Impact of ultrasonicated Lactobacillus delbrueckii subsp. bulgaricus, Streptococcus thermophilus and Lactiplantibacillus plantarum AF1 on the safety and bioactive properties of stirred yoghurt during storage.

In this study, the effects of ultrasonicated Lactobacillus delbrueckii subsp. bulgaricus, Streptococcus thermophilus and Lactiplantibacillus plantarum AF1 (100 W, 30 kHz, 3 min) on the safety and bioactive properties of stirred yoghurt during storage (4 °C for 21 days) were investigated. The results showed that sonicated cultures were more effective in reducing pathogens than untreated ones. The highest antioxidant activity (DPPH and ABTS), α-glucosidase and α-amylase inhibition capacity were found in yoghurt containing sonicated probiotic + sonicated yoghurt starter cultures (P + Y + ). The highest amount of peptides (12.4 mg/g) was found in P + Y + yoghurts at the end of the storage time. There were not significant differences between the exopolysaccharide content of P + Y+ (17.30 mg/L) and P + Y- (17.20 mg/L) yoghurts, although it was significantly (P ≤ 0.05) higher than the other samples. The use of ultrasonicated cultures could enhance the safety of stirred yoghurt and improve its functional and bioactive properties.

Lactobacillus delbrueckii UFV-H2b20 increases IFN-γ production and CD39+CD73+ Treg cell numbers in lungs, and protects mice against experimental allergic asthma.

Asthma is a disorder characterized by airflow obstruction, inflammation, declining airway function, bronchial hyperresponsiveness and tissue remodelling. Probiotics are defined as "live microorganisms that, when administered in adequate amounts, confer a health benefit on the host". The use of probiotics is becoming increasingly studied and recent evidence has suggested that it may provide therapeutic benefits in asthma and other diseases. Lactobacillus delbrueckii UFV-H2b20 fulfils all the requirements to be classified as probiotic. Previous studies have already shown the ability of L. delbrueckii UFV-H2b20 to stimulate the immune system. Our objective was to evaluate the protective effects of L. delbrueckii UFV-H2b20 in experimental allergic asthma. We used a murine model of ovalbumin-induced allergic airway inflammation to mimic allergic asthma. Oral treatment with L. delbrueckii UFV-H2b20 improves respiratory parameters and inhibits the inflammatory response in the lungs by decreasing the numbers of inflammatory monocytes, eosinophils and alveolar macrophages, as well as IgE levels. Treatment increased the IFN-γ/IL-4 cytokine ratio. Levels of IL-10 in the lungs were also increased in treated animals. Our results also showed that the probiotic administration increases the number of CD39+CD73+ T regulatory lymphocytes in the lung, suggesting a role for purinergic signals in the regulation of inflammation promoted by the treatment. Understanding the mechanisms of modulation of the immune system by probiotics could allow the development of probiotic preparations that are safe and have a direct action. Our results suggest that oral administration of L. delbrueckii UFV-H2b20 could be helpful to treat chronic inflammatory airway diseases, such as asthma.

Fermented milk of cheese-derived Lactobacillus delbrueckiisubsp.bulgaricus displays potentials in alleviating alcohol-induced hepatic injury and gut dysbiosis in mice.

An isolate of Lactobacillus delbrueckii subsp. bulgaricus (L. bulgaricus L7) with robust antioxidant capacity was screened from traditional fermented Xinjiang cheese. Here, we focused on evaluating the effect of L. bulgaricus fermented milk on acute alcoholic liver disease prevention using a mice model, with glutathione treated mice as positive control. The results showed that both fermented milk and glutathione feeding could relieve alcohol-induced oxidative stress and inflammatory responses significantly. However, fermented milk feeding seemed to hold more promise in restoring gut dysbiosis relative to glutathione. Enhanced abundance of potential pathogens, Porphyromonas sp. and Enterococcus sp., induced by alcohol was considerably attenuated by additional feeding of fermented milk. Different scenario was firstly observed when additionally fed with glutathione in this study, showing remarkably increased abundance of Bacteroides sp. and Enterococcus sp. Our results suggested the more robust capability of L. bulgaricus fermented milk in restoring alcohol-induced gut dysbiosis relative to glutathione, indicating its potential protective effects on alcohol-induced hepatic injury.

The Administration of the Synbiotic Lactobacillus bulgaricus 6c3 Strain, Inulin and Fructooligosaccharide Decreases the Concentrations of Indoxyl Sulfate and Kidney Damage in a Rat Model.

Indoxyl sulfate (IS) is involved in the progression of chronic kidney disease (CKD) and in its cardiovascular complications. One of the approaches proposed to decrease IS is the administration of synbiotics. This work aimed to search for a probiotic strain capable to decrease serum IS levels and mix it with two prebiotics (inulin and fructooligosaccharide (FOS)) to produce a putative synbiotic and test it in a rat CKD model. Two groups of Sprague-Dawley rats were nephrectomized. One group (Lac) received the mixture for 16 weeks in drinking water and the other no (Nef). A control group (C) included sham-nephrectomized rats. Serum creatinine and IS concentrations were measured using high-performance liquid chromatography with diode array detector (HPLC-DAD). Optical microscopy and two-photon excitation microscopy was used to study kidney and heart samples. The Lac group, which received the synbiotic, reduced IS by 0.8% while the Nef group increased it by 38.8%. Histological analysis of kidneys showed that the Lac group increased fibrotic areas by 12% and the Nef group did it by 25%. The synbiotic did not reduce cardiac fibrosis. Therefore, the putative synbiotic showed that function reducing IS and the progression of CKD in a rat model, but no heart protection was observed.

Soymilk fermentation: effect of cooling protocol on cell viability during storage and in vitro gastrointestinal stress.

This work covers soymilk fermentation by starter and probiotic cultures and explores the influence of cooling protocol on cell viability, organic acid production, sugar consumption, fatty acid profile, and cell survival to in vitro gastrointestinal stress. After fermentation at 37 °C by mono- or co-cultures of Streptococcus thermophilus (St), Lactobacillus bulgaricus (Lb), and Lactobacillus paracasei (Lp), fermented soymilk was cooled directly at 4 °C for 28 days or cooled in two phases (TPC), i.e., by preceding that step by another at 25 °C for 8 h. Soybean milk fermentation by Lb alone lasted longer (15 h) than by StLb or StLbLp (9 h). In ternary culture, TPC increased Lp viability, linoleic, and lactic acid concentrations by 3.8, 22.6, and 96.2%, respectively, whereas the cooling protocol did not influence Lp and St counts after in vitro gastrointestinal stress. Graphical abstract.

Meat Native Lactic Acid Bacteria Capable to Inhibit Salmonella sp. and Escherichia coli.

In this study, lactic acid bacteria (LAB) strains were isolated from ground beef, and it was analyzed if they have any effect on the growth of two reference bacteria (Salmonella sp. and Escherichia coli). It was found that five isolates showed an inhibitory effect in both reference bacteria by spot at the lawn assay. These bacteria were selected to perform growth kinetics in co-culture to determine if they modify the growth parameters of the reference bacteria. Subsequently, LAB cultures and three treatments (crude extract, thermally treated and thermally treated with neutral pH) of cells free supernatants (CFS) were screened by the agar well diffusion assay. In co-culture, selected LAB altered the growth rate and reduce the maximum population of both reference bacteria. While, LAB cultures and CFS also showed antimicrobial activity, and there was no significant difference among CFS treatments. LAB isolated from ground beef showed an antimicrobial effect against the reference bacteria that could be used for meat biopreservation purposes.

Lactobacillus delbrueckii Ameliorates Intestinal Integrity and Antioxidant Ability in Weaned Piglets after a Lipopolysaccharide Challenge.

This study was conducted to evaluate the effect of dietary supplementation with Lactobacillus delbrueckii (LAB) on intestinal morphology, barrier function, immune response, and antioxidant capacity in weaned piglets challenged with lipopolysaccharide (LPS). A total of 36 two-line crossbred (Landrace × large Yorkshire) weaned piglets (28 days old) were divided into three groups: (1) nonchallenged control (CON); (2) LPS-challenged control (LPS); and (3) LAB+LPS treatment (0.2% LAB+LPS). Compared to the LPS piglets, the LAB+LPS piglets improved intestinal morphology, indicated by greater (P < 0.05) villus height in the duodenum and ileum; villus height : crypt depth ratio in the duodenum, jejunum, and ileum, as well as decreased (P < 0.05) crypt depth in the jejunum and ileum; and better intestinal barrier function, indicated by upregulated (P < 0.05) mRNA expression of tight junction proteins in the intestinal mucosa. Moreover, compared to the LPS piglets, LAB significantly decreased (P < 0.05) concentrations of TNF-α and IL-1ß in the small intestine and increased (P < 0.05) IL-10 levels in the jejunum and ileum. Additionally, LAB increased (P < 0.05) T-AOC activities of the colon, GSH concentrations of the jejunum, and mRNA expression of CAT and Cu/Zn-SOD, while reduced (P < 0.05) MDA concentrations in the jejunum and ileum in LPS-changed piglets. Collectively, our results indicate that supplementation of LAB improved intestinal integrity and immune response and alleviated intestinal oxidative damage in LPS-challenged piglets.

Enhancing spray drying tolerance of Lactobacillus bulgaricus by intracellular trehalose delivery via electroporation.

Spray-drying is an efficient drying technique for preparing probiotic powders, but the high temperatures employed during the process results in low survival rates of lactic acid bacteria. This study aimed to enhance spray-drying tolerance of lactic acid bacteria by intracellular delivery of trehalose via electroporation. Diverse electroporation conditions were applied to Lactobacillus delbrueckii ssp. bulgaricus sp1.1 cells exposed to 10% trehalose prior to spray drying with 30% re-constituted skimmed milk. Survival rates of spray-dried bacteria increased with an intracellular trehalose content of ≥3.5 µg/107 colony-forming units (CFU) and reached 100% with intracellular trehalose content of 10.1 µg/107 CFU. The application of two electroporation pulses at 2.5 kV/cm helped increase the survival rate of L. bulgaricus from 38% to 61% after spray drying. Membrane damage and pore formation caused by excessive pulsed electric field treatment resulted in cell death after spray drying. Sufficient intracellular trehalose protected cell walls and membranes from further damage by spray drying. Multi-pulse electroporation of trehalose into lactic acid bacteria prior to spray drying can potentially increase cell viability.

Lactobacillus delbrueckii subsp. bulgaricus 2038 and Streptococcus thermophilus 1131 Induce the Expression of the REG3 Family in the Small Intestine of Mice via the Stimulation of Dendritic Cells and Type 3 Innate Lymphoid Cells.

Accumulating evidence clarifies that intestinal barrier function, for example, by the mucus layer, antimicrobial peptides, immune systems, and epithelial tight junctions, plays crucial roles in maintaining our health. We reported previously that yogurt fermented with Lactobacillus delbrueckii subsp. bulgaricus 2038 and Streptococcus thermophilus 1131 induced the gene expression of the regenerating family member 3 (REG3) family, which encodes antimicrobial peptides in the small intestine, although it was unclear how the yogurt activated the intestinal cells related to it. Here, we evaluated the cytokine production from the intestinal immune cells stimulated by these strains in vitro and in vivo to elucidate the mechanism for the induction of the REG3 family by the yogurt. The results showed that stimulation by both strains induced interleukin (IL)-23 production from bone marrow-derived dendritic cells (DCs) and IL-22 production from small intestinal lamina propria (LP) cells. In addition, oral administration of these strains to mice increased IL-23p19+ LPDCs and IL-22+ type 3 innate lymphoid cells and induced the expression of Reg3g in small intestinal tissue. Moreover, we showed that the activities for the induction of IL-23 by DCs were strain dependent on L. bulgaricus and S. thermophilus and that S. thermophilus 1131, which is the predominant species in the yogurt, exhibited relatively higher activity compared to the other strains of S. thermophilus. Our findings suggested that these yogurt starter strains, L. bulgaricus 2038 and S. thermophilus 1131, have the potential to maintain and improve intestinal barrier function by stimulating immune cells in the LP.

Effect of cheese containing Lactobacillus delbrueckii subsp. Lactis CRL 581 on blood pressure in prehypertensive and stage 1 hypertensive subjects / Efecto de un queso con LactobacillusdelbrueckiisubspLactis CRL 581 sobre la hipertensión arterial en individuos con prehipertensión o estadio 1 de hipertensión arterial

Hypertension is one of the main risk factors for cardiovascular disease. Functional foods containing bioactive peptides have been proposed as a strategy to decrease blood pressure (BP) in subjects under no pharmacological treatment. The aim of this study was to compare the effect of low-sodium, low-fat (LSLF) cheese and LSLF cheese containing Lactobacillus delbrueckii subsp. lactis CRL 581 (LSLF581) on BP in pre-hypertensive and stage 1 hypertensive subjects. Sixty-one pre-hypertensive and stage 1 hypertensive subjects assigned to one of twos (LSLF, n= 29 and LSLF581, n= 32) participated in this 12-month prospective, randomized, double-blind, crossover trial. Twenty-four h ambulatory BP monitoring was performed at the beginning and at the end of each four-week study period. Systolic and diastolic BP decreased in both study groups, but differences between groups were not significant (systolic, -1.78 and -0.2 mmHg; diastolic, -1.54 and -0.42 mmHg in LSLF581 and LSLF, respectively). Although our results could not support a BP lowering effect of LSLF581, small BP reductions could favorably prevent cardiovascular disease development.

La hipertensión arterial es uno de los principales factores de riesgo de enfermedad cardiovascular. Los alimentos funcionales que contienen biopéptidos constituyen una estrategia útil para disminuir la presión arterial (PA) en personas que no están bajo tratamiento farmacológico. El objetivo del estudio fue comparar el efecto de un queso bajo en sodio y bajo en grasas (BSBG) y el mismo queso con Lactobacillus delbrueckii subsp. lactis CRL 581 (BSBG581) sobre la PA en personas con prehipertensión y estadio 1 de hipertensión arterial. Realizamos un estudio prospectivo, randomizado, cruzado y doble ciego durante 12 meses en 61 personas con prehipertensión y estadio 1 de hipertensión arterial, asignadas a dos grupos: BSBG (n= 29) y BSBG581 (n= 32). Se realizó monitoreo ambulatorio de la PA (MAPA) durante 24 h al comienzo y al final de cada etapa del estudio (cuatro semanas). La PA sistólica y diastólica disminuyó en ambos grupos, aunque las diferencias entre grupos no fueron significativas (sistólica, -1.78 y -0.2 mmHg; diastólica -1.54 y -0.42 mmHg en BSBG581 y BSBG respectivamente). Aunque nuestros resultados no pueden confirmar el efecto hipotensor del queso BSBG581, las reducciones moderadas de la PA podrían prevenir el desarrollo de enfermedad cardiovascular.

Lactobacillus delbrueckii subsp. bulgaricus F17 and Leuconostoc lactis H52 supernatants delay the decay of strawberry fruits: a microbiome perspective.

Strawberries are vulnerable to physical injuries and microbial invasion. To explore if beneficial lactic acid bacteria can improve the shelf life and edible quality of postharvest strawberry fruits, the effects of Lactobacillus delbrueckii subsp. bulgaricus (ital.) F17 (F17) and Leuconostoc lactis (ital.) H52 (H52) inoculation on the strawberry microbial community structure and saleable characteristics were examined by bacterial 16S rRNA and fungal ITS sequencing techniques. Lactobacillus (ital.) F17 and Leuconostoc lactis (ital.) H52 isolated from the traditional fermented yak milk in the Qinghai-Tibetan Plateau were used as the potential probiotic inocula. Samples from treated strawberries stored at 25 °C for 0, 12, 24, 48, and 72 hours were analyzed for their pH, weight loss percentage, decay percentage, total soluble solid content (SSC) and microbial counts, and for microbiome community diversity and canonical correspondence analysis. The results showed that F17 and H52 did not only significantly reduce the weight loss and decay percentage of strawberry fruits, but also delayed the decrease of the total SSC and pH (P < 0.05). In addition, F17 and H52 significantly inhibited the growth and colonization of aerobic mesophilic bacteria, yeast, mold and coliform bacteria. In particular, by comparing the microbiota composition of the samples, F17 significantly inhibited Pantoea, Mycospherella, unclassified_Pleosporales, Aureobasidium and Phoma at the genus level, whereas H52 inhibited Bacillus, Streptophyta, Mycospherella, Aureobasidium and Phoma. Moreover, analysis of alpha and beta diversity revealed that F17 and H52 had a significantly greater inhibitory effect on bacterial species compared to fungi. The results of canonical correspondence analysis revealed that the total SSC and pH were positively correlated with bacteria, whereas the decay percentage, weight loss percentage and total SSC were positively associated with fungi. Additionally, Podosphaera, Hanseniaspora, Botrytis and unclassified_Pleosporales were positively correlated with strawberry fruit decay and weight loss percentage. As a general result, Lactobacillus F17 and Leuconostoc lactis H52 have the potential to promote biological preservation, which is economically important to reduce the loss due to strawberry spoilage.

Improvement of Redox State and Functions of Immune Cells as Well as of Behavioral Response in Aged Mice After Two-Week Supplementation of Fermented Milk with Probiotics.

The homeostatic systems, such as the nervous and immune systems, show deterioration in aging as a consequence of the age-related oxidative-inflammatory stress establishment. The supplementation with fermented milk containing probiotic bacteria could be a good nutritional strategy to improve homeostatic system functions in aged individuals through the modulation of their redox state. The aim of the present study was to evaluate the effect of 2-week supplementation with a commercial fermented milk containing yogurt species (Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus), and the probiotic Lactobacillus casei DN-114001 on behavior, redox state, and immune cell functions of aged mice as well as on their life span. Aged female ICR-CD1 mice were supplemented with fermented milk containing these probiotics for 2 weeks. After this period, a variety of behavioral tests were performed and several parameters of redox state and function of peritoneal leukocytes were analyzed. The results showed that the 2-week supplementation of fermented milk containing probiotics improved behavior (such as muscular vigor, exploratory activity, and anxiety-like behavior) as well as the redox state and functions of peritoneal immune cells in aged mice. In conclusion, the present study shows that the supplementation with fermented milk containing probiotics for a short period of time could be a good nutritional strategy to promote healthy aging.

Interspecies Inhibition of Porphyromonas gingivalis by Yogurt-Derived Lactobacillus delbrueckii Requires Active Pyruvate Oxidase.

Despite a growing interest in using probiotic microorganisms to prevent disease, the mechanisms by which probiotics exert their action require further investigation. Porphyromonas gingivalis is an important pathogen implicated in the development of periodontitis. We isolated several strains of Lactobacillus delbrueckii from dairy products and examined their ability to inhibit P. gingivalis growth in vitro We observed strain-specific inhibition of P. gingivalis growth in vitro Whole-genome sequencing of inhibitory and noninhibitory strains of L. delbrueckii revealed significant genetic differences supporting the strain specificity of the interaction. Extracts of the L. delbrueckii STYM1 inhibitory strain contain inhibitory activity that is abolished by treatment with heat, proteinase K, catalase, and sodium sulfite. We purified the inhibitory protein(s) from L. delbrueckii STYM1 extracts using ammonium sulfate precipitation, anion-exchange chromatography, and gel filtration chromatography. Pyruvate oxidase was highly enriched in the purified samples. Lastly, we showed that purified, catalytically active, recombinant pyruvate oxidase is sufficient to inhibit P. gingivalis growth in vitro without the addition of cofactors. Further, using a saturated transposon library, we isolated transposon mutants of P. gingivalis in the feoB2 (PG_1294) gene that are resistant to killing by inhibitory L. delbrueckii, consistent with a mechanism of hydrogen peroxide production by pyruvate oxidase. Our results support the current understanding of the importance of strain selection, not simply species selection, in microbial interactions. Specific L. delbrueckii strains or their products may be effective in the treatment and prevention of P. gingivalis-associated periodontal disease.IMPORTANCEP. gingivalis is implicated in the onset and progression of periodontal disease and associated with some systemic diseases. Probiotic bacteria represent an attractive preventative therapy for periodontal disease. However, the efficacy of probiotic bacteria can be variable between studies. Our data support the known importance of selecting particular strains of bacteria for probiotic use, not simply a single species. Specifically, in the context of probiotic intervention of periodontitis, our data suggest that high-level expression of pyruvate oxidase with hydrogen peroxide production in L. delbrueckii could be an important characteristic for the design of a probiotic supplement or a microbial therapeutic.

Evaluation of productive biofilms for continuous lactic acid production.

In white biotechnology research, the putative superiority of productive biofilms to conventional biotransformation processes based on planktonic cultures has been increasingly discussed in recent years. In the present study, we chose lactic acid production as a model application to evaluate biofilm potential. A pure culture of Lactobacillus bacteria was grown in a tubular biofilm reactor. The biofilm system was cultivated monoseptically in a continuous mode for more than 3 weeks. The higher cell densities that could be obtained in the continuous biofilm system compared with the planktonic culture led to a significantly increased space-time yield. The productivity reached 80% of the maximum value 10 days after start-up and no subsequent decline was observed, confirming the suitability of the system for long-term fermentation. The analysis of biofilm performance revealed that productivity increases with the flow velocity. This is explained by the reduced retention time of the liquid phase in the reactor, and, thus, a minor pH drop caused by the released lactic acid. At low flow velocities, the pH drops to a value where growth and production are significantly inhibited. The biofilm was visualized by magnetic resonance imaging to analyze biofilm thickness. To deepen the understanding of the biofilm system, we used a simple model for cell growth and lactic acid production.

Physico-chemical approach for characterizing probiotics at the solid and dispersed states.

A physico-chemical approach was used for characterizing and generating fingerprints of single (L. bulgaricus and S. thermophilus) and multiple (Vivomixx) probiotic species. Such a methodology included thermal, colloidal, and surface analyses of powder (solid-in-gaseous phase) and dispersed (solid-in-aqueous phase) samples. Decomposition and transition phases analyzed by thermogravimetry and differential scanning calorimetry provide specific qualitative and quantitative data that serve as a probiotic fingerprint, and therefore a product quality control for each sample. Investigation of colloidal and surface properties of dispersed samples by light scattering and contact angle measurements informs on the probiotic size average, electrokinetic charge, and surface hydrophobicity. Besides their relevance in identity control, the physico-chemical data are also useful in probiotic performance prediction, since they govern the most crucial microbial functionalities such as thermostability, aggregation, and adhesion.

Effect of Lactobacillus delbrueckii LAB4 on hepatic and pancreatic sympathetic nerve activity and blood glucose levels in rats.

Various lactobacilli have been suggested to exert beneficial effects in humans. In this study, we examined the effects of intraduodenal (ID) administration of heat-killed Lactobacillus delbrueckii LAB4 (LAB4) on activities of efferent sympathetic nerves innervating the liver and pancreas. Consequently, it was observed that ID administration of LAB4 significantly reduced either the efferent hepatic sympathetic nerve activity (hepatic-SNA) or pancreatic sympathetic nerve activity (pancreatic-SNA) in urethane-anaesthetised rats. Moreover, the effect of acute and chronic administration of LAB4 (1×109 cells/ml) on hyperglycaemia induced by intracranial injection of 2-deoxy-D-glucose (2DG) were examined in conscious rats. We found that LAB4 significantly inhibited 2DG-induced hyperglycaemia. These findings suggest that ID administration of heat-killed LAB4 might lower plasma glucose level via changes in the autonomic nervous system in rats.

Short communication: Influence of an aqueous myrrh suspension on yogurt culture bacteria over yogurt shelf life.

Myrrh is an essential oil and natural flavoring approved by the US Food and Drug Administration, and it has antibacterial and antifungal activity against pathogens. Our objective was to determine the effect of an aqueous myrrh suspension on Streptococcus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus counts in peptone solution and yogurt, as well as pH and titratable acidity of yogurt during 5 wk of storage at 1 to 4°C. The myrrh suspension (10% wt/vol) was prepared and incorporated into a pure culture dilution in peptone and into yogurt mix at a 1% (vol/vol) level. A control with no myrrh was also prepared, and 3 replications were conducted. Streptococcus thermophilus were enumerated using Streptococcus thermophilus agar with aerobic incubation at 37°C for 24 h, and Lactobacillus delbrueckii ssp. bulgaricus were enumerated using de Man, Rogosa, and Sharpe agar adjusted to pH 5.2, with anaerobic incubation at 43°C for 72 h. During the 8-h period after inoculation, S. thermophilus and L. delbrueckii ssp. bulgaricus counts in peptone solution at 37°C and 43°C, respectively, were not significantly different in the presence or absence of the aqueous myrrh suspension. Counts of S. thermophilus in yogurt containing myrrh (mean ± SD; 4.96 ± 0.58 log cfu/mL) were not significantly different from those in the control yogurt (4.87 ± 0.39 log cfu/mL). The log counts for L. delbrueckii ssp. bulgaricus in yogurt containing myrrh (5.04 ± 1.44 log cfu/mL) and those of the control (5.52 ± 1.81 log cfu/mL) did not differ, and the counts remained within 1 log of each other throughout 5 wk of storage. The pH of the yogurts containing the aqueous myrrh suspension was not significantly different from that of the control yogurts, and their pH values were within 0.1 pH unit of each other in any given week. Titratable acidity values remained steady around 1.1 to 1.2% lactic acid for both yogurt types throughout the storage period, with no significant differences between them. Yogurt culture bacteria can survive in the presence of a myrrh suspension in yogurt with no significant change in pH or titratable acidity. Therefore, it may be beneficial to add an aqueous myrrh suspension to yogurt.

Amelioration of regulatory T cells by Lactobacillus delbrueckii and Lactobacillus rhamnosus in pristane-induced lupus mice model.

Regulatory T cells (Tregs) play an indispensable role in the control of immune responses and induction of peripheral tolerance. Dysregulation of Tregs is involved in the pathogenesis of systemic lupus erythematosus (SLE). Tolerogenic probiotics have shown beneficial effects in the control of autoimmune diseases. We evaluated the prophylactic and therapeutic effects of Lactobacillus delbrueckii and Lactobacillus rhamnosus on Tregs and their related molecules in pristane-induced lupus mice model. Fifty-four female BALB/c mice (3-5 weeks) were randomly divided into nine groups. Lupus was induced in all groups using pristane. Prophylactic groups were treated from Day 0 (at the time of pristane injection) and treatment groups were treated 2 months later with L. rhamnosus, L. delbrueckii, mix of both probiotics, and prednisolone. One group was considered as SLE-induced control group without any treatment. Presence of antinuclear antibodies (ANA), antidouble-stranded DNA (anti-dsDNA), antiribonucleoprotein (anti-RNP), proteinuria, and serum level of creatinine, urea, the expression of forkhead box P3 (Foxp3), interleukin 6 (IL-6), IL-10, transforming growth factor ß, and the number of Tregs were determined. SLE induction by pristane led to the formation of lipogranuloma, presence of ANA, anti-dsDNA, and anti-RNP. Probiotics consumption decreased the level of lipogranuloma, ANA, and anti-dsDNA. In addition, in probiotics receiving groups, Tregs and the expression level of Foxp3 increased, while IL-6 decreased. The effect of probiotics in the prophylactic group was more prominent. The results may indicate the effectiveness of L. delbrueckii and L. rhamnosus in the enhancement of Tregs and the decrease of inflammatory cytokines and disease severity in SLE-induced mice.