L. Rhamnosus GG Research Articles

Metabolic Regulation of Longevity and Immune Response in Caenorhabditis elegans by Ingestion of Lacticaseibacillus rhamnosus IDCC 3201 Using Multi-Omics Analysis.

Probiotics, specifically Lacticaseibacillus rhamnosus, have garnered attention for their potential health benefits. This study focuses on evaluating the probiotic properties of candidate probiotics L. rhamnosus IDCC 3201 (3201) using the Caenorhabditis elegans surrogate animal model, a well-established in vivo system for studying host-bacteria interactions. The adhesive ability to the host's gastrointestinal tract is a crucial criterion for selecting potential probiotic bacteria. Our findings demonstrated that 3201 exhibits significantly higher adhesive capabilities compared with Escherichia coli OP50 (OP50), a standard laboratory food source for C. elegans and is comparable with the widely recognized probiotic L. rhamnosus GG (LGG). In lifespan assay, 3201 significantly increased the longevity of C. elegans compared with OP50. In addition, preconditioning with 3201 enhanced C. elegans immune response against four different foodborne pathogenic bacteria. To uncover the molecular basis of these effects, transcriptome analysis elucidated that 3201 modulates specific gene expression related to the innate immune response in C. elegans. C-type lectin-related genes and lysozyme-related genes, crucial components of the immune system, showed significant upregulation after feeding 3201 compared with OP50. These results suggested that preconditioning with 3201 may enhance the immune response against pathogens. Metabolome analysis revealed increased levels of fumaric acid and succinic acid, metabolites of the citric acid cycle, in C. elegans fed with 3201 compared with OP50. Furthermore, there was an increase in the levels of lactic acid, a well-known antimicrobial compound. This rise in lactic acid levels may have contributed to the robust defense mechanisms against pathogens. In conclusion, this study demonstrated the probiotic properties of the candidate probiotic L. rhamnosus IDCC 3201 by using multi-omics analysis.

Stachyose in combination with L. rhamnosus GG ameliorates acute hypobaric hypoxia-induced intestinal barrier dysfunction through alleviating inflammatory response and oxidative stress

High altitude is closely related to intestinal mucosal damage and intestinal microbiota imbalance, and there is currently no effective prevention and treatment measures. In this study, the effects of stachyose (STA), L. rhamnosus GG (LGG) and their combination on inflammatory response, oxidatve stress and intestinal barrier function in mice exposed to acute hypobaric hypoxia were investigated. Our results indicated the combination of STA and LGG could more effectively regulate intestinal microbiota disorders caused by hypobaric hypoxia than STA or LGG alone. When mice were administered with STA + LGG, the content of short chain fatty acids (SCFAs) especially butyric acid significantly increased, which helped intestinal cells to form tight connections, improve the level of anti-inflammatory cytokine (TGF-β) and antioxidant enzymes (SOD, CAT, GSH-Px), and decrease the expression of pro-inlammatory cytokines and hypoxia-inducing factors (IFN-γ, IL-1β, IL-6, TNF-α and HIF-1α), thereby enhance the strong intestinal barrier function. Furthermore, the synbiotics significantly reduced the ratio of Firmicutes to Bacteroidetes, while significantly increased the relative abundance of Rikenella, Bacteroides, Odoribacter, Ruminiclostridium_5 and Gordonibacter, which were correlated with production of SCFAs and anti-inflammatory role. Correlation analysis showed that the protective effect of synbiotics on intestinal barrier function was associated with its anti-inflammatory activity and antioxidant capacity. It provided a strong foundation for further research on the role of STA and LGG in maintaining normal intestinal function at high altitude. Our study has identified and demonstrated a new synbiotic that may be one of the ideal intervention measures for preventing and treating intestinal dysfunction at high altitude.

Exploring the fatty acid double bond hydration activities of Lacticaseibacillus rhamnosus strains

The fatty acid double bond hydratases (FADBH) are involved in the detoxification of unsaturated fatty acids and the production of multi-functional hydroxy fatty acids. Thereby, we have investigated the fatty acid hydration activities of Lacticaseibacillus rhamnosus strains including the ones isolated from the oral microbiome. Interestingly, the fatty acid hydration activities were different among L. rhamnosus strains; one of the isolated oral strains (DM065) exhibited 0.14 μmol/g dry cells/min (U/g dry cells) for hydration of linoleic acid, whereas the well-known probiotics, L. rhamnosus GG (LGG) showed 1.66 U/g dry cells. With an aim to examine the critical factors to determine microbial hydration activities, the FADBH of LGG (OhyLr_LGG) was cloned, engineered to have maltose-binding protein as a soluble fusion partner, and subjected to kinetic and mutation studies. The catalytic efficiencies of OhyLr_LGG for oleic and linoleic acid were 0.102 and 0.066 s−1μM−1, respectively. These values are comparable to those of OhyA from Stenotrophomonas maltophilia (Sm_OhyA2), which was one of the most active enzymes. In addition, the T545K mutation of OhyLr_LGG led to a 76 % reduction in the linoleic acid hydration activity (0.016 s−1μM−1). Since the OhyLr_DM065 possesses K545, the T545K substitution could be one of the major reasons for the lower hydration activities of the DM065 strain. Thereby, it was concluded that the amino acid sequence of FADBH would be one of the key factors to determine the production of hydroxy fatty acids of Lactobacillus probiotics.

Stabilising and functional effects of Spirulina (Arthrospira platensis) protein isolate on encapsulated Lacticaseibacillus rhamnosus GG during processing, storage and gastrointestinal digestion

The present study investigated Spirulina (Arthrospiraplatensis) protein isolate (SPI) for its ability to preserve the biological activity of L. rhamnosus GG (LGG) cells under diverse physicochemical stressors associated with the lyophilisation process, storage, and in vitro digestion. The lyoprotective and stabilising effects of SPI were compared to whey protein isolate (WPI) and pea protein isolate (PPI). The microstructural, physicochemical, and thermal properties of the probiotic lyophilisates were also assessed. Overall, SPI demonstrated superior lyoprotective and storage stabilising effects compared to WPI, although it was less efficient than PPI. Elevated storage temperature and relative humidity (RH) conditions accelerated LGG inactivation rates, especially in the case of WPI, which was primarily attributed to increased LGG's metabolic activity. The fermentation of the probiotic freeze-drying media impaired LGG’s ability to withstand the physicochemical stressors during lyophilization and storage. However, the pre-fermentation step improved LGG’s resistance to harsh acidic conditions in simulated gastric fluids. Bile salts and pancreases did not significantly affect LGG's survivability, with WPI and PPI showing the most effectiveness. Employing an in vitro co-culture model of the gut epithelium, WPI and PPI demonstrated satisfactory adhesion of LGG cells to the mucus layer, displaying the highest cell adhesion potential. In conclusion, SPI appears to be a promising wall material for probiotic cell encapsulation, serving as an alternative to WPI.

Postbiotic Preparation of Lacticaseibacillus rhamnosus GG against Diarrhea and Oxidative Stress Induced by Spike Protein of SARS-CoV-2 in Human Enterocytes.

The Spike protein of SARS-CoV-2 acts as an enterotoxin able to induce chloride secretion and production of reactive oxygen species (ROS), involved in diarrhea pathogenesis. L. rhamnosus GG (LGG) is recommended in pediatric acute gastroenteritis guidelines as a therapy independent of infectious etiology. We tested a postbiotic preparation of LGG (mLGG) in an in vitro model of COVID-associated diarrhea. Caco-2 cell monolayers mounted in Ussing chambers were exposed to Spike protein, and electrical parameters of secretory effect (Isc and TEER) were recorded in the Ussing chambers system. Oxidative stress was analyzed by measuring ROS production (DCFH-DA), GSH levels (DNTB), and lipid peroxidation (TBARS). Experiments were repeated after mLGG pretreatment of cells. The Isc increase induced by Spike was consistent with the secretory diarrhea pattern, which was dependent on oxidative stress defined by a 2-fold increase in ROS production and lipid peroxidation and variation in glutathione levels. mLGG pretreatment significantly reduced the secretory effect (p = 0.002) and oxidative stress, namely ROS (p < 0.001), lipid peroxidation (p < 0.001), and glutathione level changes (p < 0.001). LGG counteracts Spike-induced diarrhea by inhibiting the enterotoxic effect and oxidative stress. The LGG efficacy in the form of a postbiotic depends on metabolites secreted in the medium with antioxidant properties similar to NAC. Because SARS-CoV-2 is an enteric pathogen, the efficacy of LGG independent of etiology in the treatment of acute gastroenteritis is confirmed by our data.

Probiotic Lactobacillus plantarum Ln4 Showing Antimicrobial and Antibiofilm Effect against Streptococcus mutans KCTC 5124 Causing Dental Caries.

Dental caries has known as an infectious disease that is considered a serious global public health problem. Recently, report indicate that probiotics play a vital role in maintaining oral health. Therefore, this study aimed to evaluate the prevention effects of Lactobacillus plantarum Ln4 against dental infection by the pathogenic bacterium Streptococcus mutans KCTC 5124 through biofilm formation inhibition. To evaluate such prevention effects against S. mutans KCTC 5124, antimicrobial activity, auto-aggregation, co-aggregation, cell surface hydrophobicity, total exopolysaccharide (EPS) production rate, and biofilm formation were analyzed. Results showed that L. plantarum Ln4 showed higher antimicrobial activity than L. rhamnosus GG (LGG). In the group treated with L. plantarum Ln4, the co-aggregation (58.85%), cell surface hydrophobicity (16.75%), and EPS production rate (73.29%) values were lower than those of LGG and the negative control. Additionally, crystal violet staining and confocal laser scanning microscopy (CLSM) revealed that L. plantarum Ln4 effectively inhibited biofilm formation in S. mutans KCTC 5124. Therefore, L. plantarum Ln4 could be used in the industry as a probiotics to prevent and improve oral health.

The effect of probiotic Lactobacillus rhamnosus GG on Candida albicans and Candida tropicalis biofilm formation: A preliminary study

Lactobacillus rhamnosus are Gram-positive and lactic acid-producing bacteria. Meanwhile, Candida albicans and Candida tropicalis are opportunistic fungi that cause oral candidiasis. This study aimed to determine the effect of LGG on the biofilm formation of C. tropicalis and C. albicans with the hypothesis that LGG inhibits the biofilm of the yeasts. C. albicans ATCC MYA-4901 and C. tropicalis ATCC 13803 were standardised to 1x106 cells to form a mono-species biofilm. L. rhamnosus GG (LGG) was standardised to 1x107 cells, equivalent to absorbance 0.5 at OD620nm. The microorganisms were cultivated in nutrient broth in a 96-well plate and incubated at 37°C for 24 h and 48 h. Co-culture biofilm was developed by combining Candida spp. with LGG in the same well at a similar concentration as the mono-culture. Crystal violet assay was conducted to assess the biofilm biomass with absorbance measured at OD620nm wavelength. After 24 hours, polymicrobial biofilms of C. albicans with LGG decreased by 37.1 ± 9.2%. At 48 hours, it further decreased to 44.7 ± 5.9%. For C. tropicalis, co-culture biofilms with LGG decreased by 16.3 ± 5.9% and 35.7 ± 7.6% after 24 h and 48 h incubation, respectively. LGG significantly reduced C. albicans biofilm compared to C. tropicalis (P&lt;0.05). In conclusion, LGG has antibiofilm activity against C. albicans and C. tropicalis. However, further study is needed to conclude the effect against other species strains.

The effect of synbiotic-fluoride therapy on multi-species biofilm

ObjectivesThe study objective was to examine the effect of synbiotic-fluoride (SF) therapy within a multi-species cariogenic biofilm model system comprising of S. mutans, S. sanguinis, and S. gordonii. MethodsThe SF therapy was prepared using 2% L-arginine (Arg), 0.2% NaF and probiotic L. rhamnosus GG (LRG). The 8 treatment groups were: Group 1: No treatment, Group 2: 2% Arg, Group 3: 0.2% NaF, Group 4: LRG, Group 5: 2% Arg+0.2% NaF, Group 6: 2% Arg+LRG, Group 7: 0.2% NaF+LRG, and Group 8: SF therapy (2% Arg+0.2% NaF +LRG). Multi-species biofilm model over 96 h comprising Streptococcus mutans, Streptococcus sanguinis, and Streptococcus gordonii was utilized. The biofilms received cariogenic challenge and SF therapy 2 × /day. The extracellular matrix components were analyzed for carbohydrates, proteins, and extra-cellular DNA (eDNA). The live/dead cells were imaged and quantified using confocal microscopy. The viable/dead bacterial concentrations were estimated using propidium monoazide-quantitative polymerase chain reaction (PMA-qPCR). The gene expressions for gtfB, sagP, arcA, argG, and argH were measured using real-time reverse transcriptase qPCR. ResultsCarbohydrates and protein content with SF therapy were higher than non-LRG containing groups, while eDNA content was lower than other groups (p<0.05). Live bacterial proportions determined using confocal imaging with SF therapy were the lowest (p<0.05). The 2% Arg+LRG and SF therapy showed higher viable L. rhamnosus GG than 0.2% NaF+LRG (p<0.05). The dead S. mutans with SF therapy were higher than the other groups (p<0.05) with no difference from 2% Arg+0.2% NaF and 2% Arg+LRG (p>0.05). The SF therapy significantly downregulates gtfB and upregulates sagP, arcA, argG, argH gene expression (p<0.05). ConclusionSynbiotic-fluoride therapy effectuates multi-fold changes in the multi-species biofilm matrix and cellular components leading to superior ecological homeostasis than its individual contents, prebiotics (arginine), probiotic (L. rhamnosus GG), and fluorides (NaF). Clinical significanceThe ecological-based synbiotic-fluoride caries-preventive therapy aids in maintaining biofilm homeostasis to preempt/restore dysbiosis thereby sustaining dynamic-diverse health-associated microbial stability significant as a preventive regimen for high caries-risk patients.

Live or Heat-Killed Lactobacillus rhamnosus Aerosolization Decreases Adenomatous Lung Cancer Development in a Mouse Carcinogen-Induced Tumor Model.

An immunosuppressive microenvironment in lung concurs to pre-malignant lesions progression to cancer. Here, we explore if perturbing lung microbiota, which contribute to immunosuppression, by antibiotics or probiotic aerosol interferes with lung cancer development in a mouse carcinogen-induced tumor model. Urethane-injected mice were vancomycin/neomycin (V/N)-aerosolized or live or dead L. rhamnosus GG (L.RGG)-aerosolized, and tumor development was evaluated. Transcriptional profiling of lungs and IHC were performed. Tumor nodules number, diameter and area were reduced by live or heat-killed L.RGG, while only a decrease in nodule diameter was observed in V/N-treated lungs. Both L.RGG and V/N reduced Tregs in the lung. In L.RGG-treated groups, the gene encoding the joining chain (J chain) of immunoglobulins was increased, and higher J chain protein and IgA levels were observed. An increased infiltration of B, NK and myeloid-derived cells was predicted by TIMER 2.0. The Kaplan-Meier plotter revealed an association between high levels of J chain mRNA and good prognosis in lung adenocarcinoma patients that correlated with increased B and CD4 T cells and reduced Tregs and M2 macrophages. This study highlights L.RGG aerosol efficacy in impairing lung cancer growth by promoting local immunity and points to this non-invasive strategy to treat individuals at risk of lung cancer.

Effect of a novel synbiotic on Streptococcus mutans

We examined the effect of L-arginine - (i) on the growth of L. rhamnosus GG (LrG) and (ii) combined LrG synbiotic on the growth of cariogenic S. mutans. Viability of LrG was assessed using MTT/XTT assays, confocal imaging with ADS activity measurement. The effect of L-arginine (0.5%/1%/2%) (2×/24 h) with LrG on S. mutans was evaluated by measuring the colony forming units, biofilm biomass, real-time qPCR and confocal imaging. The pH of the spent media was measured immediately and 24 h post-treatment with assessment of lactic acid. The LrG viability was highest with 2% L-arginine (p < 0.001). Confocal imaging showed that 2% L-arginine increased biofilm thickness of LrG. The 2% L-arginine and LrG synbiotic significantly inhibited the growth of S. mutans (p < 0.001) reducing the viable counts (p = 0.002) and biofilm biomass (p < 0.001). The pH of spent media was the highest when treated with 2% L-arginine and LrG synbiotic (p < 0.001) with no difference between post-treatment and 24 h post-treatment (p > 0.05). Conversely, the 2% L-arginine and LrG synbiotic showed the lowest lactic acid production (p < 0.001). This study demonstrated that L-arginine enhanced the growth of LrG. The 2% L-arginine and LrG synbiotic synergistically inhibits the growth of S. mutans with significant potential to develop as an anti-caries regimen.

Systematic review with meta-analysis: Lactobacillus rhamnosus GG for treating acute gastroenteritis in children - a 2019 update.

Recently, evidence from a large randomised controlled trial (RCT) negated efficacy of Lactobacillus rhamnosus GG for treating acute gastroenteritis in children. To review RCTs in which Lrhamnosus GG was used to treat acute gastroenteritis in children. The Cochrane Library, MEDLINE, and EMBASE databases were searched from May 2013 (end of last search) to January 2019. The primary outcomes were stool volume and duration of diarrhoea. Eighteen RCTs (n=4208) were included. Compared with placebo or no treatment, Lrhamnosus GG use had no effect on stool volume but was associated with a reduced duration of diarrhoea (15 RCTs, n=3820, mean difference, MD -0.85day, 95% CI -1.15 to -0.56). Lrhamnosus GG was effective when used at a daily dose of ≥1010 CFU or <1010 CFU; however, the latter produced results of borderline significance. Lrhamnosus GG was more effective when used in European countries compared with non-European countries, particularly when considered by region. Lrhamnosus GG use was associated with a reduced duration of hospitalisation. One RCT found that Lrhamnosus GG had no effect on the total clinical severity score at 14days after enrolment. Despite a recent large RCT demonstrating no effect of Lrhamnosus GG, current evidence shows that, overall, Lrhamnosus GG reduced both the duration of diarrhoea (with a higher impact in European countries) and hospitalisation in inpatients. These findings should be viewed in the context of the high heterogeneity and methodological limitations of the included trials.

Lactobacillus plantarum ZS2058 and Lactobacillus rhamnosus GG Use Different Mechanisms to Prevent Salmonella Infection in vivo

Pathogen-induced infectious diseases pose great threats to public health. Accordingly, many studies have investigated effective strategies targeting pathogenic infections. We previously reported the preventive effects of Lactobacillus plantarum ZS2058 (ZS2058) and L. rhamnosus GG (LGG) against Salmonella spp. in a murine model. Here, we compared the mechanisms underlying the preventive effects of these Lactobacillus strains in vivo. Notably, reduced C-reactive protein levels were observed with both ZS2058 and LGG, which suggests abrogated anti-infection and inflammatory responses. ZS2058 more efficiently reduced the pathogenicity of Salmonella by increasing the level of propionic acid in feces and production of mucin 2 in the mouse colon and activity through the interleukin (IL)-23/IL-22 and IL-23/IL-17 pathways. Meanwhile, LGG more strongly alleviated gut inflammation, as indicated by changes in the levels of tissue necrosis factor (TNF)-α, IL-10 and myeloperoxidase (MPO) in infected mice. Moreover, both ZS2058 and LGG restored the levels of interferon (INF)-γ, a cytokine suppressed by Salmonella, albeit through different pathways. Our results demonstrate that ZS2058 and LGG prevent Salmonella infection via different mechanisms.

The Foodborne Strain Lactobacillus fermentum MBC2 Triggers pept-1-Dependent Pro-Longevity Effects in Caenorhabditis elegans.

Lactic acid bacteria (LAB) are involved in several food fermentations and many of them provide strain-specific health benefits. Herein, the probiotic potential of the foodborne strain Lactobacillus fermentum MBC2 was investigated through in vitro and in vivo approaches. Caenorhabditis elegans was used as an in vivo model to analyze pro-longevity and anti-aging effects. L. fermentum MBC2 showed a high gut colonization capability compared to E. coli OP50 (OP50) or L. rhamnosus GG (LGG). Moreover, analysis of pumping rate, lipofuscin accumulation, and body bending showed anti-aging effects in L. fermentum MBC2-fed worms. Studies on PEPT-1 mutants demonstrated that pept-1 gene was involved in the anti-aging processes mediated by this bacterial strain through DAF-16, whereas the oxidative stress protection was PEPT-1 independent. Moreover, analysis of acid tolerance, bile tolerance, and antibiotic susceptibility were evaluated. L. fermentum MBC2 exerted beneficial effects on nematode lifespan, influencing energy metabolism and oxidative stress resistance, resulted in being tolerant to acidic pH and able to adhere to Caco-2 cells. Overall, these findings provide new insight for application of this strain in the food industry as a newly isolated functional starter. Furthermore, these results will also shed light on C. elegans molecular players involved in host-microbe interactions.

Dual Effects of Cell Free Supernatants from Lactobacillus acidophilus and Lactobacillus rhamnosus GG in Regulation of MMP-9 by Up-Regulating TIMP-1 and Down-Regulating CD147 in PMADifferentiated THP-1 Cells.

Objective Recent studies have reported dysregulated expression of matrix metalloproteinases (MMPs), especially MMP-2, MMP-9, tissue inhibitor of metalloproteinase-1, -2 (TIMP-1, TIMP-2), and extracellular matrix metalloproteinase inducer (EMMPRIN/CD147) in activated macrophages of patients with inflammatory diseases. Therefore, MMP-2, MMP-9, and their regulators may represent a new target for treatment of inflammatory diseases. Probiotics, which are comprised of lactic acid bacteria, have the potential to modulate inflammatory responses. In this experimental study, we investigated the anti-inflammatory effects of cell-free supernatants (CFS) from Lactobacillus acidophilus (L. acidophilus) and L. rhamnosus GG (LGG) in phorbol myristate acetate (PMA)-differentiated THP-1 cells. Materials and Methods In this experimental study, PMA-differentiated THP-1 cells were treated with CFS from L. acidophilus, LGG and uninoculated bacterial growth media (as a control). The expression of MMP-2, MMP-9, TIMP-1, and TIMP-2 mRNAs were determined using real-time quantitative reverse transcription polymerase chain reaction (RT- PCR). The levels of cellular surface expression of CD147 were assessed by flow cytometry, and the gelatinolytic activity of MMP-2 and MMP-9 were determined by zymography. Results Our results showed that CFS from both L. acidophilus and LGG significantly inhibited the gene expression of MMP-9 (P=0.0011 and P=0.0005, respectively), increased the expression of TIMP-1 (P<0.0001), decreased the cell surface expression of CD147 (P=0.0307 and P=0.0054, respectively), and inhibited the gelatinolytic activity of MMP-9 (P=0.0003 and P<0.0001, respectively) in PMA-differentiated THP-1 cells. Although, MMP-2 expression and activity and TIMP-2 expression remained unchanged. ConclusionOur results indicate that CFS from L. acidophilus and LGG possess anti-inflammatory properties and can modulate the inflammatory response.

Lactobacillus plantarum HAC01 regulates gut microbiota and adipose tissue accumulation in a diet-induced obesity murine model.

The functional features of Lactobacillus plantarum HAC01 (HAC01), isolated from fermented Korean kimchi, were studied with regard to the fat mass, immunometabolic biomarkers and dysbiosis in a diet-induced obesity (DIO) murine model. L. rhamnosus GG (LGG) served as reference strain and a PBS-treated group as control. The administration of L. plantarum HAC01 resulted in reduction of the mesenteric adipose depot, the conjunctive tissue closely associated with the gastrointestinal tract, where lipid oxidative gene expression was upregulated compared to the control group. Metagenome analysis of intestinal microbiota showed that both strains HAC01 and LGG influenced specific bacterial families such as the Lachnospiraceae and Ruminococcaceae rather than the phyla Firmicutes and Bacteroidetes as a whole. The relative abundance of the Lachnospiraceae (phylum Firmicutes) was significantly higher in both LAB-treated groups than in the control. Comparing the impact of the two Lactobacillus strains on microbial composition in the gut also suggests strain-specific effects. The study emphasises the need for deeper studies into functional specificity of a probiotic organism at the strain level. Alleviation of obesity-associated dysbiosis by modulation of the gut microbiota appears to be associated with "indicator" bacterial taxa such as the family Lachnospiraceae. This may provide further insight into mechanisms basic to the mode of probiotic action against obesity and associated dysbiosis.

Lactobacillus rhamnosus CCFM1107 treatment ameliorates alcohol-induced liver injury in a mouse model of chronic alcohol feeding.

Lactobacillus rhamnosus CCFM1107 was screened for high antioxidative activity from 55 lactobacilli. The present study attempted to explore the protective properties of L. rhamnosus CCFM1107 in alcoholic liver injury. A mouse model was induced by orally feeding alcohol when simultaneously treated with L. rhamnosus CCFM1107, the drug Hu-Gan- Pian (HGP), L. rhamnosus GG (LGG), and L. plantarum CCFM1112 for 3 months. Biochemical analysis was performed for both serum and liver homogenate. Detailed intestinal flora and histological analyses were also carried out. Our results indicated that the administration of L. rhamnosus CCFM1107 significantly inhibited the increase in the levels of serum aminotransferase and endotoxin, as well as the levels of triglyceride (TG) and cholesterol (CHO) in the serum and in the liver. Glutathione (GSH), glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) were elevated while the levels of malondialdehyde (MDA) were decreased. The enteric dysbiosis caused by alcohol was restored by increasing the numbers of both lactobacilli and bifidobacteria and decreasing the numbers of both enterococci and enterobacter. Histological analysis confirmed the protective effect of L. rhamnosus CCFM1107. Compared with the other lactobacilli and to the drug Hu-Gan-Pian, there is a high chance that L. rhamnosus CCFM1107 provides protective effects on alcoholic liver injury by reducing oxidative stress and restoring the intestinal flora.

Amelioration of ovalbumin induced allergic symptoms in Balb/c mice by potentially probiotic strains of lactobacilli

To evaluate the antiallergic effect of newly characterised probiotic strains, Lactobacillus fermentum NWS29, Lactobacillus casei NWP08 and Lactobacillus rhamnosus NWP13, mice were divided into six experimental groups: control, ovalbumin (OVA), NWS29, NWP08, NWP13 and L. rhamnosus GG (LGG). Mice were immunised and probiotics were administered via oral gavage followed by challenge with OVA. After last challenge with OVA, inflammatory cells in bronchoalveolar lavage fluid (BALF), recruitment of inflammatory cells in airways and OVA-specific immunoglobulin E (IgE) in serum were determined by Giemsa, haematoxylin and eosin (HE) staining, and ELISA, respectively. Relative mRNA expression of interleukins (IL-4, IL-5, IL-10, IL-13 and IL-17), transforming growth factor-β (TGF-β) and interferon-γ (IFN-γ) in lung and spleen tissue was determined by real time RT-PCR. OVA-specific IgE levels, recruitment of eosinophils and mRNA expressions of inflammatory cytokines were remarkably increased in OVA-exposed mice compared with the control group. Administration of NWS29 and NWP13 suppressed inflammatory cell infiltration in airways and BALF, and level of OVA-specific IgE in serum of OVA-exposed mice. Furthermore, NWS29 and NWP13 also abrogated the mRNA expression of 1L-4, IL-5, IL-13 and TGF-β in mice immunised and exposed to OVA. Our findings suggest that NWS29 and NWP13 might be good candidates for the prevention of allergic airway inflammation.

Lactobacillus rhamnosus BFE 5264 and Lactobacillus plantarum NR74 Promote Cholesterol Excretion Through the Up-Regulation of ABCG5/8 in Caco-2 Cells.

The effect of two putative probiotic strains, Lactobacillus rhamnosus BFE5264 and Lactobacillus plantarum NR74, on the control of cholesterol efflux in enterocytes was assessed by focusing on the promotion of ATP-binding cassette sub-family G members 5 and 8 (ABCG5 and ABCG8). Differentiated Caco-2 enterocytes were treated with live bacteria, heat-killed bacteria, a bacterial cell wall fraction, and metabolites and were subjected to cholesterol uptake assay, mRNA analysis, and protein analyses. Following LXR-transfection by incubation with CHO-K1 cells in DNA-lipofectin added media, the luciferase assay was conducted for LXR analysis. Treatment of Caco-2 cells with L. rhamnosus BFE5264 (isolated from traditional fermented Maasai milk) and L. plantarum NR74 (isolated from Korean kimchi) resulted in the up-regulation of LXR, concomitantly with the elevated expression of ABCG5 and ABCG8. This was associated with the promotion of cholesterol efflux at significantly higher levels compared to the positive control strain L. rhamnosus GG (LGG). The experiment with CHO-K1 cells confirmed up-regulation of LXR-beta by the test strains, and treatment with the live L. rhamnosus BFE5264 and L. plantarum NR74 strains significantly increased cholesterol efflux. Heat-killed cells and cell wall fractions of both LAB strains induced the upregulation of ABCG5/8 through LXR activation. By contrast, LAB metabolites did not show any effect on ABCG5/8 and LXR expression. Data from this study suggest that LAB strains, such as L. rhamnosus BFE5264 and L. plantarum NR74, may promote cholesterol efflux in enterocytes, and thus potentially contribute to the prevention of hypercholesterolemia and atherosclerosis.

Antimicrobial activity against Shigella sonnei and probiotic properties of wild lactobacilli from fermented food

Four lactobacilli strains ( Lactobacillus paracasei subp. paracasei M5-L, Lactobacillus rhamnosus J10-L, Lactobacillus casei Q8-L and L. rhamnosus GG (LGG), were systematically assessed for the production of antimicrobial substances active towards Shigella sonnei, Escherichia coli and Salmonella typhimurium. Agar-well assay showed that the four lactobacilli strains displayed strong antibacterial activity towards S. sonnei. The nature of antimicrobial substances was also investigated and shown to be dependent on the production of organic acids, in particular the lactic acid. Time-kill assay showed that the viability of the S. sonnei was decreased by 2.7–3.6 log CFU/ml after contact with CFCS (cell-free culture supernatants) of four lactobacilli for 2 h, which confirmed the result of the agar-well assay. Further analysis of the organic acid composition in the CFCS revealed that the content of lactic acid range from 227 to 293 mM. In addition, the aggregations properties, adherence properties and tolerance to simulated gastrointestinal conditions were also investigated in vitro tests. The result suggested that the M5-L, J10-L and Q8-L strains possess desirable antimicrobial activity towards S. sonnei and probiotic properties as LGG and could be potentially used as novel probiotic strains in the food industry.

Antiviral Activity ofLactobacillus spp.and Polysaccharide

Lactobacillus species have been widely used in both human and animals to prevent or treat gastrointestinal disorders. Recently, it was reported that Lactobacillus spp. inhibited infections by respiratory and gastroenteric viruses; however, its mechanism is not clear. Lactobacillus spp. play direct and indirect roles in the inhibitory effects of viral replication. 1) In vitro study: Highest protection effects were showed with the known probiotics L. rhamnosus GG (LGG) and L. casei Shirota against both rotavirus (RV) and transmissible gastroenteritis virus (TGEV). 2) In vivo study: L. acidophilus had significant immunopotentiating effects, and was therefore recommended for use as a safe oral adjuvant for rotavirus vaccines in pigs. Oral administration of lactobacilli, such as LGG and L. gasseri, might protect a host animal from influenza virus (IFV) infection. Polysaccharides are regarded to be potentially useful and biologically active as an ingredient for pharmaceutical uses due to a variety of biological activities. Especially, sulphated polysaccharides exhibit broad-spectrum antiviral activity against enveloped viruses in vitro. With respect to human immunodeficiency virus type 1 (HIV-1), its in vitro antiviral activity is, specifically, the inhibition of virus-cell attachment, the first step in the infection process. Recently, it was reported that sulphated polysaccharides exhibited antiviral activity against HBV, HCMV, HSV and IFV. In conclusion, Lactobacillus spp. and polysaccharides with antiviral activity against diverse viruses are potential candidates as ingredients for probiotics and medicine candidate for the prevention and treatment of viral infections in animals and humans.