Casei CRL Research Articles

Biological control of green and blue molds on postharvest lemon by lactic acid bacteria

Postharvest green and blue molds caused mainly by Penicillium digitatum and P. italicum conduce to economic losses in citrus production. Here, the potential antifungal activity of four lactobacilli strains was assessed against local isolates of these fungi to control postharvest diseases on lemons. Inhibitory activity of L. paraplantarum CRL 1905, L. fermentum CRL 973, L. casei CRL 1110 and L. reuteri CRL1101 strains was assayed by the culture overlay method. Also, inhibition of conidial germination by cell-free supernatants (CFS) obtained from 24 and 48 h-cultures of these lactobacilli strains (CFS24 and CFS48, respectively) was tested by microtiter assay. CRL 1905 showed the strongest fungicidal activity and was selected for further studies. When the antifungal compound/s produced by CRL 1905 strain were investigated, it was observed that the ability of CFS24 to inhibit conidial germination was lost after pH neutralization, inferring an acidic nature of the metabolite/s. Finally, to detect whether CFS24 had a potential application to control of Penicillium rot on lemons, a fruit decay test was performed. It was demonstrated that ten-fold concentrated CFS24 was able to decrease the disease incidence by ∼ 80 %. In conclusion, the use of extracellular components derived from CRL 1905 with antifungal activity could be an eco-friendly alternative to control postharvest decays of lemon.

Effect of Lactobacillus (L. acidophilus NCIB1899, L. casei CRL 431, L. paracasei LP33) fermentation on free and bound polyphenolic, antioxidant activities in three Chenopodium quinoa cultivars.

The application of lactic acid bacteria (LAB) fermentation to the production of probiotic beverages is a common method for modifying the health-related functional characteristics and phytochemical content of such beverages. This study evaluated the effect of fermentation with Lactobacillus acidophilus NCIB1899, Lactobacillus casei CRL 431, and Lactobacillus paracasei LP33 on the total phenolic contents (PCs), flavonoid contents (FCs), phenolic profiles, and antioxidant capacities of the solvent-extractable (free) and cell-wall-bound (bound) fractions in quinoa varying in bran color. Compared with unfermented beverages, LAB fermentation significantly increased the free PCs and free FCs by 15.7%-79.4% and 7.6%-84.3%, respectively. The bound PCs increased, whereas bound FCs decreased in fermented black and red quinoa juice. The increments of procyanidin B2 , protocatechuic acid, p-hydroxybenzaldehyde, rutin, and kaempferol through 30h fermentation exceeded 189%-622%, 13.8%-191%, 55.6%-100%, 48.5%-129%, and 120%-325%, respectively. However, the contents of catechin, procyanidin B1 , and ferulic acid decreased with fermentation. Overall, L. acidophilus NCIB1899, L. casei CRL431, and L. paracasei LP33 strains may be suitable for producing fermented quinoa probiotic beverages. L. acidophilus NCIB1899 was superior for fermentation to L. casei CRL431 and L. paracasei LP33. Red and black quinoa had significantly higher total (sum of free and bound) PC and FC concentrations and antioxidant capacities than white quinoa (p<0.05) because of their higher concentrations of proanthocyanins and polyphenol, respectively. PRACTICAL APPLICATION: In this study, different LAB (L. acidophilus NCIB1899, L. casei CRL431, and L. paracasei LP33) were singly inoculated on aqueous solutions from quinoa to ferment probiotic beverage and to compare the metabolic capacity of LAB strains on nonnutritive phytochemicals (phenolic compounds). We observed that LAB fermentation greatly enhanced the phenolic and antioxidant activity of quinoa. The comparison indicated that the L. acidophilus NCIB1899 strain has the highest fermentation metabolic capacity.

Long-term benefits of probiotics and calcium supplementation during childhood, and other biomedical and socioenvironmental factors, on adolescent neurodevelopmental outcomes

• Probiotics supplementation in childhood improve adolescent neurodevelopment. • The effects of probiotics on neurodevelopment are strain-specific. • Low calcium supplementation resulted in lower BDNF as compared to regular calcium. • Combined childhood interventions with probiotics and socioenvironmental components are warranted. We evaluated the impact of 6-month probiotics and calcium supplementation at 1–6 years of age on neurodevelopment in adolescence, along with the effects of other biomedical and socioenvironmental factors. We re-enrolled 238 adolescents 10-years after supplementation with low-lactose milk with either low calcium (LC; ∼50 mg/d; n = 53), regular calcium (RC; ∼440 mg/d; n = 70), RC with 5x10 8 CFU/d Lactobacillus reuteri DSM17938 (reuteri; n = 55), or RC with 5x10 8 CFU/d L. casei CRL431 (casei; n = 60). Compared to RC, the casei group scored 0.38 SD (effect size, 0.04–0.72) higher on the Raven’s Progressive Matrices; the reuteri group was 0.38 SD (0.01–0.75) lower on the Children’s Depression Inventory; and the LC and younger adolescents in the reuteri group were 0.36 (0.01–0.71) and 0.49 SD (0.02–0.95) lower in brain-derived neurotrophic factor. Diet quality, physical activity, and home environment contributed similar effect sizes. Probiotics supplementation in childhood have strain-specific long-term neurodevelopmental benefits and integration with socioenvironmental interventions are warranted.

Probiotic Consumption Boosts Thymus in Obesity and Senescence Mouse Models.

The ability of the immune system to respond to different pathogens throughout life requires the constant production and selection of T cells in the thymus. This immune organ is very sensitive to age, infectious processes and nutrition disorders (obesity and malnutrition). Several studies have shown that the incorporation of some probiotic bacteria or probiotic fermented milk in the diet has beneficial effects, not only at the intestinal level but also on distant mucosal tissues, improving the architecture of the thymus in a malnutrition model. The aim of the present study was to determine whether supplementation with the probiotic strain Lactobacillus casei CRL 431 and/or its cell wall could improve body weight, intestinal microbiota and thymus structure and function in both obese and aging mice. We evaluated probiotic administration to BALB/c mice in 2 experimental mouse models: obesity and senescence, including mice of different ages (21, 28, 45, 90 and 180 days). Changes in thymus size and histology were recorded. T-lymphocyte population and cytokine production were also determined. The consumption of probiotics improved the cortical/medullary ratio, the production and regulation of cytokines and the recovery of mature T-lymphocyte populations of the thymus in obese and old mice. Probiotic incorporation into the diet could not only modulate the immune system but also lead to thymus function recovery, thus improving quality of life.

Tenth year reenrollment randomized trial investigating the effects of childhood probiotics and calcium\xa0supplementation on height and weight at adolescence

Microbiota and its modification with specific probiotics in early life could provide long term health benefits. Probiotics and calcium strengthen intestinal integrity and may support linear growth. This study investigated the long-term effects of childhood probiotics and calcium supplementation on growth in adolescence. We re-enrolled 238 adolescents aged 11–18 years from 494 children 10-years after 6-months of supplementation with either low-lactose milk fortified with low levels of calcium (LC, ∼50 mg/day, n = 53/124), with regular levels of calcium (RC, ∼440 mg/day, n = 70/126), or with regular calcium + 5 x 108 CFU/day Lactobacillus reuteri DSM 17938 (Reuteri, n = 55/124), or regular calcium + 5 x 108 CFU/day L. casei CRL 431 (Casei, n = 60/120). Changes in height-for-age z-score (HAZ) and body mass index-for-age z-score (BMIZ) were determined from the end of intervention to re-enrollment. General linear models were used to assess the effects on HAZ and BMIZ of group, gender, living area, maternal education, family income, physical activity, diet quality, nutritional status, and gut integrity as determined by urinary lactulose/mannitol ratio (L:M). Adolescent mean age was 15.3 years, mean HAZ was − 1.11, mean BMIZ was − 0.2 and median L:M (n = 155) was 0.23. Changes in HAZ and BMIZ were not significantly different between Casei, Reuteri, LC compared to RC. However, a significant decrease in BMIZ was observed among female adolescents in the Casei compared to RC group (− 0.5 SD, 95% CI − 0.8 to − 0.003, p = 0.048). Childhood probiotic and calcium supplementation may therefore selectively affect female adolescents.Clinical trial registration: This follow-up study has been registered at www.clinicaltrials.gov, Registry name: Rina Agustina, Registration number: NCT04046289, First Registration Date 06/08/19. web link: https://www.clinicaltrials.gov/ct2/show/NCT04046289.

Probiotic Bacteria and Their Cell Walls Induce Th1-Type Immunity Against Salmonella Typhimurium Challenge.

Probiotics have been associated with a variety of health benefits. They can act as adjuvant to enhance specific immune response. Bacterial cell wall (CW) molecules are key structures that interact with host receptors promoting probiotic effects. The adjuvant capacity underlying this sub-cellular fraction purified from Lactobacillus casei CRL431 and L. paracasei CNCMI-1518 remains to be characterized. We interrogated the molecular and cellular events after oral feeding with probiotic-derived CW in addition to heat-inactivated Salmonella Typhimurium and their subsequent protective capacity against S. Typhimurium challenge. Intact probiotic bacteria were orally administered for comparison. We find that previous oral feeding with probiotics or their sub-cellular fraction reduce bacterial burden in spleen and liver after Salmonella challenge. Antibody responses after pathogen challenge were negligible, characterized by not major changes in the antibody-mediated phagocytic activity, and in the levels of total and Salmonella-specific intestinal sIgA and serum IgG, respectively. Conversely, the beneficial effect of probiotic-derived CW after S. Typhimurium challenge were ascribed to a Th1-type cell-mediated immunity which was characterized by augmentation of the delayed-type hypersensitivity response. The cell-mediated immunity associated with the oral feeding with probiotic-derived CW was accompanied with a Th1-cell polarizing cytokines, distinguished by increase IFN-γ/IL-4 ratio. Similar results were observed with the intact probiotics. Our study identified molecular events associated with the oral administration of sub-cellular structures derived from probiotics and their adjuvant capacity to exert immune modulatory function.

Protective Effect of Lacticaseibacillus casei CRL 431 Postbiotics on Mitochondrial Function and Oxidative Status in Rats with Aflatoxin B1-Induced Oxidative Stress.

Studies have shown that the intracellular content of probiotic (postbiotics) has antioxidant properties, which can improve the antioxidant status in vivo. However, its absorption and mechanisms underlying the protective effects are still unknown. The antioxidant capacity of Lacticaseibacillus casei CRL431 (IC-431) postbiotics was determined after an in vitro simulated digestive process. Permeability of antioxidant constituents of IC-431 was determined by an ex vivo everted duodenum assay. Aflatoxin B1-induced oxidative stress rat models were established and treated with IC-431; biomarkers of hepatic mitochondrial function and H2O2 levels, oxidative stress, and oxidative stress index (OSi) were examined. The antioxidant capacity of IC-431 (477±45.25μmol TroloxEquivalent/L) was reduced by exposure to the simulated digestive process. No difference (p>0.05) was found among digested and the permeate fraction of IC-431. A protective effect was observed by significantly lower OSi and higher liver glutathione peroxidase and catalase activities. Lower H2O2 production, a higher degree of mitochondrial uncoupling, and lower mitochondrial respiration coefficient were also observed (p<0.05). These results suggest that IC-431 antioxidant components permeate intestinal barriers to enter the bloodstream and regulate antioxidant status during AFB1-induced oxidative stress by reducing hepatic mitochondrial dysfunction, thus enhancing antioxidant enzyme response.

Milk fermented by Lactobacillus casei CRL431 administered as an immune adjuvant in models of breast cancer and metastasis under chemotherapy.

Chemotherapy is the most common treatment for breast cancer and its metastasis; however, it affects the patients' quality of life. Previously, it was demonstrated that milk fermented by Lactobacillus casei CRL431 (probiotic fermented milk (PFM)) exerted benefits against breast cancer metastasis by modulating the immune response in a mouse model. The aim of this work was to evaluate PFM administration on the side effects of capecitabine and on its anti-tumour/anti-metastatic effects. In vitro, 4T1 breast cancer cells were treated with capecitabine in the presence of immune cells' conditioned media from mice administered with PFM. Cell viability was evaluated by MTT assay. In vivo, BALB/c mice (healthy, bearing breast cancer or with potential metastasis) were treated or not with capecitabine and administered with PFM. Blood cell counts, intestinal damages, lung histology and serum cytokines were evaluated. Results showed that capecitabine's toxicity on 4T1 cells was improved by the immune cells from mice that received PFM when the lower dose of capecitabine was evaluated. PFM reduced capecitabine side effects in all the mouse models and decreased intestinal mucositis and mortality. PFM administration to mice under chemotherapy maintained the anti-cancer/anti-metastasis effect of capecitabine with similar or decreased values for serum IL-10 and TNF-α and decreased IL-6, a cytokine related to poor prognosis in advanced cancer patients. In addition, PFM by itself reduced metastasis without side effects and improved the host's immune response. PFM has a potential to be administered as an immune adjuvant in patients under chemotherapy without affecting the treatment. KEY POINTS: • Milk fermented by L. casei CRL431 (PFM) diminished capecitabine side effects. • Capecitabine's toxicity on 4T1 cells was improved by the PFM-stimulated immune cells. • PFM maintained anti-cancer/anti-metastasis effect of capecitabine in mouse models. Graphical abstract.

Lactobacillus casei CRL431 modulates hemostatic activation induced by protein malnourishment and pneumococcal respiratory infection.

Previously, we demonstrated that Lactobacillus casei CRL431, a well-known immunomodulatory bacterium, beneficially regulates coagulation activation, fibrin formation in lung, and the pro-inflammatory state induced by protein malnourishment and pneumococcal infection. In this study, we deepen in the understanding of the mechanisms involved in the immunoregulatory activity of L. casei CRL431 during a nutritional repletion process by evaluating (a) platelet and endothelial activation, (b) tissue factor (TF) expression, and (c) protease-activated receptor (PAR) activation in an experimental bacterial respiratory infection model in malnourished mice. Our findings demonstrate for the first time that the repletion diet supplemented with L. casei CRL431 was effective to normalize platelet counts in blood, modulate platelet activation and their recruitment into the lung, and regulate local and systemic TF expression and endothelial activation, which were affected by malnourishment. Streptococcus pneumoniae challenge induced local and systemic increase of platelet counts, PARs activation, P-selectin and TF expression, as well as endothelial activation in both well-nourished and malnourished mice. Malnourished animals evidenced the highest alterations of the parameters evaluated while the mice fed with the probiotic bacterium had similar behavior to normal controls but with lower PAR activation in lung. These results demonstrate that supplementation of repletion diet with L. casei CRL431 is effective to modulate alterations induced by malnourishment and pneumococcal infection, restraining coagulation activation, the inflammatory process, and lung damage. These observations contribute to set the basis for the application of probiotic functional foods to modulate the inflammation-hemostasis interactions altered by malnourishment or bacterial respiratory infections. KEY POINTS: • Pneumococcal infection increases pro-coagulant state induced by protein malnourishment. • Repletion with L. casei CRL431 modulates platelet, TF, and endothelial activation. • L. casei CRL431 improves immune-coagulative response in protein malnourishment.

Effect of the intracellular content from Lactobacillus casei CRL-431 on the antioxidant properties of breast milk: Randomized double-blind controlled trial

Breast milk (BM) provides antioxidant components that play a key role in protecting the neonate against oxidative stress. Therefore, different strategies have been pursued to preserve or increase its antioxidant levels. In this sense, studies have reported that probiotics may improve the antioxidant capacity of BM; however, the intracellular content of probiotics have not yet been assessed. Hence, the aim of this study was to evaluate in a randomized double-blind controlled clinical study the effect of the intracellular content of Lactobacillus casei CRL-431 (IC-431) on the antioxidant capacity and some enzymatic and non-enzymatic antioxidants, as well as on indicators of the degree of the oxidation on BM. For this purpose, nursing mothers from the first to the twelfth month of lactation, were randomized into two groups (n = 8); to either receive an edible gel with IC-431 or without IC-431 (placebo). Despite that no significant differences (p > 0.05) were found between groups on the total antioxidant capacity, enzymatic and non-enzymatic antioxidants, and biomarkers of oxidative stress in BM, the supplementation of IC-431 showed a positive trend on increasing total antioxidant parameters and a slight decrease in oxidative stress markers. Thus, IC-431 may be used as a potential supplement for nursing mothers.

Human probiotic bacteria attenuate Pseudomonas aeruginosa biofilm and virulence by quorum-sensing inhibition

This work investigated chloroform extracts from culture supernatants of two human probiotic bacteria, Lactobacillus casei CRL 431 and Lactobacillus acidophilus CRL 730 for the production of virulence factors and quorum sensing (QS) interference against three Pseudomonas aeruginosa strains. Both extracts inhibited biofilm biomass (up to 50%), biofilm metabolic activity (up to 39%), the production of the enzyme elastase (up to 63%) and pyocyanin (up to 77%), and decreased QS, without presenting any antibacterial acgivity. In addition, the chloroform extracts of both strains disrupted preformed biofilms of the three strains of P. aeruginosa analyzed (up to 40%). GC-MS analysis revealed that the major compounds detected in the bioactive extracts were four diketopiperazines. This study suggests that the metabolites of L. casei and L. acidophilus could be a promising alternative to combat the pathogenicity of P. aeruginosa.

In Silico Prediction and In Vitro Assessment of Multifunctional Properties of Postbiotics Obtained From Two Probiotic Bacteria.

In this study, a global metabolite profile using Raman spectroscopy analysis was obtained in order to predict, by an in silico prediction of activity spectra for substance approach, the bioactivities of the intracellular content (IC) and cell wall (CW) fractions obtained from Lactobacillus casei CRL 431 and Bacillus coagulans GBI-30 strains. Additionally, multifunctional in vitro bioactivity of IC and CW fractions was also assessed. The metabolite profile revealed a variety of compounds (fatty acids, amino acids, coenzyme, protein, amino sugars), with significant probable activities (Pa > 0.7) as immune-stimulant, anti-inflammatory, neuroprotective, antiproliferative, immunomodulator, and antineoplastic, among others. Moreover, in vitro assays exhibited that both IC and CW fractions presented angiotensin-converting enzyme-inhibitory (> 90%), chelating (> 79%), and antioxidant (ca. 22-57 cellular antioxidant activity units) activities. Our findings based on in silico and in vitro analyses suggest that L. casei CRL 431 and B. coagulans GBI-30 strains appear to be promising sources of postbiotics and may impart health benefits by their multifunctional properties.

Milk fermented by Lactobacillus casei CRL431 modifies cytokine profiles associated to different stages of breast cancer development in mice.

Breast cancer is one of the leading causes of death worldwide. It is recognised that immune system influences its promotion, progression, and metastasis, as well as their responsiveness to therapies. Previously, it was reported that milk fermented by Lactobacillus casei CRL431 decreased tumour growth and metastasis in a mouse breast cancer model, through the modulation of the host immune response. The aim of the present work was to analyse the systemic immune response induced by the administration of probiotic fermented milk (PFM) at different stages of cancer development, evaluating cytokines produced by splenocytes stimulated in vitro with 4T1 tumour cells, or its conditioned medium (CM). Groups of healthy mice and mice bearing 4T1 tumour or suffering metastasis after tumour surgery were studied. Results showed that at the early stages, PFM maintained pro-inflammatory response associated to the delay or the inhibition of tumour growth. PFM administration to mice bearing tumour maintained an important inflammatory response; however, in contrast to the milk group, this response was regulated to avoid exacerbation of inflammation. In the metastasis model, the benefits of PFM were associated to avoid the immunosuppression associated to high interleukin-10 levels. In conclusion, as cancer cells induce modifications of the immune response to favour their own growth at each stage of cancer development, PFM administration stimulated different profile of cytokines to respond to these modifications and fight against cancer cells.

Oral administration of milk fermented by Lactobacillus casei CRL431 was able to decrease metastasis from breast cancer in a murine model by modulating immune response locally in the lungs

Abstract The host immune system is an important factor to combat metastasis. In this work, it was evaluated the immunomodulation exerted by milk fermented with the probiotic strain Lactobacillus casei CRL431 (PFM) when was administered to mice in the metastatic stage of breast cancer. Mice received PFM were compared to animals given milk. PFM administration diminished metastasis in the lungs and increased the survival of the animals. Systemically, PFM administration decreased pro-inflammatory cytokines and locally in the lungs (metastatic organs) decreased F4/80+ cells, principally IL-10/F4/80+ cells. The highest percentages for CD4+ and CD4+CD8+ cells were observed in PFM group. Finally, immune cells from lungs of mice given PFM showed lower production of most cytokines evaluated when they were re-stimulated in vitro with tumour cells. The results obtained suggest that modulation of immune cells in the lungs by PFM could be a strategy to fight against tumour cells in the metastatic sites.

An insight on antioxidant properties of the intracellular content of Lactobacillus casei CRL-431

Recent studies have shown that the intracellular content of lactic acid bacteria may be a source of metabolites with antioxidant properties. In order to determine the potential participation of relevant intracellular components on its antioxidant properties, as well as their possible interactions, different enzymatic and chemical treatments were applied to either Lactobacillus casei CRL-431 or its intracellular content (IC-CRL431). Total antioxidant capacity (TAC) of IC-CRL431 with and without (control) treatments was determined by the OxHLIA method. GABA, B-vitamin complex and polysaccharide structures did not have a significant (P > 0.05) contribution on TAC. However, a significant (P < 0.05) reduction of TAC was observed after buthionine treatment and removal of proteinaceous and lipid fractions (13.1, 22.6 and 25.5%, respectively). Additionally, a synergistic interaction was observed between glutathione (GSH) and the lipid or proteinaceous components. However, GSH-lipid-proteinaceous components showed an additive interaction, while an antagonist interaction between lipid and proteinaceous constituents was observed. These results suggest that lipid or proteinaceous compounds, as well as GHS may be the main metabolites involved in the antioxidant activity of IC-CRL431.

Modulatory Effect of the Intracellular Content of Lactobacillus casei CRL 431 Against the Aflatoxin B1-Induced Oxidative Stress in Rats.

It has been recognized that lactic acid bacteria exhibit antioxidant properties, which have been mainly endorsed to the intact viable bacteria. However, recent studies have shown that intracellular content (IC) may also be good sources of antioxidative metabolites, which may potentially contribute to oxidative homeostasis in vivo. Hence, the modulatory effect of the intracellular content of Lactobacillus casei CRL 431 (IC431) on aflatoxin B1 (AFB1)-induced oxidative stress in rats was evaluated on the basis of its influence on hepatic lipid peroxidation (LPO), antioxidant status-antioxidant capacity (TAC), catalase (CAT), and glutathione peroxidase (GPx) activities; and on the oxidative stress index (OSi). Results demonstrated that CAT and GPx activities, and TAC, determined in plasma samples, were significantly (P <0.05) higher in rats treated with AFB1 plus IC431 (3.98μM/min/mg protein, 1.88μM/min/mg protein, and 238.7μM Trolox equivalent, respectively) than AFB1-treated rats (3.47μM/min/mg protein, 1.46μM/min/mg protein, and 179.7μM Trolox equivalent, respectively). Furthermore, plasma and liver tissue samples from rats treated with AFB1 plus IC431 showed significantly (P <0.05) lower LPO values (52 and 51%, respectively) and OSi (59 and 51%, respectively) than AFB1-treated rats. Hence, our results proved that the intracellular content of Lact. casei CRL 431 contains metabolites that are capable to modulate the antioxidant defense systems in living organism, which may help to ameliorate the damage associated to AFB1-induced oxidative stress.

Non-Viable Lactobacillus Casei Beneficially Modulates Poly I:C Immune Response in Co-Cultures of Human Cells.

Polyinosinic:polycytidylic acid (Poly-IC) has been used as a viral stimulus to mimic in vivo and in vitro infection induced by some viruses. To determine whether non-viable Lactobacillus casei CRL431 (LcM) can modulate the immune response induced by Poly I:C in co-culture models of peripheral blood mononuclear cells (PBMC) and A549 cells. T and NK cell activation was evaluated by flow cytometry and levels of TNF-α, IFN-γ, IL-10, IL-29, and IL-17 by ELISA. Cells in direct contact with A549 (PBMC-A549) and cells with no contact with it (PBMC//A549) were used for this purpose. PBMCs alone and both co-culture systems were stimulated for 24 h with the following stimuli: LPS (10 µg/ml), LcM (106 UFC/ml), Poly I:C (2 µg/ml), Poly I:C+LcM, and LcM (3 h)+Poly I:C. Moreover, unstimulated cells were used as a control. Poly I:C and LcM (3 h)+Poly I:C in PBMC-A549 showed a significant increase in the percentage of CD8+ expression (p<0.05). All stimuli induced significant activation from T CD4+, CD8+ cells compared with unstimulated PBMCs in both co-culture cells system. However, activation percentages were higher in direct co-culture. Poly I:C induced a higher level of pro-inflammatory TNF-α and IFN-γ cytokines as well as IL-17 and IL-29 with lower IL-10 levels in both co-culture systems while LcM induced a beneficial pattern of cytokines that would regulate Poly I:C effect. This in vitro model allowed us to highlight the potential of LcM as a modulator of anti-viral immune response and suggest its potential use in formulations against RNA respiratory viruses.

Optimization of compositional and structural properties in probiotic sausage production.

In this study, the effects of different fat levels and different particle sizes on compositional and structural characteristics of probiotic fermented sausage were investigated. In order to obtain probiotic character, Lactobacillus casei CRL431 was added. The physicochemical, microbiological and sensory analysis were done. The effect of fat level x mincer hole diameter interaction on hardness values were statistically significant (p<0.005). At the end of the fermentation-ripening period, L.casei CRL-431 count has reached to sufficient microbial count (10(6) cfu/g of probiotic bacteria) to demonstrate the character of probiotic food. A significant positive correlation was found between L.casei CRL431 count and surface appearance, texture and overall acceptability scores (r=0.60, 0.52, 0.53). The values of TBARS number of probiotic sucuk samples increased during fermentation-ripening. A significant correlation between taste-aroma scores and fat level was detected (r=-0.61,p=0.0008). Consiquently, the best sensorial quality was determined in L3 samples and the worst sensorial quality was determined in H8 samples.

Inhibition of Growth and Metastasis of Breast Cancer in Mice by Milk Fermented With Lactobacillus casei CRL 431.

Breast cancer is the second cause of death in women, who are especially related to uncontrolled metastasis. It was previously demonstrated that the administration of milk fermented by Lactobacillus casei CRL 431 [fermented milk (FM)] delayed the tumor growth in a murine breast cancer model. In this work we evaluated if the administration of FM to mice, starting when the tumor was measurable, can affect not only the tumor growth, but also the extravasation of tumor cells and the lung metastasis. The evaluation of immune cells-infiltrating tumors and lungs was also performed. Tumor volume was calculated. Whole blood, lungs, and liver were processed to count the number of colonies formed by tumor cells. Blood serum was obtained for monocyte chemoattractant protein-1, interleukin (IL)-10, and IL-6 determination, lung tissues for histologic observations, and tumor tissues for angiogenesis determination. Mice that received FM were compared with animals given milk or to the controls without any especial supplementation. The results showed that FM administration to mice decreased or suppressed tumor growth, with less tumor vascularity, extravasation of tumor cells, and lung metastasis. These benefits were associated to modulation of the immune response by decreasing the infiltration of macrophages in both the tumor and the lungs. FM administration maintained an increased antitumor response associated to CD8 lymphocytes, and also increased CD4 lymphocytes that can be involved in the modulation of the immune response. The future evaluation of cytokine profiles will allow knowing more about subpopulation of macrophages and lymphocytes associated to the beneficial effect of this probiotic in the breast cancer model.

Role of probiotics and functional foods in health: gut immune stimulation by two probiotic strains and a potential probiotic yoghurt.

There are numerous reports that show the benefits on the health attributed to the probiotic consumptions. Most of the studies were performed using animal models and only some of them were validated in controlled human trials. The present review is divided in two sections. In the first section we describe how the probiotic microorganisms can interact with the intestinal epithelial cells that are the first line of cell in the mucosal site, focusing in the studies of two probiotic strains: Lactobacillus casei DN-114001 (actually Lactobacillus paracasei CNCMI-1518) and Lactobacillus casei CRL 431. Then we describe same beneficial effects attributed to probiotic administration and the administration of fermented milks containing these microorganisms or potential probiotic yoghurt, principally on the immune system and on the intestinal barrier in different experimental mouse models like enteropathogenic infection, malnutrition, cancer and intestinal inflammation.