Probiotic Strain Lactobacillus Research Articles

Effect of co-encapsulation using a calcium alginate matrix and fructooligosaccharides with gelatin coating on the survival of Lactobacillus paracasei cells.

The demand for functional foods is increasing each year because consumers are gaining awareness about the importance of a healthy diet in the proper functioning of the body. Probiotics are among the most commonly known, commercialized, and studied foods. However, the loss of viability of probiotic products is observed during their formulation, processing, and storage. This study aimed to investigate the co-encapsulation of two Lactobacillus paracasei probiotic strains (LBC81 and ELBAL) with fructooligosaccharides (FOS) in a calcium alginate matrix using extrusion technology with gelatin as a coating material. The viability of the strains under gastrointestinal conditions and in storage at low temperature was also assessed. An immobilization yield of more than 59% was observed for both bacterial strains. Exposure to 2% biliary salts led to a decrease in the viability of free cells in the two L. paracasei strains, whereas the viability of microencapsulated cells increased up to 47%. After 35 days of storage at 4°C, the population of free cells was reduced, but microencapsulated cells remained stable after storage at low temperature. LBC81 bacteria microencapsulated with 1.5% FOS coated with gelatin were the most resistant to the stressful environments tested. Therefore, these results showed that co-encapsulation with FOS in a calcium alginate matrix coated with gelatin improved L. paracasei survival and may be useful for the development of more resistant probiotics and new functional foods.

Therapeutic and Prophylactic Effect of the Experimental Bacteriophage Treatment to Control Diarrhea Caused by E.coli in Newborn Calves.

The prevalence of antibiotic-resistant bacteria causing neonatal diarrhea in calves has become a serious problem in the control of infection. Due to increasing antibiotic resistance, bacteriophages with probiotics are considered the best alternative. The aim of the study was to evaluate the use of a suppository containing probiotic strains of Lactobacillus spp. and bacteriophages specific for pathogenic E. coli in young calves with diarrhea. The study evaluated therapeutic and prophylactic effects (specific and nonspecific humoral response). The study was carried out on 24 female HF calves, aged 2 to 7 days and weighing from 35 to 46 kg. The calves were divided into four groups (n = 6) as follows: Group 1, healthy control that received no medicine; Group 2, positive control with diarrhea; Group 3, healthy calves that received medicine; Group 4, calves with diarrhea that received medicine. The animals received suppositories containing Lactobacillus spp. and bacteriophages specific for pathogenic E. coli for 5 days. On the first day, the calves received the suppositories twice—in the morning and 12 h later; subsequently they were administered once a day. The health status of the calves was observed for 11 days after the first application of suppositories. A protective and preventive effect of the experimental therapy was obtained in the research. The probiotic-phage suppositories reduced the duration of diarrhea in calves, completely eliminating it within 24–48 h after use. The therapy stimulated the activation of immune mechanisms in calves, which translated into an enhanced specific and nonspecific response and increased resistance to infection.

Comparison of the effects of single probiotic strains Lactobacillus casei Zhang and Bifidobacterium animalis ssp. lactis Probio-M8 and their combination on volatile and nonvolatile metabolomic profiles of yogurt

There has been a growing interest in cofermentation of starter cultures with probiotics in milk. In this study, we analyzed the effects of adding the single probiotics Lactobacillus casei Zhang (Zhang) or Bifidobacterium animalis ssp. lactis Probio-M8 (M8) or a combination of Zhang and M8 to starter cultures on volatile and nonvolatile metabolomic profiles after 14 d of storage at 4°C and compared using a liquid chromatography-tandem mass spectrometry (LC-MS) and GC-MS-based metabolomics approach. Principal component analysis, heatmap plots, and Spearman correlation results showed that Zhang alone had a greater effect on volatile and nonvolatile metabolomic profiles than M8 alone. The combination of Zhang and M8 had additive effects on the production of metabolites. For volatile metabolites, the levels of acetaldehyde, diacetyl, acetoin, and acetic acid were higher for the combination of Zhang and M8 compared with either single probiotic culture. Significantly increased nonvolatile components induced by adding Zhang were identified were enriched in the galactose, amino- and nucleotide sugar, fructose and mannose, purine, phenylalanine metabolism, and arginine biosynthesis pathways. The metabolism and biosynthesis of starch, sucrose, tyrosine, galactose metabolism, and aminoacyl-tRNA biosynthesis were significantly upregulated by adding the combination of Zhang and M8. This work provides a detailed insight into different effects of Zhang and M8 used alone or in combination on the volatile and nonvolatile metabolomic profiles of yogurts.

Bio-preservation of chocolate mousse with free and immobilized cells of Lactobacillus plantarum D2 and lemon (Citrus lemon L.) or grapefruit (Citrus paradisi L.) zest essential oils.

The bio-preservation of food products using various natural ingredients and metabolites from various types of beneficial microorganisms released during targeted fermentation is a method that simultaneously has a preservative effect on the food product and provides a model of its composition in order to ensure its functional and health properties. This double effect can be achieved by incorporating ingredients with proven preservative and functional effects into the food product, such as essential oils from various plant species and probiotic bacteria. The aim of the present research was to study the synergistic effect of selected probiotic lactic acid bacteria (LAB) and essential oils with high antimicrobial activity against pathogenic and spoilage microorganisms for the bio-preservation of chocolate mousse food emulsion. The susceptibility of the selected probiotic strain Lactobacillus plantarum D2 to different concentrations of the selected lemon or grapefruit essential oil was examined using the disc-diffusion method. Nine chocolate mousse variants were prepared with the inclusion of free or immobilized cells of the probiotic strain L. plantarum D2 and/or lemon or grapefruit zest essential oils. The chocolate mousse variants were stored for 20 days in refrigerated conditions, and changes in the concentration of viable lactobacilli cells, the pH and the microbiological purity were monitored in accordance with standard requirements by taking samples on the 0th, 5th, 10th, 15th, and 20th days of storage. An organoleptic evaluation of the chocolate variants was performed on the 0th day. Concentrations of up to 1% lemon or grapefruit essential oil did not affect the growth of the probiotic strain L. plantarum D2, which revealed opportunities for their joint application for the bio-preservation of food emulsions. The obtained chocolate mousse variants were characterized by preserved organoleptic characteristics and microbiological safety. Free or immobilized probiotic L. plantarum D2 cells applied alone or in combination with lemon or grapefruit essential oils provided bio-preservation of the food emulsions, maintaining a high concentration of viable cells (106-107 cfu/g) during storage under refrigerated conditions for 20 days. The combined application of free or immobilized probiotic LAB and lemon or grapefruit essential oils resulted in better bio-preservation results than in the use of probiotic LAB or essential oils alone, thus suggesting a synergistic effect between the two bio-preservative agents. Moreover, the obtained chocolate mousse emulsions can be classified as functional foods and the chocolate mousse food matrix can successfully be used as a vehicle for delivery of probiotic LAB to a wide range of food consumers. The obtained results and the developed successful bio-preservation strategy for the production of chocolate mousse food emulsions would provide grounds for the future selection of other probiotic lactobacilli strains, essential oils and synergistic combinations of them for the development of successful bio-preservation strategies for other types of food and beverage products.

Dairy goats productivity using the probiotic preparation “Plantarum” in the diet

The influence of the experimental probiotic “Plantarum” on the productive and some exterior-constitutional features of dairy Saanen breed goats was studied. The preparation was developed in the microbiology laboratory of milk and dairy products of the department “Siberian Research Institute for Cheese Making” of the Federal State Budgetary Scientific Institution “Federal Altai Scientific Center of Agrobiotechnology” (FSBSI FASCA). The composition of the preparation includes pure cultures of probiotic strains of lactobacilli and propionic acid bacteria from the “Siberian collection of microorganisms”. The probiotic preparation in liquid form was introduced into concentrated feed (oats). The positive effect of the use of the probiotic “Plantarum” on the average daily milk yield of the experimental groups of fully developed (assessed by the exterior) pregnant female goats was established. A significant increase in milk yield was observed in the second and third groups by 1.66% (p < 0.05) and 3.27% (p < 0.05), respectively. With an increase in the average daily milk yield, the main physical and chemical parameters of milk (mass fraction of fat, mass fraction of protein) of the experimental groups did not decrease. There was a tendency to improve the safety of young animals in the second and third groups with an increase in the probiotic dose. At this stage of the work, the optimal dose with the maximum positive effect of introducing the probiotic preparation into the diet of experimental animals (0.8 ml/kg of body weight per day) was established. In this connection, it is necessary to conduct an additional experiment with an increase in the dose of probiotic administration when feeding it to experimental animals.

Preliminary evaluation of potential prebiotic capacity of selected legumes and seed mucilage on the probiotic strain Lactobacillus rhamnosus GG

The characterization of the prebiotic potential of legumes and mucilage are essential and crucial for the development of symbiotic food products. The aim of the present study was to compare and to determine the prebiotic capacity of selected legumes, namely adzuki bean, mung bean, black cowpea, and mucilages from chia seed and flaxseed on the growth of Lactobacillus rhamnosus GG. Resistance towards acid, pancreatin hydrolysis, and the prebiotic scores of the tested substances was determined based on growth promotion after 24 h of incubation. Results revealed that flaxseed mucilage was more resistant against hydrolysis by acid (1.47%) and pancreatin (2.64%) compared to the other samples (5.64 – 18.06% for acid and 10.34 – 15.57% for pancreatin). The relative prebiotic scores for flaxseed mucilage and black cowpea were 98% and 94%, respectively, which were higher than commercial prebiotics including inulin, fructooligosaccharides, and isomaltooligosaccharides. The optimum concentrations of flaxseed mucilage and black cowpea during 36 h of fermentation were 0.8% and 0.4% (w/v), respectively. The findings indicated that flaxseed mucilage was partially digested during gastrointestinal transit and it promotes the growth of the L. rhamnosus GG. The potential prebiotic capacity of flaxseed mucilage and its symbiotic relationship with L. rhamnosus GG suggests that they can be incorporated together for the development of functional foods.

Growth and adhesion inhibition of pathogenic bacteria by live and heat-killed food-origin Lactobacillus strains or their supernatants.

The study aimed to evaluate qualitatively and quantitatively the antimicrobial capacity of 10 potential probiotic Lactobacillus strains against model enteropathogens and spoilage microorganisms. The probiotic strains (live and heat-killed forms) were also assessed for their ability to inhibit adhesion of selected pathogens to Caco-2 cells. The largest inhibition zones (the diffusion method) were connected with the usage of whole bacteria cultures (WBC), also high and moderate with cell-free supernatant (CFS) and the lowest with cell-free neutralized supernatant (CNS). The highest antagonistic activity of Lactobacillus strains was observed against L. monocytogenes strains, moderate activity against Salmonella, Shigella, Escherichia coli, Pseudomonas and, the lowest against S.aureus, Bacillus and Enterococcus. The inhibition of adhesion to Caco-2 cells was very high in the case of E. coli, Salmonella and L. monocytogenes, and moderate in the case of S.aureus. On average, the inhibition effect was higher when pathogenic bacteria were treated by WBC, than heat-killed Lactobacillus. Although, in most samples, the effect was not significantly different (P> 0.05). The strains Lb. brevis O24 and Lb. rhamnosus K3 showed the biggest overall antimicrobial properties, and were most effective in adherence inhibition of investigated indicator strains. These bacteria or their metabolites can be used for the production of various foods or pharmaceutical products.

Cytokine Secretion, Viability, and Real-Time Proliferation of Apical-Papilla Stem Cells Upon Exposure to Oral Bacteria.

The use of stem cells from the apical papilla (SCAPs) has been proposed as a means of promoting root maturation in permanent immature teeth, and plays a significant role in regenerative dental procedures. However, the role of SCAPs may be compromised by microenvironmental factors, such as hypoxic conditions and the presence of bacteria from infected dental root canals. We aim to investigate oral bacterial modulation of SCAP in terms of binding capacity using flow cytometry and imaging, real-time cell proliferation monitoring, and cytokine secretion (IL-6, IL-8, and TGF-β isoforms) under anaerobic conditions. SCAPs were exposed to key species in dental root canal infection, namely Actinomyces gerensceriae, Slackia exigua, Fusobacterium nucleatum, and Enterococcus faecalis, as well as two probiotic strains, Lactobacillus gasseri strain B6 and Lactobacillus reuteri (DSM 17938). We found that A. gerensceriae, S. exigua, F. nucleatum, and E. faecalis, but not the Lactobacillus probiotic strains bind to SCAPs on anaerobic conditions. Enterococcus faecalis and F. nucleatum exhibited the strongest binding capacity, resulting in significantly reduced SCAP proliferation. Notably, F. nucleatum, but not E. faecalis, induce production of the proinflammatory chemokine IL-8 and IL-10 from SCAPs. Production of TGF-β1 and TGF-β2 by SCAPs was dependent on species, cell line, and time, but secretion of TGF-β3 did not vary significantly over time. In conclusion, SCAP response is compromised when exposed to bacterial stimuli from infected dental root canals in anaerobic conditions. Thus, stem cell-mediated endodontic regenerative studies need to include microenvironmental conditions, such as the presence of microorganisms to promote further advantage in the field.

Selection of probiotic Lactobacillus strains with antimicrobial activity to be used as biocontrol agents in food industry

Ninety-eight Lactobacillus (Lb.) strains were screened to select those with the best antimicrobial and probiotic properties. Firstly, a screening based on growth kinetics under gastrointestinal tract (GIT) conditions allowed to select 28 strains, which were assayed for autoaggregation, coaggregation and hydrophobicity. 7.1% were strongly autoaggregating strains after 4 h of incubation. Strains belonging to Lb. plantarum and Lb. paraplantarum species showed the highest coaggregation percentages with the pathogens tested (Salmonella choleraesuis and Staphylococcus aureus). Regarding hydrophobicity, there was correlation between the results obtained for xylene and toluene. Principal Component Analysis (PCA) of these results allowed to select 20 strains as potential probiotics, that were used for further assays of biofilms formation (ranged between 53 and 75%) and adhesion to Caco-2/TC7 cells (around 51–97%). Furthermore, 51% of the ninety-eight strains showed antimicrobial activity against four species indicators (Salmonella choleraesuis, Staphylococcus aureus, Bacillus cereus and Listeria monocytogenes). Results from all the assays performed allowed to select 12 strains attending to either their antimicrobial activity or the probiotic potential and only two of them Lb. paracasei Lb38 and Lb. brevis Lb99, stood up for both properties. Therefore, these strains could be proposed to be used as biocontrol agents in the food industry.

Lactobacillus acidophilus Induces a Strain-specific and Toll-Like Receptor 2–Dependent Enhancement of Intestinal Epithelial Tight Junction Barrier and Protection Against Intestinal Inflammation

Defective intestinal tight junction (TJ) barrier is an important pathogenic factor of inflammatory bowel disease. To date, no effective therapies that specifically target the intestinal TJ barrier are available. The purpose of this study was to identify probiotic bacterial species or strains that induce a rapid and sustained enhancement of intestinal TJ barrier and protect against the development of intestinal inflammation by targeting the TJ barrier. After high-throughput screening of >20 Lactobacillus and other probiotic bacterial species or strains, a specific strain of Lactobacillus acidophilus, referred to as LA1, uniquely produced a marked enhancement of the intestinal TJ barrier. LA1 attached to the apical membrane surface of intestinal epithelial cells in a Toll-like receptor (TLR)-2-dependent manner and caused a rapid increase in enterocyte TLR-2 membrane expression and TLR-2/TLR-1 and TLR-2/TLR-6 hetero-complex-dependent enhancement in intestinal TJ barrier function. Oral administration of LA1 caused a rapid enhancement in mouse intestinal TJ barrier, protected against a dextran sodium sulfate (DSS) increase in intestinal permeability, and prevented the DSS-induced colitis in a TLR-2- and intestinal TJ barrier-dependent manner. In conclusion, we report for the first time that a specific strain of LA causes a strain-specific enhancement of intestinal TJ barrier through a novel mechanism that involves the TLR-2 receptor complex andprotects against the DSS-induced colitis by targeting the intestinal TJ barrier.

Encapsulation of probiotic strain Lactobacillus rhamnosus GG with black bean extract in alginate-pectin microcapsules

Encapsulation of probiotic strain Lactobacillus rhamnosus GG with black bean extract in alginate-pectin microcapsules

Development of Eco-friendly Probiotic Edible Coatings Based on Chitosan, Alginate and Carboxymethyl Cellulose for Improving the Shelf Life of UF Soft Cheese

The objective of the current work was to evaluate the efficiency of novel antimicrobial edible coatings based on chitosan (CH), sodium alginate (SA), and carboxymethyl cellulose (CMC) with an eco-friendly antimicrobial microcrystalline cellulose (AMCC) and probiotic strains (Bifidobacterium lactis, Lactobacillus acidophilus, and Lactobacillus casei). These edible films were applied for preservatives UF soft cheese for 45 days, instead of using traditional plastic sheet. The probiotic edible films were evaluated by using SEM, FT-IR tools. Additionally, the mechanical properties, water vapor permeability, water solubility, and antimicrobial properties were examined. The fashioned probiotic edible films had an antimicrobial effect against all tested microbes, the high microbial effect was observed for edible films with CH and SA. Furthermore, the coated cheese was evaluated chemically, microbiologically, and sensory during 45 days. The dry matter, protein, and fat contents of cheese treatments coated with SA and CMC decreased during the storage period. Additionally, the probiotic counts in all films were more than 8.0 log CFU/g after 45 days. It was also observed that the edible films containing SA and CH can preserve cheese from spoilage. Correspondingly, the sensory scores were indicated the overall acceptability of cheese in this study was SA, CMC, and CH followed by control. Therefore, the formulation of the antimicrobial edible coating can be applied for soft cheese to control the spoilage and maintain the stability of products.

Characterization of structure/prebiotic potential correlation of glucans and oligosaccharides synthetized by glucansucrases from fructophilic lactic acid bacteria from honey bee Apis mellifera

In this work, we reported production of glucansucrases with molecular weights of about 300 kDa by strains of fructophilic lactic acid bacteria (FLAB) Lactobacillus pentosus AG8, Lactobacillus kunkeei AG9, AG10 and AG11 isolated from the gut of honey bee Apis mellifera. From sucrose, these enzymes synthesize average to high-molecular-weight dextran-type glucans ranging from 8.5 × 105 to >4 × 106 Da and containing 16 to 22% α-(1→3)-linked glucose units, with 5 to 8% branching in their structures. Enzyme preparations from the strains were applied in the synthesis of glucooligosaccharides (GOSs) with degrees of polymerization (DP) from 3 to 7 using maltose/sucrose ratios (M/S) from 8 to 0.12. The yields and composition of the obtained oligosaccharide products were strongly influenced by the ratios of the acceptor and donor of glucose units in the reactions. The highest yields of GOSs (>50 g/L) were achieved at M/S = 1, and the lowest content of α-(1→6) linkages (71%) combined with increased proportion of the products with DP > 3 were determined at M/S = 0.5. GOSs preparations from these two ratios were able to maintain the growth and acids production of three probiotic strains of lactobacilli, suggesting potential application as prebiotics.

Influence of sea buckthorn juice addition on the growth of microbial food cultures

Abstract The aim of the article was to investigate the effect of sea buckthorn juice addition on the growth of microbial cultures in growth medium and juice mixtures. Pure sea buckthorn juice was found to inhibit the growth of all 11 monitored microbial cultures. Lactobacillus plantarum CCM 7039, Lactobacillus plantarum K816, Lactobacillus brevis CCM 1815 and, to a lesser extent, the probiotic strain Lactobacillus rhamnosus GG, grew in a growth medium containing a 25 % addition of sea buckthorn juice. Lactobacillus plantarum K816 and Lactobacillus brevis CCM 1815 grew better in this mixture than in pure growth medium. Moreover, we focused on finding a suitable ratio of sea buckthorn and apple juice for Lactobacillus plantarum CCM 7039, leading to malolactic fermentation, which results in an increase in the pH value and an improvement in the sensory properties of juices. The intention was to incorporate the highest possible addition of sea buckthorn juice while maintaining the viability of Lactobacillus plantarum CCM 7039 for malolactic fermentation to occur. The best results were achieved using 40 % sea buckthorn juice. Practical application of the results points to the possibility of preparing a fermented fruit beverage and a dairy product containing sea buckthorn juice. The results of this work extend the current options of sea buckthorn juice processing increasing thus the consumption of healthy juice.

Isolation of Novel Probiotic Lactobacillus and Enterococcus Strains From Human Salivary and Fecal Sources.

Probiotics are non-pathogenic microorganisms that can interact with the gastrointestinal microbiota. They have numerous beneficial health effects that include enhancement of the host immune response, antiallergic, antimicrobial, anti-cancer, and anti-inflammatory properties. Probiotics are capable of restoring the impaired microbiome of a dysbiotic gut. They can be isolated from different environments. However, it is frequently suggested that probiotics for human use should come from human sources. The objective of this study was to isolate and characterize novel probiotic strains from the saliva and feces of healthy human individuals. To meet the criteria for probiotic attributes, the isolates were subjected to numerous standard morphological and biochemical tests. These tests included Gram staining, catalase tests, antibiotic susceptibility testing, hemolytic and antagonistic evaluation, tolerance tests involving temperature, NaCl levels, pH and bile salts, adherence ability assays, and genotypic characterization involving 16S rRNA gene sequencing. From 26 saliva and 11 stool samples, 185 microbial strains were isolated. Based on morphological and biochemical characteristics, 14 potential probiotic candidates were selected and identified genotypically. The new strains belonged to Lactobacillus fermentum, Enterococcus faecium, and Enterococcus hire. The selected strains were non-hemolytic, showed high tolerance to low pH and bile salts, and strong adherence abilities. Furthermore, the strains displayed a wide range of antimicrobial activities, particularly against antibiotic-resistant pathogens such as methicillin resistant Staphylococcus aureus (MRSA). Moreover, five of the selected isolates demonstrated antiproliferative features against human colon cancer cell line (Caco-2). The results of this investigation confirm the diversity of microbial populations in the human gut and saliva, and since these strains are of human origin, they will highly likely display maximal activities in food and drugs set for human use. Hence, the new strains of this study require additional in vivo experiments to assess their health-promoting effects.

Short communication: Chemical structure, concentration, and pH are key factors influencing antimicrobial activity of conjugated bile acids against lactobacilli

Effects of chemical structure, concentration, and pH on antimicrobial activity of conjugated bile acids were investigated in 4 strains of lactobacilli. Considerable differences were observed in the antimicrobial activity between the 6 human conjugated bile acids, including glycocholic acid, taurocholic acid, glycodeoxycholic acid, taurodeoxycholic acid, glycochenodeoxycholic acid, and taurochenodeoxycholic acid. Glycodeoxycholic acid and glycochenodeoxycholic acid generally showed significantly higher antimicrobial activity against the lactobacilli, but glycocholic acid and taurocholic acid exhibited the significantly lower antimicrobial activity. Glycochenodeoxycholic acid was selected for further analysis, and the results showed its antimicrobial activity was concentration-dependent, and there was a significantly negative linear correlation (R2 > 0.98) between bile-antimicrobial index and logarithmic concentration of the bile acid for each strain of lactobacilli. Additionally, the antimicrobial activity of glycochenodeoxycholic acid was also observed to be pH-dependent, and it was significantly enhanced with the decreasing pH, with the result that all the strains of lactobacilli were unable to grow at pH 5.0. In conclusion, chemical structure, concentration, and pH are key factors influencing antimicrobial activity of conjugated bile acids against lactobacilli. This study provides theoretical guidance and technology support for developing a scientific method for evaluating the bile tolerance ability of potentially probiotic strains of lactobacilli.

New pyran derivative with antioxidant and anticancer properties isolated from the probiotic Lactobacillus plantarum H24 strain

This work was aimed to prepare, isolate and identify antioxidant and cytotoxic compound from the culture filtrate of a probiotic lactobacillus strain. New compound, plantarone (1), together with two known compounds, kojic acid (2) and methyl dodecanoate (3), were isolated from the ethyl acetate extract of the culture filtrate of probiotic Lactobacillus plantarum H24. Their structures were elucidated using spectroscopic methods including 2 D NMR, HRMS analyses. Isolated compounds were screened for antioxidant and cytotoxic activities against Caco-2 colon cancer cells. Compounds 1 and 2 showed lowers DPPH radical scavenging activities (p < 0.05) with IC50 values of 66.3 ± 0.34 μM and 50.2 ± 0.28 μM respectively, compared to standard butylated hydroxyanisole (BHA: IC50 = 44.2 ± 0.24 μM). Whereas only compound 1 showed a good cytotoxicity activity with inhibition value of 60.72 ± 3.55%. Accordingly, L. plantarum H24 could be used to prevent oxidative stress and its injuries, improving human health.

Specific Lactobacillus probiotic strains decrease transepithelial glucose transport through GLUT2 downregulation in intestinal epithelial cell models

Although human clinical studies have suggested probiotic effects on blood glucose levels, knowledge about molecular mechanisms is still scarce. To test the hypothesis that selected Lactobacillus probiotic bacteria could regulate the activity of enterocyte glucose transporters, we aimed to measure in vitro effects of selected Lactobacillus probiotic bacteria on transcription and translation of intestinal glucose transporters sodium-dependent glucose cotransporter 1 (SGLT1) and glucose transporter 2 (GLUT2) as well as transepithelial glucose transport. Lactobacillus plantarum strains (PCS20 and PCS26), Lactobacillus rhamnosus GG (LGG) (ATCC 53103) and Lactobacillus acidophilus (L acidophilus) (ATCC 4356) were co-cultivated with noncarcinogenic porcine enterocytes (CLAB) and human epithelial colorectal adenocarcinoma cells (Caco-2) (ATCC HTB-37). Changes in transcription and expression of SGLT1 and GLUT2 were strain and cell line-specific. In CLAB, LGG was the most potent SGLT1 up-regulator, and PCS26 the most potent down-regulator of GLUT2 transcription, which was also reflected on the protein level. In Caco-2, all tested strains tended to downregulate GLUT2 gene expression, while L acidophilus most effectively reduced GLUT2 protein levels. Statistically significant effect of PCS26 and L acidophilus on GLUT2 molecular and protein levels in CLAB and Caco-2 cell lines, respectively, was also followed by a decreased rate of transepithelial glucose transport. Careful selection of specific Lactobacillus probiotic strains could be used to downregulate glucose absorption in intestinal epithelial cells and thereby could be beneficial as a support treatment of pathologies related to glucose homeostasis.

Effects of a Potential Probiotic Strain Lactobacillus gasseri ATCC 33323 on Helicobacter pylori-Induced Inflammatory Response and Gene Expression in Coinfected Gastric Epithelial Cells.

In the present study, we aimed to investigate the modulatory effects of a potential probiotic bacterium Lactobacillus gasseri ATCC 33323 on Helicobacter pylori-induced inflammatory response and gene expression in human gastric adenocarcinoma (AGS) cell line. The gastric epithelial cells were coinfected with a collection of H. pylori clinical strains alone or in combination with L. gasseri at a multiplicity of infection (MOI) of 1:100 for each bacterium, and incubated for different time points of 3, 6, and 12h. IL-8 secretion from coinfected AGS cells after incubation at each time point was measured by an enzyme-linked immunosorbent assay (ELISA). The mRNA expression of IL-8, Bcl-2, β-catenin, integrin α5, and integrin β1 genes was determined by quantitative RT-PCR amplification of total RNA extracted from coinfected epithelial cells. L. gasseri significantly (P<0.05 and P<0.01) decreased the production of IL-8 in AGS cells coinfected with H. pylori strains at 6h post-infection. We also detected that L. gasseri significantly (P<0.05) down-regulated the gene expression level of IL-8 in H. pylori-stimulated AGS cells after 6 and 12h of coinfection. Similarly, L. gasseri caused a significant decrease (P<0.05) in mRNA expression of Bcl-2, β-catenin, integrin α5, and integrin β1 genes in AGS cells at 3 and 6h after infection with H. pylori strains as compared with non-infected control cells. In conclusion, our results demonstrated that L. gasseri amelioratesH. pylori-induced inflammation and could be developed as a supplementation to the current treatment regimens administrated against H. pylori infection.

Supplementation of Lactobacillus Probiotic Strains Supports Gut- Brain-Axis and Defends Autistic Deficits Occurred by Valproic Acid-Induced Prenatal Model of Autism

Supplementation of Lactobacillus Probiotic Strains Supports Gut- Brain-Axis and Defends Autistic Deficits Occurred by Valproic Acid-Induced Prenatal Model of Autism