Adhesion and aggregation ability of probiotic strain Lactobacillus acidophilus M92

Red ginseng dietary fiber promotes probiotic properties of Lactiplantibacillus plantarum and alters bacterial metabolism

Korean red ginseng has been widely used as an herbal medicine. Red ginseng dietary fiber (RGDF) is a residue of the processed ginseng product but still contains bioactive constituents that can be applied as prebiotics. In this study, we evaluated changes on fermentation profiles and probiotic properties of strains that belong to family Lactobacillaceae with RGDF supplementation. Metabolomic analyses were performed to understand specific mechanisms on the metabolic alteration by RGDF and to discover novel bioactive compounds secreted by the RGDF-supplemented probiotic strain. RGDF supplementation promoted short-chain fatty acid (SCFA) production, carbon source utilization, and gut epithelial adhesion of Lactiplantibacillus plantarum and inhibited attachment of enteropathogens. Intracellular and extracellular metabolome analyses revealed that RGDF induced metabolic alteration, especially associated with central carbon metabolism, and produced RGDF-specific metabolites secreted by L. plantarum, respectively. Specifically, L. plantarum showed decreases in intracellular metabolites of oleic acid, nicotinic acid, uracil, and glyceric acid, while extracellular secretion of several metabolites including oleic acid, 2-hydroxybutanoic acid, hexanol, and butyl acetate increased. RGDF supplementation had distinct effects on L. plantarum metabolism compared with fructooligosaccharide supplementation. These findings present potential applications of RGDF as prebiotics and bioactive compounds produced by RGDF-supplemented L. plantarum as novel postbiotic metabolites for human disease prevention and treatment.

The Emerging Role of Probiotics and their Derivatives against Biofilm-Producing MRSA: A Scoping Review

Background

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the main bacterial pathogens causing chronic infections, mainly because of its capacity to produce biofilm. Biofilm production is one of the underlying strategies for antibacterial drug resistance. Accordingly, preventing and attenuating biofilm production has become an emerging approach to controlling persistent infections. Therefore, this scoping review is aimed at surveying the published literature describing the usage of probiotics and their derivatives against biofilm-producing MRSA.

Methods

Updated literature searches were conducted across seven electronic databases including Web of Science, PubMed, Scopus, Cochrane Library, ProQuest, Embase, and Google Scholar to identify all original published articles about probiotics against MRSA. In this regard, studies were summarized and analyzed in the present review.

Results

In the reviewed studies, various microorganisms and compounds were used as probiotics as follows: Lactobacillus species (8 studies), Enterococcus species (4 studies), Bacillus species (2 studies), Streptomyces species (2 studies), Saccharomyces cerevisiae (1 study), Corynebacterium accolens (1 study), and Lactococcus lactis derived Nisin (3 studies). Based on our comprehensive search, 21 studies with eligibility criteria were included in the present review including 12 studies on clinical strains, 6 studies on ATCC, 2 studies simultaneously on clinical and standard strains, and finally 1 study on food sample.

Conclusions

Our study showed that there was an increasing trend in the number of publications reporting probiotics against biofilm-producing MRSA. The results of this scoping review could use to guide the undertaking of the subsequent systematic reviews. In summary, probiotics with antimicrobial and antibiofilm properties can use as an embedded agent in food products or as a biopharmaceutical in the prevention and treatment of MRSA infections.

The Human Milk Microbiota Produces Potential Therapeutic Biomolecules and Shapes the Intestinal Microbiota of Infants

Human milk not only provides a perfect balance of nutrients to meet all the needs of the infant in the first months of life but also contains a variety of bacteria that play a key role in tailoring the neonatal faecal microbiome. Microbiome analysis of human milk and infant faeces from mother-breastfed infant pairs was performed by sequencing the V1-V3 region of the 16S rRNA gene using the Illumina MiSeq platform. According to the results, there is a connection in the composition of the microbiome in each mother-breastfed infant pair, supporting the hypothesis that the infant's gut is colonised with bacteria from human milk. MiSeq sequencing also revealed high biodiversity of the human milk microbiome and the infant faecal microbiome, whose composition changes during lactation and infant development, respectively. A total of 28 genetically distinct strains were selected by hierarchical cluster analysis of RAPD-PCR (Random Amplified Polymorphic DNA-Polymerase Chain Reaction) electrophoresis profiles of 100 strains isolated from human milk and identified by 16S RNA sequencing. Since certain cellular molecules may support their use as probiotics, the next focus was to detect (S)-layer proteins, bacteriocins and exopolysaccharides (EPSs) that have potential as therapeutic biomolecules. SDS-PAGE (Sodium Dodecyl-Sulfate Polyacrylamide Gel Electrophoresis) coupled with LC-MS (liquid chromatography-mass spectrometry) analysis revealed that four Levilactobacillus brevis strains expressed S-layer proteins, which were identified for the first time in strains isolated from human milk. The potential biosynthesis of plantaricin was detected in six Lactiplantibacillus plantarum strains by PCR analysis and in vitro antibacterial studies. ¹H NMR (Proton Nuclear Magnetic Resonance) analysis confirmed EPS production in only one strain, Limosilactobacillus fermentum MC1. The overall microbiome analysis suggests that human milk contributes to the establishment of the intestinal microbiota of infants. In addition, it is a promising source of novel Lactobacillus strains expressing specific functional biomolecules.

Honeybee-associated lactic acid bacteria and their probiotic potential for human use

This study aims to identify lactic acid bacteria (LAB) isolated from honeybees (Apis mellifera workers and larvae) in detail and to determine their functional probiotic properties. A total of 11 strains were classified based on morphological and biochemical characteristics. Preliminary probiotic properties of strains, that were molecularly identified using 16 S rRNA, such as antimicrobial activity, tolerance to digestive conditions, aggregation ability, were investigated. The antimicrobial properties of strains were tested against a wide range of human pathogens. All strains that showed γ-hemolysis and did not contain bacteriophages were considered safe. The strains' survivability checked for 0.3% bile and 3.0-7.8 pH contents was promising. The highest autoaggregation ranged from 14.7 to 30.76% after 4 h. Tested LAB strains markedly exhibited coaggregation with Listeria monocytogenes and Escherichia coli. According to the results, tested bacteria showed significant antagonistic effects against pathogens, and positive probiotic characteristics compatible with in vitro gastrointestinal tract conditions. The results suggest that Apis mellifera LAB symbionts may have a probiotic potential, and be effective and safe candidates for human use. This study provides an addition to the development of the current knowledge by defining in detail honeybee-associated bacteria and determining their probiotic potential.

The Influence of the Degree of Thermal Inactivation of Probiotic Lactic Acid Bacteria and Their Postbiotics on Aggregation and Adhesion Inhibition of Selected Pathogens

The study aimed to evaluate the effect of thermal inactivation of potentially probiotic lactic acid bacteria (LAB) strains isolated from food on their ability to compete with pathogenic microorganisms. Five strains of LAB, previously isolated from food and characterized, one commercial reference strain of Lactiplantibacillus plantarum 299v, and two indicator strains of Staphylococcus aureus 25923 and Listeriamonocytogenes 15313 were used in the study. The experiment consisted in applying a stress factor (high temperature: 80 °C, at a different time: 5, 15, and 30 min) to the tested LAB cells to investigate the in vitro properties such as hydrophobicity abilities (against p-xylene and n-hexadecane), auto-aggregation, co-aggregation with pathogens, and inhibition of pathogens adhesion to the porcine gastric mucin. The bacterial strains showed various hydrophobicity to p-xylene (36-73%) and n-hexadecane (11-25%). The affinity for solvents expanded with increasing thermal inactivation time. All LAB isolates were able to auto-aggregate (ranging from 17 to 49%). Bacterial strains subjected to 5 and 15 min of thermal inactivation had the highest auto-aggregation ability in comparison to viable and heat-killed cells for 30 min. The LAB strains co-aggregated with pathogens to different degrees; among them, the highest scores of co-aggregation were observed for L. monocytogenes, reaching 27% (with 15 min of heat-killed LAB cells). All LAB strains reduced the adherence of pathogenic bacteria in the competition test, moreover, heat-killed cells (especially 15 min inactivated) were more efficient than viable cells. The properties of selected LAB strains as moderately heat-stressed forms analyzed in the study increased the prevention of colonization and elimination of pathogenic bacteria in the in vitro model of gastrointestinal tract. The thermal inactivation process may therefore preserve and modifies some characteristics of bacterial cells.

Evaluation of Safety and Probiotic Potential of Enterococcus faecalis MG5206 and Enterococcus faecium MG5232 Isolated from Kimchi, a Korean Fermented Cabbage

The purpose of this study was to evaluate the genotypic and phenotypic toxicity of Enterococcus faecalis MG5206 and Enterococcus faecium MG5232 isolated from kimchi (fermented vegetable cabbage). In this study, the genotypic toxicity of the strains MG5206 and MG5232 was identified through whole-genome sequencing analysis, and phenotypic virulence, such as susceptibility to antibiotics, hemolytic activity, and gelatinase and hyaluronidase activities, was also evaluated. In addition, the in vivo toxicity of both strains was evaluated using an acute oral administration test in Sprague–Dawley rats. In all the tests, both the strains were determined to be safety by confirming that they did not show antibiotic resistance or virulence factors. In addition, these strains exhibited a low level of autoaggregation ability (37.2–66.3%) and hydrophobicity, as well as a high survival rate in gastrointestinal condition in vitro. Therefore, the safety and high gastrointestinal viability of E. faecalis MG5206 and E. faecium MG5232 suggests that both the strains could be utilized in food as potential probiotics in the future.

New Potentially Probiotic Strains Isolated from Humans – Comparison of Properties with Strains from Probiotic Products and ATCC Collection

Lactic acid bacteria are used in various types of probiotic products. Due to the constantly growing probiotics market, new strains with pro-health properties are sought. The present study compared 39 strains of Lactobacillus, Lacticaseibacillus, and Lactiplantibacillus, isolated from probiotic products and healthy people. The current research aimed to search for new, potentially probiotic strains. For this purpose the relationship between Lactobacillaceae strains was carried out; moreover, the basic properties of probiotic microorganisms, such as survival at low pH and bile salt environment, antibiotic susceptibility, aggregation and antagonism were estimated. The properties of these isolates were also compared with the properties of probiotic strains from the ATCC collection. In comparing the genetic relationship (PFGE method) between the tested isolates, it was observed that some of them show a high degree of similarity. All tested strains tolerated an environment with a pH value of 3.0, and the addition of 0.3% bile salt; showed auto-aggregation properties and displayed antagonism against pathogenic microorganisms. In the present study, the bacteria were susceptible to tetracycline, chloramphenicol and ampicillin; the resistance to vancomycin

depended on the bacteria type. All the properties were strain-depended. Most of the tested strains had properties comparable to the reference strains. Three L. acidophilus strains isolated from cervical swabs seem to be promising candidates for probiotic strains.

Preventive and therapeutic effect of Lactobacillus paracasei ZFM54 on Helicobacter pylori-induced gastritis by ameliorating inflammation and restoring gastric microbiota in mice model

Helicobacter pylori is the most prevalent pathogen causing chronic gastritis, gastroduodenal ulcers, and gastric tumors and is asymptomatically present in 50% of the world's population. This research is focused on investigating the effect of Lactobacillus paracasei ZFM 54 (CCTCC NO:2016667) on attenuating H. pylori-induced gastritis. H. pylori ZJC03 isolated from a patient with gastritis harbored the virulence genes of vacA and cagA and was highly resistant to metronidazole (MIC > 256 μg/mL). In vitro analysis revealed that the potential anti-H. pylori characteristics of L. paracasei ZFM54 in terms of 65.57 ± 1.87% survival rate in simulated gastric juices at a pH of 2.0, 69.00 ± 2.73% auto-aggregation, 30.28 ± 2.24% co-aggregation, 70.27 ± 2.23% urease inhibition, and 57.89 ± 1.27% radical scavenging. In H. pylori infectious mice, L. paracasei ZFM54 pre- and post-treatment reduced the levels of malondialdehyde in liver tissues to 0.71 ± 0.04 nmol/mgprot (p < 0.05) and 0.70 ± 0.06 nmol/mgprot (p < 0.05), respectively. Glutathione levels were increased to 1.78 ± 0.02 μmol/gprot (p < 0.05) and 1.76 ± 0.52 μmol/gprot (p < 0.05), respectively. L. paracasei ZFM54 significantly inhibited H. pylori-mediated inflammation observed in gastric mucosal repair and downregulated the mRNA expression of pro-inflammatory cytokines IFN-γ, IL-1β, and IL-6 (p < 0.01). Importantly, L. paracasei ZFM54 increased Firmicutes and Actinobacteriota and decreased the relative abundance of bacterial taxa belonging to Campilobacterota and Proteobacteria. With the preventive and therapeutic administration of L. paracasei ZFM54, significant reductions in the average relative abundance of genera Helicobacter, Muribaculum, Staphylococcus, Lachnospiraceae_NK4A136_group, Prevotellaceae_UCG-001, Alloprevotella, and Oscillibacter were observed compared to infected mice. These findings suggest that L. paracasei ZFM 54 has the potential to protect against H. pylori infection by ameliorating inflammation and restoring the gastric microbiota.

The Detection of Potential Native Probiotics Lactobacillus spp. against Salmonella Enteritidis, Salmonella Infantis and Salmonella Kentucky ST198 of Lebanese Chicken Origin

Salmonella continues to be a major threat to public health, especially with respect to strains from a poultry origin. In recent years, an increasing trend of antimicrobial resistance (AMR) in Salmonella spp. was observed due to the misuse of antibiotics. Among the approaches advised for overcoming AMR, probiotics from the Lactobacillus genus have increasingly been considered for use as effective prophylactic and therapeutic agents belonging to the indigenous microbiota. In this study, we isolated lactobacilli from the ilea and ceca of hens and broilers in order to evaluate their potential probiotic properties. Four species were identified as Limosilactobacillusreuteri (n = 22, 45.8%), Ligilactobacillussalivarius (n = 20, 41.6%), Limosilactobacillus fermentum (n = 2, 4.2%) and Lactobacillus crispatus (n = 1, 2%), while three other isolates (n = 3, 6.25%) were non-typable. Eight isolates, including Ligilactobacillussalivarius (n = 4), Limosilactobacillusreuteri (n = 2), L. crispatus (n = 1) and Lactobacillus spp. (n = 1) were chosen on the basis of their cell surface hydrophobicity and auto/co-aggregation ability for further adhesion assays using the adenocarcinoma cell line Caco-2. The adhesion rate of these strains varied from 0.53 to 10.78%. Ligilactobacillussalivarius A30/i26 and 16/c6 and Limosilactobacillus reuteri 1/c24 showed the highest adhesion capacity, and were assessed for their ability to compete in and exclude the adhesion of Salmonella to the Caco-2 cells. Interestingly, Ligilactobacillussalivarius 16/c6 was shown to significantly exclude the adhesion of the three Salmonella serotypes, S. Enteritidis, S. Infantis and S. Kentucky ST 198, to Caco-2 cells. The results of the liquid co-culture assays revealed a complete inhibition of the growth of Salmonella after 24 h. Consequently, the indigenous Ligilactobacillussalivarius 16/c6 strain shows promising potential for use as a preventive probiotic added directly to the diet for the control of the colonization of Salmonella spp. in poultry.

Characterization and potential oral probiotic properties of Lactobacillus plantarum FT 12 and Lactobacillus brevis FT 6 isolated from Malaysian fermented food

OBJECTIVE

This study aims to characterise the lactic acid bacteria (LAB) isolated from local Malaysian fermented foods with oral probiotics properties.

DESIGN

The LAB strains isolated from Malaysian fermented foods, Lactobacillus brevis FT 6 and Lactobacillus plantarum FT 12, were assessed for their antimicrobial properties against Porphyromonas gingivalis ATCC 33277 via disc diffusion assay. Anti-biofilm properties were determined by treating the overnight P. gingivalis ATCC 33277 biofilm with different concentrations of LAB cell-free supernatant (LAB CFS). Quantification of biofilm was carried out by measuring the optical density of stained biofilm. The ability of L. brevis FT 6 and L. plantarum FT 12 to tolerate salivary amylase was also investigated. Acid production with different sugars was carried out by pH measurement and screening for potential antimicrobial organic acid by disc diffusion assay of neutralised probiotics CFS samples. In this study, L. rhamnosus ATCC 7469, a commercial strain was used to compare the efficacy of the isolated strain with the commercial strain.

RESULTS

Lactobacillus brevis FT 6 and L. plantarum FT 12 possess antimicrobial activity against P. gingivalis with inhibition diameters of more than 10 mm, and the results were comparable with L. rhamnosus ATCC 7469. The MIC and MBC assay results for all tested strains were recorded to be 25 µl/µl concentration. All LAB CFS reduced biofilm formation proportionally to the CFS concentration and tolerated salivary amylase with more than 50% viability. Overnight cultures of all lactic acid bacteria strains showed a pH reduction and neutralised CFS of all lactic acid bacteria strains did not show any inhibition towards P. gingivalis.

CONCLUSIONS

These results indicate that the isolated probiotics have the potential as probiotics to be used as a supportive oral health treatment, especially against a periodontal pathogen, P. gingivalis.

Probiotic and Antifungal Attributes of Lactic Acid Bacteria Isolates from Naturally Fermented Brazilian Table Olives

Research with fermented olives as a source of wild Lactic Acid Bacteria (LAB) strains with probiotic and biotechnological characteristics constitutes a promising field of work. The present study evaluated in vitro probiotic, antifungal, and antimycotoxigenic potential of LAB isolates from naturally fermented Brazilian table olives. Among fourteen LAB isolates, the Levilactobacillus brevis CCMA 1762, Lactiplantibacillus pentosus CCMA 1768, and Lacticaseibacillus paracasei subsp. paracasei CCMA 1770 showed potential probiotic and antifungal properties. The isolates showed resistance to pH 2.0 (survival ≥ 84.55), bile salts (survival ≥ 99.44), and gastrointestinal tract conditions (survival ≥ 57.84%); hydrophobic cell surface (≥27%); auto-aggregation (≥81.38%); coaggregation with Escherichia coli INCQS 00181 (≥33.97%) and Salmonella Enteritidis ATCC 564 (≥53.84%); adhesion to the epithelial cell line Caco-2 (≥5.04%); antimicrobial activity against the bacteria S. Enteritidis ATCC 564 (≥6 mm), Listeria monocytogenes ATCC 19117 (≥6 mm), Staphylococcus aureus ATCC 8702 (≥3 mm), and the fungi Penicillium nordicum MUM 08.16 (inhibition ≥ 64.8%). In addition, the strains showed the ability to adsorb the mycotoxins aflatoxin B1 (≥40%) and ochratoxin A (≥34%). These results indicate that LAB strains from naturally fermented Brazilian table olives are potentially probiotic and antifungal candidates that can be used for food biopreservation.

Saccharomyces cerevisiae does not undergo a quorum sensing-dependent switch of budding pattern

Saccharomyces cerevisiae can alter its morphology to a filamentous form associated with unipolar budding in response to environmental stressors. Induction of filamentous growth is suggested under nitrogen deficiency in response to alcoholic signalling molecules through quorum sensing. To investigate this further, we analysed the budding pattern of S. cerevisiae cells over time under low nitrogen conditions while concurrently measuring cell density and extracellular metabolite concentration. We found that the proportion of cells displaying unipolar budding increased between local cell densities of 4.8 × 10⁶ and 5.3 × 10⁷ cells/ml. This increase in unipolar budding was not reproduced with cells growing at the critical cell density and in conditioned media. Growth under high nitrogen conditions also resulted in increased unipolar budding between local cell densities of 5.2 × 10⁶ and 8.2 × 10⁷ cells/ml, but with differences in metabolite concentration compared to low nitrogen conditions. Neither cell density, metabolite concentration, nor nitrogen deficiency were therefore sufficient to increase unipolar budding. Therefore, by using the budding pattern as an early indicator of filamentous growth, our results suggest that quorum sensing may not control the switch of budding behaviour in S. cerevisiae. Only a high concentration of the putative signalling molecule, 2-phenylethanol, resulted in an increase in unipolar budding. However, this concentration was not physiologically relevant, suggesting toxicity rather than a known quorum sensing mechanism.

Antimicrobial Activity from Putative Probiotic Lactic Acid Bacteria for the Biological Control of American and European Foulbrood Diseases

The balance of the gut microbiome is important for the honey bee’s growth and development, immune function and defense against pathogens. The use of a beneficial bacteria-based strategy for the prevention and biocontrol of American foulbrood (AFB) and European foulbrood (EFB) diseases in honey bees offers interesting prospects. Lactic acid bacteria (LAB) are common inhabitants of the gastrointestinal tract of the honey bee. Among LABs associated with bee gut microbiota, Lactiplantibacillus plantarum (previously Lactobacillus plantarum) and Apilactobacillus kunkeei (formerly classified as Lactobacillus kunkeei) are two of the most abundant species. In this study, four Lactiplantibacillus plantarum strains and four Apilactobacillus kunkeei strains, isolated from the gastrointestinal tract of honey bee (Apis mellifera L.) were selected for their in vitro inhibition ability of Paenibacillus larvae ATCC 9545 and Melissococccus plutonius ATCC 35311. In addition, these LABs have been characterized through some biochemical and functional characteristics: cell surface properties (hydrophobicity and auto-aggregation), carbohydrates assimilation and enzymatic activities. The antimicrobial, biochemical and cell surface properties of these LABs have been functional to their candidature as potential probiotics in beekeeping and for the biocontrol of AFB and EFB diseases.

Adhesion and Colonization of the Probiotic Lactobacillus plantarum HC-2 in the Intestine of Litopenaeus Vannamei Are Associated With Bacterial Surface Proteins

Surface proteins are a type of proteins expressed on the surface of bacteria that play an important role in cell wall synthesis, maintenance of cell morphology, and signaling with the host. Our previous study showed that the probiotic Lactobacillus plantarum HC-2 improved the growth performance and immune response of Litopenaeus vannamei. To further investigate the probiotic mechanism, we determined the automatic aggregation ability of the bacteria and surface hydrophobicity of HC-2 after being treated with 5 M of lithium chloride (LiCl) and observed the morphology and adhesion of the bacteria to HCT116 cells. The results showed that with the removal of the HC-2 surface protein, the auto-aggregation ability and surface hydrophobicity of HC-2 decreased, and the crude mucus layer coated on the bacterial surface gradually dissociated. The adhesion rate of HC-2 to HCT116 cells decreased from 98.1 to 20.9%. Moreover, a total of 201 unique proteins were identified from the mixture of the surface proteins by mass spectrometry (MS). Several proteins are involved in transcription and translation, biosynthetic or metabolic process, cell cycle or division, cell wall synthesis, and emergency response. Meanwhile, a quantitative real-time PCR qPCR_ showed that HC-2 was mainly colonized in the midgut of shrimp, and the colonization numbers were 15 times higher than that in the foregut, while the colonization rate in the hindgut was lower. The adhesion activity measurement showed that the adhesion level of HC-2 to crude intestinal mucus of L. vannamei was higher than that of bovine serum albumin (BSA) and collagen, and the adhesion capacity of the bacterial cells decreased with the extension of LiCl-treatment time. Finally, we identified the elongation factor Tu, Type I glyceraldehyde-3-phosphate dehydrogenase, small heat shock protein, and 30S ribosomal protein from the surface proteins, which may be the adhesion proteins of HC-2 colonization in the shrimp intestine. The above results indicate that surface proteins play an important role in maintaining the cell structure stability and cell adhesion. Surface proteomics analysis contributes to describing potential protein-mediated probiotic-host interactions. The identification of some interacting proteins in this work may be beneficial to further understand the adhesion/colonization mechanism and probiotic properties of L. plantarum HC-2 in the shrimp intestine.

Isolation, Characterization, and Identification Candidate of Probiotic Bacteria Isolated from Wadi Papuyu (Anabas testudineus Bloch.) a Fermented Fish Product from Central Kalimantan, Indonesia

During the wadi fermentation process, some microorganisms can grow, including lactic acid bacteria (LAB), affecting the taste and texture of the final product. Some LAB strains are used as probiotics such as the Lactobacillus and Bifidobacterium groups. This study aimed at isolating, in vitro characterizing, and identifying microbial isolates from wadi papuyu (Anabas testudineus Bloch.). The stages started from sample collection, manufacture of wadi papuyu by fermentation for 8 days, isolation of bacteria from wadi papuyu, in vitro characterization, and identification of bacterial isolates with VITEK 2 Compact and PCR-sequencing methods 16S rRNA and 18S rRNA. The number of microbial colonies growing on MRS agar and MHA was 22 in total, while after purification and characterization it was observed only 4 different microbial isolates. Candidates are tested to determine whether they meet the criteria to be candidates for probiotic cultures. The in vitro testing of four isolates showed that they do not possess probiotic characteristics, especially in autoaggregation tests. Identification results using the VITEK 2 Compact method and 16S rRNA gene PCR-sequencing showed that of the 4 isolated strains, three were bacterial and one belonged to yeasts.

Bioprophylactic potential of novel human colostrum probiotics via apoptotic induction of colon cancer cells and cell immune activation

The potential and modes of action of novel human colostrum probiotics were investigated with the aim of studying their application as an alternative in the bioprophylactic and biotherapy of colon cancer. A total of 218 isolates of Gram-positive rod and cocci bacteria obtained from the colostrum of 50 healthy lactating females were collected. Beneficial probiotic criteria from these isolates, which included growth inhibition against seven foodborne pathogens (Helicobacter pylori, Escherichia coli, Salmonella Enteritidis, Salmonella Typhimurium, Staphylococcus aureus, Bacillus cereus and Listeria monocytogenes), no blood haemolysis and tolerance to acid and bile salt conditions, resulted in only eight probiotic bacteria successfully inhibiting the proliferation of colon cancer cells at rates of 32.47-61.21%. Two probiotic bacteria with higher anticancer efficacy (Streptococcus salivarius CP163 and S. salivarius CP208) were identified using 16S rRNA sequences. High rates of cell surface hydrophobicity, autoaggregation and coaggregation were obtained from both probiotics. The probiotic mode of action involved synergic probiotic adhesion to colon cancer cells that triggered SCFA bioproduction. Apoptotic induction of colon cancer cell death through caspase-2 activity, DNA fragmentation and morphological change as assessed by AO/PI staining were also observed. Immune stimulation by S. salivarius CP163 and S. salivarius CP208 resulted in B and T-cell lymphocyte activation. This study suggests that these novel human colostrum probiotics could be applied as a functional food to facilitate a bioprophylactic strategy in colon cancer.

Adhesion and aggregation properties of Lactobacillaceae strains as protection ways against enteropathogenic bacteria

The adhesion and aggregation are characteristic attributes of probiotic strains belonging to Lactobacillaceae genus. Due to these properties the host organisms can avoid colonisation of the intestinal tract by enteropathogenic bacteria. The presented research includes a comparison of the properties of various strains belonging to different Lactobacillaceae species and isolated from different sources The aim of this study was to investigate the ability of Lactocaseibacillus rhamnosus, Lactiplantibacillus plantarum, and Lactobacillus strains (L. acidophilus, L. gasseri, L. ultunensis) from probiotic products and clinical specimens to direct and competitive adherence to Caco-2 and HT-29 cell lines. Furthermore, the ability of lactobacilli and enteropathogenic bacteria, E. coli, E. faecalis, and S. Typhimurium, to auto- and co-aggregation was also investigated.

The results showed that all tested strains adhered to Caco-2 and HT-29 cell lines. Though, the factor of adhesion depended on the species and origin of the strain. L. rhamnosus strains showed a lowest degree of adherence as compared to L. plantarum and Lactobacillus sp. strains. On the other side both, L. rhamnosus and L. acidophilus strains reduced the pathogenic bacteria in competition adherence test most effectively. All tested lactobacilli strains were characterised by auto- and co-aggregation abilities, to various degrees. The properties of Lactobacillaceae strains analysed in this study, like adhesion abilities, competitive adherence, auto- and co-aggregation, may affect the prevention of colonisation and elimination of pathogenic bacteria in gastrointestinal tract.

Evaluation of Potential Probiotic Properties of a Strain of Lactobacillus plantarum for Shrimp Farming: From Beneficial Functions to Safety Assessment

In recent years the safety of probiotics has received increasing attention due to the possible transfer and spread of virulence factors (VFs) and antibiotic resistance genes (ARGs) among microorganisms. The safety of a strain of Lactobacillus plantarum named W2 was evaluated in phenotype and genotype in the present study. Its probiotic properties were also evaluated both in vivo and in vitro, including adherence properties, antibacterial properties and beneficial effects on the growth and immunity of Pacific white shrimp, Penaeus vannamei. Hemolysis tests, antibiotic resistance tests and whole genome sequence analysis showed that W2 had no significant virulence effects and did not carry high virulence factors. W2 was found to be sensitive to chloramphenicol, clindamycin, gentamicin, kanamycin and tetracycline, and to be resistant to ampicillin and erythromycin. Most ARGs have no transfer risk and a few have transfer risk but no significant enrichment in human-associated environments. The autoaggregation of W2 was 82.6% and the hydrophobicity was 81.0%. Coaggregation rate with Vibrio parahaemolyticus (24.9%) was significantly higher than Vibrio's autoaggregation rate (17.8%). This suggested that W2 had adhesion potential to mucosal/intestinal surfaces and was able to attenuate the adherence of V. parahaemolyticus. In addition, several adhesion-related protein genes, including 1 S-layer protein, 1 collagen-binding protein and 9 mucus-binding proteins were identified in the W2 genome. W2 had efficiently antagonistic activity against 7 aquatic pathogenic strains. Antagonistic components analysis indicated that active antibacterial substances might be organic acids. W2 can significantly promote the growth of shrimp when supplemented with 1 × 10¹⁰ cfu/kg live cells. Levels of 7 serological immune indicators and expression levels of 12 hepatopancreatic immune-related genes were up-regulated, and the mortality of shrimp exposed to V. parahaemolyticus was significantly reduced. Based on the above, L. plantarum W2 can be applied safely as a potential probiotic to enhance the growth performance, immunity capacity and disease resistance of P. vannamei.

Anti-inflammation and adhesion enhancement properties of the multifunctional LPxTG-motif surface protein derived from the Lactobacillus reuteri DSM 8533

LPxTG-motif protein (LMP) is one kind of a precursor protein that contains a conserved LPxTG-motif at the C-terminus, which can be recognized by sortase A (SrtA) and covalently bind to the bacterial peptidoglycan. In this study, LMP derived from Lactobacillus reuteri (L. reuteri) was heterologous expressed and the tolerance and intestinal colonization ability of the LMP on L. reuteri were analyzed in simulated gastrointestinal fluid. Meanwhile, the anti-inflammatory activity of LMP was also evaluated in the LPS-stimulated RAW 264.7 cell model. The results indicated that LMP can promote the intestinal survival rate and adhesion characteristics of L. reuteri and enhanced the autoinducer-2 (AI-2) signaling molecule of the Lactobacillus strains in quorum sensing. Furthermore, LMP can inhibit the expressions of inflammatory cytokine TNF-α and IL-1β via ERK-JNK related MAPK signaling cascades. These findings provide a better understanding of the multifunctional LPxTG-motif surface protein derived from L. reuteri in the gastrointestinal tract environment.

In vitro evaluation of probiotic properties and antioxidant activities of Bifidobacterium strains from infant feces in the Uyghur population of northwestern China

Purpose

Bifidobacterium is an important probiotic used in food and medicine production. The probiotic properties of bifidobacteria are strain specific, so it is necessary to evaluate the probiotic properties of bifidobacteria isolated from specific populations, especially when developing products suitable for specific populations. The objective of this study was to evaluate the probiotic potential and safety of bifidobacteria isolated from healthy Uyghur infants from northwestern China.

Methods

In this study, antimicrobial activity, antibiotic sensitivity, hemolytic, acid and bile tolerance, hydrophobicity, co-aggregation, auto-aggregation, and antioxidant activity were evaluated.

Results

Based on antagonistic activity spectrum against seven intestinal pathogenic bacteria, 14 excellent strains were initially selected. Among 14 strains, four bifidobacteria strains (BF17-4, BF52-1, BF87-3, and BF88-5) were superior to strain Lactobacillus rhamnosus GG in cell surface hydrophobicity and auto-aggregation percentages and close to strain GG in co-aggregation with Escherichia coli EPEC O127: K63 (CICC 10411). The antioxidant activities of each of the 14 bifidobacteria strains varied with the cell components. Most of the strains were sensitive to all the antimicrobials tested, except kanamycin and amikacin.

Conclusion

BF17-4 and BF52-1 are good candidates for further in vivo studies and further used in functional foods.

Strain-dependent effectivity, and protective role against enzymes of S-layers in Lactiplantibacillus plantarum strains

The present study investigated whether the surface layer (S-layer), which is known to have a varying effect from strain to strain on aggregation, adhesion ability, also has an effect on the resistance of bacteria to digestive enzymes, phenol, lysozymes. The effect of S-layers on the resistance against various enzymes, aggregation and adhesion abilities, and strain specificity were determined of eight Lactiplantibacillus plantarum strains. Strains were treated with 5 M lithium chloride (LiCl) to extract the S-layers, the presence of this layer in those microorganisms was demonstrated by polyacrylamide gel electrophoresis. Scanning electron microscopy was used to visualize the separation of the S-layer, which surrounds the microorganism, from the microorganism by the LiCl. The images were taken three times, once at the beginning, once 30 min later, and once at the end of this process, which took 2 h in total. The effect against enzymes varied depending on the strain, but it was determined that all the tested strains had a serious loss of viability against phenol in the absence of an S-layer. Lpb. plantarum DA100 showed a maximum decrease against gastrointestinal system enzymes after the LiCl (96.48 ± 0.03% before and 66.46 ± 0.01% after LiCl). Lpb. plantarum DA255 showed a significant decrease against lysozyme (99.11 ± 0.00% before and 62.80 ± 0.0% after LiCl). Removal of the S-layer greatly affected the adhesion ability of some strains, while for others there was hardly any change. The results showed that the role of the S-layer may be strain-specific, the rate of effect can vary. The primary function of S-layer proteins is thought to contribute to the adhesion ability of bacteria. There are limited studies that have reported the protective property of this layer against various enzymes, however, our results showed that S-layer could be one of the resistance strategies developed by bacteria against enzymes.

Survivability of Kluyveromyces marxianus Isolated From Korean Kefir in a Simulated Gastrointestinal Environment

Kluyveromyces marxianus accounts for > 90% of the yeast population of kefir, and recently, its probiotic potential has been actively explored with a focus on its health benefits and safety. Herein, the survivability of five kefir-isolated K. marxianus strains (Km A1–A5) in a simulated gastrointestinal (GI) environment was evaluated and compared with those of commercial probiotic yeast, Saccharomyces boulardii MYA-796. To further explore the potential to survive in the host GI tract, biochemical activities, hydrophobicity assay, biofilm formation, auto-aggregation analysis, and phenol tolerance of the strains were assessed. K. marxianus A4 exhibited the best survivability among all tested strains, including the clinically proven probiotic yeast strain S. boulardii MYA-796 (p = 0.014) in the artificial GI tract ranging from pH 2.0 to 7.5. In addition, the five K. marxianus strains and S. boulardii MYA-796 displayed different assimilation of lactose, xylitol, D-sorbitol, and DL-lactate, indicating that K. marxianus metabolized a wide range of substances and, thus, might be more feasible to nourish themselves in the host GI tract for survival. K. marxianus strains showed a greater hydrophobicity of cell surface, abilities to biofilm formation and auto-aggregation, and phenol tolerance than S. boulardii MYA-796, suggesting greater potential for survival in the host GI tract.

The In Vitro Analysis of Postbiotics in Functional Labneh to Be Used as Powerful Tool to Improve Cell Surfaces Properties and Adherence Potential of Probiotic Strains

Postbiotics are functional bioactive substances manufactured during fermentation in a food matrix, which can be used to improve human health, but their influence on the adhesion potential and physicochemical cell surface of probiotics is still unclear. We examined the postbiotic influence produced by Escherichia coli Nissle 1917 in functional labneh on cell surface properties (auto-aggregation, hydrophobicity, and co-aggregation) and the adhesion capacities of three probiotic strains. The most commonly detected effects of probiotics, particularly Lsyn−7, were an increase in auto-aggregation, hydrophobicity, co-aggregation, and adhesion ability of the tested strains. Lactobacillus rhamnosus with Lsyn−7 (59%) presented the highest hydrophobicity, whereas the least adhesion to xylene was detected in L. rhamnosus with LHM. Lactobacillus casei with Lsyn−7 showed the highest auto-aggregation after 24 h (60.55%). Moreover, it also has a strong adhesion to Caco-2 cells and effectively prevents the binding of Salmonella Typhimurium to Caco-2 cells. Lactobacillus plantarum with Lsyn−7 presented the strongest co-aggregation with Staphylococcus aureus (85.1%), S. Typhimurium (85.02%) and Listeria monocytogenes (77.4%). The adherence potential of tested probiotic strains was highly correlated with auto-aggregation, hydrophobicity, co-aggregation, and competitive inhibition of L. monocytogenes and S. Typhimurium. The findings suggest that Lsyn−7 can be a candidate to promote the adhesion potential of selected probiotic strains. For the reason that the application of probiotic strains has been more interested in their positive influences in the gastrointestinal tract, it is essential to use some functional compounds, such as postbiotics, to improve adhesion abilities and cell surface properties in terms of bacterial binding.

Novel Developments on Stimuli-Responsive Probiotic Encapsulates: From Smart Hydrogels to Nanostructured Platforms

Biomaterials engineering and biotechnology have advanced significantly towards probiotic encapsulation with encouraging results in assuring sufficient bioactivity. However, some major challenges remain to be addressed, and these include maintaining stability in different compartments of the gastrointestinal tract (GIT), favoring adhesion only at the site of action, and increasing residence times. An alternative to addressing such challenges is to manufacture encapsulates with stimuli-responsive polymers, such that controlled release is achievable by incorporating moieties that respond to chemical and physical stimuli present along the GIT. This review highlights, therefore, such emerging delivery matrices going from a comprehensive description of addressable stimuli in each GIT compartment to novel synthesis and functionalization techniques to currently employed materials used for probiotic’s encapsulation and achieving multi-modal delivery and multi-stimuli responses. Next, we explored the routes for encapsulates design to enhance their performance in terms of degradation kinetics, adsorption, and mucus and gut microbiome interactions. Finally, we present the clinical perspectives of implementing novel probiotics and the challenges to assure scalability and cost-effectiveness, prerequisites for an eventual niche market penetration.

Mitigation of potentially toxic elements in food products by probiotic bacteria: A comprehensive review

Potentially toxic elements (PTEs) as non-degradable elements (especially carcinogenic types for humans such as lead (Pb), cadmium (Cd), mercury (Hg), and arsenic (As)) are widely distributed in the environment. They are one of the most concerned pollutants that can be absorbed and accumulated in the human body, primarily via contaminated water and foods. Acute or chronic poisoning of humans to PTEs can pose some serious risks for human health even at low concentrations. In this context, some methods are introduced to eliminate or reduce their concentration. While the biological treatment by bacterial strains, particularly probiotic bacteria, is considered as an effective method for reducing or eliminating of them. The consumption of probiotics as nonpathogenic microorganisms at regular and adequate dose offer some beneficial health impacts, it can also be applied to remove PTEs in both alive and non-alive states. This review aimed to provide an overview regarding the efficacy of different types of probiotic bacteria for PTEs removal from various environments such as food, water, in vitro, and in vivo conditions.

Probiotic Potentiality from Versatile Lactiplantibacillus plantarum Strains as Resource to Enhance Freshwater Fish Health

Dietary probiotic supplementation has the potential to enhance the health of fish and their disease resistance. In this study, some properties of ten Lactiplantibacillus plantarum strains have been evaluated, for their potential use as probiotics in freshwater fish diet. In particular, antimicrobial activity, antioxidant activity, the potentiality to survive the gastrointestinal transit and persist in the intestine, were evaluated in vitro. The experimental tests were carried out at 15 °C and 30 °C to determine the suitability of these lactic acid bacteria to be used as probiotics in the diet of fish grown at different temperatures. The results demonstrated that the evaluated Lp. plantarum strains, which often have significant differences among themselves, are characterized by important functional characteristics such as cell surface properties (auto-aggregation and hydrophobicity), ability to produce antioxidant substances, capacity to survive in the presence of 0.3% bile salts and acidic environment (2.5 pH), antagonistic activity against some fish opportunistic pathogens (A. salmonicida, Ps. aeruginosa, E. coli and C. freundii) and other unwanted bacteria present in fish products (S. aureus and L. innocua). The outcomes suggest that these Lp. plantarum strains may be candidates as probiotics in warm- and cold-water aquaculture.

Influence of culture conditions on co-aggregation of probiotic yeast Saccharomyces boulardii with Candida spp. and their auto-aggregation

Systemic infections caused by pathogenic Candida species pose a significant threat to public health in the past decades due to increasing resistance to existing antifungal drugs. Given this scenario, probiotics have been suggested as an alternative approach for managing Candida infections. Hence, the purpose of this study was to evaluate whether probiotic yeast Saccharomyces boulardii co-aggregate with Candida spp. as well as to determine their auto-aggregation ability in dependence on temperature (28 °C, 37 °C, 42 °C) and pH (4.5, 7.0, 8.5) after 5 h and 24 h. Our results revealed that the aggregation of tested yeasts was lower in the first 5 h but increased significantly after 24 h. All strains were able to auto-aggregate in different degrees ranging from 47.46 to 95.95% assessed at 24 h of incubation. Among them the highest auto-aggregation values had C. albicans and C. krusei strains followed by probiotic strain S. boulardii, while the less were observed in C. glabrata strains. In addition, co-aggregation between probiotic and Candida strains was strain-specific. It was evident that S. boulardii significantly inhibited the aggregation of C. albicans ATCC 10261, C. krusei ATCC 6258, and C. glabrata ZIM 2369. However, in C. glabrata ZIM 2382, the aggregation was even enhanced. Temperature and pH also affected the ability to aggregate in a different way only after 5 h of incubation, with the highest cell aggregation evidenced at temperature 37 °C in most cases and pH 4.5. These findings may be of importance when trying to establish probiotic use against pathogenic Candida species.

Phenotypic Assessment of Probiotic and Bacteriocinogenic Efficacy of Indigenous LAB Strains from Human Breast Milk

Breast milk is the combination of bioactive compounds and microflora that promote newborn’s proper growth, gut flora, and immunity. Thus, it is always considered the perfect food for newborns. Amongst their bioactives, probiotic communities—especially lactic acid bacteria (LAB)—are characterized from breast milk over the first month of parturition. In this study, seven LAB were characterized phenotypically and genotypically as Levilactobacillus brevis BDUMBT08 (MT673657), L. gastricus BDUMBT09 (MT774596), L. paracasei BDUMBT10 (MT775430), L. brevis BDUMBT11 (MW785062), L. casei BDUMBT12 (MW785063), L. casei BDUMBT13 (MW785178), and Brevibacillus brevis M2403 (MK371781) from human breast milk. Their tolerance to lysozyme, acid, bile, gastric juice, pancreatic juice, and NaCl and potential for mucoadhesion, auto-aggregation, and co-aggregation with pathogens are of great prominence in forecasting their gut colonizing ability. They proved their safety aspects as they were negative for virulence determinants such as hemolysis and biofilm production. Antibiogram of LAB showed their sensitivity to more than 90% of the antibiotics tested. Amongst seven LAB, three isolates (L. brevis BDUMBT08 and BDUMBT11, and L. gatricus BDUMBT09) proved their bacteriocin producing propensity. Although the seven LAB isolates differed in their behavior, their substantial probiotic properties with safety could be taken as promising probiotics for further studies to prove their in vivo effects, such as health benefits, in humans.

Current Perspectives on Gastrointestinal Models to Assess Probiotic-Pathogen Interactions

There are different models available that mimic the human intestinal epithelium and are thus available for studying probiotic and pathogen interactions in the gastrointestinal tract. Although, in vivo models make it possible to study the overall effects of a probiotic on a living subject, they cannot always be conducted and there is a general commitment to reduce the use of animal models. Hence, in vitro methods provide a more rapid tool for studying the interaction between probiotics and pathogens; as well as being ethically superior, faster, and less expensive. The in vitro models are represented by less complex traditional models, standard 2D models compromised of culture plates as well as Transwell inserts, and newer 3D models like organoids, enteroids, as well as organ-on-a-chip. The optimal model selected depends on the research question. Properly designed in vitro and/or in vivo studies are needed to examine the mechanism(s) of action of probiotics on pathogens to obtain physiologically relevant results.

Limosilactobacillus fermentum MG4295 Improves Hyperglycemia in High-Fat Diet-Induced Mice

Hyperglycemia due to uncontrolled glucose regulation is widely known as cause of diabetes, non-alcoholic fatty liver disease (NAFLD), and other complications. NAFLD refers to a condition in which fat is excessively accumulated, whether inflamed or not, and has caused serious medical problems in recent years. The aim of this study was to explore the antihyperglycemia effects of Limosilactobacillus fermentum MG4295 (L. fermentum MG4295) in high-fat diet (HFD)-induced in vivo. We demonstrated the suitability of L. fermentum MG4295 as a probiotic by observing its stability, survivability, and proliferation under simulated gastrointestinal conditions, and safety, antibiotic susceptibility, hemolysis, and enzyme activity. The potential antihyperglycemic activity of L. fermentum MG4295 was investigated in an HFD and sugar-water-induced mouse model. Administration of this strain for 12 weeks showed an improved trend in glucose tolerance, insulin, alanine amino transferase, total cholesterol, low-density lipoprotein cholesterol, and glucagon-like peptide-1. Histopathological analysis revealed that L. fermentum MG4295 significantly reduced the histopathological scores of hepatic steatosis, inflammation, and hepatocellular hypertrophy in liver tissues and lipid content in adipose tissues. Administration of L. fermentum MG4295 upregulated IRS-1, AKT, and GLUT4 and downregulated G6Pc and PEPCK expression in liver and/or muscle tissues. Our results suggest that L. fermentum MG4295 can improve hyperglycemia. Furthermore, it can be used as a dietary functional supplement to manage blood glucose.

Multi-functional Potential of Five Lactic Acid Bacteria Strains Derived from Giant Panda (Ailuropoda melanoleuca)

The multi-functional properties of lactic acid bacteria (LAB) on host health have been a popular research topic. The aim of present study was to assess the multi-functional potential of five LAB strains isolated from giant panda. In this study, we analyzed five giant panda LAB strains (Weissella confuse WJ202003 (W3), WJ202009 (W9), WJ202021 (W21), BSP201703 (X₃); Lactiplantibacillus plantarum BSGP201683 (G83)) and found that they exhibited rapid growth as well as strong acid production capacity. The five LAB strains possessed high cell surface hydrophobicity to the four tested solvents (xylene, hexadecane, chloroform, ethyl acetate; except strain W9), auto-aggregation ability, co-aggregation ability with three pathogens (Escherichia coli, Enterotoxigenic Escherichia coli, Salmonella), adhesion ability to Caco-2 cell line, and strongly biofilm formation ability, suggesting an adhesion property. As investigated for their antioxidative potential, all the strains showed good tolerance to H₂O₂, high scavenging ability against 1, 1-diphenyl-2-picrylhydrazyl (DPPH), and hydroxyl (OH^-), and reduction ability. Furthermore, the five LAB strains could produce multiple probiotic substances, including exopolysaccharide (EPS), gamma-aminobutyric acid (GABA), bile salt hydrolase (BSH), cellulase (only strain G83), and protease (except strain X₃), which was the first to report the production of EPS, GABA, BSH, cellulase, and protease in giant panda-derived LAB strain. These results demonstrated that strains W3, W9, W21, X₃, and G83 had multi-functional potential and could be utilized as potential probiotics for giant panda.

A novel probiotic strain of Lactobacillus fermentum TIU19 isolated from Haria beer showing both in vitro antibacterial and antibiofilm properties upon two multi resistant uro-pathogen strains

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L. fermentum TIU19 was isolated from the ethnic traditional rice beverage, Haria.

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L. fermentum TIU19 showed antagonistic activity against uro-pathogens in both planktonic and biofilm conditions.

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L. fermentum TIU19 had potential probiotic traits.

Probiotics with antimicrobial activity are gaining interest as a topic in the research field. Urinary tract infections (UTIs), acquired in the hospital or the community, are among the most prevalent infections. The emergence of multidrug resistance (MDR) uro-pathogens has made the current situation more critical in terms of global public health. To face this situation, in this study, Lactobacillus fermentum TIU19 (L. fermentum TIU19) was isolated and characterized as a new probiotic strain of the rice-based fermented beverage Haria. Subsequently, we also investigated its application as a biological agent that inhibits the growth of multidrug-resistant uro-pathogens, Escherichia coli, and Enterococcus faecalis. The results showed that, the isolated strain L. fermentum TIU19 was sensitive to all antibiotics tested except vancomycin and was devoid of virulence factors, such as haemolytic and gelatinase activities. Therefore, it may be considered safe for public health. It has many probiotic properties, such as survival in simulated gastrointestinal fluid, antioxidant activity, β-galactosidase producing ability, high cell surface hydrophobicity, adhesion ability to epithelial cells, and strong biofilm producer. The growth inhibitory and antibiofilm activities were shown against two uro-pathogens. All these results suggest that L. fermentum TIU19 can be explored as a potential probiotic with antagonistic activity against MDR uro-pathogenic E. coli and E. faecalis.

In Vitro Probiotic Characteristics and Whole Genome Sequence Analysis of Lactobacillus Strains Isolated from Cattle-Yak Milk

Cattle-yak milk is an important raw material and an indispensable source of high-quality food for local farmers and herdsmen to produce ghee, milk residue, yogurt, and other dairy products. In this study, Lactobacillus strains were isolated from cattle-yak milk for potential probiotic candidates using a series of in vitro tests, including probiotic characterization and safety evaluation (antibiotic susceptibility and hemolytic ability). The results found that the Lactobacillus rhamnosus CY12 strain showed a high survival rate in bile salts, under acid conditions, and in the gastrointestinal juice environment, as well as showing high antimicrobial activity and adhesive potential. The safety evaluation showed that all strains were considered non-hemolytic. In addition, the whole-genome sequencing indicated that the strain CY12 spanned 2,506,167 bp, with an average length of 881 bp; the GC content in the gene region (%) was 47.35, contained 1347 protein-coding sequences, and accounted for 85.72% of the genome. The genome annotation showed that genes mainly focused on the immune system process, metabolic process, carbohydrate utilization, carbon metabolism, galactose metabolism, and biological adhesion, etc. This study revealed that the Lactobacillus rhamnosus CY12 strain might be an excellent potential probiotic in the development of feed additives for animals and has the ability to promote health.

Isolation and probiotic potential of lactic acid bacteria from swine feces for feed additive composition

Animal microbiota is becoming an object of interest as a source of beneficial bacteria for commercial use. Moreover, the escalating problem of bacterial resistance to antibiotics is threatening animals and humans; therefore, in the last decade intensive search for alternative antimicrobials has been observed. In this study, lactic acid bacteria (LAB) were isolated from suckling and weaned pigs feces (376) and characterized to determine their functional properties and usability as pigs additives. Selection of the most promising LAB was made after each stage of research. Isolates were tested for their antimicrobial activity (376) and susceptibility to antibiotics (71). Selected LAB isolates (41) were tested for the production of organic acids, enzymatic activity, cell surface hydrophobicity and survival in gastrointestinal tract. Isolates selected for feed additive (5) were identified by MALDI-TOF mass spectrometry and partial sequence analysis of 16S rRNA gene, represented by Lentilactobacillus, Lacticaseibacillus (both previously classified as Lactobacillus) and Pediococcus genus. Feed additive prototype demonstrated high viability after lyophilization and during storage at 4 °C and − 20 °C for 30 days. Finally, feed additive was tested for survival in simulated alimentary tract of pigs, showing viability at the sufficient level to colonize the host. Studies are focused on obtaining beneficial strains of LAB with probiotic properties for pigs feed additive.

Interference of Lactiplantibacillus plantarum with Pseudomonas aeruginosa on the infected burns in Wistar rats

Burns are the most prevalent type of trauma in the world, and they have a high fatality rate. For cutaneous wound healing, modern and natural therapies, particularly probiotic supplements, have lately been considered. The goal of this study was to see how Lactiplantibacillus plantarum affected wound healing as well as the antibacterial activity of probiotic lactobacilli against Pseudomonas aeruginosa. The glass slide method was used to assess anti-adhesion activity, and the HPLC method was used to quantify anti-adhesion chemicals in cell-free supernatant (CFS). MDR P. aeruginosa was administered subcutaneously directly on the burn after induction of second-degree wounds. Three groups of animals were created. Every day, the supernatants were sprayed for therapy, and the wound healing was monitored. Lactobacilli bacteria had good anti-adhesion effects on P. aeruginosa, according to our findings, and HPLC research revealed that their inhibitory effect could be attributable to four main organic acids: lactic acid, acetic acid, citric acid, and succinic acid. When the effect of treatments on fibroblastic cells was examined, it was discovered that the group treated with L. plantarum supernatants had the most fibroblastic cells when compared to the non-treated group. Furthermore, the bacteria increased the number of fibroblastic cells, re-epithelialization in the wound area, and the thickness of the epidermis and dermis layers. Lactobacilli bacteria's antimicrobial activity against MDR P. aeruginosa was determined by prevents infection. These findings revealed that L. plantarum can treat a P. aeruginosa infection in a second-degree burn and can significantly reduce inflammation.