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Background: The use of beneficial bacteria like Lactobacillus spp. is a potential innovative approach to fight antibiotic-resistant pathogens. Klebsiella pneumoniae is one of the most concerning multi drug-resistant (MDR) pathogens, and its ability to colonize the human gut is considered to be the main reason for recurrent infections in critically ill patients., Methods: In this study, Lactobacillus gasseri 1A-TV, already described for its probiotic activity, was characterized at the genomic level. Moreover, its cell-free supernatant (CFS) was tested for antimicrobial activity against extended-spectrum β-lactamase (ESBL)- and carbapenemase (KPC)-producing K. pneumoniae clinical isolates., Results: Whole-genome sequencing showed that the L. gasseri 1A-TV genome was of 2,018,898 bp in size with 34.9% GC content, containing 1,937 putative protein coding sequences, 55 tRNA, and 4 rRNA detected by RAST and classified in 20 functional groups by Cluster of Orthologous Genes (COG). BAGEL4 (BActeriocin GEnome minimal tooL) and the antiSMASH 7.0 pipeline identified two bacteriocin biosynthetic gene clusters (BBGCs), namely, BBGC1 that comprises two class IIc bacteriocins including gassericin A-like bacteriocin, and BBGC2 carrying the class III bacteriocin helveticin J. Strikingly, 1A-TV CFS inhibited the growth of all K. pneumoniae isolates only after 8 h of incubation, showing a bactericidal effect at 24 h and interfering, even at lower concentrations, with the biofilm production of biofilm-producer strains independently of a bactericidal effect. NMR analysis of CFS identified and quantified several metabolites involved in carbohydrate metabolism and amino acid metabolism, and organic acids like ethanol, lactate, acetate, and succinate. Finally, in vitro assays of 1A-TV showed significant co-aggregation effects against carbapenem-resistant K. pneumoniae , namely, strains 1, 2, 3, and 7., Conclusions: Our findings highlight the antimicrobial activity of 1A-TV as a probiotic candidate or its CFS as a natural bioproduct active against MDR K. pneumoniae strains, underlining the importance of novel therapeutic strategies for prevention and control of ESBL- and carbapenemase-producing K. pneumoniae colonization., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Vertillo Aluisio, Mezzatesta, Cafiso, Scuderi, Stefani and Santagati.)

Mutations in the FUT2 gene that result in a lack of expression of histo-blood group antigens on secreted glycoproteins may shape the vaginal microbiota with consequences for birth outcome. To test this, we analysed the relationship between secretor status, vaginal microbiota and gestational length in an ethnically diverse cohort of 302 pregnant women, including 82 who delivered preterm. Lactobacillus gasseri and L. jensenii were found to have distinct co-occurrence patterns with other microbial taxa in non-secretors. Moreover, non-secretors with Lactobacillus spp. depleted high diversity vaginal microbiota in early pregnancy had significantly shorter gestational length than Lactobacillus spp. dominated non-secretors (mean of 241.54 days (sd=47.14) versus 266.21 (23.61); P -value=0.0251). Similar gestational length differences were observed between non-secretors with high vaginal diversity and secretors with Lactobacillus spp. dominance (mean of 262.52 days (SD=27.73); p - value =0.0439) or depletion (mean of 266.05 days (SD=20.81); p - value =0.0312). Our data highlight secretor status and blood-group antigen expression as being important mediators of vaginal microbiota-host interactions in the context of preterm birth risk.

Vaginitis, a prevalent gynecological condition in women, is mainly caused by an imbalance in the vaginal micro-ecology. The two most common types of vaginitis are vaginal bacteriosis and vulvovaginal candidiasis, triggered by the virulent Gardnerella vaginalis and Candida albicans, respectively. In this study, a strain capable of inhibiting G. vaginalis and C. albicans was screened from vaginal secretions and identified as Lactobacillus gasseri based on 16S rRNA sequences. The strain, named L. gasseri VHProbi E09, could inhibit the growth of G. vaginalis and C. albicans under co-culture conditions by 99.07% ± 0.26% and 99.95% ± 0.01%, respectively. In addition, it could significantly inhibit the adhesion of these pathogens to vaginal epithelial cells. The strain further showed the ability to inhibit the enteropathogenic bacteria Escherichia coli and Salmonella enteritidis, to tolerate artificial gastric and intestinal fluids and to adhere to intestinal Caco-2 cells. These results suggest that L. gasseri VHProbi E09 holds promise for clinical trials and animal studies whether administered orally or directly into the vagina. Whole-genome analysis also revealed a genome consisting of 1752 genes for L. gasseri VHProbi E09, with subsequent analyses identifying seven genes related to adhesion and three genes related to bacteriocins. These adhesion- and bacteriocin-related genes provide a theoretical basis for understanding the mechanism of bacterial inhibition of the strain. The research conducted in this study suggests that L. gasseri VHProbi E09 may be considered as a potential probiotic, and further research can delve deeper into its efficacy as an agent which can restore a healthy vaginal ecosystem., (© 2024. The Author(s).)

Lactobacillus contribute to maintain the human healthy and use for nutritional additives as probiotics. In this study, a cholesterol-lowering bacterium, Lactobacillus gasseri TF08-1, was isolated from the feces of a healthy adolescent, and its probiotic potentials were evaluated through genomic mining and in vitro test. The assembled draft genome comprised of 1,974,590 bp and was predicted total of 1,940 CDSs. The annotation of the genome revealed that L. gasseri TF08-1 harbored abundant categories of functional genes in metabolic and information processing. Moreover, strain TF08-1 has capacity to utilize D-Glucose, Sucrose, D-Maltose, Salicin, D-Xylose, D-Cellobiose, D-Mannose, and D-Trehalose, as the carbon source. The safety assessment showed strain TF08-1 contained few antibiotic resistance genes and virulence factors and was only resistant to 2 antibiotics detected by antimicrobial susceptibility test. A high bile salt hydrolase activity was found and a cholesterol-reducing effect was determined in vitro, which the result showed a remarkable cholesterol removal capability of L. gasseri TF08-1 with an efficiency of 84.40 %. This study demonstrated that the strain showed great capability of exopolysaccharide production, and tolerance to acid and bile salt. Therefore, these results indicate that L. gasseri TF08-1 can be considered as a safe candidate for probiotic, especially its potential in biotherapeutic for metabolic diseases., Competing Interests: Conflicts of interest The authors declare no conflict of interests., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: Antimicrobial and antifungal species are essential members of the healthy human microbiota. Several different species of lactobacilli that naturally inhabit the human body have been explored for their probiotic capabilities including strains of the species Lactobacillus gasseri . However, L. gasseri (identified by 16S rRNA gene sequencing) has been associated with urogenital symptoms. Recently a new sister taxon of L. gasseri was described: L. paragasseri . L. paragasseri is also posited to have probiotic qualities., Methods: Here, we present a genomic investigation of all ( n  = 79) publicly available genome assemblies for both species. These strains include isolates from the vaginal tract, gastrointestinal tract, urinary tract, oral cavity, wounds, and lungs., Results: The two species cannot be distinguished from short-read sequencing of the 16S rRNA as the full-length gene sequences differ only by two nucleotides. Based upon average nucleotide identity (ANI), we identified 20 strains deposited as L. gasseri that are in fact representatives of L. paragasseri . Investigation of the genic content of the strains of these two species suggests recent divergence and/or frequent gene exchange between the two species. The genomes frequently harbored intact prophage sequences, including prophages identified in strains of both species. To further explore the antimicrobial potential associated with both species, genome assemblies were examined for biosynthetic gene clusters. Gassericin T and S were identified in 46 of the genome assemblies, with all L. paragasseri strains including one or both bacteriocins. This suggests that the properties once ascribed to L. gasseri may better represent the L. paragasseri species., Competing Interests: Alan J. Wolfe serves on the Scientific Advisor Boards of Pathnostics and Urobiome Therapeutics., (©2022 Ene et al.)

Lactobacilli are a promising natural tool against vaginal dysbiosis and infections. However, new local delivery systems and additional knowledge about their distribution and mechanism of action would contribute to the development of effective medicine. This will be facilitated by the introduction of the techniques for effective, inexpensive, and real-time tracking of these probiotics following their release. Here, we engineered three model vaginal lactobacilli ( Lactobacillus crispatus ATCC 33820, Lactobacillus gasseri ATCC 33323, and Lactobacillus jensenii ATCC 25258) and a control Lactobacillus plantarum ATCC 8014 to express fluorescent proteins with different spectral properties, including infrared fluorescent protein (IRFP), green fluorescent protein (GFP), red fluorescent protein (mCherry), and blue fluorescent protein (mTagBFP2). The expression of these fluorescent proteins differed between the Lactobacillus species and enabled quantification and discrimination between lactobacilli, with the longer wavelength fluorescent proteins showing superior resolving power. Each Lactobacillus strain was labeled with an individual fluorescent protein and incorporated into poly (ethylene oxide) nanofibers using electrospinning, as confirmed by fluorescence and scanning electron microscopy. The lactobacilli retained their fluorescence in nanofibers, as well as after nanofiber dissolution. To summarize, vaginal lactobacilli were incorporated into electrospun nanofibers to provide a potential solid vaginal delivery system, and the fluorescent proteins were introduced to distinguish between them and allow their tracking in the future probiotic-delivery studies.

The vaginal microbiota, normally characterized by lactobacilli presence, is crucial for vaginal health. Members belonging to L. crispatus and L. gasseri species exert crucial protective functions against pathogens, although a total comprehension of factors that influence their dominance in healthy women is still lacking. Here we investigated the complete genome sequence and comprehensive phenotypic profile of L. crispatus strain BC5 and L. gasseri strain BC12, two vaginal strains featured by anti-bacterial and anti-viral activities. Phenotype microarray (PM) results revealed an improved capacity of BC5 to utilize different carbon sources as compared to BC12, although some specific carbon sources that can be associated to the human diet were only metabolized by BC12, i.e. uridine, amygdalin, tagatose. Additionally, the two strains were mostly distinct in the capacity to utilize the nitrogen sources under analysis. On the other hand, BC12 showed tolerance/resistance towards twice the number of stressors (i.e. antibiotics, toxic metals etc.) with respect to BC5. The divergent phenotypes observed in PM were supported by the identification in either BC5 or BC12 of specific genetic determinants that were found to be part of the core genome of each species. The PM results in combination with comparative genome data provide insights into the possible environmental factors and genetic traits supporting the predominance of either L. crispatus BC5 or L. gasseri BC12 in the vaginal niche, giving also indications for metabolic predictions at the species level.

Diverse Lactobacillus strains are widely used as probiotic cultures in the dairy and dietary supplement industries, and specific strains, such as Lactobacillus acidophilus NCFM, have been engineered for the development of biotherapeutics. To expand the Lactobacillus manipulation toolbox with enhanced efficiency and ease, we present here a CRISPR (clustered regularly interspaced palindromic repeats)-SpyCas9 D10A nickase (Cas9 N )-based system for programmable engineering of L. acidophilus NCFM, a model probiotic bacterium. Successful single-plasmid delivery system was achieved with the engineered pLbCas9 N vector harboring cas9 N under the regulation of a Lactobacillus promoter and a cloning region for a customized single guide RNA (sgRNA) and editing template. The functionality of the pLbCas9 N system was validated in NCFM with targeted chromosomal deletions ranging between 300 bp and 1.9 kb at various loci ( rafE , lacS , and ltaS ), yielding 35 to 100% mutant recovery rates. Genome analysis of the mutants confirmed precision and specificity of the pLbCas9 N system. To showcase the versatility of this system, we also inserted an mCherry fluorescent-protein gene downstream of the pgm gene to create a polycistronic transcript. The pLbCas9 N system was further deployed in other species to generate a concurrent single-base substitution and gene deletion in Lactobacillus gasseri ATCC 33323 and an in-frame gene deletion in Lactobacillus paracasei Lpc-37, highlighting the portability of the system in phylogenetically distant Lactobacillus species, where its targeting activity was not interfered with by endogenous CRISPR-Cas systems. Collectively, these editing outcomes illustrate the robustness and versatility of the pLbCas9 N system for genome manipulations in diverse lactobacilli and open new avenues for the engineering of health-promoting lactic acid bacteria. IMPORTANCE This work describes the development of a lactobacillus CRISPR-based editing system for genome manipulations in three Lactobacillus species belonging to the lactic acid bacteria (LAB), which are commonly known for their long history of use in food fermentations and as indigenous members of healthy microbiotas and for their emerging roles in human and animal commercial health-promoting applications. We exploited the established CRISPR-SpyCas9 nickase for flexible and precise genome editing applications in Lactobacillus acidophilus and further demonstrated the efficacy of this universal system in two distantly related Lactobacillus species. This versatile Cas9-based system facilitates genome engineering compared to conventional gene replacement systems and represents a valuable gene editing modality in species that do not possess native CRISPR-Cas systems. Overall, this portable tool contributes to expanding the genome editing toolbox of LAB for studying their health-promoting mechanisms and engineering of these beneficial microbes as next-generation vaccines and designer probiotics., (Copyright © 2021 American Society for Microbiology.)

Background: Lactobacillus gasseri OLL2809 can highly induce interleukin (IL)-12 production in immune cells. Even though beneficial properties of this strain for both humans and animals have been reported, the mechanism by which the bacteria induces the production of IL-12 in immune cells remains elusive. In this study, we investigated the mechanism of induction of IL-12 using a mouse macrophage cell line J774.1., Results: Inhibition of phagocytosis of L. gasseri OLL2809, and myeloid differentiation factor 88 and Toll-like receptors (TLRs) 7 and 9 signalling attenuated IL-12 production in J774.1 cells. Total RNA and genomic DNA of L. gasseri OLL2809, when transferred to the J774.1 cells, also induced IL-12 production. The difference in the IL-12-inducing activity of Lactobacilli is attributed to the susceptibility to phagocytosis, but not to a difference in the total RNA and genomic DNA of each strain., Conclusion: We concluded that total RNA and genomic DNA of phagocytosed L. gasseri OLL2809 induce IL-12 production in J774.1 cell via TLRs 7 and 9, and the high IL-12-inducing activity of L. gasseri OLL2809 is due to its greater susceptibility to phagocytosis.

Bacteriocins are antimicrobial peptides produced by bacteria, and their production is regarded as a desirable probiotic trait. We found that Lactobacillus gasseri LM19, a strain isolated from human milk, produces several bacteriocins, including a novel bacteriocin, gassericin M. These bacteriocins were purified from culture and synthesised to investigate their activity and potential synergy. L. gasseri LM19 was tested in a complex environment mimicking human colon conditions; it not only survived, but expressed the seven bacteriocin genes and produced short-chain fatty acids. Metagenomic analysis of these in vitro colon cultures showed that co-inoculation of L. gasseri LM19 with Clostridium perfringens gave 16S ribosomal RNA metagenomic profiles with more similarity to controls than to vessels inoculated with C. perfringens alone. These results indicate that L. gasseri LM19 could be an interesting candidate for maintaining homeostasis in the gut environment.

Background: Lactobacillus gasseri as a probiotic has history of safe consumption is prevalent in infants and adults gut microbiota to maintain gut homeostasis., Results: In this study, to explore the genomic diversity and mine potential probiotic characteristics of L. gasseri, 92 strains of L. gasseri were isolated from Chinese human feces and identified based on 16 s rDNA sequencing, after draft genomes sequencing, further average nucleotide identity (ANI) value and phylogenetic analysis reclassified them as L. paragasseri (n = 79) and L. gasseri (n = 13), respectively. Their pan/core-genomes were determined, revealing that L. paragasseri had an open pan-genome. Comparative analysis was carried out to identify genetic features, and the results indicated that 39 strains of L. paragasseri harboured Type II-A CRISPR-Cas system while 12 strains of L. gasseri contained Type I-E and II-A CRISPR-Cas systems. Bacteriocin operons and the number of carbohydrate-active enzymes were significantly different between the two species., Conclusions: This is the first time to study pan/core-genome of L. gasseri and L. paragasseri, and compare their genetic diversity, and all the results provided better understating on genetics of the two species.

Lactobacilli play an important role in the maintenance of a healthy vaginal microbiota, and some select species are widely used as probiotics. Vaginal isolates of Lactobacillus gasseri DSM 14869 and Lactobacillus rhamnosus DSM 14870 were previously selected to develop the probiotic EcoVag capsules and showed therapeutic effects in women with bacterial vaginosis (BV). However, the molecular mechanisms involved in their probiotic activity are largely unknown. In this study, we identified three cell surface molecules in L. gasseri DSM 14869 that promote adhesion to vaginal epithelial cells (VEC) by constructing dedicated knockout mutants, including exopolysaccharides (EPSs), a protein containing MucBP-like domains (N506_1778), and a putative novel adhesin (N506_1709) with rib/alpha-like domain repeats. EPS knockout mutants revealed 20-fold and 14-fold increases in adhesion to Caco-2 and HeLa cells, respectively, compared with wild type, while the adhesion to VEC was reduced 30% by the mutation, suggesting that EPSs might mediate tissue tropism for vaginal cells. A significant decrease in adhesion to Caco-2 cells, HeLa cells, and VEC was observed in the N506_1778 knockout mutant. The N506_1709 mutant showed no significant difference for the adhesion to Caco-2 and HeLa cells compared with wild type (WT); in contrast, the adhesion to VEC revealed a significant decrease (42%), suggesting that N506_1709 might mediate specific binding to stratified squamous epithelial cells, and this putative novel adhesin was annotated as Lactobacillus vaginal epithelium adhesin (LVEA). Thus, we have discovered an important role for EPSs and a novel adhesin, LVEA, in the adhesive capacity of a vaginal probiotic Lactobacillus strain. IMPORTANCE Lactobacilli are known to contribute to the maintenance of a healthy vaginal microbiota and some are selected as probiotics for the prevention or treatment of urogenital diseases, such as bacterial vaginosis. However, the molecular mechanisms for these health-promoting effects are not fully understood. Here, we functionally identified three cell surface factors of a Lactobacillus gasseri strain potentially involved in its adhesion to vaginal epithelial cells, including exopolysaccharides (EPSs) and two sortase-dependent proteins (N506_1778 and N506_1709). We could demonstrate the tissue-specific adhesion of EPSs to vaginal cells and that N506_1709 might be a novel adhesin specifically mediating bacterial binding to stratified squamous epithelial cells. The results provide important new information on the molecular mechanisms of vaginal Lactobacillus spp. adhesion., (Copyright © 2019 American Society for Microbiology.)

Lactobacillus gasseri LA327, isolated from the large intestine tissue in humans, is a bacteriocinogenic strain with two kinds of class IIb bacteriocin structural genes, i.e., those for gassericin T (GT) and acidocin LF221A (Acd LF221A). In this study, DNA sequencing of the genes for GT and Acd LF221A from L. gasseri LA327 revealed that the amino acid sequences for GT corresponded with those for GT genes, except for GatK (histidine kinase). However, Acd LF221A genes had analogues which differed in at least one amino acid residue, to encode a class IIb bacteriocin designated gassericin S (GS). The LA327 strain retained antimicrobial activity after the deletion of the GT structural genes ( gatAX ); however, both GS and GT activities were lost by deletion of the putative ABC transporter gene ( gatT ). This indicates that the LA327 strain produces GS and GT and that GS secretion is performed via GT genes with the inclusion of gatT Homologous expression using deletion mutants of GS and GT, each containing a single peptide, elucidated that GS (GasAX) and GT (GatAX) showed synergistic activity as class IIb bacteriocins and that no synergistic activity was observed between GS and GT peptides. The molecular mass of GS was estimated to be theoretical ca. 5,400 Da by in situ activity assay after SDS-PAGE, clarifying that GS was actually expressed as an active class IIb bacteriocin. Furthermore, the stability of expressed GS to pH, heat, and protease was determined. IMPORTANCE Bacteriocins are regarded as potential alternatives for antibiotics in the absence of highly resistant bacteria. In particular, two-peptide (class IIb) bacteriocins exhibit the maximum activity through the synergy of two components, and their antimicrobial spectra are known to be relatively wide. However, there are few reports of synergistic activity of class IIb bacteriocins determined by isolation and purification of individual peptides. Our results clarified the interaction of each class IIb component peptide for GT and GS via the construction of homologous mutants, which were not dependent on the purification. These data may contribute to understanding the mechanisms of action by which class IIb bacteriocins exhibit wide antibacterial spectra., (Copyright © 2019 American Society for Microbiology.)

Lactobacillus gasseri is a human commensal which carries CRISPR-Cas, an adaptive immune system that protects the cell from invasive mobile genetic elements (MGEs). However, MGEs occasionally escape CRISPR targeting due to DNA mutations that occur in sequences involved in CRISPR interference. To better understand CRISPR escape processes, a plasmid interference assay was used to screen for mutants that escape CRISPR-Cas targeting. Plasmids containing a target sequence and a protospacer adjacent motif (PAM) were transformed for targeting by the native CRISPR-Cas system. Although the primary outcome of the assay was efficient interference, a small proportion of the transformed population overcame targeting. Mutants containing plasmids that had escaped were recovered to investigate the genetic routes of escape and their relative frequencies. Deletion of the targeting spacer in the native CRISPR array was the dominant pattern of escape, accounting for 52-70 % of the mutants from two L. gasseri strains. We repeatedly observed internal deletions in the chromosomal CRISPR array, characterized by polarized excisions from the leader end that spanned 1-15 spacers, and systematically included the leader-proximal targeting spacer. This study shows that deletions of spacers within CRISPR arrays constitute a key escape mechanism to evade CRISPR targeting, while preserving the functionality of the CRISPR-Cas system. This mechanism enables cells to maintain an active immune system, but allows the uptake of potentially beneficial plasmids. Our study revealed the co-occurrence of other genomic mutations associated with various phenotypes, showing how this selection process uncovers population diversification.

A total of 22 Lactobacillus strains, which were isolated from infant feces were evaluated for their probiotic potential along with resistance to low pH and bile salts. Eight isolates (L. reuteri 3M02 and 3M03, L. gasseri 4M13, 4R22, 5R01, 5R02, and 5R13, and L. rhamnosus 4B15) with high tolerance to acid and bile salts, and ability to adhere to the intestine were screened from 22 strains. Further, functional properties of 8 Lactobacillus strains, such as anti-oxidation, inhibition of α-glucosidase activity, cholesterol-lowering, and anti-inflammation were evaluated. The properties were strain-specific. Particularly, two strains of L. rhamnosus, 4B15 (4B15) and L. gasseri 4M13 (4M13) showed considerably higher anti-oxidation, inhibition of α-glucosidase activity, and cholesterol-lowering, and greater inhibition of nitric oxide production than other strains. Moreover, the two selected strains substantially inhibited the release of inflammatory mediators such as TNF-α, IL-6, IL-1β, and IL-10 stimulated the treatment of RAW 264.7 macrophages with LPS. In addition, whole genome sequencing and comparative genomic analysis of 4B15 and 4M13 indicated them as novel genomic strains. These results suggested that 4B15 and 4M13 showed the highest probiotic potential and have an impact on immune health by modulating pro-inflammatory cytokines.

While the CRISPR-Cas9 system from S. pyogenes is a powerful genome engineering tool, additional programmed nucleases would enable added flexibility in targeting space and multiplexing. Here, we characterized a CRISPR-Cas9 system from L. gasseri and found that it has modest activity in a cell-free lysate assay but no activity in mammalian cells even when altering promoter, position of tag sequences and NLS, and length of crRNA:tracrRNA. In the lysate assay we tested over 400 sequential crRNA target sequences and found that the Lga Cas9 PAM is NNGA/NDRA, different than NTAA predicted from the native bacterial host. In addition, we found multiple instances of consecutive crRNA target sites, indicating flexibility in either PAM sequence or distance from the crRNA target site. This work highlights the need for characterization of new CRISPR systems and highlights the non-triviality of porting them into eukaryotes as gene editing tools.

Lactobacillus rhamnosus DSM 14870 and Lactobacillus gasseri DSM 14869 were previously isolated from the vaginal epithelial cells (VEC) of healthy women and selected for the development of the vaginal EcoVag ® probiotic capsules. EcoVag ® was subsequently shown to provide long-term cure and reduce relapse of bacterial vaginosis (BV) as an adjunct to antibiotic therapy. To identify genes potentially involved in probiotic activity, we performed genome sequencing and characterization of the two strains. The complete genome analysis of both strains revealed the presence of genes encoding functions related to adhesion, exopolysaccharide (EPS) biosynthesis, antimicrobial activity, and CRISPR adaptive immunity but absence of antibiotic resistance genes. Interesting features of L. rhamnosus DSM 14870 genome include the presence of the spaCBA-srtC gene encoding spaCBA pili and interruption of the gene cluster encoding long galactose-rich EPS by integrases. Unique to L. gasseri DSM 14869 genome was the presence of a gene encoding a putative (1456 amino acid) new adhesin containing two rib/alpha-like repeats. L. rhamnosus DSM 14870 and L. gasseri DSM 14869 showed acidification of the culture medium (to pH 3.8) and a strong adhesion capability to the Caco-2 cell line and VEC. L. gasseri DSM 14869 could produce a thick (40nm) EPS layer and hydrogen peroxide. L. rhamnosus DSM 14870 was shown to produce SpaCBA pili and a 20nm EPS layer, and could inhibit the growth of Gardnerella vaginalis, a bacterium commonly associated with BV. The genome sequences provide a basis for further elucidation of the molecular basis for their probiotic functions., (Copyright © 2017 Elsevier GmbH. All rights reserved.)