sp., Bacillus sp., Klebsiella sp., Escherichia coli, and Pseudomonas pseudoalcaligenes isolated from the trachea of healthy turkeys were evaluated as probiotic candidates in the search for new alternatives to solve antimicrobial resistance issues in poultry. In current study phenotypic and genotypic capacity to produce bacteriocin-like substances, efficacy to inhibit the growth of avian pathogens, susceptibility to antimicrobials of bacteria isolated from the respiratory microbiota of healthy turkeys, and the presence of virulence-associated genes (VAGs) predictors of Avian Pathogenic Escherichia coli (APEC) were evaluated. Nine E. coli and one Klebsiella sp. strains produced bacteriocin-like substances, and all harbored the cvaA gene. Some strains also showed antagonistic activity against APEC. Multidrug-resistant profile was found in 54% of the strains. Six strains of bacteriocin-like substances producing E. coli also harbored 3-5 VAGs. The study showed that two bacterial genuses (Klebsiella sp. and E. coli) present desirable probiotic characteristics. Our results identified strains with potential for poultry's respiratory probiotic.

Changes in bovine milk bacterial microbiome from healthy and subclinical mastitis affected animals of the Girolando, Gyr, Guzera, and Holstein breeds

Raw milk samples were collected from 200 dairy cows belonging to Girolando 1/2, Gyr, Guzera, and Holstein breeds, and the bacterial diversity was explored using 16S rRNA amplicon sequencing. SCC analysis showed that 69 animals were classified as affected with subclinical mastitis. The milk bacterial microbiome was dominated by Firmicutes, Proteobacteria, and Actinobacteria, with an increase of Firmicutes in animals with subclinical mastitis and Proteobacteria in healthy animals. At the family and genus level, the milk bacterial microbiome was dominated by Staphylococcus, Acinetobacter, Pseudomonas, members of the family Enterobacteriaceae, Lactococcus, Aerococcus, members of the family Rhizobiaceae, Anaerobacillus, Streptococcus, members of the family Intrasporangiaceae, members of the family Planococcaceae, Corynebacterium, Nocardioides, and Chryseobacterium. Significant differences in alpha and beta diversity analysis suggest an effect of udder health status and breed on the composition of raw bovine milk microbiota. LEfSe analysis showed 45 and 51 discriminative taxonomic biomarkers associated with udder health status and with one of the four breeds respectively, suggesting an effect of subclinical mastitis and breed on the microbiota of milk in cattle.

Pediococcus pentosaceus: Screening and Application as Probiotics in Food Processing

Lactic acid bacteria (LAB) are vital probiotics in the food processing industry, which are widely spread in food additives and products, such as meat, milk, and vegetables. Pediococcus pentosaceus (P. pentosaceus), as a kind of LAB, has numerous probiotic effects, mainly including antioxidant, cholesterol-lowering, and immune effects. Recently, the applications in the probiotic- fermentation products have attracted progressively more attentions. However, it is necessary to screen P. pentosaceus with abundant functions from diverse sources due to the limitation about the source and species of P. pentosaceus. This review summarized the screening methods of P. pentosaceus and the exploration methods of probiotic functions in combination with the case study. The screening methods included primary screening and rescreening including gastric acidity resistance, bile resistance, adhesion, antibacterial effects, etc. The application and development prospects of P. pentosaceus were described in detail, and the shortcomings in the practical application of P. pentosaceus were evaluated to make better application of P. pentosaceus in the future.

Unraveling the probiotic efficiency of bacterium Pediococcus pentosaceus OBK05 isolated from buttermilk: An in vitro study for cholesterol assimilation potential and antibiotic resistance status

The present study describes the probiotic potential and functional properties of the lactic acid bacterium Pediococcus pentosaceus OBK05 isolated from buttermilk. The isolate OBK05 was assessed for its probiotic properties. The isolate showed notable tolerance to pH 2.0 and 3.0 (8.44, 8.35 log CFU/mL), oxbile of 0.5% at 2 and 4 h of incubation (6.97, 6.35 log CFU/mL) and higher aggregation (auto-aggregation, adhesion to hydrocarbons) than the referral strain, Lactobacillus acidophilus MTCC 10307. The adhesion efficiency to HT-29 cells was found to be maximum, corresponding to 93.5% and 97% at 1 and 2 h incubation, respectively. In addition, the isolate OBK05 showed antagonistic solid activity against bacterial pathogens like Pseudomonas aeruginosa MTCC 424 and Bacillus subtilis MTCC 1133. The phenotypic antibiotic resistance of the isolate was examined before and after curing plasmids. Among the known five structural genes responsible for different antibiotic resistance, four genes indicating antibiotic resistance to kanamycin-Aph (3´´)-III, streptomycin-strA, vancomycin-vanA and ciprofloxacin-gyrA were detected by PCR amplification of genomic DNA. Further, the horizontal gene transfer from OBK05 isolate to pathogens was not found for these antibiotic resistance markers when filter and food mating were carried out as no transconjugants developed on media plates containing respective antibiotics. This indicates that the intrinsic resistance is harbored on chromosomal genes, and hence it is nontransferable to other microbes. In addition, strain OBK05 exhibited good DPPH scavenging activity of 56 to 77% and liberated free amino acid from conjugated bile acid. The strain OBK05 demonstrated a strong ability to reduce cholesterol at 12 h (17%), 24 h (27%) and 48 h (67%) of incubation.

Probiotic Pediococcus pentosaceus ABY 118 to Modulation of ChIFN-γ and ChIL-10 in Broilers Infected by Eimeria tenella Oocyst

Eimeria causes coccidiosis, which has long been recognized as a disease in chickens that significantly affects the economy. The global chicken population continues to grow, and its contribution to food security increases, making it increasingly important to produce chicken meat that is safe for human and health. This study aims to prove Pediococcus pentosaceus ABY 118 to modulation of ChIFN-γ and ChIL-10 in chickens infected with E. tenella oocysts. This study used 100 of day-old chickens (DOC), randomly divided into 5 treatments; each treatment consists of 20 chickens. The treatments was as follows: P0 (−): negative control; P0 (+): positive control; P1: monensin; P2: probiotic 1.5 × 10⁸ CFU/ml; and P3: probiotic 3.0 × 10⁸ CFU/ml. At the age of 20 days, Eimeria tenella (E. tenella) oocysts were inoculated orally at a dose of 1 × 10⁴. The probiotic P. pentosaceus ABY 118 was given orally through drinking water from DOC to 35 days. Monensin was given orally through feed from the age of 14–26 days. The results of statistical analysis showed that there was a significant difference (P < 0.05) between treatments on ChIFN-γ and ChIL-10 at 6 and 8 days postinfected with E. tenella oocysts. Based on the results of this study, it can be concluded that the use of P. pentosaceus ABY 118 isolates at a dose of 1.5 × 10⁸ CFU/ml and 3.0 × 10⁸ CFU/ml per liter of drinking water can increase health by stimulation of ChIFN-γ and ChIL-10 in broiler infected with E. tenella oocyst.

Prospecting of potentially probiotic lactic acid bacteria from bovine mammary ecosystem: imminent partners from bacteriotherapy against bovine mastitis

Mastitis is one of the most important causes of loss of cattle production, burdening producers due to the increased cost of milk production and decreased herd productivity. The development of alternative methods for the treatment and prevention of mastitis other than traditional chemical antibiotic therapy needs to be implemented to meet international pressures to reduce the use of these drugs and promote the elimination of multiresistant microbial strains from the environment. Treatment with probiotic bacteria or yeast strains offers a possible strategy for the control of mastitis. The objective of this work was to isolate, identify, and characterize lactic bacteria from milk and the intramammary duct of Gyr, Guzerat, Girolando 1/2, and Holstein cattle breeds from Brazil. Samples of 115 cows were taken, a total of 192 bacteria isolates belonging to 30 species were obtained, and 81 were selected to evaluate their probiotic potential in in vitro characterization tests. In general, bacteria isolated from the mammary gland have low autoaggregation, cell surface hydrophobicity, and co-aggregation with mastitis etiological bacteria Staphylococcus aureus and Escherichia coli. Also, they have biofilm assembly capacity, inability to produce exopolysaccharides, high production of H₂O₂, and strong antagonism against mastitis pathogens. Ten lactic bacteria isolates were used in co-culture with human MDA-MB-231 breast epithelial cells to assess their adhesion capacity and impairment of the S. aureus invasion. Our results, therefore, contribute to the future production of new prevention and treatment tools for bovine mastitis.

Isolation and Evaluation of Probiotic Potential of Lactic Acid Strains From Healthy Equines for Potential Use in Salmonella Infection

The objective of the present study was to evaluate the probiotic properties, security and antibacterial ability in vivo of isolated strains from healthy equine. In the present study, two Pediococcus acidilactici (P1 and P2) and two Lactobacillus equi (L1 and L2) were isolated. All isolates were died when exposed to pH 2.0 for 3 hours but survived at pH 3.0 and pH 4.0 with differential survival rate, and there is a higher survival rate at pH 4.0. Similarly, the isolates showed different tolerance to bile. The viable bacteria count was sustained at high levels in a tolerance test with artificial gastrointestinal fluid. The isolates survived and grew at temperatures between 37 and 55°C but died at 65°C. Four strains exhibited inhibitory activity against pathogens, including Salmonella typhimurium (CVCC542), Escherichia coli (C83902), Staphylococcus aureus (BNCC186335), and Pasteurella multocida (clinical isolate). These isolates exhibited differential antibiotic susceptibility. In safety trials, all isolates were γ-hemolytic, and the oral toxicity of strains P1 (gavaged with 1 × 109 CFU/day) and L1 (gavaged with 1 × 109 CFU/day) were analyzed in mice. There were no effects on the overall health status of mice. There were no prominent differences in the incidence of bacteria translocation to blood, liver, and spleen. Mice gavaged with Pediococcus acidilactici P1 (1 × 108 CFU/day) or Lactobacillus equi L1 (1 × 108 CFU/day) as prevention showed lower rates of diarrhea and mortality after being challenged with Salmonella typhimurium (4 × 106 CFU signal dose, 0.1 mL by intragastric gavage). The results indicate that the isolated strains could act as potential probiotics, providing a new way to reduce salmonella infection, which merit future application studies.

In vitro probiotic properties of Pediococcus pentosaceus L1 and its effects on enterotoxigenic Escherichia coli-induced inflammatory responses in porcine intestinal epithelial cells

This study aimed to evaluate in vitro probiotic characteristics of Pediococcus pentosaceus strain L1 from pickled radish and investigate its impacts on inflammatory responses in porcine intestinal epithelial cells (IEC) to enterotoxigenic Escherichia coli (ETEC) F4⁺. The abilities of P. pentosaceus L1 to tolerate gastrointestinal conditions and to antagonize ETEC F4⁺ growth were determined. Adhesion of P. pentosaceus L1 and its effect on ETEC F4⁺ adhesion to porcine IPEC-J2 IEC were evaluated. Furthermore, the effects of this strain on proinflammatory gene expression and cytokines/chemokine production in porcine IPEC-J2 IEC induced by ETEC F4⁺ were determined. P. pentosaceus L1 showed good tolerance to the medium adjusted at pH 2.5 and consequently supplemented with 0.3% oxgall. Reduction of ETEC F4⁺ growth in co-culture with L1 was found. Effective adhesion of L1 to porcine. IPEC-J2 IEC was observed under these conditions. P. pentosaceus L1 decreased the adhesion of ETEC F4⁺ to IPEC-J2 IEC and the extent of inhibition of ETEC F4⁺ adhesion depended on the timing of L1 addition. Further analysis revealed down-regulation of expression of ETEC F4⁺-induced proinflammatory genes encoding interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and interleukin-8 (IL-8) in IPEC-J2 IEC. Expression of the genes involved in NF-κB pathway, including RELA and NFKB1, were also repressed, as was production of IL-6, TNF-α, and IL-8. These results indicate that P. pentosaceus L1 may have potential as a probiotic for control of ETEC infection in pigs.

Comparative Genomics of Pediococcus pentosaceus Isolated From Different Niches Reveals Genetic Diversity in Carbohydrate Metabolism and Immune System

Pediococcus pentosaceus isolated from fermented food and the gastrointestinal tracts of humans and animals have been widely identified, and some strains have been reported to reduce inflammation, encephalopathy, obesity and fatty liver in animals. In this study, the genomes of 65 P. pentosaceus strains isolated from human and animal feces and different fermented food were sequenced and comparative genomics analysis was performed on all strains along with nine sequenced representative strains to preliminarily reveal the lifestyle of P. pentosaceus, and investigate the genomic diversity within this species. The results reveal that P. pentosaceus is not host-specific, and shares core genes encoding proteins related to translation, ribosomal structure and biogenesis and signal transduction mechanisms, while its genetic diversity relates mainly to carbohydrate metabolism, and horizontally transferred DNA, especially prophages and bacteriocins encoded on plasmids. Additionally, this is the first report of a type IIA CRISPR/Cas system in P. pentosaceus. This work provides expanded resources of P. pentosaceus genomes, and offers a framework for understanding the biotechnological potential of this species.

Differential Immune Response of Lactobacillus plantarum 286 Against Salmonella Typhimurium Infection in Conventional and Germ-Free Mice

We aimed at evaluating in vivo the probiotic potential of Lactobacillus plantarum 286 against Salmonella enterica serov. Typhimurium. Colonization capacity and antagonistic activity were determined in feces of gnotobiotic mice. Survival to infection, translocation, histopathology, IgA and cytokine levels (IL-10, IL-6, IFN-γ, TNF-α, TGF-β) were determined both in conventional and germ-free mice followed L. plantarum 286 administration and Salmonella infection. L. plantarum 286 colonized the intestine of gnotobiotic mice, where it produced antagonistic substances against S. Typhimurium. In conventional animals, the administration of this strain increased intestinal IgA levels and reduced the inflammatory response and the tissue damage caused by S. Typhimurium. Reduction of tissue damage in the intestine and liver of germ-free animals was also observed, however the immune response elicited was different in either model. L. plantarum 286 showed in vivo probiotic properties in both murine models. Probiotic capacity results may depend on the animal model chosen.

Predominance of Lactobacillus plantarum Strains in Peruvian Amazonian Fruits

The objective of this research was the identification and characterization of lactic acid bacteria (LAB) isolated from Peruvian Amazonian fruits. Thirty-seven isolates were obtained from diverse Amazonian fruits. Molecular characterization of the isolates was performed by ARDRA, 16S-23S ITS RFLP and rep-PCR using GTG₅ primers. Identification was carried out by sequencing the 16S rDNA gene. Phenotypic characterization included nutritional, physiological and antimicrobial resistance tests. Molecular characterization by Amplified Ribosomal DNA Restriction Analysis (ARDRA) and 16S-23S ITS RFLP resulted in four restriction profiles while GTG₅ analysis showed 14 banding patterns. Based on the 16S rDNA gene sequence, the isolates were identified as Lactobacillus plantarum (75.7%), Weissella cibaria (13.5%), Lactobacillus brevis (8.1%), and Weissella confusa (2.7%). Phenotypic characterization showed that most of the isolates were homofermentative bacilli, able to ferment glucose, maltose, cellobiose, and fructose and grow in a broad range of temperatures and pH. The isolates were highly susceptible to ampicillin, amoxicillin, clindamycin, chloramphenicol, erythromicyn, penicillin, and tetracycline and showed great resistance to kanamycin, gentamycin, streptomycin, sulfamethoxazole/trimethoprim, and vancomycin. No proteolytic or amylolytic activity was detected. L. plantarum strains produce lactic acid in higher concentrations and Weissella strains produce exopolymers only from sucrose. Molecular methods allowed to accurately identify the LAB isolates from the Peruvian Amazonian fruits, while phenotypic methods provided information about their metabolism, physiology and other characteristics that may be useful in future biotechnological processes. Further research will focus especially on the study of L. plantarum strains.

Lactobacillus fermentum and Lactobacillus plantarum increased gut microbiota diversity and functionality, and mitigated Enterobacteriaceae, in a mouse model

Probiotics should bring 'balance' to the intestinal microbiota by stimulating beneficial bacteria, whilst mitigating adverse ones. Balance can also be interpreted as high alpha-diversity. Contrary, Escherichia coli is often regarded as an adverse component of the resident intestinal microbiota. The aim of the present study was to implement a mouse model for in vivo screening of Lactobacillus-strains for ability to increase gut-microbiota diversity and to mitigate E. coli. Mice were divided into six groups, two dietary control-groups and four groups administered strains of Lactobacillus fermentum and/or Lactobacillus plantarum. All animals were pre-treated with antibiotics, and E. coli in order to equalise the microbiota from the start. After 7 weeks of Lactobacillus administration, the animals were sacrificed: DNA was extracted from caecum tissue, and the microbiota composition was analysed with terminal restriction fragment length polymorphism (T-RFLP) and 16S rRNA gene sequencing. The diversity of the caecal microbiota decreased when the dietary carbohydrate source was limited to corn starch. Conversely, the diversity was restored by Lactobacillus-supplements. The tested combinations of two Lactobacillus strains exerted different influences, not only on the taxonomic level, but also on the inferred microbiome functions. The mixture of L. fermentum GOS47 and L. fermentum GOS1 showed potential for anti-inflammatory activity and short chain fatty acid production. On the other hand, co-administration of L. fermentum GOS57 and L. plantarum GOS42 significantly decreased the viable count of Enterobacteriaceae. These results warrant further investigation of the tested strains as candidates for probiotics. Furthermore, the findings demonstrated that the current experimental animal model is suitable for in vivo studies of the effect of bacterial supplements on the gut-microbiota.

Lactobacillus acidophilus suppresses intestinal inflammation by inhibiting endoplasmic reticulum stress

BACKGROUND AND AIM

Nuclear factor kappa B (NF-κB) activation and endoplasmic reticulum (ER) stress signaling play significant roles in the pathogenesis of inflammatory bowel disease (IBD). Thus, we evaluated whether new therapeutic probiotics have anti-colitic effects, and we investigated their mechanisms related to NF-κB and ER-stress pathways.

METHODS

Luciferase, nitric oxide, and cytokine assays using HT-29 or RAW264.7 cells were conducted. Mouse colitis was induced using dextran sulfate sodium and confirmed by disease activity index and histology. Macrophages and T-cell subsets in isolated peritoneal cavity cells and splenocytes were analyzed by flow cytometry. Gene and cytokine expression profiles were determined using reverse-transcription polymerase chain reaction.

RESULTS

Lactobacillus acidophilus (LA1) and Pediococcus pentosaceus inhibited nitric oxide production in RAW264.7 cells, but only LA1 inhibited Tnfa and induced Il10 expression. LA1 increased the lifespan of dextran sulfate sodium-treated mice and attenuated the severity of colitis by inducing M2 macrophages in peritoneal cavity cells and Th2 and Treg cells in splenocytes. The restoration of goblet cells in the colon was accompanied by the induction of Il10 expression and the suppression of pro-inflammatory cytokines. Additionally, we found that LA1 exerts an anti-colitic effect by improving ER stress in HT-29 cells as well as in vivo.

CONCLUSIONS

We showed that LA1 significantly interferes with ER stress and suppresses NF-κB activation. Our findings suggest that LA1 can be used as a potent immunomodulator in IBD treatment, and the regulation of ER stress may have significant implications in treating IBD.

Opposing effect of Lactobacillus on in vitro Klebsiella pneumoniae in biofilm and in an in vivo intestinal colonisation model

Beneficial bacteria represent potential sources of therapy, particularly in the battle against antibiotic-resistant pathogens. The Gram-negative bacillus Klebsiella pneumoniae is not only a paradigm of multi-resistant opportunistic pathogen, but it is also able to colonise the human intestine and displays a high capacity to form biofilm. In this study, the anti-biofilm activity of 140 neutralised Lactobacillus supernatants was assessed against K. pneumoniae. Among the 13 strains whose supernatant significantly impaired biofilm formation, Lactobacillus plantarum CIRM653 was selected because it was also able to impair K. pneumoniae preformed biofilm, independently of a bactericidal effect. Mixed K. pneumoniae/L. plantarum CIRM653 biofilms had reduced tridimensional structures associated with a significant decrease in K. pneumoniae biomass. Further investigation showed that L. plantarum CIRM653 supernatant induced transcriptional modifications of K. pneumoniae biofilm-related genes, including down-regulation of the quorum sensing-related lsr operons and over-expression of type 3 pili structure genes. Increased production of type 3 pili was validated by Western-blot, hemagglutination and adhesion assays. L. plantarum CIRM653 activity against K. pneumoniae was also assessed in a murine intestinal colonisation model: a constant faecal pathogen burden was observed, as against a gradual decrease in the control group. These results reveal that an in vitro a priori attracting anti-biofilm activity of Lactobacillus might be counterbalanced by an in vivo behaviour in a complex microbiota environment with potential deleterious dispersal of highly adherent K. pneumoniae cells, raising the question of the accuracy of in vitro assays in screening of beneficial microbes.

Milk fermented by Lactobacillus species from Brazilian artisanal cheese protect germ-free-mice against Salmonella Typhimurium infection

Ingestion of milks fermented by Lactobacillus strains showing probiotic properties is an important tool to maintain gastrointestinal health. In this study, Lactobacillus rhamnosus D1 and Lactobacillus plantarum B7, isolated from Brazilian artisanal cheese, were used as starters for the functional fermented milks to assess their probiotic properties in a gnotobiotic animal model. Male germ-free Swiss mice received a single oral dose of milk fermented by each sample, and were challenged with Salmonella Typhimurium five days afterwards. Milk fermented by both Lactobacillus strains maintained counts above 108 cfu/ml during cold storage. Lactobacillus strains colonised the gut of the germ-free-mice, maintaining their antagonistic effect. This colonisation led to a protective effect against Salmonella challenge, as demonstrated by reduced pathogen translocation and histological lesions, when compared to control group, especially for Lactobacillus rhamnosus D1. Additionally, mRNA expression of inflammatory (interferon gamma, interleukin (IL)-6, tumour necrosis factor alpha) and anti-inflammatory (transforming growth factor β1) cytokines was augmented in animals previously colonised and then challenged, when compared to other experimental groups. Lactobacillus plantarum B7 colonisation also promoted higher expression of IL-17, showing a proper maturation of colonised germ-free-mice immune system. IL-5 was stimulated by both strains’ colonisation and not by S. Typhimurium challenge.

Selection of new lactic acid bacteria strains bearing probiotic features from mucosal microbiota of healthy calves: Looking for immunobiotics through in vitro and in vivo approaches for immunoprophylaxis applications

From the birth, since their mucosal microbiota and immune system are not fully developed, newborn calves are susceptible to several mucosal pathogenic microorganisms. Operating through humoral and non-humoral mechanisms in the host, several lactic acid bacteria strains bearing probiotic features are often employed in livestock as food supplement, improving animal production performance, promoting health and reducing the severity of mucosal infections. Accordingly, we isolated, species-level identified and screened for their probiotic potentials seventy lactic acid bacteria strains from upper airway, vaginal and intestinal mucosa of healthy calves. Based on in vitro approaches, we selected three strains: Lactobacillus fermentum V3B-08 isolated from upper airway mucosa, Weissella hellenica V1V-30 isolated from vaginal mucosa and Lactobacillus farciminis B4F-06 isolated from intestinal mucosa were used to mono-colonize germ-free mice in the same site in which these strains were isolated, aiming to characterize their immunomodulatory features. These strains were able to colonize germ-free mice mucosa and trigger sIgA synthesis at a local level, in addition to stimulating, in different ways, adaptive immune responses at a systemic level.